Ectodermal Wnt6 is an early negative regulator of limb chondrogenesis in the chicken embryo

PubMed Central

2010-01-01

Background Pattern formation of the limb skeleton is regulated by a complex interplay of signaling centers located in the ectodermal sheath and mesenchymal core of the limb anlagen, which results, in the forelimb, in the coordinate array of humerus, radius, ulna, carpals, metacarpals and digits. Much less understood is why skeletal elements form only in the central mesenchyme of the limb, whereas muscle anlagen develop in the peripheral mesenchyme ensheathing the chondrogenic center. Classical studies have suggested a role of the limb ectoderm as a negative regulator of limb chondrogenesis. Results In this paper, we investigated the molecular nature of the inhibitory influence of the ectoderm on limb chondrogenesis in the avian embryo in vivo. We show that ectoderm ablation in the early limb bud leads to increased and ectopic expression of early chondrogenic marker genes like Sox9 and Collagen II, indicating that the limb ectoderm inhibits limb chondrogenesis at an early stage of the chondrogenic cascade. To investigate the molecular nature of the inhibitory influence of the ectoderm, we ectopically expressed Wnt6, which is presently the only known Wnt expressed throughout the avian limb ectoderm, and found that Wnt6 overexpression leads to reduced expression of the early chondrogenic marker genes Sox9 and Collagen II. Conclusion Our results suggest that the inhibitory influence of the ectoderm on limb chondrogenesis acts on an early stage of chondrogenesis upsteam of Sox9 and Collagen II. We identify Wnt6 as a candidate mediator of ectodermal chondrogenic inhibition in vivo. We propose a model of Wnt-mediated centripetal patterning of the limb by the surface ectoderm. PMID:20334703

HOXA13 and HOXD13 expression during development of the syndactylous digits in the marsupial Macropus eugenii

PubMed Central

2012-01-01

Background Kangaroos and wallabies have specialised limbs that allow for their hopping mode of locomotion. The hindlimbs differentiate much later in development but become much larger than the forelimbs. The hindlimb autopod has only four digits, the fourth of which is greatly elongated, while digits two and three are syndactylous. We investigated the expression of two genes, HOXA13 and HOXD13, that are crucial for digit patterning in mice during formation of the limbs of the tammar wallaby. Results We describe the development of the tammar limbs at key stages before birth. There was marked heterochrony and the hindlimb developed more slowly than the forelimb. Both tammar HOXA13 and HOXD13 have two exons as in humans, mice and chickens. HOXA13 had an early and distal mRNA distribution in the tammar limb bud as in the mouse, but forelimb expression preceded that in the hindlimb. HOXD13 mRNA was expressed earlier in the forelimb than the hindlimb and was predominantly detected in the interdigital tissues of the forelimb. In contrast, the hindlimb had a more restricted expression pattern that appeared to be expressed at discrete points at both posterior and anterior margins of the limb bud, and was unlike expression seen in the mouse and the chicken. Conclusions This is the first examination of HOXA and HOXD gene expression in a marsupial. The gene structure and predicted proteins were highly conserved with their eutherian orthologues. Interestingly, despite the morphological differences in hindlimb patterning, there were no modifications to the polyalanine tract of either HOXA13 or HOXD13 when compared to those of the mouse and bat but there was a marked difference between the tammar and the other mammals in the region of the first polyserine tract of HOXD13. There were also altered expression domains for both genes in the developing tammar limbs compared to the chicken and mouse. Together these findings suggest that the timing of HOX gene expression may contribute to the heterochrony of the forelimb and hindlimb and that alteration to HOX domains may influence phenotypic differences that lead to the development of marsupial syndactylous digits. PMID:22235805

Deep-time evolution of regeneration and preaxial polarity in tetrapod limb development.

PubMed

Fröbisch, Nadia B; Bickelmann, Constanze; Olori, Jennifer C; Witzmann, Florian

2015-11-12

Among extant tetrapods, salamanders are unique in showing a reversed preaxial polarity in patterning of the skeletal elements of the limbs, and in displaying the highest capacity for regeneration, including full limb and tail regeneration. These features are particularly striking as tetrapod limb development has otherwise been shown to be a highly conserved process. It remains elusive whether the capacity to regenerate limbs in salamanders is mechanistically and evolutionarily linked to the aberrant pattern of limb development; both are features classically regarded as unique to urodeles. New molecular data suggest that salamander-specific orphan genes play a central role in limb regeneration and may also be involved in the preaxial patterning during limb development. Here we show that preaxial polarity in limb development was present in various groups of temnospondyl amphibians of the Carboniferous and Permian periods, including the dissorophoids Apateon and Micromelerpeton, as well as the stereospondylomorph Sclerocephalus. Limb regeneration has also been reported in Micromelerpeton, demonstrating that both features were already present together in antecedents of modern salamanders 290 million years ago. Furthermore, data from lepospondyl 'microsaurs' on the amniote stem indicate that these taxa may have shown some capacity for limb regeneration and were capable of tail regeneration, including re-patterning of the caudal vertebral column that is otherwise only seen in salamander tail regeneration. The data from fossils suggest that salamander-like regeneration is an ancient feature of tetrapods that was subsequently lost at least once in the lineage leading to amniotes. Salamanders are the only modern tetrapods that retained regenerative capacities as well as preaxial polarity in limb development.

Development and evolution of the mammalian limb: adaptive diversification of nails, hooves, and claws.

PubMed

Hamrick, M W

2001-01-01

Paleontological evidence indicates that the evolutionary diversification of mammals early in the Cenozoic era was characterized by an adaptive radiation of distal limb structures. Likewise, neontological data show that morphological variation in distal limb integumentary appendages (e.g., nails, hooves, and claws) can be observed not only among distantly related mammalian taxa but also among closely related species within the same clade. Comparative analysis of nail, claw, and hoof morphogenesis reveals relatively subtle differences in mesenchymal and epithelial patterning underlying these adult differences in distal limb appendage morphology. Furthermore, studies of regulatory gene expression during vertebrate claw development demonstrate that many of the signaling molecules involved in patterning ectodermal derivatives such as teeth, hair, and feathers are also involved in organizing mammalian distal limb appendages. For example, Bmp4 signaling plays an important role during the recruitment of mesenchymal cells into the condensations forming the terminal phalanges, whereas Msx2 affects the length of nails and claws by suppressing proliferation of germinal epidermal cells. Evolutionary changes in the form of distal integumentary appendages may therefore result from changes in gene expression during formation of mesenchymal condensations (Bmp4, posterior Hox genes), induction of the claw fold and germinal matrix (shh), and/or proliferation of epidermal cells in the claw matrix (Msx1, Msx2). The prevalence of convergences and parallelisms in nail and claw structure among mammals underscores the existence of multiple morphogenetic pathways for evolutionary change in distal limb appendages.

Right upper limb bud triplication and polythelia, left sided hemihypertrophy and congenital hip dislocation, facial dysmorphism, congenital heart disease, and scoliosis: disorganisation-like spectrum or patterning gene defect?

PubMed Central

Sabry, M A; al-Saleh, Q; al-Saw'an, R; al-Awadi, S A; Farag, T I

1995-01-01

A Somali female baby with right upper limb triplication, polythelia, left sided hemihypertrophy, congenital hip dislocation, facial dysmorphism, congenital heart disease, and scoliosis is described. It seems that the above described pattern of anomalies has not been reported before. The possible developmental genetic mechanism responsible for this phenotype is briefly discussed. Images PMID:7562971

Attenuated sensing of SHH by Ptch1 underlies evolution of bovine limbs.

PubMed

Lopez-Rios, Javier; Duchesne, Amandine; Speziale, Dario; Andrey, Guillaume; Peterson, Kevin A; Germann, Philipp; Unal, Erkan; Liu, Jing; Floriot, Sandrine; Barbey, Sarah; Gallard, Yves; Müller-Gerbl, Magdalena; Courtney, Andrew D; Klopp, Christophe; Rodriguez, Sabrina; Ivanek, Robert; Beisel, Christian; Wicking, Carol; Iber, Dagmar; Robert, Benoit; McMahon, Andrew P; Duboule, Denis; Zeller, Rolf

2014-07-03

The large spectrum of limb morphologies reflects the wide evolutionary diversification of the basic pentadactyl pattern in tetrapods. In even-toed ungulates (artiodactyls, including cattle), limbs are adapted for running as a consequence of progressive reduction of their distal skeleton to symmetrical and elongated middle digits with hoofed phalanges. Here we analyse bovine embryos to establish that polarized gene expression is progressively lost during limb development in comparison to the mouse. Notably, the transcriptional upregulation of the Ptch1 gene, which encodes a Sonic hedgehog (SHH) receptor, is disrupted specifically in the bovine limb bud mesenchyme. This is due to evolutionary alteration of a Ptch1 cis-regulatory module, which no longer responds to graded SHH signalling during bovine handplate development. Our study provides a molecular explanation for the loss of digit asymmetry in bovine limb buds and suggests that modifications affecting the Ptch1 cis-regulatory landscape have contributed to evolutionary diversification of artiodactyl limbs.

Shared Enhancer Activity in the Limbs and Phallus and Functional Divergence of a Limb-Genital cis-Regulatory Element in Snakes.

PubMed

Infante, Carlos R; Mihala, Alexandra G; Park, Sungdae; Wang, Jialiang S; Johnson, Kenji K; Lauderdale, James D; Menke, Douglas B

2015-10-12

The amniote phallus and limbs differ dramatically in their morphologies but share patterns of signaling and gene expression in early development. Thus far, the extent to which genital and limb transcriptional networks also share cis-regulatory elements has remained unexplored. We show that many limb enhancers are retained in snake genomes, suggesting that these elements may function in non-limb tissues. Consistent with this, our analysis of cis-regulatory activity in mice and Anolis lizards reveals that patterns of enhancer activity in embryonic limbs and genitalia overlap heavily. In mice, deletion of HLEB, an enhancer of Tbx4, produces defects in hindlimbs and genitalia, establishing the importance of this limb-genital enhancer for development of these different appendages. Further analyses demonstrate that the HLEB of snakes has lost hindlimb enhancer function while retaining genital activity. Our findings identify roles for Tbx4 in genital development and highlight deep similarities in cis-regulatory activity between limbs and genitalia. Copyright © 2015 Elsevier Inc. All rights reserved.

Developmental origin of limb size variation in lizards.

PubMed

Andrews, Robin M; Skewes, Sable A

2017-05-01

In many respects, reptile hatchlings are fully functional, albeit miniature, adults. This means that the adult morphology must emerge during embryonic development. This insight emphasizes the connection between the mechanisms that generate phenotypic variation during embryonic development and the action of selection on post-hatching individuals. To determine when species-specific differences in limb and tail lengths emerge during embryonic development, we compared allometric patterns of early limb growth of four distantly related species of lizards. The major questions addressed were whether early embryonic limb and tail growth is characterized by the gradual (continuous allometry) or by the abrupt emergence (transpositional allometry) of size differences among species. Our observations supported transpositional allometry of both limbs and tails. Species-specific differences in limb and tail length were exhibited when limb and tail buds first protruded from the body wall. Genes known to be associated with early limb development of tetrapods are obvious targets for studies on the genetic mechanisms that determine interspecific differences in relative limb length. Broadly comparative studies of gene regulation would facilitate understanding of the mechanisms underlying adaptive variation in limb size, including limb reduction and loss, of squamate reptiles. © 2017 Wiley Periodicals, Inc.

Analysis of the expression and function of Wnt-5a and Wnt-5b in developing and regenerating axolotl (Ambystoma mexicanum) limbs.

PubMed

Ghosh, Sukla; Roy, Stéphane; Séguin, Carl; Bryant, Susan V; Gardiner, David M

2008-05-01

Urodele amphibians are unique adult vertebrates because they are able to regenerate body parts after amputation. Studies of urodele limb regeneration, the key model system for vertebrate regeneration, have led to an understanding of the origin of blastema cells and the importance of positional interactions between blastema cells in the control of growth and pattern formation. Progress is now being made in the identification of the signaling pathways that regulate dedifferentiation, blastema morphogenesis, growth and pattern formation. Members of the Wnt family of secreted proteins are expressed in developing and regenerating limbs, and have the potential to control growth, pattern formation and differentiation. We have studied the expression of two non-canonical Wnt genes, Wnt-5a and Wnt-5b. We report that they are expressed in equivalent patterns during limb development and limb regeneration in the axolotl (Ambystoma mexicanum), and during limb development in other tetrapods, implying conservation of function. Our analysis of the effects of ectopic Wnt-5a expression is consistent with the hypothesis that canonical Wnt signaling functions during the early stages of regeneration to control the dedifferentiation of stump cells giving rise to the regeneration-competent cells of the blastema.

Developmental Patterning as a Quantitative Trait: Genetic Modulation of the Hoxb6 Mutant Skeletal Phenotype

PubMed Central

Kappen, Claudia

2016-01-01

The process of patterning along the anterior-posterior axis in vertebrates is highly conserved. The function of Hox genes in the axis patterning process is particularly well documented for bone development in the vertebral column and the limbs. We here show that Hoxb6, in skeletal elements at the cervico-thoracic junction, controls multiple independent aspects of skeletal pattern, implicating discrete developmental pathways as substrates for this transcription factor. In addition, we demonstrate that Hoxb6 function is subject to modulation by genetic factors. These results establish Hox-controlled skeletal pattern as a quantitative trait modulated by gene-gene interactions, and provide evidence that distinct modifiers influence the function of conserved developmental genes in fundamental patterning processes. PMID:26800342

Gdf11 is a negative regulator of chondrogenesis and myogenesis in the developing chick limb.

PubMed

Gamer, L W; Cox, K A; Small, C; Rosen, V

2001-01-15

GDF11, a new member of the TGF-beta gene superfamily, regulates anterior/posterior patterning in the axial skeleton during mouse embryogenesis. Gdf11 null mice display skeletal abnormalities that appear to represent anterior homeotic transformations of vertebrae consistent with high levels of Gdf11 expression in the primitive streak, presomitic mesoderm, and tail bud. However, despite strong Gdf11 expression in the limb throughout development, this structure does not appear to be affected in the knockout mice. In order to understand this dichotomy of Gdf11 expression versus Gdf11 function, we identified the chicken Gdf11 gene and studied its role during limb formation. In the early limb bud, Gdf11 transcripts are detected in the subectodermal mesoderm at the distal tip, in a region overlapping the progress zone. At these stages, Gdf11 is excluded from the central core mesenchyme where precartilaginous condensations will form. Later in development, Gdf11 continues to be expressed in the distal most mesenchyme and can also be detected more proximally, in between the forming skeletal elements. When beads incubated in GDF11 protein were implanted into the early wing bud, GDF11 caused severe truncations of the limb that affected both the cartilage elements and the muscle. Limb shortening appeared to be the result of an inhibition of chondrogenesis and myogenesis and using an in vitro micromass assay, we confirmed the negative effects of GDF11 on both myogenic and chondrogenic cell differentiation. Analysis of molecular markers of skeletal patterning revealed that GDF11 induced ectopic expression of Hoxd-11 and Hoxd-13, but not of Hoxa-11, Hoxa-13, or the Msx genes. These data suggest that GDF11 may be involved in controlling the late distal expression of the Hoxd genes during limb development and that misregulation of these Hox genes by excess GDF11 may cause some of the observed alterations in skeletal element shape. In addition, GDF11 induced the expression of its own antagonist follistatin, indicating that the activity of GFD11 may be limited by a negative feedback mechanism. The data from our studies in the chick suggest that Gdf11 plays a role in the formation and development of the avian limb skeleton.

Differential expression of myogenic regulatory genes and Msx-1 during dedifferentiation and redifferentiation of regenerating amphibian limbs.

PubMed

Simon, H G; Nelson, C; Goff, D; Laufer, E; Morgan, B A; Tabin, C

1995-01-01

An amputated limb of an adult urodele amphibian is capable of undergoing regeneration. The new structures form from an undifferentiated mass of cells called the regenerative blastema. The cells of the blastema are believed to derive from differentiated tissues of the adult limb. However, the exact source of these cells and the process by which they undergo dedifferentiation are poorly understood. In order to elucidate the molecular and cellular basis for dedifferentiation we isolated a number of genes which are potential regulators of the process. These include Msx-1, which is believed to support the undifferentiated and proliferative state of cells in the embryonic limb bud; and two members of the myogenic regulatory gene family, MRF-4 and Myf-5, which are expressed in differentiated muscle and regulate muscle-specific gene activity. As anticipated, we find that Msx-1 is strongly up-regulated during the initiation of regeneration. It remains expressed throughout regeneration but is not found in the fully regenerated limb. The myogenic gene MRF-4 has the reverse expression pattern. It is expressed in adult limb muscle, is rapidly shut off in early regenerative blastemas, and is only reexpressed at the completion of regeneration. These kinetics are paralleled by those of a muscle-specific Myosin gene. In contrast Myf-5, a second member of the myogenic gene family, continues to be expressed throughout the regenerative process. Thus, MRF-4 and Myf-5 are likely to play distinct roles during regeneration. MRF-4 may directly regulate muscle phenotype and as such its repression may be a key event in dedifferentiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Conditional inactivation of Has2 reveals a crucial role for hyaluronan in skeletal growth, patterning, chondrocyte maturation and joint formation in the developing limb.

PubMed

Matsumoto, Kazu; Li, Yingcui; Jakuba, Caroline; Sugiyama, Yoshinori; Sayo, Tetsuya; Okuno, Misako; Dealy, Caroline N; Toole, Bryan P; Takeda, Junji; Yamaguchi, Yu; Kosher, Robert A

2009-08-01

The glycosaminoglycan hyaluronan (HA) is a structural component of extracellular matrices and also interacts with cell surface receptors to directly influence cell behavior. To explore functions of HA in limb skeletal development, we conditionally inactivated the gene for HA synthase 2, Has2, in limb bud mesoderm using mice that harbor a floxed allele of Has2 and mice carrying a limb mesoderm-specific Prx1-Cre transgene. The skeletal elements of Has2-deficient limbs are severely shortened, indicating that HA is essential for normal longitudinal growth of all limb skeletal elements. Proximal phalanges are duplicated in Has2 mutant limbs indicating an involvement of HA in patterning specific portions of the digits. The growth plates of Has2-deficient skeletal elements are severely abnormal and disorganized, with a decrease in the deposition of aggrecan in the matrix and a disruption in normal columnar cellular relationships. Furthermore, there is a striking reduction in the number of hypertrophic chondrocytes and in the expression domains of markers of hypertrophic differentiation in the mutant growth plates, indicating that HA is necessary for the normal progression of chondrocyte maturation. In addition, secondary ossification centers do not form in the central regions of Has2 mutant growth plates owing to a failure of hypertrophic differentiation. In addition to skeletal defects, the formation of synovial joint cavities is defective in Has2-deficient limbs. Taken together, our results demonstrate that HA has a crucial role in skeletal growth, patterning, chondrocyte maturation and synovial joint formation in the developing limb.

Conditional inactivation of Has2 reveals a crucial role for hyaluronan in skeletal growth, patterning, chondrocyte maturation and joint formation in the developing limb

PubMed Central

Matsumoto, Kazu; Li, Yingcui; Jakuba, Caroline; Sugiyama, Yoshinori; Sayo, Tetsuya; Okuno, Misako; Dealy, Caroline N.; Toole, Bryan P.; Takeda, Junji; Yamaguchi, Yu; Kosher, Robert A.

2009-01-01

Summary The glycosaminoglycan hyaluronan (HA) is a structural component of extracellular matrices and also interacts with cell surface receptors to directly influence cell behavior. To explore functions of HA in limb skeletal development, we conditionally inactivated the gene for HA synthase 2, Has2, in limb bud mesoderm using mice that harbor a floxed allele of Has2 and mice carrying a limb mesoderm-specific Prx1-Cre transgene. The skeletal elements of Has2-deficient limbs are severely shortened, indicating that HA is essential for normal longitudinal growth of all limb skeletal elements. Proximal phalanges are duplicated in Has2 mutant limbs indicating an involvement of HA in patterning specific portions of the digits. The growth plates of Has2-deficient skeletal elements are severely abnormal and disorganized, with a decrease in the deposition of aggrecan in the matrix and a disruption in normal columnar cellular relationships. Furthermore, there is a striking reduction in the number of hypertrophic chondrocytes and in the expression domains of markers of hypertrophic differentiation in the mutant growth plates, indicating that HA is necessary for the normal progression of chondrocyte maturation. In addition, secondary ossification centers do not form in the central regions of Has2 mutant growth plates owing to a failure of hypertrophic differentiation. In addition to skeletal defects, the formation of synovial joint cavities is defective in Has2-deficient limbs. Taken together, our results demonstrate that HA has a crucial role in skeletal growth, patterning, chondrocyte maturation and synovial joint formation in the developing limb. PMID:19633173

The HoxD cluster is a dynamic and resilient TAD boundary controlling the segregation of antagonistic regulatory landscapes

PubMed Central

Rodríguez-Carballo, Eddie; Lopez-Delisle, Lucille; Zhan, Ye; Fabre, Pierre J.; Beccari, Leonardo; El-Idrissi, Imane; Huynh, Thi Hanh Nguyen; Ozadam, Hakan; Dekker, Job; Duboule, Denis

2017-01-01

The mammalian HoxD cluster lies between two topologically associating domains (TADs) matching distinct enhancer-rich regulatory landscapes. During limb development, the telomeric TAD controls the early transcription of Hoxd genes in forearm cells, whereas the centromeric TAD subsequently regulates more posterior Hoxd genes in digit cells. Therefore, the TAD boundary prevents the terminal Hoxd13 gene from responding to forearm enhancers, thereby allowing proper limb patterning. To assess the nature and function of this CTCF-rich DNA region in embryos, we compared chromatin interaction profiles between proximal and distal limb bud cells isolated from mutant stocks where various parts of this boundary region were removed. The resulting progressive release in boundary effect triggered inter-TAD contacts, favored by the activity of the newly accessed enhancers. However, the boundary was highly resilient, and only a 400-kb deletion, including the whole-gene cluster, was eventually able to merge the neighboring TADs into a single structure. In this unified TAD, both proximal and distal limb enhancers nevertheless continued to work independently over a targeted transgenic reporter construct. We propose that the whole HoxD cluster is a dynamic TAD border and that the exact boundary position varies depending on both the transcriptional status and the developmental context. PMID:29273679

Mutations in WNT7A cause a range of limb malformations, including Fuhrmann syndrome and Al-Awadi/Raas-Rothschild/Schinzel phocomelia syndrome.

PubMed

Woods, C G; Stricker, S; Seemann, P; Stern, R; Cox, J; Sherridan, E; Roberts, E; Springell, K; Scott, S; Karbani, G; Sharif, S M; Toomes, C; Bond, J; Kumar, D; Al-Gazali, L; Mundlos, S

2006-08-01

Fuhrmann syndrome and the Al-Awadi/Raas-Rothschild/Schinzel phocomelia syndrome are considered to be distinct limb-malformation disorders characterized by various degrees of limb aplasia/hypoplasia and joint dysplasia in humans. In families with these syndromes, we found homozygous missense mutations in the dorsoventral-patterning gene WNT7A and confirmed their functional significance in retroviral-mediated transfection of chicken mesenchyme cell cultures and developing limbs. The results suggest that a partial loss of WNT7A function causes Fuhrmann syndrome (and a phenotype similar to mouse Wnt7a knockout), whereas the more-severe limb truncation phenotypes observed in Al-Awadi/Raas-Rothschild/Schinzel phocomelia syndrome result from null mutations (and cause a phenotype similar to mouse Shh knockout). These findings illustrate the specific and conserved importance of WNT7A in multiple aspects of vertebrate limb development.

Mutations in WNT7A Cause a Range of Limb Malformations, Including Fuhrmann Syndrome and Al-Awadi/Raas-Rothschild/Schinzel Phocomelia Syndrome

PubMed Central

Woods, C. G.; Stricker, S.; Seemann, P.; Stern, R.; Cox, J.; Sherridan, E.; Roberts, E.; Springell, K.; Scott, S.; Karbani, G.; Sharif, S. M.; Toomes, C.; Bond, J.; Kumar, D.; Al-Gazali, L.; Mundlos, S.

2006-01-01

Fuhrmann syndrome and the Al-Awadi/Raas-Rothschild/Schinzel phocomelia syndrome are considered to be distinct limb-malformation disorders characterized by various degrees of limb aplasia/hypoplasia and joint dysplasia in humans. In families with these syndromes, we found homozygous missense mutations in the dorsoventral-patterning gene WNT7A and confirmed their functional significance in retroviral-mediated transfection of chicken mesenchyme cell cultures and developing limbs. The results suggest that a partial loss of WNT7A function causes Fuhrmann syndrome (and a phenotype similar to mouse Wnt7a knockout), whereas the more-severe limb truncation phenotypes observed in Al-Awadi/Raas-Rothschild/Schinzel phocomelia syndrome result from null mutations (and cause a phenotype similar to mouse Shh knockout). These findings illustrate the specific and conserved importance of WNT7A in multiple aspects of vertebrate limb development. PMID:16826533

Msx genes are expressed in the carapacial ridge of turtle shell: a study of the European pond turtle, Emys orbicularis.

PubMed

Vincent, Christine; Bontoux, Martine; Le Douarin, Nicole M; Pieau, Claude; Monsoro-Burq, Anne-Hélène

2003-09-01

The turtle shell forms by extensive ossification of dermis ventrally and dorsally. The carapacial ridge (CR) controls early dorsal shell formation and is thought to play a similar role in shell growth as the apical ectodermal ridge during limb development. However, the molecular mechanisms underlying carapace development are still unknown. Msx genes are involved in the development of limb mesenchyme and of various skeletal structures. In particular, precocious Msx expression is recorded in skeletal precursors that develop close to the ectoderm, such as vertebral spinous processes or skull. Here, we have studied the embryonic expression of Msx genes in the European pond turtle, Emys orbicularis. The overall Msx expression in head, limb, and trunk is similar to what is observed in other vertebrates. We have focused on the CR area and pre-skeletal shell condensations. The CR expresses Msx genes transiently, in a pattern similar to that of fgf10. In the future carapace domain, the dermis located dorsal to the spinal cord expresses Msx genes, as in other vertebrates, but we did not see expansion of this expression in the dermis located more laterally, on top of the dermomyotomes. In the ventral plastron, although the dermal osseous condensations form in the embryonic Msx-positive somatopleura, we did not observe enhanced Msx expression around these elements. These observations may indicate that common mechanisms participate in limb bud and CR early development, but that pre-differentiation steps differ between shell and other skeletal structures and involve other gene activities than that of Msx genes.

A case report: a heterozygous deletion (2791_2805 del) in exon 18 of the filamin C gene causing filamin C-related myofibrillar myopathies in a Chinese family.

PubMed

Miao, Jing; Su, Fei-Fei; Liu, Xue-Mei; Wei, Xiao-Jing; Yuan, Yun; Yu, Xue-Fan

2018-06-04

Filamin C-related myofibrillar myopathies (MFM) are progressive skeletal myopathies with an autosomal dominant inheritance pattern. The conditions are caused by mutations of the filamin C gene (FLNC) located in the chromosome 7q32-q35 region. Genetic variations in the FLNC gene result in various clinical phenotypes. We describe a 43-year-old woman who suffered filamin C-related MFM, with symptoms first presenting in the proximal muscles of the lower limbs and eventually spreading to the upper limbs and distal muscles. The patient's serum level of creatine kinase was mildly increased. Mildy myopathic changes in the electromyographic exam and moderate lipomatous alterations in lower limb MRI were found. Histopathological examination revealed increased muscle fiber size variability, disturbances in oxidative enzyme activity, and the presence of abnormal protein aggregates and vacuoles in some muscle fibers. Ultrastructural analysis showed inclusions composed of thin filaments and interspersed granular densities. DNA sequencing analysis detected a novel 15-nucleotide deletion (c.2791_2805del, p.931_935del) in the FLNC gene. The patient's father, sister, brother, three paternal aunts, one paternal uncle, and the uncle's son also had slowly progressive muscle weakness, and thus, we detected an autosomal dominant inheritance pattern of the disorder. A novel heterogeneous 15-nucleotide deletion (c.2791_2805del, p.931_935del) in the Ig-like domain 7 of the FLNC gene was found to cause filamin C-related MFM. This deletion in the FLNC gene causes protein aggregation, abnormalities in muscle structure, and impairment in muscle fiber function, which leads to muscle weakness.

Comparative transgenic analysis of enhancers from the human SHOX and mouse Shox2 genomic regions.

PubMed

Rosin, Jessica M; Abassah-Oppong, Samuel; Cobb, John

2013-08-01

Disruption of presumptive enhancers downstream of the human SHOX gene (hSHOX) is a frequent cause of the zeugopodal limb defects characteristic of Léri-Weill dyschondrosteosis (LWD). The closely related mouse Shox2 gene (mShox2) is also required for limb development, but in the more proximal stylopodium. In this study, we used transgenic mice in a comparative approach to characterize enhancer sequences in the hSHOX and mShox2 genomic regions. Among conserved noncoding elements (CNEs) that function as enhancers in vertebrate genomes, those that are maintained near paralogous genes are of particular interest given their ancient origins. Therefore, we first analyzed the regulatory potential of a genomic region containing one such duplicated CNE (dCNE) downstream of mShox2 and hSHOX. We identified a strong limb enhancer directly adjacent to the mShox2 dCNE that recapitulates the expression pattern of the endogenous gene. Interestingly, this enhancer requires sequences only conserved in the mammalian lineage in order to drive strong limb expression, whereas the more deeply conserved sequences of the dCNE function as a neural enhancer. Similarly, we found that a conserved element downstream of hSHOX (CNE9) also functions as a neural enhancer in transgenic mice. However, when the CNE9 transgenic construct was enlarged to include adjacent, non-conserved sequences frequently deleted in LWD patients, the transgene drove expression in the zeugopodium of the limbs. Therefore, both hSHOX and mShox2 limb enhancers are coupled to distinct neural enhancers. This is the first report demonstrating the activity of cis-regulatory elements from the hSHOX and mShox2 genomic regions in mammalian embryos.

Development of five digits is controlled by a bipartite long-range cis-regulator.

PubMed

Lettice, Laura A; Williamson, Iain; Devenney, Paul S; Kilanowski, Fiona; Dorin, Julia; Hill, Robert E

2014-04-01

Conservation within intergenic DNA often highlights regulatory elements that control gene expression from a long range. How conservation within a single element relates to regulatory information and how internal composition relates to function is unknown. Here, we examine the structural features of the highly conserved ZRS (also called MFCS1) cis-regulator responsible for the spatiotemporal control of Shh in the limb bud. By systematically dissecting the ZRS, both in transgenic assays and within in the endogenous locus, we show that the ZRS is, in effect, composed of two distinct domains of activity: one domain directs spatiotemporal activity but functions predominantly from a short range, whereas a second domain is required to promote long-range activity. We show further that these two domains encode activities that are highly integrated and that the second domain is crucial in promoting the chromosomal conformational changes correlated with gene activity. During limb bud development, these activities encoded by the ZRS are interpreted differently by the fore limbs and the hind limbs; in the absence of the second domain there is no Shh activity in the fore limb, and in the hind limb low levels of Shh lead to a variant digit pattern ranging from two to four digits. Hence, in the embryo, the second domain stabilises the developmental programme providing a buffer for SHH morphogen activity and this ensures that five digits form in both sets of limbs.

The HoxD cluster is a dynamic and resilient TAD boundary controlling the segregation of antagonistic regulatory landscapes.

PubMed

Rodríguez-Carballo, Eddie; Lopez-Delisle, Lucille; Zhan, Ye; Fabre, Pierre J; Beccari, Leonardo; El-Idrissi, Imane; Huynh, Thi Hanh Nguyen; Ozadam, Hakan; Dekker, Job; Duboule, Denis

2017-11-15

The mammalian HoxD cluster lies between two topologically associating domains (TADs) matching distinct enhancer-rich regulatory landscapes. During limb development, the telomeric TAD controls the early transcription of Hoxd genes in forearm cells, whereas the centromeric TAD subsequently regulates more posterior Hoxd genes in digit cells. Therefore, the TAD boundary prevents the terminal Hoxd13 gene from responding to forearm enhancers, thereby allowing proper limb patterning. To assess the nature and function of this CTCF-rich DNA region in embryos , we compared chromatin interaction profiles between proximal and distal limb bud cells isolated from mutant stocks where various parts of this boundary region were removed. The resulting progressive release in boundary effect triggered inter-TAD contacts, favored by the activity of the newly accessed enhancers. However, the boundary was highly resilient, and only a 400-kb deletion, including the whole-gene cluster, was eventually able to merge the neighboring TADs into a single structure. In this unified TAD, both proximal and distal limb enhancers nevertheless continued to work independently over a targeted transgenic reporter construct. We propose that the whole HoxD cluster is a dynamic TAD border and that the exact boundary position varies depending on both the transcriptional status and the developmental context. © 2017 Rodríguez-Carballo et al.; Published by Cold Spring Harbor Laboratory Press.

The mouse homeobox gene, S8, is expressed during embryogenesis predominantly in mesenchyme.

PubMed

Opstelten, D J; Vogels, R; Robert, B; Kalkhoven, E; Zwartkruis, F; de Laaf, L; Destrée, O H; Deschamps, J; Lawson, K A; Meijlink, F

1991-03-01

The murine S8 gene, originally identified by Kongsuwan et al. [EMBO J. 7(1988)2131-2138] encodes a homeodomain which resembles those of the paired family. We studied the expression pattern during mid-gestation embryogenesis of S8 by in situ hybridization. Expression was detected locally in craniofacial mesenchyme, in the limb, the heart and the somites and sclerotomes all along the axis, and was absent from the central and peripheral nervous system, splanchnopleure, and endodermal derivatives. This pattern differs considerably from that of most previously described homeobox containing genes. By genetic analysis, the gene was located on chromosome 2, about 20 cM from the HOX-4 cluster.

A regulatory network of two galectins mediates the earliest steps of avian limb skeletal morphogenesis

PubMed Central

2011-01-01

Background The skeletal elements of vertebrate embryonic limbs are prefigured by rod- and spot-like condensations of precartilage mesenchymal cells. The formation of these condensations depends on cell-matrix and cell-cell interactions, but how they are initiated and patterned is as yet unresolved. Results Here we provide evidence that galectins, β-galactoside-binding lectins with β-sandwich folding, play fundamental roles in these processes. We show that among the five chicken galectin (CG) genes, two, CG-1A, and CG-8, are markedly elevated in expression at prospective sites of condensation in vitro and in vivo, with their protein products appearing earlier in development than any previously described marker. The two molecules enhance one another's gene expression but have opposite effects on condensation formation and cartilage development in vivo and in vitro: CG-1A, a non-covalent homodimer, promotes this process, while the tandem-repeat-type CG-8 antagonizes it. Correspondingly, knockdown of CG-1A inhibits the formation of skeletal elements while knockdown of CG-8 enhances it. The apparent paradox of mutual activation at the gene expression level coupled with antagonistic roles in skeletogenesis is resolved by analysis of the direct effect of the proteins on precartilage cells. Specifically, CG-1A causes their aggregation, whereas CG-8, which has no adhesive function of its own, blocks this effect. The developmental appearance and regulation of the unknown cell surface moieties ("ligands") to which CG-1A and CG-8 bind were indicative of specific cognate- and cross-regulatory interactions. Conclusion Our findings indicate that CG-1A and CG-8 constitute a multiscale network that is a major mediator, earlier-acting than any previously described, of the formation and patterning of precartilage mesenchymal condensations in the developing limb. This network functions autonomously of limb bud signaling centers or other limb bud positional cues. PMID:21284876

Multi-view light-sheet imaging and tracking with the MaMuT software reveals the cell lineage of a direct developing arthropod limb

PubMed Central

Stamataki, Evangelia; Harich, Benjamin; Guignard, Léo; Preibisch, Stephan; Shorte, Spencer; Keller, Philipp J

2018-01-01

During development, coordinated cell behaviors orchestrate tissue and organ morphogenesis. Detailed descriptions of cell lineages and behaviors provide a powerful framework to elucidate the mechanisms of morphogenesis. To study the cellular basis of limb development, we imaged transgenic fluorescently-labeled embryos from the crustacean Parhyale hawaiensis with multi-view light-sheet microscopy at high spatiotemporal resolution over several days of embryogenesis. The cell lineage of outgrowing thoracic limbs was reconstructed at single-cell resolution with new software called Massive Multi-view Tracker (MaMuT). In silico clonal analyses suggested that the early limb primordium becomes subdivided into anterior-posterior and dorsal-ventral compartments whose boundaries intersect at the distal tip of the growing limb. Limb-bud formation is associated with spatial modulation of cell proliferation, while limb elongation is also driven by preferential orientation of cell divisions along the proximal-distal growth axis. Cellular reconstructions were predictive of the expression patterns of limb development genes including the BMP morphogen Decapentaplegic. PMID:29595475

Gene expression in spider appendages reveals reversal of exd/hth spatial specificity, altered leg gap gene dynamics, and suggests divergent distal morphogen signaling.

PubMed

Prpic, Nikola-Michael; Janssen, Ralf; Wigand, Barbara; Klingler, Martin; Damen, Wim G M

2003-12-01

Leg development in Drosophila has been studied in much detail. However, Drosophila limbs form in the larva as imaginal discs and not during embryogenesis as in most other arthropods. Here, we analyze appendage genes in the spider Cupiennius salei and the beetle Tribolium castaneum. Differences in decapentaplegic (dpp) expression suggest a different mode of distal morphogen signaling suitable for the specific geometry of growing limb buds. Also, expression of the proximal genes homothorax (hth) and extradenticle (exd) is significantly altered: in the spider, exd is restricted to the proximal leg and hth expression extends distally, while in insects, exd is expressed in the entire leg and hth is restricted to proximal parts. This reversal of spatial specificity demonstrates an evolutionary shift, which is nevertheless compatible with a conserved role of this gene pair as instructor of proximal fate. Different expression dynamics of dachshund and Distal-less point to modifications in the regulation of the leg gap gene system. We comment on the significance of this finding for attempts to homologize leg segments in different arthropod classes. Comparison of the expression profiles of H15 and optomotor-blind to the Drosophila patterns suggests modifications also in the dorsal-ventral patterning system of the legs. Together, our results suggest alterations in many components of the leg developmental system, namely proximal-distal and dorsal-ventral patterning, and leg segmentation. Thus, the leg developmental system exhibits a propensity to evolutionary change, which probably forms the basis for the impressive diversity of arthropod leg morphologies.

Distal Limb Patterning Requires Modulation of cis-Regulatory Activities by HOX13

DOE PAGES

Sheth, Rushikesh; Barozzi, Iros; Langlais, David; ...

2016-12-13

The combinatorial expression of Hox genes along the body axes is a major determinant of cell fate and plays a pivotal role in generating the animal body plan. Loss of HOXA13 and HOXD13 transcription factors (HOX13) leads to digit agenesis in mice, but how HOX13 proteins regulate transcriptional outcomes and confer identity to the distal-most limb cells has remained elusive. Here, we report on the genome-wide profiling of HOXA13 and HOXD13 in vivo binding and changes of the transcriptome and chromatin state in the transition from the early to the late-distal limb developmental program, as well as in Hoxa13–/–; Hoxd13–/– limbs. Ourmore » results show that proper termination of the early limb transcriptional program and activation of the late-distal limb program are coordinated by the dual action of HOX13 on cis-regulatory modules.« less

Development of five digits is controlled by a bipartite long-range cis-regulator

PubMed Central

Lettice, Laura A.; Williamson, Iain; Devenney, Paul S.; Kilanowski, Fiona; Dorin, Julia; Hill, Robert E.

2014-01-01

Conservation within intergenic DNA often highlights regulatory elements that control gene expression from a long range. How conservation within a single element relates to regulatory information and how internal composition relates to function is unknown. Here, we examine the structural features of the highly conserved ZRS (also called MFCS1) cis-regulator responsible for the spatiotemporal control of Shh in the limb bud. By systematically dissecting the ZRS, both in transgenic assays and within in the endogenous locus, we show that the ZRS is, in effect, composed of two distinct domains of activity: one domain directs spatiotemporal activity but functions predominantly from a short range, whereas a second domain is required to promote long-range activity. We show further that these two domains encode activities that are highly integrated and that the second domain is crucial in promoting the chromosomal conformational changes correlated with gene activity. During limb bud development, these activities encoded by the ZRS are interpreted differently by the fore limbs and the hind limbs; in the absence of the second domain there is no Shh activity in the fore limb, and in the hind limb low levels of Shh lead to a variant digit pattern ranging from two to four digits. Hence, in the embryo, the second domain stabilises the developmental programme providing a buffer for SHH morphogen activity and this ensures that five digits form in both sets of limbs. PMID:24715461

Sonic hedgehog: restricted expression and limb dysmorphologies

PubMed Central

Hill, Robert E; Heaney, Simon JH; Lettice, Laura A

2003-01-01

Sonic hedgehog, SHH, is required for patterning the limb. The array of skeletal elements that compose the hands and feet, and the ordered arrangement of these bones to form the pattern of fingers and toes are dependent on SHH. The mechanism of action of SHH in the limb is not fully understood; however, an aspect that appears to be important is the localized, asymmetric expression of Shh. Shh is expressed in the posterior margin of the limb bud in a region defined as the zone of polarizing activity (ZPA). Analysis of mouse mutants which have polydactyly (extra toes) shows that asymmetric expression of Shh is lost due to the appearance of an ectopic domain of expression in the anterior limb margin. One such polydactylous mouse mutant, sasquatch (Ssq), maps to the corresponding chromosomal region of the human condition pre-axial polydactyly (PPD) and thus represents a model for this condition. The mutation responsible for Ssq is located 1 Mb away from the Shh gene; however, the mutation disrupts a long-range cis-acting regulator of Shh expression. By inference, human pre-axial polydactyly results from a similar disruption of Shh expression. Other human congenital abnormalities also map near the pre-axial polydactyly locus, suggesting a major chromosomal region for limb dysmorphologies. The distinct phenotypes range from loss of all bones of the hands and feet to syndactyly of the soft tissue and fusion of the digits. We discuss the role played by Shh expression in mouse mutant phenotypes and the human limb dysmorphologies. PMID:12587915

Identification of reference genes and validation for gene expression studies in diverse axolotl (Ambystoma mexicanum) tissues.

PubMed

Guelke, Eileen; Bucan, Vesna; Liebsch, Christina; Lazaridis, Andrea; Radtke, Christine; Vogt, Peter M; Reimers, Kerstin

2015-04-10

For the precise quantitative RT-PCR normalization a set of valid reference genes is obligatory. Moreover have to be taken into concern the experimental conditions as they bias the regulation of reference genes. Up till now, no reference targets have been described for the axolotl (Ambystoma mexicanum). In a search in the public database SalSite for genetic information of the axolotl we identified fourteen presumptive reference genes, eleven of which were further tested for their gene expression stability. This study characterizes the expressional patterns of 11 putative endogenous control genes during axolotl limb regeneration and in an axolotl tissue panel. All 11 reference genes showed variable expression. Strikingly, ACTB was to be found most stable expressed in all comparative tissue groups, so we reason it to be suitable for all different kinds of axolotl tissue-type investigations. Moreover do we suggest GAPDH and RPLP0 as suitable for certain axolotl tissue analysis. When it comes to axolotl limb regeneration, a validated pair of reference genes is ODC and RPLP0. With these findings, new insights into axolotl gene expression profiling might be gained. Copyright © 2015 Elsevier B.V. All rights reserved.

FGFR3 is a target of the homeobox transcription factor SHOX in limb development.

PubMed

Decker, Eva; Durand, Claudia; Bender, Sebastian; Rödelsperger, Christian; Glaser, Anne; Hecht, Jochen; Schneider, Katja U; Rappold, Gudrun

2011-04-15

The short stature homeobox gene SHOX encodes a transcription factor which is important for normal limb development. In humans, SHOX deficiency has been associated with various short stature syndromes including Leri-Weill dyschondrosteosis (LWD), Langer mesomelic dysplasia and Turner syndrome as well as non-syndromic idiopathic short stature. A common feature of these syndromes is disproportionate short stature with a particular shortening of the forearms and lower legs. In our studies employing microarray analyses and cell culture experiments, we revealed a strong positive effect of SHOX on the expression of the fibroblast growth factor receptor gene FGFR3, another well-known factor for limb development. Luciferase reporter gene assays show that SHOX activates the extended FGFR3 promoter, and results from chromatin immunoprecipitation (ChIP)-sequencing, ChIP and electrophoretic mobility shift assay experiments suggest a direct binding of SHOX to multiple upstream sequences of FGFR3. To further investigate these regulations in a cellular system for limb development, the effect of viral overexpression of Shox in limb bud derived chicken micromass cultures was tested. We found that Fgfr3 was negatively regulated by Shox, as demonstrated by quantitative real-time polymerase chain reaction and in situ hybridization. This repressive effect might explain the almost mutually exclusive expression patterns of Fgfr3 and Shox in embryonic chicken limbs. A negative regulation that occurs mainly in the mesomelic segments, a region where SHOX is known to be strongly expressed, offers a possible explanation for the phenotypes seen in patients with FGFR3 (e.g. achondroplasia) and SHOX defects (e.g. LWD). In summary, these data present a link between two frequent short stature phenotypes.

Linkage Study Revealed Complex Haplotypes in a Multifamily due to Different Mutations in CAPN3 Gene in an Iranian Ethnic Group.

PubMed

Mojbafan, Marzieh; Tonekaboni, Seyed Hassan; Abiri, Maryam; Kianfar, Soudeh; Sarhadi, Ameneh; Nilipour, Yalda; Tavakkoly-Bazzaz, Javad; Zeinali, Sirous

2016-07-01

Calpainopathy is an autosomal recessive form of limb girdle muscular dystrophies which is caused by mutation in CAPN3 gene. In the present study, co-segregation of this disorder was analyzed with four short tandem repeat markers linked to the CAPN3 gene. Three apparently unrelated Iranian families with same ethnicity were investigated. Haplotype analysis and sequencing of the CAPN3 gene were performed. DNA sample from one of the patients was simultaneously sent for next-generation sequencing. DNA sequencing identified two mutations. It was seen as a homozygous c.2105C>T in exon 19 in one family, a homozygous novel mutation c.380G>A in exon 3 in another family, and a compound heterozygote form of these two mutations in the third family. Next-generation sequencing also confirmed our results. It was expected that, due to the rare nature of limb girdle muscular dystrophies, affected individuals from the same ethnic group share similar mutations. Haplotype analysis showed two different homozygote patterns in two families, yet a compound heterozygote pattern in the third family as seen in the mutation analysis. This study shows that haplotype analysis would help in determining presence of different founders.

Opposing Functions of the ETS Factor Family Define Shh Spatial Expression in Limb Buds and Underlie Polydactyly

PubMed Central

Lettice, Laura A.; Williamson, Iain; Wiltshire, John H.; Peluso, Silvia; Devenney, Paul S.; Hill, Alison E.; Essafi, Abdelkader; Hagman, James; Mort, Richard; Grimes, Graeme; DeAngelis, Carlo L.; Hill, Robert E.

2012-01-01

Summary Sonic hedgehog (Shh) expression during limb development is crucial for specifying the identity and number of digits. The spatial pattern of Shh expression is restricted to a region called the zone of polarizing activity (ZPA), and this expression is controlled from a long distance by the cis-regulator ZRS. Here, members of two groups of ETS transcription factors are shown to act directly at the ZRS mediating a differential effect on Shh, defining its spatial expression pattern. Occupancy at multiple GABPα/ETS1 sites regulates the position of the ZPA boundary, whereas ETV4/ETV5 binding restricts expression outside the ZPA. The ETS gene family is therefore attributed with specifying the boundaries of the classical ZPA. Two point mutations within the ZRS change the profile of ETS binding and activate Shh expression at an ectopic site in the limb bud. These molecular changes define a pathogenetic mechanism that leads to preaxial polydactyly (PPD). PMID:22340503

Genomic regression of claw keratin, taste receptor and light-associated genes provides insights into biology and evolutionary origins of snakes.

PubMed

Emerling, Christopher A

2017-10-01

Regressive evolution of anatomical traits often corresponds with the regression of genomic loci underlying such characters. As such, studying patterns of gene loss can be instrumental in addressing questions of gene function, resolving conflicting results from anatomical studies, and understanding the evolutionary history of clades. The evolutionary origins of snakes involved the regression of a number of anatomical traits, including limbs, taste buds and the visual system, and by analyzing serpent genomes, I was able to test three hypotheses associated with the regression of these features. The first concerns two keratins that are putatively specific to claws. Both genes that encode these keratins are pseudogenized/deleted in snake genomes, providing additional evidence of claw-specificity. The second hypothesis is that snakes lack taste buds, an issue complicated by conflicting results in the literature. I found evidence that different snakes have lost one or more taste receptors, but all snakes examined retained at least one gustatory channel. The final hypothesis addressed is that the earliest snakes were adapted to a dim light niche. I found evidence of deleted and pseudogenized genes with light-associated functions in snakes, demonstrating a pattern of gene loss similar to other dim light-adapted clades. Molecular dating estimates suggest that dim light adaptation preceded the loss of limbs, providing some bearing on interpretations of the ecological origins of snakes. Copyright © 2017 Elsevier Inc. All rights reserved.

The role of early development in mammalian limb diversification: a descriptive comparison of early limb development between the Natal long-fingered bat (Miniopterus natalensis) and the mouse (Mus musculus).

PubMed

Hockman, Dorit; Mason, Mandy K; Jacobs, David S; Illing, Nicola

2009-04-01

Comparative embryology expands our understanding of unique limb structures, such as that found in bats. Bat forelimb digits 2 to 5 are differentially elongated and joined by webbing, while the hindlimb digits are of similar length in many species. We compare limb development between the mouse and the Natal long-fingered bat, Miniopterus natalensis, to pinpoint the stage at which their limbs begin to differ. The bat forelimb differs from the mouse at Carollia stage (CS) 14 with the appearance of the wing membrane primordia. This difference is enhanced at CS 15 with the posterior expansion of the hand plate. The bat hindlimb begins to differ from the mouse between CS 15 and 16 when the foot plate undergoes a proximal expansion resulting in digit primordia of very similar length. Our findings support recent gene expression studies, which reveal a role for early patterning in the development of the bat limb. Copyright 2009 Wiley-Liss, Inc.

BMP-Mediated Functional Cooperation between Dlx5;Dlx6 and Msx1;Msx2 during Mammalian Limb Development

PubMed Central

Vieux-Rochas, Maxence; Bouhali, Kamal; Mantero, Stefano; Garaffo, Giulia; Provero, Paolo; Astigiano, Simonetta; Barbieri, Ottavia; Caratozzolo, Mariano F.; Tullo, Apollonia; Guerrini, Luisa; Lallemand, Yvan; Robert, Benoît

2013-01-01

The Dlx and Msx homeodomain transcription factors play important roles in the control of limb development. The combined disruption of Msx1 and Msx2, as well as that of Dlx5 and Dlx6, lead to limb patterning defects with anomalies in digit number and shape. Msx1;Msx2 double mutants are characterized by the loss of derivatives of the anterior limb mesoderm which is not observed in either of the simple mutants. Dlx5;Dlx6 double mutants exhibit hindlimb ectrodactyly. While the morphogenetic action of Msx genes seems to involve the BMP molecules, the mode of action of Dlx genes still remains elusive. Here, examining the limb phenotypes of combined Dlx and Msx mutants we reveal a new Dlx-Msx regulatory loop directly involving BMPs. In Msx1;Dlx5;Dlx6 triple mutant mice (TKO), beside the expected ectrodactyly, we also observe the hallmark morphological anomalies of Msx1;Msx2 double mutants suggesting an epistatic role of Dlx5 and Dlx6 over Msx2. In Msx2;Dlx5;Dlx6 TKO mice we only observe an aggravation of the ectrodactyly defect without changes in the number of the individual components of the limb. Using a combination of qPCR, ChIP and bioinformatic analyses, we identify two Dlx/Msx regulatory pathways: 1) in the anterior limb mesoderm a non-cell autonomous Msx-Dlx regulatory loop involves BMP molecules through the AER and 2) in AER cells and, at later stages, in the limb mesoderm the regulation of Msx2 by Dlx5 and Dlx6 occurs also cell autonomously. These data bring new elements to decipher the complex AER-mesoderm dialogue that takes place during limb development and provide clues to understanding the etiology of congenital limb malformations. PMID:23382810

BMP-mediated functional cooperation between Dlx5;Dlx6 and Msx1;Msx2 during mammalian limb development.

PubMed

Vieux-Rochas, Maxence; Bouhali, Kamal; Mantero, Stefano; Garaffo, Giulia; Provero, Paolo; Astigiano, Simonetta; Barbieri, Ottavia; Caratozzolo, Mariano F; Tullo, Apollonia; Guerrini, Luisa; Lallemand, Yvan; Robert, Benoît; Levi, Giovanni; Merlo, Giorgio R

2013-01-01

The Dlx and Msx homeodomain transcription factors play important roles in the control of limb development. The combined disruption of Msx1 and Msx2, as well as that of Dlx5 and Dlx6, lead to limb patterning defects with anomalies in digit number and shape. Msx1;Msx2 double mutants are characterized by the loss of derivatives of the anterior limb mesoderm which is not observed in either of the simple mutants. Dlx5;Dlx6 double mutants exhibit hindlimb ectrodactyly. While the morphogenetic action of Msx genes seems to involve the BMP molecules, the mode of action of Dlx genes still remains elusive. Here, examining the limb phenotypes of combined Dlx and Msx mutants we reveal a new Dlx-Msx regulatory loop directly involving BMPs. In Msx1;Dlx5;Dlx6 triple mutant mice (TKO), beside the expected ectrodactyly, we also observe the hallmark morphological anomalies of Msx1;Msx2 double mutants suggesting an epistatic role of Dlx5 and Dlx6 over Msx2. In Msx2;Dlx5;Dlx6 TKO mice we only observe an aggravation of the ectrodactyly defect without changes in the number of the individual components of the limb. Using a combination of qPCR, ChIP and bioinformatic analyses, we identify two Dlx/Msx regulatory pathways: 1) in the anterior limb mesoderm a non-cell autonomous Msx-Dlx regulatory loop involves BMP molecules through the AER and 2) in AER cells and, at later stages, in the limb mesoderm the regulation of Msx2 by Dlx5 and Dlx6 occurs also cell autonomously. These data bring new elements to decipher the complex AER-mesoderm dialogue that takes place during limb development and provide clues to understanding the etiology of congenital limb malformations.

The evolutionary history of the development of the pelvic fin/hindlimb

PubMed Central

Don, Emily K; Currie, Peter D; Cole, Nicholas J

2013-01-01

The arms and legs of man are evolutionarily derived from the paired fins of primitive jawed fish. Few evolutionary changes have attracted as much attention as the origin of tetrapod limbs from the paired fins of ancestral fish. The hindlimbs of tetrapods are derived from the pelvic fins of ancestral fish. These evolutionary origins can be seen in the examination of shared gene and protein expression patterns during the development of pelvic fins and tetrapod hindlimbs. The pelvic fins of fish express key limb positioning, limb bud induction and limb outgrowth genes in a similar manner to that seen in hindlimb development of higher vertebrates. We are now at a point where many of the key players in the development of pelvic fins and vertebrate hindlimbs have been identified and we can now readily examine and compare mechanisms between species. This is yielding fascinating insights into how the developmental programme has altered during evolution and how that relates to anatomical change. The role of pelvic fins has also drastically changed over evolutionary history, from playing a minor role during swimming to developing into robust weight-bearing limbs. In addition, the pelvic fins/hindlimbs have been lost repeatedly in diverse species over evolutionary time. Here we review the evolution of pelvic fins and hindlimbs within the context of the changes in anatomical structure and the molecular mechanisms involved. PMID:22913749

T-Box Genes in Drosophila Limb Development.

PubMed

Pflugfelder, G O; Eichinger, F; Shen, J

2017-01-01

T-box genes are essential for limb development in vertebrates and arthropods. The Drosophila genome encodes eight T-box genes, six of which are expressed in limb ontogenesis. The Tbx20-related gene pair midline and H15 is essential for dorso-ventral patterning of the Drosophila legs. The three Tbx6-related Dorsocross genes are required for epithelial remodeling during wing development. The Drosophila gene optomotor-blind (omb) is the only member of the Tbx2 subfamily in the fly and is predominantly involved in wing development. Omb is essential for wing development and is sufficient to promote the development of a second wing pair. Targeted manipulations of omb expression have shown that the bulk omb requirement for wing development can be deconstructed into a number of individual functions. Even though omb expression in the wing disc is symmetrical with regard to the anterior/posterior (A/P) compartment boundary, anterior and posterior knockdowns have distinct consequences: Anterior Omb is required for the maintenance of a straight A/P lineage restriction boundary. Posterior Omb suppresses formation of an apical epithelial fold along the A/P boundary. Drosophila T-box gene expression is not confined to the ectoderm-derived epithelia of the imaginal discs. Both Doc and Omb are prominently expressed in leg disc muscle precursor cells. Omb is also strongly expressed in a tracheal branch that invades the extracellular matrix of the wing disc. The function of Doc and Omb in the latter tissues is not known, indicative of the many questions still open in the field. © 2017 Elsevier Inc. All rights reserved.

Movement patterns of limb coordination in infant rolling.

PubMed

Kobayashi, Yoshio; Watanabe, Hama; Taga, Gentaro

2016-12-01

Infants must perform dynamic whole-body movements to initiate rolling, a key motor skill. However, little is known regarding limb coordination and postural control in infant rolling. To address this lack of knowledge, we examined movement patterns and limb coordination during rolling in younger infants (aged 5-7 months) that had just begun to roll and in older infants (aged 8-10 months) with greater rolling experience. Due to anticipated difficulty in obtaining measurements over the second half of the rolling sequence, we limited our analysis to the first half. Ipsilateral and contralateral limbs were identified on the basis of rolling direction and were classified as either a stationary limb used for postural stability or a moving limb used for controlled movement. We classified the observed movement patterns by identifying the number of stationary limbs and the serial order of combinational limb movement patterns. Notably, older infants performed more movement patterns that involved a lower number of stationary limbs than younger infants. Despite the wide range of possible movement patterns, a small group of basic patterns dominated in both age groups. Our results suggest that the fundamental structure of limb coordination during rolling in the early acquisition stages remains unchanged until at least 8-10 months of age. However, compared to younger infants, older infants exhibited a greater ability to select an effective rotational movement by positioning themselves with fewer stationary limbs and performing faster limb movements.

Differential expression of homeobox-containing genes Msx-1 and Msx-2 and homeoprotein Msx-2 expression during chick craniofacial development.

PubMed

Nishikawa, K; Nakanishi, T; Aoki, C; Hattori, T; Takahashi, K; Taniguchi, S

1994-03-01

The expression pattern of chick Msx-1 and Msx-2 homeobox genes in craniofacial primordia was examined by in situ hybridization using cRNA probes. Both genes were expressed in the distal region of the facial primordia, where the distribution of Msx-2 expression was restricted distally within the Msx-1 expression domain. On the contrary, Msx-2 expression in the lateral choroid plexus and cranial skull was broader and more intensive than Msx-1 expression. Our findings suggest that these two genes cooperate to play differential roles in craniofacial development. Msx-2 protein was detected immunohistochemically, and its localization essentially corresponded to the mRNA expression pattern, substantiating the involvement of Msx-2 protein as a transcriptional regulator in developing limb and face.

Analysis of the pattern of expression of the Fanconi anemia group C (Facc) gene during murine development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krasnoshtein, F.; Buchwald, M.

1994-09-01

Fanconi anemia (FA) is an autosomal recessive disorder characterized by a variety of congenital and skeletal malformations, progressive pancytopanenia and predisposition to malignancies. FA cells display chromosomal instability and hypersensitivity to DNA-damaging agents. Both the human and the corresponding murine cDNAs have been cloned in our lab. Here we describe the expression of Facc during mouse development, using mRNA in situ hybridization. Our aim is to obtain clues on the possible function of the Facc gene product during development that may help elucidate basic defect(s) in FA. In addition, knowledge of the exact pattern of Facc expression will assist inmore » interpreting the phenotypes of mutant mice, currently being developed. In embryos the gene is diffusely expressed over the entire embryo, with higher hybridization levels in the mesenchyme and in both upper and lower extremities. Specific expression of Facc is seen in the perichondrium and marrow of long bones of hind limbs/hip; long bones of front limbs/shoulder region; developing digits of front and hind paws; and ribs. The signal is also detected in the following regions: cranial/frontal; facial/periorbital and maxillary/mandibular, hair follicles, diaphragm and lung. In addition, generalized Facc expression is seen during these embryonic stages. The pattern of Facc expression is consistent with the known skeletal abnormalities in FA patients, which include radial ray deformities, metacarpal hypoplasia, and abnormalities of lower limbs, ribs, head and face. The signal in the lung is consistent with the lung lobe absence and abnormal pulmonary drainage that have been detected in some FA patients. The sloped forehead and microcephaly in FA patients may have some association with the signal seen in the frontal region of the mouse cranium. Taken together, our results suggest that Facc is directly involved in the development of various embryonic tissues, particularly bone.« less

Adult Rat Bones Maintain Distinct Regionalized Expression of Markers Associated with Their Development

PubMed Central

Rawlinson, Simon C. F.; McKay, Ian J.; Ghuman, Mandeep; Wellmann, Claudia; Ryan, Paul; Prajaneh, Saengsome; Zaman, Gul; Hughes, Francis J.; Kingsmill, Virginia J.

2009-01-01

The incidence of limb bone fracture and subsequent morbidity and mortality due to excessive bone loss is increasing in the progressively ageing populations of both men and women. In contrast to bone loss in the weight-bearing limb, bone mass in the protective skull vault is maintained. One explanation for this could be anatomically diverse bone matrix characteristics generated by heterogeneous osteoblast populations. We have tested the hypothesis that adult bones demonstrate site-specific characteristics, and report differences at the organ, cell and transcriptome levels. Limb bones contain greater amounts of polysulphated glycosaminoglycan stained with Alcian Blue and have significantly higher osteocyte densities than skull bone. Site-specific patterns persist in cultured adult bone-derived cells both phenotypically (proliferation rate, response to estrogen and cell volumes), and at the level of specific gene expression (collagen triple helix repeat containing 1, reelin and ras-like and estrogen-regulated growth inhibitor). Based on genome-wide mRNA expression and cluster analysis, we demonstrate that bones and cultured adult bone-derived cells segregate according to site of derivation. We also find the differential expression of genes associated with embryological development (Skull: Zic, Dlx, Irx, Twist1 and Cart1; Limb: Hox, Shox2, and Tbx genes) in both adult bones and isolated adult bone-derived cells. Together, these site-specific differences support the view that, analogous to different muscle types (cardiac, smooth and skeletal), skull and limb bones represent separate classes of bone. We assign these differences, not to mode of primary ossification, but to the embryological cell lineage; the basis and implications of this division are discussed. PMID:20027296

Downregulation of the Petunia hybrida alpha-expansin gene PhEXP1 reduces the amount of crystalline cellulose in cell walls and leads to phenotypic changes in petal limbs.

PubMed

Zenoni, Sara; Reale, Lara; Tornielli, Giovanni Battista; Lanfaloni, Luisa; Porceddu, Andrea; Ferrarini, Alberto; Moretti, Chiaraluce; Zamboni, Anita; Speghini, Adolfo; Ferranti, Francesco; Pezzotti, Mario

2004-02-01

The expansins comprise a family of proteins that appear to be involved in the disruption of the noncovalent bonds between cellulose microfibrils and cross-linking glycans, thereby promoting wall creep. To understand better the expansion process in Petunia hybrida (petunia) flowers, we isolated a cDNA corresponding to the PhEXP1 alpha-expansin gene of P. hybrida. Evaluation of the tissue specificity and temporal expression pattern demonstrated that PhEXP1 is preferentially expressed in petal limbs during development. To determine the function of PhEXP1, we used a transgenic antisense approach, which was found to cause a decrease in petal limb size, a reduction in the epidermal cell area, and alterations in cell wall morphology and composition. The diminished cell wall thickness accompanied by a reduction in crystalline cellulose indicates that the activity of PhEXP1 is associated with cellulose metabolism. Our results suggest that expansins play a role in the assembly of the cell wall by affecting either cellulose synthesis or deposition.

Downregulation of the Petunia hybrida α-Expansin Gene PhEXP1 Reduces the Amount of Crystalline Cellulose in Cell Walls and Leads to Phenotypic Changes in Petal Limbs

PubMed Central

Zenoni, Sara; Reale, Lara; Tornielli, Giovanni Battista; Lanfaloni, Luisa; Porceddu, Andrea; Ferrarini, Alberto; Moretti, Chiaraluce; Zamboni, Anita; Speghini, Adolfo; Ferranti, Francesco; Pezzotti, Mario

2004-01-01

The expansins comprise a family of proteins that appear to be involved in the disruption of the noncovalent bonds between cellulose microfibrils and cross-linking glycans, thereby promoting wall creep. To understand better the expansion process in Petunia hybrida (petunia) flowers, we isolated a cDNA corresponding to the PhEXP1 α-expansin gene of P. hybrida. Evaluation of the tissue specificity and temporal expression pattern demonstrated that PhEXP1 is preferentially expressed in petal limbs during development. To determine the function of PhEXP1, we used a transgenic antisense approach, which was found to cause a decrease in petal limb size, a reduction in the epidermal cell area, and alterations in cell wall morphology and composition. The diminished cell wall thickness accompanied by a reduction in crystalline cellulose indicates that the activity of PhEXP1 is associated with cellulose metabolism. Our results suggest that expansins play a role in the assembly of the cell wall by affecting either cellulose synthesis or deposition. PMID:14742876

Detection of Genes Regulated by Lmx1b During Limb Dorsalization

PubMed Central

Feenstra, Jennifer M.; Kanaya, Kohei; Pira, Charmaine U; Hoffman, Sarah E.; Eppey, Richard J.; Oberg, Kerby C.

2012-01-01

Lmx1b is a homeodomain transcription factor that regulates dorsal identity during limb development. Lmx1b knockout (KO) mice develop distal ventral-ventral limbs. Although induction of Lmx1b is linked to Wnt7a expression in the dorsal limb ectoderm, the downstream targets of Lmx1b that accomplish limb dorsalization are unknown. To identify genes targeted by Lmx1b, we compared gene arrays from Lmx1b KO and wildtype mouse limbs during limb dorsalization, i.e., 11.5, 12.5, and 13.5 days post coitum. We identified 54 target genes differentially expressed in all three stages. Several skeletal targets, including Emx2, Matrilin1 and Matrilin4, demonstrated a loss of scapular expression in the Lmx1b KO mice, supporting a role for Lmx1b in scapula development. Furthermore, the relative abundance of extracellular matrix-related soft tissue targets regulated by Lmx1b, such as collagens and proteoglycans, suggests a mechanism which includes changes in the extracellular matrix composition to accomplish limb dorsalization. Our study provides the most comprehensive characterization of genes regulated by Lmx1b during limb development to-date and provides targets for further investigation. PMID:22417325

Distinct Patterns of Desynchronized Limb Regression in Malagasy Scincine Lizards (Squamata, Scincidae)

PubMed Central

Miralles, Aurélien; Hipsley, Christy A.; Erens, Jesse; Gehara, Marcelo; Rakotoarison, Andolalao; Glaw, Frank; Müller, Johannes; Vences, Miguel

2015-01-01

Scincine lizards in Madagascar form an endemic clade of about 60 species exhibiting a variety of ecomorphological adaptations. Several subclades have adapted to burrowing and convergently regressed their limbs and eyes, resulting in a variety of partial and completely limbless morphologies among extant taxa. However, patterns of limb regression in these taxa have not been studied in detail. Here we fill this gap in knowledge by providing a phylogenetic analysis of DNA sequences of three mitochondrial and four nuclear gene fragments in an extended sampling of Malagasy skinks, and microtomographic analyses of osteology of various burrowing taxa adapted to sand substrate. Based on our data we propose to (i) consider Sirenoscincus Sakata & Hikida, 2003, as junior synonym of Voeltzkowia Boettger, 1893; (ii) resurrect the genus name Grandidierina Mocquard, 1894, for four species previously included in Voeltzkowia; and (iii) consider Androngo Brygoo, 1982, as junior synonym of Pygomeles Grandidier, 1867. By supporting the clade consisting of the limbless Voeltzkowia mira and the forelimb-only taxa V. mobydick and V. yamagishii, our data indicate that full regression of limbs and eyes occurred in parallel twice in the genus Voeltzkowia (as hitherto defined) that we consider as a sand-swimming ecomorph: in the Voeltzkowia clade sensu stricto the regression first affected the hindlimbs and subsequently the forelimbs, whereas the Grandidierina clade first regressed the forelimbs and subsequently the hindlimbs following the pattern prevalent in squamates. Timetree reconstructions for the Malagasy Scincidae contain a substantial amount of uncertainty due to the absence of suitable primary fossil calibrations. However, our preliminary reconstructions suggest rapid limb regression in Malagasy scincids with an estimated maximal duration of 6 MYr for a complete regression in Paracontias, and 4 and 8 MYr respectively for complete regression of forelimbs in Grandidierina and hindlimbs in Voeltzkowia. PMID:26042667

Distinct patterns of desynchronized limb regression in malagasy scincine lizards (squamata, scincidae).

PubMed

Miralles, Aurélien; Hipsley, Christy A; Erens, Jesse; Gehara, Marcelo; Rakotoarison, Andolalao; Glaw, Frank; Müller, Johannes; Vences, Miguel

2015-01-01

Scincine lizards in Madagascar form an endemic clade of about 60 species exhibiting a variety of ecomorphological adaptations. Several subclades have adapted to burrowing and convergently regressed their limbs and eyes, resulting in a variety of partial and completely limbless morphologies among extant taxa. However, patterns of limb regression in these taxa have not been studied in detail. Here we fill this gap in knowledge by providing a phylogenetic analysis of DNA sequences of three mitochondrial and four nuclear gene fragments in an extended sampling of Malagasy skinks, and microtomographic analyses of osteology of various burrowing taxa adapted to sand substrate. Based on our data we propose to (i) consider Sirenoscincus Sakata & Hikida, 2003, as junior synonym of Voeltzkowia Boettger, 1893; (ii) resurrect the genus name Grandidierina Mocquard, 1894, for four species previously included in Voeltzkowia; and (iii) consider Androngo Brygoo, 1982, as junior synonym of Pygomeles Grandidier, 1867. By supporting the clade consisting of the limbless Voeltzkowia mira and the forelimb-only taxa V. mobydick and V. yamagishii, our data indicate that full regression of limbs and eyes occurred in parallel twice in the genus Voeltzkowia (as hitherto defined) that we consider as a sand-swimming ecomorph: in the Voeltzkowia clade sensu stricto the regression first affected the hindlimbs and subsequently the forelimbs, whereas the Grandidierina clade first regressed the forelimbs and subsequently the hindlimbs following the pattern prevalent in squamates. Timetree reconstructions for the Malagasy Scincidae contain a substantial amount of uncertainty due to the absence of suitable primary fossil calibrations. However, our preliminary reconstructions suggest rapid limb regression in Malagasy scincids with an estimated maximal duration of 6 MYr for a complete regression in Paracontias, and 4 and 8 MYr respectively for complete regression of forelimbs in Grandidierina and hindlimbs in Voeltzkowia.

Genomic Correlates of Relationship QTL Involved in Fore- versus Hind Limb Divergence in Mice

PubMed Central

Pavlicev, Mihaela; Wagner, Günter P.; Noonan, James P.; Hallgrímsson, Benedikt; Cheverud, James M.

2013-01-01

Divergence of serially homologous elements of organisms is a common evolutionary pattern contributing to increased phenotypic complexity. Here, we study the genomic intervals affecting the variational independence of fore- and hind limb traits within an experimental mouse population. We use an advanced intercross of inbred mouse strains to map the loci associated with the degree of autonomy between fore- and hind limb long bone lengths (loci affecting the relationship between traits, relationship quantitative trait loci [rQTL]). These loci have been proposed to interact locally with the products of pleiotropic genes, thereby freeing the local trait from the variational constraint due to pleiotropic mutations. Using the known polymorphisms (single nucleotide polymorphisms [SNPs]) between the parental strains, we characterized and compared the genomic regions in which the rQTL, as well as their interaction partners (intQTL), reside. We find that these two classes of QTL intervals harbor different kinds of molecular variation. SNPs in rQTL intervals more frequently reside in limb-specific cis-regulatory regions than SNPs in intQTL intervals. The intQTL loci modified by the rQTL, in contrast, show the signature of protein-coding variation. This result is consistent with the widely accepted view that protein-coding mutations have broader pleiotropic effects than cis-regulatory polymorphisms. For both types of QTL intervals, the underlying candidate genes are enriched for genes involved in protein binding. This finding suggests that rQTL effects are caused by local interactions among the products of the causal genes harbored in rQTL and intQTL intervals. This is the first study to systematically document the population-level molecular variation underlying the evolution of character individuation. PMID:24065733

Regeneration of limb joints in the axolotl (Ambystoma mexicanum).

PubMed

Lee, Jangwoo; Gardiner, David M

2012-01-01

In spite of numerous investigations of regenerating salamander limbs, little attention has been paid to the details of how joints are reformed. An understanding of the process and mechanisms of joint regeneration in this model system for tetrapod limb regeneration would provide insights into developing novel therapies for inducing joint regeneration in humans. To this end, we have used the axolotl (Mexican Salamander) model of limb regeneration to describe the morphology and the expression patterns of marker genes during joint regeneration in response to limb amputation. These data are consistent with the hypothesis that the mechanisms of joint formation whether it be development or regeneration are conserved. We also have determined that defects in the epiphyseal region of both forelimbs and hind limbs in the axolotl are regenerated only when the defect is small. As is the case with defects in the diaphysis, there is a critical size above which the endogenous regenerative response is not sufficient to regenerate the joint. This non-regenerative response in an animal that has the ability to regenerate perfectly provides the opportunity to screen for the signaling pathways to induce regeneration of articular cartilage and joints.

Regeneration of Limb Joints in the Axolotl (Ambystoma mexicanum)

PubMed Central

Lee, Jangwoo; Gardiner, David M.

2012-01-01

In spite of numerous investigations of regenerating salamander limbs, little attention has been paid to the details of how joints are reformed. An understanding of the process and mechanisms of joint regeneration in this model system for tetrapod limb regeneration would provide insights into developing novel therapies for inducing joint regeneration in humans. To this end, we have used the axolotl (Mexican Salamander) model of limb regeneration to describe the morphology and the expression patterns of marker genes during joint regeneration in response to limb amputation. These data are consistent with the hypothesis that the mechanisms of joint formation whether it be development or regeneration are conserved. We also have determined that defects in the epiphyseal region of both forelimbs and hind limbs in the axolotl are regenerated only when the defect is small. As is the case with defects in the diaphysis, there is a critical size above which the endogenous regenerative response is not sufficient to regenerate the joint. This non-regenerative response in an animal that has the ability to regenerate perfectly provides the opportunity to screen for the signaling pathways to induce regeneration of articular cartilage and joints. PMID:23185640

Genetic Interactions Between Shox2 and Hox Genes During the Regional Growth and Development of the Mouse Limb

PubMed Central

Neufeld, Stanley J.; Wang, Fan; Cobb, John

2014-01-01

The growth and development of the vertebrate limb relies on homeobox genes of the Hox and Shox families, with their independent mutation often giving dose-dependent effects. Here we investigate whether Shox2 and Hox genes function together during mouse limb development by modulating their relative dosage and examining the limb for nonadditive effects on growth. Using double mRNA fluorescence in situ hybridization (FISH) in single embryos, we first show that Shox2 and Hox genes have associated spatial expression dynamics, with Shox2 expression restricted to the proximal limb along with Hoxd9 and Hoxa11 expression, juxtaposing the distal expression of Hoxa13 and Hoxd13. By generating mice with all possible dosage combinations of mutant Shox2 alleles and HoxA/D cluster deletions, we then show that their coordinated proximal limb expression is critical to generate normally proportioned limb segments. These epistatic interactions tune limb length, where Shox2 underexpression enhances, and Shox2 overexpression suppresses, Hox-mutant phenotypes. Disruption of either Shox2 or Hox genes leads to a similar reduction in Runx2 expression in the developing humerus, suggesting their concerted action drives cartilage maturation during normal development. While we furthermore provide evidence that Hox gene function influences Shox2 expression, this regulation is limited in extent and is unlikely on its own to be a major explanation for their genetic interaction. Given the similar effect of human SHOX mutations on regional limb growth, Shox and Hox genes may generally function as genetic interaction partners during the growth and development of the proximal vertebrate limb. PMID:25217052

Genetic interactions between Shox2 and Hox genes during the regional growth and development of the mouse limb.

PubMed

Neufeld, Stanley J; Wang, Fan; Cobb, John

2014-11-01

The growth and development of the vertebrate limb relies on homeobox genes of the Hox and Shox families, with their independent mutation often giving dose-dependent effects. Here we investigate whether Shox2 and Hox genes function together during mouse limb development by modulating their relative dosage and examining the limb for nonadditive effects on growth. Using double mRNA fluorescence in situ hybridization (FISH) in single embryos, we first show that Shox2 and Hox genes have associated spatial expression dynamics, with Shox2 expression restricted to the proximal limb along with Hoxd9 and Hoxa11 expression, juxtaposing the distal expression of Hoxa13 and Hoxd13. By generating mice with all possible dosage combinations of mutant Shox2 alleles and HoxA/D cluster deletions, we then show that their coordinated proximal limb expression is critical to generate normally proportioned limb segments. These epistatic interactions tune limb length, where Shox2 underexpression enhances, and Shox2 overexpression suppresses, Hox-mutant phenotypes. Disruption of either Shox2 or Hox genes leads to a similar reduction in Runx2 expression in the developing humerus, suggesting their concerted action drives cartilage maturation during normal development. While we furthermore provide evidence that Hox gene function influences Shox2 expression, this regulation is limited in extent and is unlikely on its own to be a major explanation for their genetic interaction. Given the similar effect of human SHOX mutations on regional limb growth, Shox and Hox genes may generally function as genetic interaction partners during the growth and development of the proximal vertebrate limb. Copyright © 2014 by the Genetics Society of America.

Detection of genes regulated by Lmx1b during limb dorsalization.

PubMed

Feenstra, Jennifer M; Kanaya, Kohei; Pira, Charmaine U; Hoffman, Sarah E; Eppey, Richard J; Oberg, Kerby C

2012-05-01

Lmx1b is a homeodomain transcription factor that regulates dorsal identity during limb development. Lmx1b knockout (KO) mice develop distal ventral-ventral limbs. Although induction of Lmx1b is linked to Wnt7a expression in the dorsal limb ectoderm, the downstream targets of Lmx1b that accomplish limb dorsalization are unknown. To identify genes targeted by Lmx1b, we compared gene arrays from Lmx1b KO and wild type mouse limbs during limb dorsalization, i.e., 11.5, 12.5, and 13.5 days post coitum. We identified 54 target genes that were differentially expressed in all three stages. Several skeletal targets, including Emx2, Matrilin1 and Matrilin4, demonstrated a loss of scapular expression in the Lmx1b KO mice, supporting a role for Lmx1b in scapula development. Furthermore, the relative abundance of extracellular matrix-related soft tissue targets regulated by Lmx1b, such as collagens and proteoglycans, suggests a mechanism that includes changes in the extracellular matrix composition to accomplish limb dorsalization. Our study provides the most comprehensive characterization of genes regulated by Lmx1b during limb development to-date and provides targets for further investigation. © 2012 The Authors. Development, Growth & Differentiation © 2012 Japanese Society of Developmental Biologists.

Comparative Transcriptional Profiling of the Axolotl Limb Identifies a Tripartite Regeneration-Specific Gene Program

PubMed Central

Knapp, Dunja; Schulz, Herbert; Rascon, Cynthia Alexander; Volkmer, Michael; Scholz, Juliane; Nacu, Eugen; Le, Mu; Novozhilov, Sergey; Tazaki, Akira; Protze, Stephanie; Jacob, Tina; Hubner, Norbert; Habermann, Bianca; Tanaka, Elly M.

2013-01-01

Understanding how the limb blastema is established after the initial wound healing response is an important aspect of regeneration research. Here we performed parallel expression profile time courses of healing lateral wounds versus amputated limbs in axolotl. This comparison between wound healing and regeneration allowed us to identify amputation-specific genes. By clustering the expression profiles of these samples, we could detect three distinguishable phases of gene expression – early wound healing followed by a transition-phase leading to establishment of the limb development program, which correspond to the three phases of limb regeneration that had been defined by morphological criteria. By focusing on the transition-phase, we identified 93 strictly amputation-associated genes many of which are implicated in oxidative-stress response, chromatin modification, epithelial development or limb development. We further classified the genes based on whether they were or were not significantly expressed in the developing limb bud. The specific localization of 53 selected candidates within the blastema was investigated by in situ hybridization. In summary, we identified a set of genes that are expressed specifically during regeneration and are therefore, likely candidates for the regulation of blastema formation. PMID:23658691

DLX5, FGF8 and the Pin1 isomerase control ΔNp63α protein stability during limb development: a regulatory loop at the basis of the SHFM and EEC congenital malformations

PubMed Central

Restelli, Michela; Lopardo, Teresa; Lo Iacono, Nadia; Garaffo, Giulia; Conte, Daniele; Rustighi, Alessandra; Napoli, Marco; Del Sal, Giannino; Perez-Morga, David; Costanzo, Antonio; Merlo, Giorgio Roberto; Guerrini, Luisa

2014-01-01

Ectrodactyly, or Split-Hand/Foot Malformation (SHFM), is a congenital condition characterized by the loss of central rays of hands and feet. The p63 and the DLX5;DLX6 transcription factors, expressed in the embryonic limb buds and ectoderm, are disease genes for these conditions. Mutations of p63 also cause the ectodermal dysplasia–ectrodactyly–cleft lip/palate (EEC) syndrome, comprising SHFM. Ectrodactyly is linked to defects of the apical ectodermal ridge (AER) of the developing limb buds. FGF8 is the key signaling molecule in this process, able to direct proximo-distal growth and patterning of the skeletal primordial of the limbs. In the limb buds of both p63 and Dlx5;Dlx6 murine models of SHFM, the AER is poorly stratified and FGF8 expression is severely reduced. We show here that the FGF8 locus is a downstream target of DLX5 and that FGF8 counteracts Pin1–ΔNp63α interaction. In vivo, lack of Pin1 leads to accumulation of the p63 protein in the embryonic limbs and ectoderm. We show also that ΔNp63α protein stability is negatively regulated by the interaction with the prolyl-isomerase Pin1, via proteasome-mediated degradation; p63 mutant proteins associated with SHFM or EEC syndromes are resistant to Pin1 action. Thus, DLX5, p63, Pin1 and FGF8 participate to the same time- and location-restricted regulatory loop essential for AER stratification, hence for normal patterning and skeletal morphogenesis of the limb buds. These results shed new light on the molecular mechanisms at the basis of the SHFM and EEC limb malformations. PMID:24569166

A novel mutation of α-galactosidase A gene causes Fabry disease mimicking primary erythromelalgia in a Chinese family.

PubMed

Ge, Wei; Wei, Bin; Zhu, Hao; Miao, Zhigang; Zhang, Weimin; Leng, Cuihua; Li, Jizhen; Zhang, Dan; Sun, Miao; Xu, Xingshun

2017-05-01

Fabry disease is an X-linked genetic disorder caused by the mutations of α-galactosidase A (GLA, MIM 300644) gene presenting with various clinical symptoms including small-fiber peripheral neuropathy and limb burning pain. Here, we reported a Chinese pedigree with the initial diagnosis of primary erythromelalgia in an autosomal dominant (AD)-inherited pattern. Mutation analysis of SCN9A and GLA genes by direct sequencing and functional analysis of a novel mutation of GLA in cells were performed. Our data did not show any pathological mutations in SCN9A gene; however, a novel missense mutation c.139T>C (p.W47R) of GLA was identified in a male proband as well as two female carriers in this family. Enzyme assay of α-galactosidase A activity showed deficient enzyme activity in male patients and female carriers, further confirming the diagnosis of Fabry disease. Finally, a functional analysis indicated that the replacement of the 47th amino acid tryptophan (W47) with arginine (W47R) or glycine (W47G) led to reduced activity of α-galactosidase A in 293T cells. Therefore, these findings demonstrated that the novel mutation p.W47R of GLA is the cause of Fabry disease. Because Fabry disease and primary erythromelalgia share similar symptoms, it is a good strategy for clinical physicians to perform genetic mutation screenings on both SCN9A and GLA genes in those patients with limb burning pain but without a clear inheritant pattern.

How the embryo makes a limb: determination, polarity and identity

PubMed Central

Tickle, Cheryll

2015-01-01

The vertebrate limb with its complex anatomy develops from a small bud of undifferentiated mesoderm cells encased in ectoderm. The bud has its own intrinsic polarity and can develop autonomously into a limb without reference to the rest of the embryo. In this review, recent advances are integrated with classical embryology, carried out mainly in chick embryos, to present an overview of how the embryo makes a limb bud. We will focus on how mesoderm cells in precise locations in the embryo become determined to form a limb and express the key transcription factors Tbx4 (leg/hindlimb) or Tbx5 (wing/forelimb). These Tbx transcription factors have equivalent functions in the control of bud formation by initiating a signalling cascade involving Wnts and fibroblast growth factors (FGFs) and by regulating recruitment of mesenchymal cells from the coelomic epithelium into the bud. The mesoderm that will form limb buds and the polarity of the buds is determined with respect to both antero-posterior and dorso-ventral axes of the body. The position in which a bud develops along the antero-posterior axis of the body will also determine its identity – wing/forelimb or leg/hindlimb. Hox gene activity, under the influence of retinoic acid signalling, is directly linked with the initiation of Tbx5 gene expression in the region along the antero-posterior axis of the body that will form wings/forelimbs and determines antero-posterior polarity of the buds. In contrast, Tbx4 expression in the regions that will form legs/hindlimbs is regulated by the homeoprotein Pitx1 and there is no evidence that Hox genes determine antero-posterior polarity of the buds. Bone morphogenetic protein (BMP) signalling determines the region along the dorso-ventral axis of the body in which both wings/forelimbs and legs/hindlimbs develop and dorso-ventral polarity of the buds. The polarity of the buds leads to the establishment of signalling regions – the dorsal and ventral ectoderm, producing Wnts and BMPs, respectively, the apical ectodermal ridge producing fibroblast growth factors and the polarizing region, Sonic hedgehog (Shh). These signals are the same in both wings/forelimbs and legs/hindlimbs and control growth and pattern formation by providing the mesoderm cells of the limb bud as it develops with positional information. The precise anatomy of the limb depends on the mesoderm cells in the developing bud interpreting positional information according to their identity – determined by Pitx1 in hindlimbs – and genotype. The competence to form a limb extends along the entire antero-posterior axis of the trunk – with Hox gene activity inhibiting the formation of forelimbs in the interlimb region – and also along the dorso-ventral axis. PMID:26249743

How the embryo makes a limb: determination, polarity and identity.

PubMed

Tickle, Cheryll

2015-10-01

The vertebrate limb with its complex anatomy develops from a small bud of undifferentiated mesoderm cells encased in ectoderm. The bud has its own intrinsic polarity and can develop autonomously into a limb without reference to the rest of the embryo. In this review, recent advances are integrated with classical embryology, carried out mainly in chick embryos, to present an overview of how the embryo makes a limb bud. We will focus on how mesoderm cells in precise locations in the embryo become determined to form a limb and express the key transcription factors Tbx4 (leg/hindlimb) or Tbx5 (wing/forelimb). These Tbx transcription factors have equivalent functions in the control of bud formation by initiating a signalling cascade involving Wnts and fibroblast growth factors (FGFs) and by regulating recruitment of mesenchymal cells from the coelomic epithelium into the bud. The mesoderm that will form limb buds and the polarity of the buds is determined with respect to both antero-posterior and dorso-ventral axes of the body. The position in which a bud develops along the antero-posterior axis of the body will also determine its identity - wing/forelimb or leg/hindlimb. Hox gene activity, under the influence of retinoic acid signalling, is directly linked with the initiation of Tbx5 gene expression in the region along the antero-posterior axis of the body that will form wings/forelimbs and determines antero-posterior polarity of the buds. In contrast, Tbx4 expression in the regions that will form legs/hindlimbs is regulated by the homeoprotein Pitx1 and there is no evidence that Hox genes determine antero-posterior polarity of the buds. Bone morphogenetic protein (BMP) signalling determines the region along the dorso-ventral axis of the body in which both wings/forelimbs and legs/hindlimbs develop and dorso-ventral polarity of the buds. The polarity of the buds leads to the establishment of signalling regions - the dorsal and ventral ectoderm, producing Wnts and BMPs, respectively, the apical ectodermal ridge producing fibroblast growth factors and the polarizing region, Sonic hedgehog (Shh). These signals are the same in both wings/forelimbs and legs/hindlimbs and control growth and pattern formation by providing the mesoderm cells of the limb bud as it develops with positional information. The precise anatomy of the limb depends on the mesoderm cells in the developing bud interpreting positional information according to their identity - determined by Pitx1 in hindlimbs - and genotype. The competence to form a limb extends along the entire antero-posterior axis of the trunk - with Hox gene activity inhibiting the formation of forelimbs in the interlimb region - and also along the dorso-ventral axis. © 2015 Anatomical Society.

Evolution of the snake body form reveals homoplasy in amniote Hox gene function.

PubMed

Head, Jason J; Polly, P David

2015-04-02

Hox genes regulate regionalization of the axial skeleton in vertebrates, and changes in their expression have been proposed to be a fundamental mechanism driving the evolution of new body forms. The origin of the snake-like body form, with its deregionalized pre-cloacal axial skeleton, has been explained as either homogenization of Hox gene expression domains, or retention of standard vertebrate Hox domains with alteration of downstream expression that suppresses development of distinct regions. Both models assume a highly regionalized ancestor, but the extent of deregionalization of the primaxial domain (vertebrae, dorsal ribs) of the skeleton in snake-like body forms has never been analysed. Here we combine geometric morphometrics and maximum-likelihood analysis to show that the pre-cloacal primaxial domain of elongate, limb-reduced lizards and snakes is not deregionalized compared with limbed taxa, and that the phylogenetic structure of primaxial morphology in reptiles does not support a loss of regionalization in the evolution of snakes. We demonstrate that morphometric regional boundaries correspond to mapped gene expression domains in snakes, suggesting that their primaxial domain is patterned by a normally functional Hox code. Comparison of primaxial osteology in fossil and modern amniotes with Hox gene distributions within Amniota indicates that a functional, sequentially expressed Hox code patterned a subtle morphological gradient along the anterior-posterior axis in stem members of amniote clades and extant lizards, including snakes. The highly regionalized skeletons of extant archosaurs and mammals result from independent evolution in the Hox code and do not represent ancestral conditions for clades with snake-like body forms. The developmental origin of snakes is best explained by decoupling of the primaxial and abaxial domains and by increases in somite number, not by changes in the function of primaxial Hox genes.

Muscle precursor cells in the developing limbs of two isopods (Crustacea, Peracarida): an immunohistochemical study using a novel monoclonal antibody against myosin heavy chain

PubMed Central

Kreissl, S.; Uber, A.

2008-01-01

In the hot debate on arthropod relationships, Crustaceans and the morphology of their appendages play a pivotal role. To gain new insights into how arthropod appendages evolved, developmental biologists recently have begun to examine the expression and function of Drosophila appendage genes in Crustaceans. However, cellular aspects of Crustacean limb development such as myogenesis are poorly understood in Crustaceans so that the interpretative context in which to analyse gene functions is still fragmentary. The goal of the present project was to analyse muscle development in Crustacean appendages, and to that end, monoclonal antibodies against arthropod muscle proteins were generated. One of these antibodies recognises certain isoforms of myosin heavy chain and strongly binds to muscle precursor cells in malacostracan Crustacea. We used this antibody to study myogenesis in two isopods, Porcellio scaber and Idotea balthica (Crustacea, Malacostraca, Peracarida), by immunohistochemistry. In these animals, muscles in the limbs originate from single muscle precursor cells, which subsequently grow to form multinucleated muscle precursors. The pattern of primordial muscles in the thoracic limbs was mapped, and results compared to muscle development in other Crustaceans and in insects. Electronic supplementary material The online version of this article (doi:10.1007/s00427-008-0216-1) contains supplementary material, which is available to authorized users. PMID:18443823

Whorled hairless nevus of the scalp, linear hyperpigmentation, and telangiectatic nevi of the lower limbs: a novel variant of the "phacomatosis complex".

PubMed

Castori, Marco; Scarciolla, Oronzo; Morlino, Silvia; Manente, Liborio; Biscaglia, Assunta; Fragasso, Alberto; Grammatico, Paola

2012-02-01

The term "phacomatosis" refers to a growing number of sporadic genetic skin disorders characterized by the combination of two or more different nevi and possibly resulting from non-allelic twin spotting. While phacomatosis pigmentovascularis (PPV) and pigmentokeratotica represent the most common patterns, some patients do not fit with either condition and are temporarily classified as unique phenotypes. We report on an 8-year-old boy with striking right hemihypoplasia, resulting in limb asymmetry and fixed dislocation of right hip. Skin on the affected side showed three distinct nevi: (i) A whorled, hairless nevus of the scalp in close proximity with (ii) epidermal hyperpigmentation following lines of Blaschko on the neck and right upper limb, and (iii) multiple telangiectatic nevi of the right lower limb and hemiscrotum. Didymosis atricho-melanotica was proposed for the combination of adjacent patchy congenital alopecia and linear hyperpigmentation, while phacomatosis atricho-pigmento-vascularis appears to define the entire cutaneous phenotype, thus implying the involvement of three neighboring loci influencing the development of distinct constituents of the skin. Given the striking asymmetry of the observed phenotype, the effect of mosaicism (either genomic or functional) for a mutation in a single gene with pleiotropic action and influenced by the lateralization pattern of early development cannot be excluded. Copyright © 2012 Wiley Periodicals, Inc.

Genomic determinants of epidermal appendage patterning and structure in domestic birds

PubMed Central

Boer, Elena F.; Van Hollebeke, Hannah F.; Shapiro, Michael D.

2017-01-01

Variation in regional identity, patterning, and structure of epidermal appendages contributes to skin diversity among many vertebrate groups, and is perhaps most striking in birds. In pioneering work on epidermal appendage patterning, John Saunders and his contemporaries took advantage of epidermal appendage diversity within and among domestic chicken breeds to establish the importance of mesoderm-ectoderm signaling in determining skin patterning. Diversity in chickens and other domestic birds, including pigeons, is driving a new wave of research to dissect the molecular genetic basis of epidermal appendage patterning. Domestic birds are not only outstanding models for embryonic manipulations, as Saunders recognized, but they are also ideal genetic models for discovering the specific genes that control normal development and the mutations that contribute to skin diversity. Here, we review recent genetic and genomic approaches to uncover the basis of epidermal macropatterning, micropatterning, and structural variation. We also present new results that confirm expression changes in two limb identity genes in feather-footed pigeons, a case of variation in appendage structure and identity. PMID:28347644

Generation of shape complexity through tissue conflict resolution

PubMed Central

Rebocho, Alexandra B; Southam, Paul; Kennaway, J Richard; Coen, Enrico

2017-01-01

Out-of-plane tissue deformations are key morphogenetic events during plant and animal development that generate 3D shapes, such as flowers or limbs. However, the mechanisms by which spatiotemporal patterns of gene expression modify cellular behaviours to generate such deformations remain to be established. We use the Snapdragon flower as a model system to address this problem. Combining cellular analysis with tissue-level modelling, we show that an orthogonal pattern of growth orientations plays a key role in generating out-of-plane deformations. This growth pattern is most likely oriented by a polarity field, highlighted by PIN1 protein localisation, and is modulated by dorsoventral gene activity. The orthogonal growth pattern interacts with other patterns of differential growth to create tissue conflicts that shape the flower. Similar shape changes can be generated by contraction as well as growth, suggesting tissue conflict resolution provides a flexible morphogenetic mechanism for generating shape diversity in plants and animals. DOI: http://dx.doi.org/10.7554/eLife.20156.001 PMID:28166865

A unique stylopod patterning mechanism by Shox2-controlled osteogenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ye, Wenduo; Song, Yingnan; Huang, Zhen

Here, vertebrate appendage patterning is programmed by Hox-TALE factorbound regulatory elements. However, it remains unclear which cell lineages are commissioned by Hox-TALE factors to generate regional specific patterns and whether other Hox-TALE co-factors exist. In this study, we investigated the transcriptional mechanisms controlled by the Shox2 transcriptional regulator in limb patterning. Harnessing an osteogenic lineage-specific Shox2 inactivation approach we show that despite widespread Shox2 expression in multiple cell lineages, lack of the stylopod observed upon Shox2 deficiency is a specific result of Shox2 loss of function in the osteogenic lineage. ChIP-Seq revealed robust interaction of Shox2 with cis-regulatory enhancers clusteringmore » around skeletogenic genes that are also bound by Hox-TALE factors, supporting a lineage autonomous function of Shox2 in osteogenic lineage fate determination and skeleton patterning. Pbx ChIP-Seq further allowed the genome-wide identification of cis-regulatory modules exhibiting co-occupancy of Pbx, Meis and Shox2 transcriptional regulators. Integrative analysis of ChIP-Seq and RNA-Seq data and transgenic enhancer assays indicate that Shox2 patterns the stylopod as a repressor via interaction with enhancers active in the proximal limb mesenchyme and antagonizes the repressive function of TALE factors in osteogenesis.« less

A unique stylopod patterning mechanism by Shox2-controlled osteogenesis

DOE PAGES

Ye, Wenduo; Song, Yingnan; Huang, Zhen; ...

2016-06-10

Here, vertebrate appendage patterning is programmed by Hox-TALE factorbound regulatory elements. However, it remains unclear which cell lineages are commissioned by Hox-TALE factors to generate regional specific patterns and whether other Hox-TALE co-factors exist. In this study, we investigated the transcriptional mechanisms controlled by the Shox2 transcriptional regulator in limb patterning. Harnessing an osteogenic lineage-specific Shox2 inactivation approach we show that despite widespread Shox2 expression in multiple cell lineages, lack of the stylopod observed upon Shox2 deficiency is a specific result of Shox2 loss of function in the osteogenic lineage. ChIP-Seq revealed robust interaction of Shox2 with cis-regulatory enhancers clusteringmore » around skeletogenic genes that are also bound by Hox-TALE factors, supporting a lineage autonomous function of Shox2 in osteogenic lineage fate determination and skeleton patterning. Pbx ChIP-Seq further allowed the genome-wide identification of cis-regulatory modules exhibiting co-occupancy of Pbx, Meis and Shox2 transcriptional regulators. Integrative analysis of ChIP-Seq and RNA-Seq data and transgenic enhancer assays indicate that Shox2 patterns the stylopod as a repressor via interaction with enhancers active in the proximal limb mesenchyme and antagonizes the repressive function of TALE factors in osteogenesis.« less

Severe sensory neuropathy in patients with adult-onset multiple acyl-CoA dehydrogenase deficiency.

PubMed

Wang, Zhaoxia; Hong, Daojun; Zhang, Wei; Li, Wurong; Shi, Xin; Zhao, Danhua; Yang, Xu; Lv, He; Yuan, Yun

2016-02-01

Multiple Acyl-CoA dehydrogenase deficiency (MADD) is an autosomal recessive disorder of fatty acid oxidation. Most patients with late-onset MADD are clinically characterized by lipid storage myopathy with dramatic responsiveness to riboflavin treatment. Abnormalities of peripheral neuropathy have rarely been reported in patients with late-onset MADD. We describe six patients who presented with proximal limb weakness and loss of sensation in the distal limbs. Muscle biopsy revealed typical myopathological patterns of lipid storage myopathy and blood acylcarnitine profiles showed a combined elevation of multiple acylcarnitines supporting the diagnosis of MADD. However, nerve conduction investigations and sural nerve biopsies in these patients indicated severe axonal sensory neuropathy. Causative ETFDH gene mutations were found in all six cases. No other causative gene mutations were identified in mitochondrial DNA and genes associated with hereditary neuropathies through next-generation-sequencing panel. Late-onset patients with ETFDH mutations can present with proximal muscle weakness and distal sensory neuropathy, which might be a new phenotypic variation, but the precise underlying pathogenesis remains to be elucidated. Copyright © 2015. Published by Elsevier B.V.

Customization of biliopancreatic limb length to modulate and sustain antidiabetic effect of gastric bypass surgery.

PubMed

Pal, A; Rhoads, D B; Tavakkoli, A

2018-02-01

Although Roux-en-Y Gastric Bypass (RYGB) remains the most effective treatment for obesity and type 2 diabetes (T2D), many patients fail to achieve remission, or relapse. Increasing intestinal limb lengths of RYGB may improve outcomes, but the mechanistic basis for this remains unclear. We hypothesize biliopancreatic (BP) limb length modulates the antidiabetic effect of RYGB. Rats underwent RYGB with a 20-cm (RYGB-20cm) or 40-cm (RYGB-40cm) BP limb and were compared with control animals. After 2 and 4 wk, portal and systemic blood was sampled during intestinal glucose infusion. Portosystemic gradient was used to calculate intestinal glucose utilization (G util ), absorption (G absorp ), and hormone secretion. Intestinal morphology and gene expression were assessed. At 2 wk, G absorp progressively decreased with increasing BP limb length; this pattern persisted at 4 wk. G util increased ≈70% in both RYGB-20cm and -40cm groups at 2 wk. At 4 wk, G util progressively increased with limb length. Furthermore, Roux limb weight, and expression of hexokinase and preproglucagon, exhibited a similar progressive increase. At 4 wk, glucagon-like peptide-1 and -2 levels were higher after RYGB-40cm, with associated increased secretion. We conclude that BP limb length modulates multiple antidiabetic mechanisms, analogous to the dose-response relationship of a drug. Early postoperatively, a longer BP limb reduces G absorp . Later, G util , Roux limb hypertrophy, hormone secretion, and hormone levels are increased with longer BP limb. Sustained high incretin levels may prevent weight regain and T2D relapse. These data provide the basis for customizing BP limb length according to patient characteristics and desired metabolic effect. NEW & NOTEWORTHY Biliopancreatic limb length in gastric bypass modulates multiple antidiabetic mechanisms, analogous to the dose-response relationship of a drug. With a longer biliopancreatic limb, Roux limb hypertrophy, increased glucose utilization, reduced glucose absorption, and sustained high incretin levels may prevent weight regain and diabetes relapse.

Positional information in axolotl and mouse limb extracellular matrix is mediated via heparan sulfate and fibroblast growth factor during limb regeneration in the axolotl (Ambystoma mexicanum).

PubMed

Phan, Anne Q; Lee, Jangwoo; Oei, Michelle; Flath, Craig; Hwe, Caitlyn; Mariano, Rachele; Vu, Tiffany; Shu, Cynthia; Dinh, Andrew; Simkin, Jennifer; Muneoka, Ken; Bryant, Susan V; Gardiner, David M

2015-08-01

Urodele amphibians are unique among adult vertebrates in their ability to regenerate complex body structures after traumatic injury. In salamander regeneration, the cells maintain a memory of their original position and use this positional information to recreate the missing pattern. We used an in vivo gain-of-function assay to determine whether components of the extracellular matrix (ECM) have positional information required to induce formation of new limb pattern during regeneration. We discovered that salamander limb ECM has a position-specific ability to either inhibit regeneration or induce de novo limb structure, and that this difference is dependent on heparan sulfates that are associated with differential expression of heparan sulfate sulfotransferases. We also discovered that an artificial ECM containing only heparan sulfate was sufficient to induce de novo limb pattern in salamander limb regeneration. Finally, ECM from mouse limbs is capable of inducing limb pattern in axolotl blastemas in a position-specific, developmental-stage-specific, and heparan sulfate-dependent manner. This study demonstrates a mechanism for positional information in regeneration and establishes a crucial functional link between salamander regeneration and mammals.

Positional information in axolotl and mouse limb extracellular matrix is mediated via heparan sulfate and fibroblast growth factor during limb regeneration in the axolotl (Ambystoma mexicanum)

PubMed Central

Phan, Anne Q.; Lee, Jangwoo; Oei, Michelle; Flath, Craig; Hwe, Caitlyn; Mariano, Rachele; Vu, Tiffany; Shu, Cynthia; Dinh, Andrew; Simkin, Jennifer; Muneoka, Ken; Bryant, Susan V.

2015-01-01

Abstract Urodele amphibians are unique among adult vertebrates in their ability to regenerate complex body structures after traumatic injury. In salamander regeneration, the cells maintain a memory of their original position and use this positional information to recreate the missing pattern. We used an in vivo gain‐of‐function assay to determine whether components of the extracellular matrix (ECM) have positional information required to induce formation of new limb pattern during regeneration. We discovered that salamander limb ECM has a position‐specific ability to either inhibit regeneration or induce de novo limb structure, and that this difference is dependent on heparan sulfates that are associated with differential expression of heparan sulfate sulfotransferases. We also discovered that an artificial ECM containing only heparan sulfate was sufficient to induce de novo limb pattern in salamander limb regeneration. Finally, ECM from mouse limbs is capable of inducing limb pattern in axolotl blastemas in a position‐specific, developmental‐stage‐specific, and heparan sulfate‐dependent manner. This study demonstrates a mechanism for positional information in regeneration and establishes a crucial functional link between salamander regeneration and mammals. PMID:27499874

Three Hierarchies in Skeletal Muscle Fibre Classification Allotype, Isotype and Phenotype

NASA Technical Reports Server (NTRS)

Hoh, Joseph F. Y.; Hughes, Suzanne; Hugh, Gregory; Pozgaj, Irene

1991-01-01

Immunocytochemical analyses using specific anti-myosin antibodies of mammalian muscle fibers during regeneration, development, and after denervation have revealed two distinct myogenic components determining fiber phenotype. The jaw-closing muscles of the cat contain superfast fibers which express a unique myosin not found in limb muscles. When superfast muscle is transplanted into a limb muscle bed, regenerating myotubes synthesize superfast myosin independent of innervation. Reinnervation by the nerve to a fast muscle leads to the expression of superfast and not fast myosin, while reinnervation by the nerve to a slow muscle leads to the expression of a slow myosin. When limb muscle is transplanted into the jaw muscle bed, only limb myosins are synthesized. Thus jaw and limb muscles belong to distinct allotypes, each with a unique range of phenotype options, the expressions of which may be modulated by the nerve. Primary and secondary myotubes in developing jaw and limb muscles are observed to belong to different categories characterized by different patterns of myosin gene expression. By taking into consideration the pattern of myosins synthesized and the changes in fiber size after denervation, 3 types of primary (fast, slow, and intermediate) fibers can be distinguished in rat fast limb muscles. All primaries synthesize slow myosin soon after their formation, but this is withdrawn in fast and intermediate primaries at different times. After neonatal denervation, slow and intermediate primaries express slow primaries hypertrophy with other fibers atrophy. In the mature rat, the number of slow fibers in the EDL is less than the number of slow primaries. Upon denervation, hypertrophic slow fibers matching the number and topographic distribution of slow primaries appear, suggesting that a subpopulation of the slow primaries acquire the fast phenotype during adult life, but reveal their original identity as slow primaries in response to denervation by hypertrophying and synthesizing slow myosin. It is proposed that within each muscle allotype, the various isotypes of primary and secondary fibers are myogenically determined, and are derived from different lineage of myoblasts.

Digit loss in archosaur evolution and the interplay between selection and constraints.

PubMed

de Bakker, Merijn A G; Fowler, Donald A; den Oude, Kelly; Dondorp, Esther M; Navas, M Carmen Garrido; Horbanczuk, Jaroslaw O; Sire, Jean-Yves; Szczerbińska, Danuta; Richardson, Michael K

2013-08-22

Evolution involves interplay between natural selection and developmental constraints. This is seen, for example, when digits are lost from the limbs during evolution. Extant archosaurs (crocodiles and birds) show several instances of digit loss under different selective regimes, and show limbs with one, two, three, four or the ancestral number of five digits. The 'lost' digits sometimes persist for millions of years as developmental vestiges. Here we examine digit loss in the Nile crocodile and five birds, using markers of three successive stages of digit development. In two independent lineages under different selection, wing digit I and all its markers disappear. In contrast, hindlimb digit V persists in all species sampled, both as cartilage, and as Sox9- expressing precartilage domains, 250 million years after the adult digit disappeared. There is therefore a mismatch between evolution of the embryonic and adult phenotypes. All limbs, regardless of digit number, showed similar expression of sonic hedgehog (Shh). Even in the one-fingered emu wing, expression of posterior genes Hoxd11 and Hoxd12 was conserved, whereas expression of anterior genes Gli3 and Alx4 was not. We suggest that the persistence of digit V in the embryo may reflect constraints, particularly the conserved posterior gene networks associated with the zone of polarizing activity (ZPA). The more rapid and complete disappearance of digit I may reflect its ZPA-independent specification, and hence, weaker developmental constraints. Interacting with these constraints are selection pressures for limb functions such as flying and perching. This model may help to explain the diverse patterns of digit loss in tetrapods. Our study may also help to understand how selection on adults leads to changes in development.

SoxB1-driven transcriptional network underlies neural-specific interpretation of morphogen signals.

PubMed

Oosterveen, Tony; Kurdija, Sanja; Ensterö, Mats; Uhde, Christopher W; Bergsland, Maria; Sandberg, Magnus; Sandberg, Rickard; Muhr, Jonas; Ericson, Johan

2013-04-30

The reiterative deployment of a small cadre of morphogen signals underlies patterning and growth of most tissues during embyogenesis, but how such inductive events result in tissue-specific responses remains poorly understood. By characterizing cis-regulatory modules (CRMs) associated with genes regulated by Sonic hedgehog (Shh), retinoids, or bone morphogenetic proteins in the CNS, we provide evidence that the neural-specific interpretation of morphogen signaling reflects a direct integration of these pathways with SoxB1 proteins at the CRM level. Moreover, expression of SoxB1 proteins in the limb bud confers on mesodermal cells the potential to activate neural-specific target genes upon Shh, retinoid, or bone morphogenetic protein signaling, and the collocation of binding sites for SoxB1 and morphogen-mediatory transcription factors in CRMs faithfully predicts neural-specific gene activity. Thus, an unexpectedly simple transcriptional paradigm appears to conceptually explain the neural-specific interpretation of pleiotropic signaling during vertebrate development. Importantly, genes induced in a SoxB1-dependent manner appear to constitute repressive gene regulatory networks that are directly interlinked at the CRM level to constrain the regional expression of patterning genes. Accordingly, not only does the topology of SoxB1-driven gene regulatory networks provide a tissue-specific mode of gene activation, but it also determines the spatial expression pattern of target genes within the developing neural tube.

Defective ciliogenesis, embryonic lethality and severe impairment of the Sonic Hedgehog pathway caused by inactivation of the mouse complex A intraflagellar transport gene Ift122/Wdr10, partially overlapping with the DNA repair gene Med1/Mbd4

PubMed Central

Cortellino, Salvatore; Wang, Chengbing; Wang, Baolin; Bassi, Maria Rosaria; Caretti, Elena; Champeval, Delphine; Calmont, Amelie; Jarnik, Michal; Burch, John; Zaret, Kenneth; Larue, Lionel; Bellacosa, Alfonso

2009-01-01

Primary cilia are assembled and maintained by evolutionarily conserved intraflagellar transport (IFT) proteins that are involved in the coordinated movement of macromolecular cargo from the basal body to the cilium tip and back. The IFT machinery is organized in two structural complexes named complex A and complex B. Recently, inactivation in the mouse germline of Ift genes belonging to complex B revealed a requirement of ciliogenesis, or proteins involved in ciliogenesis, for Sonic Hedgehog (Shh) signaling in mammals. Here we report on a complex A mutant mouse, defective for the Ift122 gene. Ift122-null embryos show multiple developmental defects (exencephaly, situs viscerum inversus, delay in turning, hemorrhage and defects in limb development) that result in lethality. In the node, primary cilia were absent or malformed in homozygous mutant and heterozygous embryos, respectively. Impairment of the Shh pathway was apparent in both neural tube patterning (expansion of motoneurons and rostro-caudal level-dependent contraction or expansion of the dorso-lateral interneurons), and limb patterning (ectrosyndactyly). These phenotypes are distinct from both complex B IFT mutant embryos and embryos defective for the ciliary protein hennin/Arl13b, and suggest reduced levels of both Gli2/Gli3 activator and Gli3 repressor functions. We conclude that complex A and complex B factors play similar but distinct roles in ciliogenesis and Shh/Gli3 signaling. PMID:19000668

Cis-regulatory underpinnings of human GLI3 expression in embryonic craniofacial structures and internal organs.

PubMed

Abbasi, Amir A; Minhas, Rashid; Schmidt, Ansgar; Koch, Sabine; Grzeschik, Karl-Heinz

2013-10-01

The zinc finger transcription factor Gli3 is an important mediator of Sonic hedgehog (Shh) signaling. During early embryonic development Gli3 participates in patterning and growth of the central nervous system, face, skeleton, limb, tooth and gut. Precise regulation of the temporal and spatial expression of Gli3 is crucial for the proper specification of these structures in mammals and other vertebrates. Previously we reported a set of human intronic cis-regulators controlling almost the entire known repertoire of endogenous Gli3 expression in mouse neural tube and limbs. However, the genetic underpinning of GLI3 expression in other embryonic domains such as craniofacial structures and internal organs remain elusive. Here we demonstrate in a transgenic mice assay the potential of a subset of human/fish conserved non-coding sequences (CNEs) residing within GLI3 intronic intervals to induce reporter gene expression at known regions of endogenous Gli3 transcription in embryonic domains other than central nervous system (CNS) and limbs. Highly specific reporter expression was observed in craniofacial structures, eye, gut, and genitourinary system. Moreover, the comparison of expression patterns directed by these intronic cis-acting regulatory elements in mouse and zebrafish embryos suggests that in accordance with sequence conservation, the target site specificity of a subset of these elements remains preserved among these two lineages. Taken together with our recent investigations, it is proposed here that during vertebrate evolution the Gli3 expression control acquired multiple, independently acting, intronic enhancers for spatiotemporal patterning of CNS, limbs, craniofacial structures and internal organs. © 2013 The Authors Development, Growth & Differentiation © 2013 Japanese Society of Developmental Biologists.

Two human homeobox genes, c1 and c8: structure analysis and expression in embryonic development.

PubMed

Simeone, A; Mavilio, F; Acampora, D; Giampaolo, A; Faiella, A; Zappavigna, V; D'Esposito, M; Pannese, M; Russo, G; Boncinelli, E

1987-07-01

Two human cDNA clones (HHO.c1.95 and HHO.c8.5111) containing a homeobox region have been characterized, and the respective genomic regions have been partially analyzed. Expression of the corresponding genes, termed c1 and c8, was evaluated in different organs and body parts during human embryonic/fetal development. HHO.c1.95 apparently encodes a 217-amino acid protein containing a class I homeodomain that shares 60 out of 61 amino acid residues with the Antennapedia homeodomain of Drosophila melanogaster. HHO.c8.5111 encodes a 153-amino acid protein containing a homeodomain identical to that of the frog AC1 gene. Clones HHO.c1 and HHO.c8 detect by blot-hydridization one and two specific polyadenylylated transcripts, respectively. These are differentially expressed in spinal cord, backbone rudiments, limb buds (or limbs), heart, and skin of human embryos and early fetuses in the 5- to 9-week postfertilization period, thus suggesting that the c1 and c8 genes play a key role in a variety of developmental processes. Together, the results of the embryonic/fetal expression of c1 and c8 and those of two previously analyzed genes (c10 and c13) indicate a coherent pattern of expression of these genes in early human ontogeny.

Msh homeobox 1 (Msx1)- and Msx2-overexpressing bone marrow-derived mesenchymal stem cells resemble blastema cells and enhance regeneration in mice.

PubMed

Taghiyar, Leila; Hesaraki, Mahdi; Sayahpour, Forough Azam; Satarian, Leila; Hosseini, Samaneh; Aghdami, Naser; Baghaban Eslaminejad, Mohamadreza

2017-06-23

Amputation of the proximal region in mammals is not followed by regeneration because blastema cells (BCs) and expression of regenerative genes, such as Msh homeobox ( Msx ) genes, are absent in this animal group. The lack of BCs and positional information in other cells is therefore the main obstacle to therapeutic approaches for limb regeneration. Hence, this study aimed to create blastema-like cells (BlCs) by overexpressing Msx1 and Msx2 genes in mouse bone marrow-derived mesenchymal stem cells (mBMSCs) to regenerate a proximally amputated digit tip. We transduced mBMSCs with Msx1 and Msx2 genes and compared osteogenic activity and expression levels of several Msx -regulated genes ( Bmp4 , Fgf8 , and keratin 14 ( K14 )) in BlC groups, including MSX1, MSX2, and MSX1/2 (in a 1:1 ratio) with those in mBMSCs and BCs in vitro and in vivo following injection into the amputation site. We found that Msx gene overexpression increased expression of specific blastemal markers and enhanced the proliferation rate and osteogenesis of BlCs compared with mBMSCs and BCs via activation of Fgf8 and Bmp4 Histological analyses indicated full regrowth of digit tips in the Msx -overexpressing groups, particularly in MSX1/2, through endochondral ossification 6 weeks post-injection. In contrast, mBMSCs and BCs formed abnormal bone and nail. Full digit tip was regenerated only in the MSX1/2 group and was related to boosted Bmp4, Fgf8 , and K14 gene expression and to limb-patterning properties resulting from Msx1 and Msx2 overexpression. We propose that Msx -transduced cells that can regenerate epithelial and mesenchymal tissues may potentially be utilized in limb regeneration. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Wnt and FGF signals interact to coordinate growth with cell fate specification during limb development.

PubMed

ten Berge, Derk; Brugmann, Samantha A; Helms, Jill A; Nusse, Roel

2008-10-01

A fundamental question in developmental biology is how does an undifferentiated field of cells acquire spatial pattern and undergo coordinated differentiation? The development of the vertebrate limb is an important paradigm for understanding these processes. The skeletal and connective tissues of the developing limb all derive from a population of multipotent progenitor cells located in its distal tip. During limb outgrowth, these progenitors segregate into a chondrogenic lineage, located in the center of the limb bud, and soft connective tissue lineages located in its periphery. We report that the interplay of two families of signaling proteins, fibroblast growth factors (FGFs) and Wnts, coordinate the growth of the multipotent progenitor cells with their simultaneous segregation into these lineages. FGF and Wnt signals act together to synergistically promote proliferation while maintaining the cells in an undifferentiated, multipotent state, but act separately to determine cell lineage specification. Withdrawal of both signals results in cell cycle withdrawal and chondrogenic differentiation. Continued exposure to Wnt, however, maintains proliferation and re-specifies the cells towards the soft connective tissue lineages. We have identified target genes that are synergistically regulated by Wnts and FGFs, and show how these factors actively suppress differentiation and promote growth. Finally, we show how the spatial restriction of Wnt and FGF signals to the limb ectoderm, and to a specialized region of it, the apical ectodermal ridge, controls the distribution of cell behaviors within the growing limb, and guides the proper spatial organization of the differentiating tissues.

Limb girdle muscular dystrophy type 2G with myopathic-neurogenic motor unit potentials and a novel muscle image pattern.

PubMed

Cotta, Ana; Paim, Julia Filardi; da-Cunha-Junior, Antonio Lopes; Neto, Rafael Xavier; Nunes, Simone Vilela; Navarro, Monica Magalhaes; Valicek, Jaquelin; Carvalho, Elmano; Yamamoto, Lydia U; Almeida, Camila F; Braz, Shelida Vasconcelos; Takata, Reinaldo Issao; Vainzof, Mariz

2014-01-01

Limb girdle muscular dystrophy type 2G (LGMD2G) is a subtype of autosomal recessive muscular dystrophy caused by mutations in the telethonin gene. There are few LGMD2G patients worldwide reported, and this is the first description associated with early tibialis anterior sparing on muscle image and myopathic-neurogenic motor unit potentials. Here we report a 31 years old caucasian male patient with progressive gait disturbance, and severe lower limb proximal weakness since the age of 20 years, associated with subtle facial muscle weakness. Computed tomography demonstrated soleus, medial gastrocnemius, and diffuse thigh muscles involvement with tibialis anterior sparing. Electromyography disclosed both neurogenic and myopathic motor unit potentials. Muscle biopsy demonstrated large groups of atrophic and hypertrophic fibers, frequent fibers with intracytoplasmic rimmed vacuoles full of autophagic membrane and sarcoplasmic debris, and a total deficiency of telethonin. Molecular investigation identified the common homozygous c.157C > T in the TCAP gene. This report expands the phenotypic variability of telethoninopathy/ LGMD2G, including: 1) mixed neurogenic and myopathic motor unit potentials, 2) facial weakness, and 3) tibialis anterior sparing. Appropriate diagnosis in these cases is important for genetic counseling and prognosis.

Insulin-like growth factors in embryonic and fetal growth and skeletal development (Review).

PubMed

Agrogiannis, Georgios D; Sifakis, Stavros; Patsouris, Efstratios S; Konstantinidou, Anastasia E

2014-08-01

The insulin-like growth factors (IGF)-I and -II have a predominant role in fetal growth and development. IGFs are involved in the proliferation, differentiation and apoptosis of fetal cells in vitro and the IGF serum concentration has been shown to be closely correlated with fetal growth and length. IGF transcripts and peptides have been detected in almost every fetal tissue from as early in development as pre‑implantation to the final maturation stage. Furthermore, IGFs have been demonstrated to be involved in limb morphogenesis. However, although ablation of Igf genes in mice resulted in growth retardation and delay in skeletal maturation, no impact on outgrowth and patterning of embryonic limbs was observed. Additionally, various molecular defects in the Igf1 and Igf1r genes in humans have been associated with severe intrauterine growth retardation and impaired skeletal maturation, but not with truncated limbs or severe skeletal dysplasia. The conflicting data between in vitro and in vivo observations with regard to bone morphogenesis suggests that IGFs may not be the sole trophic factors involved in fetal skeletal growth and that redundant mechanisms may exist in chondro- and osteogenesis. Further investigation is required in order to elucidate the functions of IGFs in skeletal development.

Reactivation of larval keratin gene (krt62.L) in blastema epithelium during Xenopus froglet limb regeneration.

PubMed

Satoh, Akira; Mitogawa, Kazumasa; Saito, Nanami; Suzuki, Miyuki; Suzuki, Ken-Ichi T; Ochi, Haruki; Makanae, Aki

2017-12-15

Limb regeneration is considered a form of limb redevelopment because of the molecular and morphological similarities. Forming a regeneration blastema is, in essence, creating a developing limb bud in an adult body. This reactivation of a developmental process in a mature body is worth studying. Xenopus laevis has a biphasic life cycle that involves distinct larval and adult stages. These distinct developmental stages are useful for investigating the reactivation of developmental processes in post-metamorphic frogs (froglets). In this study, we focused on the re-expression of a larval gene (krt62.L) during Xenopus froglet limb regeneration. Recently renamed krt62.L, this gene was known as the larval keratin (xlk) gene, which is specific to larval-tadpole stages. During limb regeneration in a froglet, krt62.L was re-expressed in a basal layer of blastema epithelium, where adult-specific keratin (Krt12.6.S) expression was also observable. Nerves produce important regulatory factors for amphibian limb regeneration, and also play a role in blastema formation and maintenance. The effect of nerve function on krt62.L expression could be seen in the maintenance of krt62.L expression, but not in its induction. When an epidermis-stripped limb bud was grafted in a froglet blastema, the grafted limb bud could reach the digit-forming stage. This suggests that krt62.L-positive froglet blastema epithelium is able to support the limb development process. These findings imply that the developmental process is locally reactivated in an postmetamorphic body during limb regeneration. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Expression of the Fanconi anemia group A gene (Fanca) during mouse embryogenesis.

PubMed

Abu-Issa, R; Eichele, G; Youssoufian, H

1999-07-15

About 80% of all cases of Fanconi anemia (FA) can be accounted for by complementation groups A and C. To understand the relationship between these groups, we analyzed the expression pattern of the mouse FA group-A gene (Fanca) during embryogenesis and compared it with the known pattern of the group-C gene (Fancc). Northern analysis of RNA from mouse embryos at embryonic days 7, 11, 15, and 17 showed a predominant 4.5 kb band in all stages. By in situ hybridization, Fanca transcripts were found in the whisker follicles, teeth, brain, retina, kidney, liver, and limbs. There was also stage-specific variation in Fanca expression, particularly within the developing whiskers and the brain. Some tissues known to express Fancc (eg, gut) failed to show Fanca expression. These observations show that (1) Fanca is under both tissue- and stage-specific regulation in several tissues; (2) the expression pattern of Fanca is consistent with the phenotype of the human disease; and (3) Fanca expression is not necessarily coupled to that of Fancc. The presence of distinct tissue targets for FA genes suggests that some of the variability in the clinical phenotype can be attributed to the complementation group assignment.

Functional autonomy of distant-acting human enhancers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Visel, Axel; Akiyama, Jennifer A.; Shoukry, Malak

2009-02-19

Many human genes are associated with dispersed arrays of transcriptional enhancers that regulate their expression in time and space. Studies in invertebrate model systems have suggested that these elements function as discrete and independent regulatory units, but the in vivo combinatorial properties of vertebrate enhancers remain poorly understood. To explore the modularity and regulatory autonomy of human developmental enhancers, we experimentally concatenated up to four enhancers from different genes and used a transgenic mouse assay to compare the in vivo activity of these compound elements with that of the single modules. In all of the six different combinations of elementsmore » tested, the reporter gene activity patterns were additive without signs of interference between the individual modules, indicating that regulatory specificity was maintained despite the presence of closely-positioned heterologous enhancers. Even in cases where two elements drove expression in close anatomical proximity, such as within neighboring subregions of the developing limb bud, the compound patterns did not show signs of cross-inhibition between individual elements or novel expression sites. These data indicate that human developmental enhancers are highly modular and functionally autonomous and suggest that genomic enhancer shuffling may have contributed to the evolution of complex gene expression patterns in vertebrates« less

Gender differences in asymmetrical limb support patterns between subjects with and without recurrent low back pain.

PubMed

Sung, Paul S; Zipple, J Tim; Danial, Pamela

2017-04-01

New insight regarding limb-dominance effects on temporal-spatial gait parameters is needed to further investigate subjects with recurrent low back pain (LBP). Although an asymmetrical gait pattern was found to reflect natural functional differences, there is a lack of information regarding gender differences on dominant limb support patterns in subjects with LBP. The purpose of this study was to investigate temporal-spatial gait parameters based on limb dominance and gender between subjects with and without LBP. One hundred and ten right limb dominant older adults (51 subjects with LBP and 59 control subjects) participated in the study. A three-dimensional motion capture system was utilized to measure temporal-spatial gait parameters, including initial double, single, and terminal double limb support times and walking speed. The gender differences between subjects with and without LBP were analyzed based on dominance for those parameters. Overall, limb dominance demonstrated significant differences on single and terminal double limb support times as well as walking speed. Limb dominance also demonstrated interactions on group x gender for single limb support time and walking speed. The male subjects with LBP demonstrated significantly increased single limb support times on the non-dominant limb. The significant gender and group interactions based on limb dominance account for a possible pain avoidance, asymmetrical limb support pattern. The causal pathway in dominance dependency gait by unweighted ambulation might be considered as an intervention for correcting these gait deviations in subjects with LBP. The specific modification recovery profiles of the subjects with LBP could shed light on variability of current LBP experiences of the subjects and reasons for gait deviations. Clinicians need to consider the mechanism of dominant limb dependency, which requires postural control strategies in male subjects with recurrent LBP. Copyright © 2017 Elsevier B.V. All rights reserved.

Lmx1b-targeted cis-regulatory modules involved in limb dorsalization.

PubMed

Haro, Endika; Watson, Billy A; Feenstra, Jennifer M; Tegeler, Luke; Pira, Charmaine U; Mohan, Subburaman; Oberg, Kerby C

2017-06-01

Lmx1b is a homeodomain transcription factor responsible for limb dorsalization. Despite striking double-ventral (loss-of-function) and double-dorsal (gain-of-function) limb phenotypes, no direct gene targets in the limb have been confirmed. To determine direct targets, we performed a chromatin immunoprecipitation against Lmx1b in mouse limbs at embryonic day 12.5 followed by next-generation sequencing (ChIP-seq). Nearly 84% ( n =617) of the Lmx1b-bound genomic intervals (LBIs) identified overlap with chromatin regulatory marks indicative of potential cis -regulatory modules (PCRMs). In addition, 73 LBIs mapped to CRMs that are known to be active during limb development. We compared Lmx1b-bound PCRMs with genes regulated by Lmx1b and found 292 PCRMs within 1 Mb of 254 Lmx1b-regulated genes. Gene ontological analysis suggests that Lmx1b targets extracellular matrix production, bone/joint formation, axonal guidance, vascular development, cell proliferation and cell movement. We validated the functional activity of a PCRM associated with joint-related Gdf5 that provides a mechanism for Lmx1b-mediated joint modification and a PCRM associated with Lmx1b that suggests a role in autoregulation. This is the first report to describe genome-wide Lmx1b binding during limb development, directly linking Lmx1b to targets that accomplish limb dorsalization. © 2017. Published by The Company of Biologists Ltd.

Genomic determinants of epidermal appendage patterning and structure in domestic birds.

PubMed

Boer, Elena F; Van Hollebeke, Hannah F; Shapiro, Michael D

2017-09-15

Variation in regional identity, patterning, and structure of epidermal appendages contributes to skin diversity among many vertebrate groups, and is perhaps most striking in birds. In pioneering work on epidermal appendage patterning, John Saunders and his contemporaries took advantage of epidermal appendage diversity within and among domestic chicken breeds to establish the importance of mesoderm-ectoderm signaling in determining skin patterning. Diversity in chickens and other domestic birds, including pigeons, is driving a new wave of research to dissect the molecular genetic basis of epidermal appendage patterning. Domestic birds are not only outstanding models for embryonic manipulations, as Saunders recognized, but they are also ideal genetic models for discovering the specific genes that control normal development and the mutations that contribute to skin diversity. Here, we review recent genetic and genomic approaches to uncover the basis of epidermal macropatterning, micropatterning, and structural variation. We also present new results that confirm expression changes in two limb identity genes in feather-footed pigeons, a case of variation in appendage structure and identity. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Genome-wide strategies identify downstream target genes of chick connective tissue-associated transcription factors.

PubMed

Orgeur, Mickael; Martens, Marvin; Leonte, Georgeta; Nassari, Sonya; Bonnin, Marie-Ange; Börno, Stefan T; Timmermann, Bernd; Hecht, Jochen; Duprez, Delphine; Stricker, Sigmar

2018-03-29

Connective tissues support organs and play crucial roles in development, homeostasis and fibrosis, yet our understanding of their formation is still limited. To gain insight into the molecular mechanisms of connective tissue specification, we selected five zinc-finger transcription factors - OSR1, OSR2, EGR1, KLF2 and KLF4 - based on their expression patterns and/or known involvement in connective tissue subtype differentiation. RNA-seq and ChIP-seq profiling of chick limb micromass cultures revealed a set of common genes regulated by all five transcription factors, which we describe as a connective tissue core expression set. This common core was enriched with genes associated with axon guidance and myofibroblast signature, including fibrosis-related genes. In addition, each transcription factor regulated a specific set of signalling molecules and extracellular matrix components. This suggests a concept whereby local molecular niches can be created by the expression of specific transcription factors impinging on the specification of local microenvironments. The regulatory network established here identifies common and distinct molecular signatures of limb connective tissue subtypes, provides novel insight into the signalling pathways governing connective tissue specification, and serves as a resource for connective tissue development. © 2018. Published by The Company of Biologists Ltd.

The influence of asymmetric force requirements on a multi-frequency bimanual coordination task.

PubMed

Kennedy, Deanna M; Rhee, Joohyun; Jimenez, Judith; Shea, Charles H

2017-01-01

An experiment was designed to determine the impact of the force requirements on the production of bimanual 1:2 coordination patterns requiring the same (symmetric) or different (asymmetric) forces when Lissajous displays and goal templates are provided. The Lissajous displays have been shown to minimize the influence of attentional and perceptual constraints allowing constraints related to neural crosstalk to be more clearly observed. Participants (N=20) were randomly assigned to a force condition in which the left or right limb was required to produce more force than the contralateral limb. In each condition participants were required to rhythmically coordinate the pattern of isometric forces in a 1:2 coordination pattern. Participant performed 13 practice trials and 1 test trial per force level. The results indicated that participants were able to effectively coordinate the 1:2 multi-frequency goal patterns under both symmetric and asymmetric force requirements. However, consistent distortions in the force and force velocity time series were observed for one limb that appeared to be associated with the production of force in the contralateral limb. Distortions in the force produced by the left limb occurred regardless of the force requirements of the task (symmetric, asymmetric) or whether the left or right limb had to produce more force than the contralateral limb. However, distinct distortions in the right limb occurred only when the left limb was required to produce 5 times more force than the right limb. These results are consistent with the notion that neural crosstalk can influence both limbs, but may manifest differently for each limb depending on the force requirements of the task. Copyright © 2016 Elsevier B.V. All rights reserved.

Uhrf1 is indispensable for normal limb growth by regulating chondrocyte differentiation through specific gene expression.

PubMed

Yamashita, Michiko; Inoue, Kazuki; Saeki, Noritaka; Ideta-Otsuka, Maky; Yanagihara, Yuta; Sawada, Yuichiro; Sakakibara, Iori; Lee, Jiwon; Ichikawa, Koichi; Kamei, Yoshiaki; Iimura, Tadahiro; Igarashi, Katsuhide; Takada, Yasutsugu; Imai, Yuuki

2018-01-08

Transcriptional regulation can be tightly orchestrated by epigenetic regulators. Among these, ubiquitin-like with PHD and RING finger domains 1 (Uhrf1) is reported to have diverse epigenetic functions, including regulation of DNA methylation. However, the physiological functions of Uhrf1 in skeletal tissues remain unclear. Here, we show that limb mesenchymal cell-specific Uhrf1 conditional knockout mice ( Uhrf1 Δ Limb/ Δ Limb ) exhibit remarkably shortened long bones that have morphological deformities due to dysregulated chondrocyte differentiation and proliferation. RNA-seq performed on primary cultured chondrocytes obtained from Uhrf1 Δ Limb/ Δ Limb mice showed abnormal chondrocyte differentiation. In addition, integrative analyses using RNA-seq and MBD-seq revealed that Uhrf1 deficiency decreased genome-wide DNA methylation and increased gene expression through reduced DNA methylation in the promoter regions of 28 genes, including Hspb1 , which is reported to be an IL1-related gene and to affect chondrocyte differentiation. Hspb1 knockdown in cKO chondrocytes can normalize abnormal expression of genes involved in chondrocyte differentiation, such as Mmp13 These results indicate that Uhrf1 governs cell type-specific transcriptional regulation by controlling the genome-wide DNA methylation status and regulating consequent cell differentiation and skeletal maturation. © 2018. Published by The Company of Biologists Ltd.

Analysis of Msx1; Msx2 double mutants reveals multiple roles for Msx genes in limb development.

PubMed

Lallemand, Yvan; Nicola, Marie-Anne; Ramos, Casto; Bach, Antoine; Cloment, Cécile Saint; Robert, Benoît

2005-07-01

The homeobox-containing genes Msx1 and Msx2 are highly expressed in the limb field from the earliest stages of limb formation and, subsequently, in both the apical ectodermal ridge and underlying mesenchyme. However, mice homozygous for a null mutation in either Msx1 or Msx2 do not display abnormalities in limb development. By contrast, Msx1; Msx2 double mutants exhibit a severe limb phenotype. Our analysis indicates that these genes play a role in crucial processes during limb morphogenesis along all three axes. Double mutant limbs are shorter and lack anterior skeletal elements (radius/tibia, thumb/hallux). Gene expression analysis confirms that there is no formation of regions with anterior identity. This correlates with the absence of dorsoventral boundary specification in the anterior ectoderm, which precludes apical ectodermal ridge formation anteriorly. As a result, anterior mesenchyme is not maintained, leading to oligodactyly. Paradoxically, polydactyly is also frequent and appears to be associated with extended Fgf activity in the apical ectodermal ridge, which is maintained up to 14.5 dpc. This results in a major outgrowth of the mesenchyme anteriorly, which nevertheless maintains a posterior identity, and leads to formation of extra digits. These defects are interpreted in the context of an impairment of Bmp signalling.

Conserved regulation of mesenchymal gene expression by Fgf-8 in face and limb development.

PubMed

Tucker, A S; Al Khamis, A; Ferguson, C A; Bach, I; Rosenfeld, M G; Sharpe, P T

1999-01-01

Clim-2 (NLI, Lbd1) is one of two related mouse proteins that interact with Lim-domain homeoproteins. In the mouse, embryonic expression of Clim-2 is particularly pronounced in facial ectomesenchyme and limb bud mesenchyme in association with Lim genes, Lhx-6 and Lmx-1 respectively. We show that in common with both these Lim genes, Clim-2 expression is regulated by signals from overlying epithelium. In both the developing face and the limb buds we identify Fgf-8 as the likely candidate signalling molecule that regulates Clim-2 expression. We show that in the mandibular arch, as in the limb, Fgf-8 functions in combination with CD44, a cell surface binding protein, and that blocking CD44 binding results in inhibition of Fgf8-induced expression of Clim-2 and Lhx-6. Regulation of gene expression by Fgf8 in association with CD44 is thus conserved between limb and mandibular arch development.

Deciphering skeletal patterning: clues from the limb.

PubMed

Mariani, Francesca V; Martin, Gail R

2003-05-15

Even young children can distinguish a Tyrannosaurus rex from a Brontosaurus by observing differences in bone size, shape, number and arrangement, that is, skeletal pattern. But despite our extensive knowledge about cartilage and bone formation per se, it is still largely a mystery how skeletal pattern is established. Much of what we do know has been learned from studying limb development in chicken and mouse embryos. Based on the data from such studies, models for how limb skeletal pattern is established have been proposed and continue to be hotly debated.

Clinical analysis of a large kindred with the pallister ulnar-mammary syndrome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bamshad, M.; Root, S.; Carey, J.C.

1996-11-11

The ulnar-mammary syndrome (UMS) is an autosomal dominant disorder characterized by posterior limb deficiencies or duplications, apocrine/mammary gland hypoplasia and/or dysfunction, abnormal dentition, delayed puberty in males, and genital anomalies. We present the clinical descriptions of 33 members of a six generation kindred with UMS. The number of affected individuals in this family is more than the sum of all previously reported cases of UMS. The clinical expression of UMS is highly variable. While most patients have limb deficiencies, the range of abnormalities extends from hypoplasia of the terminal phalanx of the 5th digit to complete absence of the ulnamore » and 3rd, 4th, and 5th digits. Moreover, affected individuals may have posterior digital duplications with or without contralateral limb deficiencies. Apocrine gland abnormalities range from diminished axillary perspiration with normal breast development and lactation, to complete absence of the breasts and no axillary perspiration. Dental abnormalities include misplaced or absent teeth. Affected males consistently undergo delayed puberty, and both sexes have diminished to absent axillary hair. Imperforate hymen were seen in some affected women. A gene for UMS was mapped to chromosome area 12q23-q24.1. A mutation in the gene causing UMS can interfere with limb patterning in the proximal/distal, anterior/posterior, and dorsal/ventral axes. This mutation disturbs development of the posterior elements of forearm, wrist, and hand while growth and development of the anterior elements remain normal. 24 refs., 4 figs., 1 tab.« less

Expression of Msx-2 during development, regeneration, and wound healing in axolotl limbs.

PubMed

Carlson, M R; Bryant, S V; Gardiner, D M

1998-12-15

Msx genes are transcription factors that are expressed during embryogenesis of developing appendages in regions of epithelial-mesenchymal interactions. Various lines of evidence indicate that these genes function to maintain embryonic tissues in an undifferentiated, proliferative state. We have identified the axolotl homolog of Msx-2, and investigated its expression during limb development, limb regeneration, and wound healing. As in limb buds of higher vertebrates, axolotl Msx-2 is expressed in the apical epidermis and mesenchyme; however, its expression domain is more extensive, reflecting the broader region of the apical epidermal cap in amphibians. Msx-2 expression is downregulated at late stages of limb development, but is reexpressed within one hour after limb amputation. Msx-2 is also reexpressed during wound healing, and may be essential in the early stages of initiation of the limb regeneration cascade.

A novel candidate gene for mouse and human preaxial polydactyly with altered expression in limbs of Hemimelic extra-toes mutant mice.

PubMed

Clark, R M; Marker, P C; Kingsley, D M

2000-07-01

Polydactyly is a common malformation of vertebrate limbs. In humans a major locus for nonsyndromic pre-axial polydactyly (PPD) has been mapped previously to 7q36. The mouse Hemimelic extra-toes (Hx) mutation maps to a homologous chromosome segment and has been proposed to affect a homologous gene. To understand the molecular changes underlying PPD, we used a positional cloning approach to identify the gene or genes disrupted by the Hx mutation and a closely linked limb mutation, Hammertoe (Hm). High resolution genetic mapping identified a small candidate interval for the mouse mutations located 1.2 cM distal to the Shh locus. The nonrecombinant interval was completely cloned in bacterial artificial chromosomes and searched for genes using a combination of exon trapping, sample sequencing, and mapping of known genes. Two novel genes, Lmbr1 and Lmbr2, are entirely within the candidate interval we defined genetically. The open reading frame of both genes is intact in mutant mice, but the expression of the Lmbr1 gene is dramatically altered in developing limbs of Hx mutant mice. The correspondence between the spatial and temporal changes in Lmbr1 expression and the embryonic onset of the Hx mutant phenotype suggests that the mouse Hx mutation may be a regulatory allele of Lmbr1. The human ortholog of Lmbr1 maps within the recently described interval for human PPD, strengthening the possibility that both mouse and human limb abnormalities are due to defects in the same highly conserved gene.

A Computational Clonal Analysis of the Developing Mouse Limb Bud

PubMed Central

Marcon, Luciano; Arqués, Carlos G.; Torres, Miguel S.; Sharpe, James

2011-01-01

A comprehensive spatio-temporal description of the tissue movements underlying organogenesis would be an extremely useful resource to developmental biology. Clonal analysis and fate mappings are popular experiments to study tissue movement during morphogenesis. Such experiments allow cell populations to be labeled at an early stage of development and to follow their spatial evolution over time. However, disentangling the cumulative effects of the multiple events responsible for the expansion of the labeled cell population is not always straightforward. To overcome this problem, we develop a novel computational method that combines accurate quantification of 2D limb bud morphologies and growth modeling to analyze mouse clonal data of early limb development. Firstly, we explore various tissue movements that match experimental limb bud shape changes. Secondly, by comparing computational clones with newly generated mouse clonal data we are able to choose and characterize the tissue movement map that better matches experimental data. Our computational analysis produces for the first time a two dimensional model of limb growth based on experimental data that can be used to better characterize limb tissue movement in space and time. The model shows that the distribution and shapes of clones can be described as a combination of anisotropic growth with isotropic cell mixing, without the need for lineage compartmentalization along the AP and PD axis. Lastly, we show that this comprehensive description can be used to reassess spatio-temporal gene regulations taking tissue movement into account and to investigate PD patterning hypothesis. PMID:21347315

Caspase inhibition supports proper gene expression in ex vivo mouse limb cultures.

PubMed

De Valck, D; Luyten, F P

2001-10-01

We standardized conditions for ex vivo mouse limb culture to study cartilage maturation and joint formation. We compared 12.5 d.p.c. mouse forelimbs that were cultured either mounted or freely rotating for up to 72 h. Limb outgrowth progressed ex vivo at a variable rate as compared to its development in vivo, spanning approximately 48 h. Although cartilage maturation and joint formation developed grossly normal, aberrant expression of skeletal marker genes was seen. Interestingly, no regression of the interdigital webs took place in mounted cultures, in contrast to limited webbing under freely rotating conditions. Caspase inhibition, by addition of zVAD-fmk to the culture medium of freely rotating limbs, supported proper gene expression associated with skeletal development, and prevented interdigital web regression. Taken together, a freely rotating ex vivo culture for mouse limb outgrowth that is combined with caspase inhibition provides a good model to study cartilage maturation and joint formation.

Review: Biological and Molecular Differences between Tail Regeneration and Limb Scarring in Lizard: An Inspiring Model Addressing Limb Regeneration in Amniotes.

PubMed

Alibardi, Lorenzo

2017-09-01

Tissue regeneration in lizards represents a unique model of regeneration and scarring in amniotes. The tail and limb contain putative stem cells but also dedifferentiating cells contribute to regeneration. Following tail amputation, inflammation is low and cell proliferation high, leading to regeneration while the intense inflammation in the limb leads to low proliferation and scarring. FGFs stimulate tail and limb regeneration and are present in the wound epidermis and blastema while they disappear in the limb wound epidermis 2-3 weeks postamputation in the scarring outgrowth. FGFs localize in the tail blastema and the apical epidermal peg (AEP), an epidermal microregion that allows tail growth but is absent in the limb. Inflammatory cells invade the limb blastema and wound epidermis, impeding the formation of an AEP. An embryonic program of growth is activated in the tail, dominated by Wnt-positive and -negative regulators of cell proliferation and noncoding RNAs, that represent the key regenerative genes. The balanced actions of these regulators likely impede the formation of a tumor in the tail tip. Genes for FACIT and fibrillar collagens, protease inhibitors, and embryonic keratins are upregulated in the regenerating tail blastema. A strong downregulation of genes for both B and T-lymphocyte activation suggests the regenerating tail blastema is a temporal immune-tolerated organ, whereas a scarring program is activated in the limb. Wnt inhibitors, pro-inflammatory genes, negative regulators of cell proliferation, downregulation of myogenic genes, proteases, and oxidases favoring scarring are upregulated. The evolution of an efficient immune system may be the main limiting barrier for organ regeneration in amniotes, and the poor regeneration of mammals and birds is associated with the efficiency of their mature immune system. This does not tolerate embryonic antigens formed in reprogrammed embryonic cells (as for neoplastic cells) that are consequently eliminated impeding the regeneration of lost organs. © 2017 Wiley Periodicals, Inc.

Electromyographic and Neuromuscular Force Patterns Associated with Unexpectedly Loaded Rapid Limb Movements.

ERIC Educational Resources Information Center

Richardson, Charles; Simmons, Roger W.

Bi-articular, unidirectional arm movements were studied to evaluate the electromyographic (EMG) and neuromuscular force patterns that occur when a limb is unexpectedly perturbed. A series of training trials were continued with a control load spring attached to the apparatus until a pre-specified criterion for learning was attained. The limb was…

Phenotypic and immunohistochemical characterization of sarcoglycanopathies

PubMed Central

Ferreira, Ana F. B.; Carvalho, Mary S.; Resende, Maria Bernadete D.; Wakamatsu, Alda; Reed, Umbertina Conti; Marie, Suely Kazue Nagahashi

2011-01-01

INTRODUCTION: Limb-girdle muscular dystrophy presents with heterogeneous clinical and molecular features. The primary characteristic of this disorder is proximal muscular weakness with variable age of onset, speed of progression, and intensity of symptoms. Sarcoglycanopathies, which are a subgroup of the limb-girdle muscular dystrophies, are caused by mutations in sarcoglycan genes. Mutations in these genes cause secondary deficiencies in other proteins, due to the instability of the dystrophin-glycoprotein complex. Therefore, determining the etiology of a given sarcoglycanopathy requires costly and occasionally inaccessible molecular methods. OBJECTIVE: The aim of this study was to identify phenotypic differences among limb-girdle muscular dystrophy patients who were grouped according to the immunohistochemical phenotypes for the four sarcoglycans. METHODS: To identify phenotypic differences among patients with different types of sarcoglycanopathies, a questionnaire was used and the muscle strength and range of motion of nine joints in 45 patients recruited from the Department of Neurology – HC-FMUSP (Clinics Hospital of the Faculty of Medicine of the University of São Paulo) were evaluated. The findings obtained from these analyses were compared with the results of the immunohistochemical findings. RESULTS: The patients were divided into the following groups based on the immunohistochemical findings: α-sarcoglycanopathies (16 patients), β-sarcoglycanopathies (1 patient), γ-sarcoglycanopathies (5 patients), and non-sarcoglycanopathies (23 patients). The muscle strength analysis revealed significant differences for both upper and lower limb muscles, particularly the shoulder and hip muscles, as expected. No pattern of joint contractures was found among the four groups analyzed, even within the same family. However, a high frequency of tiptoe gait was observed in patients with α-sarcoglycanopathies, while calf pseudo-hypertrophy was most common in patients with non-sarcoglycanopathies. The α-sarcoglycanopathy patients presented with more severe muscle weakness than did γ-sarcoglycanopathy patients. CONCLUSION: The clinical differences observed in this study, which were associated with the immunohistochemical findings, may help to prioritize the mutational investigation of sarcoglycan genes. PMID:22012042

Transcriptomic and epigenomic characterization of the developing bat wing

PubMed Central

Eckalbar, Walter L.; Schlebusch, Stephen A.; Mason, Mandy K.; Gill, Zoe; Parker, Ash V.; Booker, Betty M.; Nishizaki, Sierra; Muswamba-Nday, Christiane; Terhune, Elizabeth; Nevonen, Kimberly; Makki, Nadja; Friedrich, Tara; VanderMeer, Julia E.; Pollard, Katherine S.; Carbone, Lucia; Wall, Jeff D.; Illing, Nicola; Ahituv, Nadav

2016-01-01

Bats are the only mammals capable of powered flight, but little is known about the genetic determinants that shape their wings. Here, we generated a genome for Miniopterus natalensis and performed RNA-seq and ChIP-seq (H3K27ac, H3K27me3) on its developing forelimb and hindlimb autopods at sequential embryonic stages to decipher the molecular events that underlie bat wing development. Over 7,000 genes and several lncRNAs, including Tbx5-as1 and Hottip, were differentially expressed between forelimb, hindlimb and different stages. ChIP-seq identified thousands of regions that are differentially modified in forelimb versus hindlimb. Comparative genomics found 2,796 bat-accelerated regions within H3K27ac peaks, several of which cluster near limb-associated genes. Pathway analyses revealed multiple ribosomal proteins and known limb patterning signaling pathways as differentially regulated, and implicated increased forelimb mesenchymal condensations with differential growth. Combined, our work outlines multiple genetic components that contribute to bat wing formation, providing a genomic blueprint for this morphological innovation. PMID:27019111

NF-kappaB mediates FGF signal regulation of msx-1 expression.

PubMed

Bushdid, P B; Chen, C L; Brantley, D M; Yull, F; Raghow, R; Kerr, L D; Barnett, J V

2001-09-01

The nuclear factor-kappaB (NF-kappaB) family of transcription factors is involved in proliferation, differentiation, and apoptosis in a stage- and cell-dependent manner. Recent evidence has shown that NF-kappaB activity is necessary for both chicken and mouse limb development. We report here that the NF-kappaB family member c-rel and the homeodomain gene msx-1 have partially overlapping expression patterns in the developing chick limb. In addition, inhibition of NF-kappaB activity resulted in a decrease in msx-1 mRNA expression. Sequence analysis of the msx-1 promoter revealed three potential kappaB-binding sites similar to the interferon-gamma (IFN-gamma) kappaB-binding site. These sites bound to c-Rel, as shown by electrophoretic mobility shift assay (EMSA). Furthermore, inhibition of NF-kappaB activity significantly reduced transactivation of the msx-1 promoter in response to FGF-2/-4, known stimulators of msx-1 expression. These results suggest that NF-kappaB mediates the FGF-2/-4 signal regulation of msx-1 gene expression. Copyright 2001 Academic Press.

Noncoding copy-number variations are associated with congenital limb malformation.

PubMed

Flöttmann, Ricarda; Kragesteen, Bjørt K; Geuer, Sinje; Socha, Magdalena; Allou, Lila; Sowińska-Seidler, Anna; Bosquillon de Jarcy, Laure; Wagner, Johannes; Jamsheer, Aleksander; Oehl-Jaschkowitz, Barbara; Wittler, Lars; de Silva, Deepthi; Kurth, Ingo; Maya, Idit; Santos-Simarro, Fernando; Hülsemann, Wiebke; Klopocki, Eva; Mountford, Roger; Fryer, Alan; Borck, Guntram; Horn, Denise; Lapunzina, Pablo; Wilson, Meredith; Mascrez, Bénédicte; Duboule, Denis; Mundlos, Stefan; Spielmann, Malte

2017-10-12

PurposeCopy-number variants (CNVs) are generally interpreted by linking the effects of gene dosage with phenotypes. The clinical interpretation of noncoding CNVs remains challenging. We investigated the percentage of disease-associated CNVs in patients with congenital limb malformations that affect noncoding cis-regulatory sequences versus genes sensitive to gene dosage effects.MethodsWe applied high-resolution copy-number analysis to 340 unrelated individuals with isolated limb malformation. To investigate novel candidate CNVs, we re-engineered human CNVs in mice using clustered regularly interspaced short palindromic repeats (CRISPR)-based genome editing.ResultsOf the individuals studied, 10% harbored CNVs segregating with the phenotype in the affected families. We identified 31 CNVs previously associated with congenital limb malformations and four novel candidate CNVs. Most of the disease-associated CNVs (57%) affected the noncoding cis-regulatory genome, while only 43% included a known disease gene and were likely to result from gene dosage effects. In transgenic mice harboring four novel candidate CNVs, we observed altered gene expression in all cases, indicating that the CNVs had a regulatory effect either by changing the enhancer dosage or altering the topological associating domain architecture of the genome.ConclusionOur findings suggest that CNVs affecting noncoding regulatory elements are a major cause of congenital limb malformations.Genetics in Medicine advance online publication, 12 October 2017; doi:10.1038/gim.2017.154.

Different regulation of limb development by p63 transcript variants.

PubMed

Kawata, Manabu; Taniguchi, Yuki; Mori, Daisuke; Yano, Fumiko; Ohba, Shinsuke; Chung, Ung-Il; Shimogori, Tomomi; Mills, Alea A; Tanaka, Sakae; Saito, Taku

2017-01-01

The apical ectodermal ridge (AER), located at the distal end of each limb bud, is a key signaling center which controls outgrowth and patterning of the proximal-distal axis of the limb through secretion of various molecules. Fibroblast growth factors (FGFs), particularly Fgf8 and Fgf4, are representative molecules produced by AER cells, and essential to maintain the AER and cell proliferation in the underlying mesenchyme, meanwhile Jag2-Notch pathway negatively regulates the AER and limb development. p63, a transcription factor of the p53 family, is expressed in the AER and indispensable for limb formation. However, the underlying mechanisms and specific roles of p63 variants are unknown. Here, we quantified the expression of p63 variants in mouse limbs from embryonic day (E) 10.5 to E12.5, and found that ΔNp63γ was strongly expressed in limbs at all stages, while TAp63γ expression was rapidly increased in the later stages. Fluorescence-activated cell sorting analysis of limb bud cells from reporter mouse embryos at E11.5 revealed that all variants were abundantly expressed in AER cells, and their expression was very low in mesenchymal cells. We then generated AER-specific p63 knockout mice by mating mice with a null and a flox allele of p63, and Msx2-Cre mice (Msx2-Cre;p63Δ/fl). Msx2-Cre;p63Δ/fl neonates showed limb malformation that was more obvious in distal elements. Expression of various AER-related genes was decreased in Msx2-Cre;p63Δ/fl limb buds and embryoid bodies formed by p63-knockdown induced pluripotent stem cells. Promoter analyses and chromatin immunoprecipitation assays demonstrated Fgf8 and Fgf4 as transcriptional targets of ΔNp63γ, and Jag2 as that of TAp63γ. Furthermore, TAp63γ overexpression exacerbated the phenotype of Msx2-Cre;p63Δ/fl mice. These data indicate that ΔNp63 and TAp63 control limb development through transcriptional regulation of different target molecules with different roles in the AER. Our findings contribute to further understanding of the molecular network of limb development.

A small population of resident limb bud mesenchymal cells express few MSC-associated markers, but the expression of these markers is increased immediately after cell culture.

PubMed

Marín-Llera, Jessica Cristina; Chimal-Monroy, Jesús

2018-05-01

Skeletal progenitors are derived from resident limb bud mesenchymal cells of the vertebrate embryos. However, it remains poorly understood if they represent stem cells, progenitors, or multipotent mesenchymal stromal cells (MSC). Derived-MSC of different adult tissues under in vitro experimental conditions can differentiate into the same cellular lineages that are present in the limb. Here, comparing non-cultured versus cultured mesenchymal limb bud cells, we determined the expression of MSC-associated markers, the in vitro differentiation capacity and their gene expression profile. Results showed that in freshly isolated limb bud mesenchymal cells, the proportion of cells expressing Sca1, CD44, CD105, CD90, and CD73 is very low and a low expression of lineage-specific genes was observed. However, recently seeded limb bud mesenchymal cells acquired Sca1 and CD44 markers and the expression of the key differentiation genes Runx2 and Sox9, while Scx and Pparg genes decreased. Also, their chondrogenic differentiation capacity decreased through cellular passages while the osteogenic increased. Our findings suggest that the modification of the cell adhesion process through the in vitro method changed the limb mesenchymal cell immunophenotype leading to the expression and maintenance of common MSC-associated markers. These findings could have a significant impact on MSC study and isolation strategy because they could explain common variations observed in the MSC immunophenotype in different tissues. © 2018 International Federation for Cell Biology.

De novo transcriptome sequencing of axolotl blastema for identification of differentially expressed genes during limb regeneration

PubMed Central

2013-01-01

Background Salamanders are unique among vertebrates in their ability to completely regenerate amputated limbs through the mediation of blastema cells located at the stump ends. This regeneration is nerve-dependent because blastema formation and regeneration does not occur after limb denervation. To obtain the genomic information of blastema tissues, de novo transcriptomes from both blastema tissues and denervated stump ends of Ambystoma mexicanum (axolotls) 14 days post-amputation were sequenced and compared using Solexa DNA sequencing. Results The sequencing done for this study produced 40,688,892 reads that were assembled into 307,345 transcribed sequences. The N50 of transcribed sequence length was 562 bases. A similarity search with known proteins identified 39,200 different genes to be expressed during limb regeneration with a cut-off E-value exceeding 10-5. We annotated assembled sequences by using gene descriptions, gene ontology, and clusters of orthologous group terms. Targeted searches using these annotations showed that the majority of the genes were in the categories of essential metabolic pathways, transcription factors and conserved signaling pathways, and novel candidate genes for regenerative processes. We discovered and confirmed numerous sequences of the candidate genes by using quantitative polymerase chain reaction and in situ hybridization. Conclusion The results of this study demonstrate that de novo transcriptome sequencing allows gene expression analysis in a species lacking genome information and provides the most comprehensive mRNA sequence resources for axolotls. The characterization of the axolotl transcriptome can help elucidate the molecular mechanisms underlying blastema formation during limb regeneration. PMID:23815514

Evolution of antero‐posterior patterning of the limb: Insights from the chick

PubMed Central

2017-01-01

Summary The developing limbs of chicken embryos have served as pioneering models for understanding pattern formation for over a century. The ease with which chick wing and leg buds can be experimentally manipulated, while the embryo is still in the egg, has resulted in the discovery of important developmental organisers, and subsequently, the signals that they produce. Sonic hedgehog (Shh) is produced by mesenchyme cells of the polarizing region at the posterior margin of the limb bud and specifies positional values across the antero‐posterior axis (the axis running from the thumb to the little finger). Detailed experimental embryology has revealed the fundamental parameters required to specify antero‐posterior positional values in response to Shh signaling in chick wing and leg buds. In this review, the evolution of the avian wing and leg will be discussed in the broad context of tetrapod paleontology, and more specifically, ancestral theropod dinosaur paleontology. How the parameters that dictate antero‐posterior patterning could have been modulated to produce the avian wing and leg digit patterns will be considered. Finally, broader speculations will be made regarding what the antero‐posterior patterning of chick limbs can tell us about the evolution of other digit patterns, including those that were found in the limbs of the earliest tetrapods. PMID:28734068

Visualisation of upper limb activity using spirals: A new approach to the assessment of daily prosthesis usage.

PubMed

Chadwell, Alix; Kenney, Laurence; Granat, Malcolm; Thies, Sibylle; Head, John S; Galpin, Adam

2018-02-01

Current outcome measures used in upper limb myoelectric prosthesis studies include clinical tests of function and self-report questionnaires on real-world prosthesis use. Research in other cohorts has questioned both the validity of self-report as an activity assessment tool and the relationship between clinical functionality and real-world upper limb activity. Previously, 1 we reported the first results of monitoring upper limb prosthesis use. However, the data visualisation technique used was limited in scope. Methodology development. To introduce two new methods for the analysis and display of upper limb activity monitoring data and to demonstrate the potential value of the approach with example real-world data. Upper limb activity monitors, worn on each wrist, recorded data on two anatomically intact participants and two prosthesis users over 1 week. Participants also filled in a diary to record upper limb activity. Data visualisation was carried out using histograms, and Archimedean spirals to illustrate temporal patterns of upper limb activity. Anatomically intact participants' activity was largely bilateral in nature, interspersed with frequent bursts of unilateral activity of each arm. At times when the prosthesis was worn prosthesis users showed very little unilateral use of the prosthesis (≈20-40 min/week compared to ≈350 min/week unilateral activity on each arm for anatomically intact participants), with consistent bias towards the intact arm throughout. The Archimedean spiral plots illustrated participant-specific patterns of non-use in prosthesis users. The data visualisation techniques allow detailed and objective assessment of temporal patterns in the upper limb activity of prosthesis users. Clinical relevance Activity monitoring offers an objective method for the assessment of upper limb prosthesis users' (PUs) activity outside of the clinic. By plotting data using Archimedean spirals, it is possible to visualise, in detail, the temporal patterns of upper limb activity. Further work is needed to explore the relationship between traditional functional outcome measures and real-world prosthesis activity.

Thermographic Patterns of the Upper and Lower Limbs: Baseline Data

PubMed Central

Cassar, Kevin; Camilleri, Kenneth P.; De Raffaele, Clifford; Mizzi, Stephen; Cristina, Stefania

2015-01-01

Objectives. To collect normative baseline data and identify any significant differences between hand and foot thermographic distribution patterns in a healthy adult population. Design. A single-centre, randomized, prospective study. Methods. Thermographic data was acquired using a FLIR camera for the data acquisition of both plantar and dorsal aspects of the feet, volar aspects of the hands, and anterior aspects of the lower limbs under controlled climate conditions. Results. There is general symmetry in skin temperature between the same regions in contralateral limbs, in terms of both magnitude and pattern. There was also minimal intersubject temperature variation with a consistent temperature pattern in toes and fingers. The thumb is the warmest digit with the temperature falling gradually between the 2nd and the 5th fingers. The big toe and the 5th toe are the warmest digits with the 2nd to the 4th toes being cooler. Conclusion. Measurement of skin temperature of the limbs using a thermal camera is feasible and reproducible. Temperature patterns in fingers and toes are consistent with similar temperatures in contralateral limbs in healthy subjects. This study provides the basis for further research to assess the clinical usefulness of thermography in the diagnosis of vascular insufficiency. PMID:25648145

Al-Awadi/Raas-Rothschild/Schinzel (AARRS) phocomelia syndrome: case report and developmental field analysis.

PubMed

Subhani, Muhammad; Akangire, Gangaram; Kulkarni, Archana; Wilson, Golder N

2009-07-01

We describe a girl infant with anomalies of the left pelvis and lower limb (pelvic, femoral, and tibial hypogenesis with absent fibula), subtle facial changes, patent foraman ovale, single umbilical artery, single kidney, and imperforate anus. The external genitalia were asymmetric and ambiguous with normal uterus and ovaries visualized by ultrasound. The anomalies are compatible with previously reported cases of Al-Awadi/Raas-Rothschild/Schinzel (AARRS) phocomelia, an autosomal recessive disorder with WNT7 gene mutations documented in one family. We suggest that AARRS phocomelia, Fuhrmann syndrome, and similar conditions comprise a spectrum, and that the anomaly pattern derives from serial action of the same signal pathways within primary (e.g., the major axes), secondary (e.g., heart or limb primordia), and/or local (e.g., tibial-fibular differentiation) developmental fields.

Expression of Wise in chick embryos.

PubMed

Shigetani, Y; Itasaki, N

2007-08-01

We have performed in situ hybridization to study the expression of Wise in early chick embryos. Wise expression is first detectable in the ectoderm at posterior levels of late neurula. As development proceeds, Wise expression is seen in specific patterns in the ectoderm of the trunk region, pharyngeal arches, limb buds, and feather buds. In addition to these areas, particular cartilages such as the ones in the maxillary process and limbs start to express Wise at the late pharyngula stage, and the expression in these cartilages becomes stronger than that in epidermal components at later stages. Importantly, Wise is expressed in regions where other signaling molecules such as Wnt, Bmp, and Shh are known to function in morphogenesis and differentiation. Direct comparisons of the expression of Wise and these genes are also demonstrated. (c) 2007 Wiley-Liss, Inc.

Dressed in black. A New Ansonia Stoliczka, 1870 (Lissamphibia: Anura: Bufonidae) from Gunung Murud, Sarawak, East Malaysia (Borneo).

PubMed

Hertwig, Stefan T; Min, Pui Yong; Haas, Alexander; Das, Indraneil

2014-06-10

A new species of stream toad of the genus Ansonia is described from Gunung Murud, Pulong Tau National Park, of northern Sarawak, Malaysia, Borneo. Ansonia vidua, sp. nov., is morphologically distinguished from its Bornean congeners by the following combination of characters: medium size (SVL of adult females 33.5-34.4 mm); body uniformly black-brown in life; absence of a visible pattern on dorsum or limbs; presence of two low interorbital ridges; shagreened skin on dorsum, sides and upper surfaces of the limbs with numerous homogeneously small, rounded warts; first finger shorter than second; reduced webbing between the toes and an absence of a sharp tarsal ridge. Uncorrected genetic distances between related taxa of > 4.3% in 16S rRNA gene support its status as a hitherto undescribed species.

Retinoic acid-independent expression of Meis2 during autopod patterning in the developing bat and mouse limb.

PubMed

Mason, Mandy K; Hockman, Dorit; Curry, Lyle; Cunningham, Thomas J; Duester, Gregg; Logan, Malcolm; Jacobs, David S; Illing, Nicola

2015-01-01

The bat has strikingly divergent forelimbs (long digits supporting wing membranes) and hindlimbs (short, typically free digits) due to the distinct requirements of both aerial and terrestrial locomotion. During embryonic development, the morphology of the bat forelimb deviates dramatically from the mouse and chick, offering an alternative paradigm for identifying genes that play an important role in limb patterning. Using transcriptome analysis of developing Natal long-fingered bat (Miniopterus natalensis) fore- and hindlimbs, we demonstrate that the transcription factor Meis2 has a significantly higher expression in bat forelimb autopods compared to hindlimbs. Validation by reverse transcriptase and quantitative polymerase chain reaction (RT-qPCR) and whole mount in situ hybridisation shows that Meis2, conventionally known as a marker of the early proximal limb bud, is upregulated in the bat forelimb autopod from CS16. Meis2 expression is localised to the expanding interdigital webbing and the membranes linking the wing to the hindlimb and tail. In mice, Meis2 is also expressed in the interdigital region prior to tissue regression. This interdigital Meis2 expression is not activated by retinoic acid (RA) signalling as it is present in the retained interdigital tissue of Rdh10 (trex/trex) mice, which lack RA. Additionally, genes encoding RA-synthesising enzymes, Rdh10 and Aldh1a2, and the RA nuclear receptor Rarβ are robustly expressed in bat fore- and hindlimb interdigital tissues indicating that the mechanism that retains interdigital tissue in bats also occurs independently of RA signalling. Mammalian interdigital Meis2 expression, and upregulation in the interdigital webbing of bat wings, suggests an important role for Meis2 in autopod development. Interdigital Meis2 expression is RA-independent, and retention of interdigital webbing in bat wings is not due to the suppression of RA-induced cell death. Rather, RA signalling may play a role in the thinning (rather than complete loss) of the interdigital tissue in the bat forelimb, while Meis2 may interact with other factors during both bat and mouse autopod development to maintain a pool of interdigital cells that contribute to digit patterning and growth.

A shift in anterior–posterior positional information underlies the fin-to-limb evolution

PubMed Central

Onimaru, Koh; Kuraku, Shigehiro; Takagi, Wataru; Hyodo, Susumu; Sharpe, James; Tanaka, Mikiko

2015-01-01

The pectoral fins of ancestral fishes had multiple proximal elements connected to their pectoral girdles. During the fin-to-limb transition, anterior proximal elements were lost and only the most posterior one remained as the humerus. Thus, we hypothesised that an evolutionary alteration occurred in the anterior–posterior (AP) patterning system of limb buds. In this study, we examined the pectoral fin development of catshark (Scyliorhinus canicula) and revealed that the AP positional values in fin buds are shifted more posteriorly than mouse limb buds. Furthermore, examination of Gli3 function and regulation shows that catshark fins lack a specific AP patterning mechanism, which restricts its expression to an anterior domain in tetrapods. Finally, experimental perturbation of AP patterning in catshark fin buds results in an expansion of posterior values and loss of anterior skeletal elements. Together, these results suggest that a key genetic event of the fin-to-limb transformation was alteration of the AP patterning network. DOI: http://dx.doi.org/10.7554/eLife.07048.001 PMID:26283004

Genetics Home Reference: Miller syndrome

MedlinePlus

... a limb bud, which grows outward. Many different proteins are involved in the normal shaping (patterning) of each limb. Once the overall pattern of a ... for This Page Biesecker LG. Exome sequencing makes medical genomics a reality. Nat Genet. 2010 ...

Transcriptome analysis of Petunia axillaris flowers reveals genes involved in morphological differentiation and metabolite transport

PubMed Central

Amano, Ikuko; Kitajima, Sakihito; Suzuki, Hideyuki; Koeduka, Takao

2018-01-01

The biosynthesis of plant secondary metabolites is associated with morphological and metabolic differentiation. As a consequence, gene expression profiles can change drastically, and primary and secondary metabolites, including intermediate and end-products, move dynamically within and between cells. However, little is known about the molecular mechanisms underlying differentiation and transport mechanisms. In this study, we performed a transcriptome analysis of Petunia axillaris subsp. parodii, which produces various volatiles in its corolla limbs and emits metabolites to attract pollinators. RNA-sequencing from leaves, buds, and limbs identified 53,243 unigenes. Analysis of differentially expressed genes, combined with gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses, showed that many biological processes were highly enriched in limbs. These included catabolic processes and signaling pathways of hormones, such as gibberellins, and metabolic pathways, including phenylpropanoids and fatty acids. Moreover, we identified five transporter genes that showed high expression in limbs, and we performed spatiotemporal expression analyses and homology searches to infer their putative functions. Our systematic analysis provides comprehensive transcriptomic information regarding morphological differentiation and metabolite transport in the Petunia flower and lays the foundation for establishing the specific mechanisms that control secondary metabolite biosynthesis in plants. PMID:29902274

Limb movements during embryonic development in the chick: evidence for a continuum in limb motor control antecedent to locomotion.

PubMed

Bradley, Nina S; Solanki, Dhara; Zhao, Dawn

2005-12-01

New imaging technologies are revealing ever-greater details of motor behavior in fetuses for clinical diagnosis and treatment. Understanding the form, mechanisms, and significance of fetal behavior will maximize imaging applications. The chick is readily available for experimentation throughout embryogenesis, making it an excellent model for this purpose. Yet in 40 yr since Hamburger and colleagues described chick embryonic behavior, we have not determined if motility belongs to a developmental continuum fundamental to posthatching behavior. This study examined kinematics and synchronized electromyography (EMG) during spontaneous limb movements in chicks at four time points between embryonic days (E) 9-18. We report that coordinated kinematic and/or EMG patterns were expressed at each time point. Variability observed in knee and ankle excursions at E15-E18 sorted into distinct in-phase and out-of-phase patterns. EMG patterns did not directly account for out-of-phase patterns, indicating study of movement biomechanics will be critical to fully understand motor control in the embryo. We also provide the first descriptions of 2- to 10-Hz limb movements emerging E15-E18 and a shift from in-phase to out-of-phase interlimb coordination E9-E18. Our findings revealed that coordinated limb movements persist across development and suggest they belong to a developmental continuum for locomotion. Limb patterns were consistent with the half center model for a locomotor pattern generator. Achievement of these patterns by E9 may thus indicate the embryo has completed a critical phase beyond which developmental progression may be less vulnerable to experimental perturbations or prenatal events.

Comparison of laterality index of upper and lower limb movement using brain activated fMRI

NASA Astrophysics Data System (ADS)

Harirchian, Mohammad Hossein; Oghabian, Mohammad Ali; Rezvanizadeh, Alireza; Bolandzadeh, Niousha

2008-03-01

Asymmetry of bilateral cerebral function, i.e. laterality, is an important phenomenon in many brain actions such as motor functions. This asymmetry maybe altered in some clinical conditions such as Multiple Sclerosis (MS). The aim of this study was to delineate the laterality differences for upper and lower limbs in healthy subjects to compare this pattern with subjects suffering from MS in advance. Hence 9 Male healthy subjects underwent fMRI assessment, while they were asked to move their limbs in a predetermined pattern. The results showed that hands movement activates the brain with a significant lateralization in pre-motor cortex in comparison with lower limb. Also, dominant hands activate brain more lateralized than the non-dominant hand. In addition, Left basal ganglia were observed to be activated regardless of the hand used, While, These patterns of Brain activation was not detected in lower limbs. We hypothesize that this difference might be attributed to this point that hand is usually responsible for precise and fine voluntary movements, whereas lower limb joints are mainly responsible for locomotion, a function integrating voluntary and automatic bilateral movements.

Pseudotyped baculovirus is an effective gene expression tool for studying molecular function during axolotl limb regeneration.

PubMed

Oliveira, Catarina R; Lemaitre, Regis; Murawala, Prayag; Tazaki, Akira; Drechsel, David N; Tanaka, Elly M

2018-01-15

Axolotls can regenerate complex structures through recruitment and remodeling of cells within mature tissues. Accessing the underlying mechanisms at a molecular resolution is crucial to understand how injury triggers regeneration and how it proceeds. However, gene transformation in adult tissues can be challenging. Here we characterize the use of pseudotyped baculovirus (BV) as an effective gene transfer method both for cells within mature limb tissue and within the blastema. These cells remain competent to participate in regeneration after transduction. We further characterize the effectiveness of BV for gene overexpression studies by overexpressing Shh in the blastema, which yields a high penetrance of classic polydactyly phenotypes. Overall, our work establishes BV as a powerful tool to access gene function in axolotl limb regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

Chicken homeobox gene Msx-1: structure, expression in limb buds and effect of retinoic acid.

PubMed

Yokouchi, Y; Ohsugi, K; Sasaki, H; Kuroiwa, A

1991-10-01

A chicken gene carrying a homeobox highly homologous to the Drosophila muscle segment homeobox (msh) gene was isolated and designated as Msx-1. Conceptual translation from the longest ORF gave a protein of 259 amino acids lacking the conserved hexapeptide. Northern analysis detected a single 2.6 kb transcript. As early as day 2 of incubation, the transcript was detected but was not found in adult tissue. In situ hybridization analysis revealed that Msx-1 expression is closely related to a particular mesenchymal cell lineage during limb bud formation. In early stage embryos, Msx-1 was expressed in the somatopleure. When primordial mesenchyme cells for limb bud were generated from the Wolffian ridge of the somatopleure, Msx-1 expression began to diminish in the posterior half of the limb bud then in the presumptive cartilage-forming mesenchyme. In developing limb buds, remarkable expression was seen in the apical ectodermal ridge (AER), which is responsible for the sustained outgrowth and development of the limb. The Msx-1 transcripts were found in the limb mesenchymal cells in the region covering the necrotic zone and ectodermal cells overlying such mesenchymal cells. Both ectodermal and mesenchymal expression in limb bud were rapidly suppressed by local treatment of retinoic acid which can generate mirror-image duplication of digits. This indicates that retinoic acid alters the marginal presumptive non-cartilage forming mesenchyme cell lineage through suppression of Msx-1 expression.

Nerves and Tissue Repair.

DTIC Science & Technology

1994-07-01

axolotl limbs are transected the concentration of transferrin in the distal limb tissue declines rapidly and limb regeneration stops. These results...transferrin binding and expression of the transferrin gene in cells of axolotl peripheral nerve indicate that both uptake and synthesis of this factor occur

Evaluation of Limb Load Asymmetry Using Two New Mathematical Models

PubMed Central

Kumar, Senthil NS; Omar, Baharudin; Joseph, Leonard H.; Htwe, Ohnmar; Jagannathan, K.; Hamdan, Nor M Y; Rajalakshmi, D.

2015-01-01

Quantitative measurement of limb loading is important in orthopedic and neurological rehabilitation. In current practice, mathematical models such as Symmetry index (SI), Symmetry ratio (SR), and Symmetry angle (SA) are used to quantify limb loading asymmetry. Literatures have identified certain limitations with the above mathematical models. Hence this study presents two new mathematical models Modified symmetry index (MSI) and Limb loading error (LLE) that would address these limitations. Furthermore, the current mathematical models were compared against the new model with the goal of achieving a better model. This study uses hypothetical data to simulate an algorithmic preliminary computational measure to perform with all numerical possibilities of even and uneven limb loading that can occur in human legs. Descriptive statistics are used to interpret the limb loading patterns: symmetry, asymmetry and maximum asymmetry. The five mathematical models were similar in analyzing symmetry between limbs. However, for asymmetry and maximum asymmetry data, the SA and SR values do not give any meaningful interpretation, and SI gives an inflated value. The MSI and LLE are direct, easy to interpret and identify the loading patterns with the side of asymmetry. The new models are notable as they quantify the amount and side of asymmetry under different loading patterns. PMID:25716372

Modification of hemiplegic compensatory gait pattern by symmetry-based motion controller of HAL.

PubMed

Kawamoto, Hiroaki; Kadone, Hideki; Sakurai, Takeru; Sankai, Yoshiyuki

2015-01-01

As one of several characteristics of hemiplegic patients after stroke, compensatory gait caused by affected limb is often seen. The purpose of this research is to apply a symmetry-based controller of a wearable type lower limb robot, Hybrid Assistive Limb (HAL) to hemiplegic patients with compensatory gait, and to investigate improvement of gait symmetry. The controller is designed respectively for swing phase and support phase according to characteristics of hemiplegic gait pattern. The controller during swing phase stores the motion of the unaffected limb and then provides motion support on the affected limb during the subsequent swing using the stored pattern to realize symmetric gait based on spontaneous limb swing. Moreover, the controller during support phase provides motion to extend hip and knee joints to support wearer's body. Clinical tests were conducted in order to assess the modification of gait symmetry. Our case study involved participation of one chronic stroke patient who performs abnormally-compensatory gait for both of the affected and unaffected limbs. As a result, the patient's gait symmetry was improved by providing motion support during the swing phase on the affected side and motion constraint during the support phase on the unaffected side. The study showed promising basis for the effectiveness of the controller for the future clinical study.

Pattern of spread and prognosis in lower limb-onset ALS

PubMed Central

TURNER, MARTIN R.; BROCKINGTON, ALICE; SCABER, JAKUB; HOLLINGER, HANNAH; MARSDEN, RACHAEL; SHAW, PAMELA J.; TALBOT, KEVIN

2011-01-01

Our objective was to establish the pattern of spread in lower limb-onset ALS (contra- versus ipsi-lateral) and its contribution to prognosis within a multivariate model. Pattern of spread was established in 109 sporadic ALS patients with lower limb-onset, prospectively recorded in Oxford and Sheffield tertiary clinics from 2001 to 2008. Survival analysis was by univariate Kaplan-Meier log-rank and multivariate Cox proportional hazards. Variables studied were time to next limb progression, site of next progression, age at symptom onset, gender, diagnostic latency and use of riluzole. Initial progression was either to the contralateral leg (76%) or ipsilateral arm (24%). Factors independently affecting survival were time to next limb progression, age at symptom onset, and diagnostic latency. Time to progression as a prognostic factor was independent of initial direction of spread. In a regression analysis of the deceased, overall survival from symptom onset approximated to two years plus the time interval for initial spread. In conclusion, rate of progression in lower limb-onset ALS is not influenced by whether initial spread is to the contralateral limb or ipsilateral arm. The time interval to this initial spread is a powerful factor in predicting overall survival, and could be used to facilitate decision-making and effective care planning. PMID:20001488

A new case of limb girdle muscular dystrophy 2G in a Greek patient, founder effect and review of the literature.

PubMed

Brusa, Roberta; Magri, Francesca; Papadimitriou, Dimitra; Govoni, Alessandra; Del Bo, Roberto; Ciscato, Patrizia; Savarese, Marco; Cinnante, Claudia; Walter, Maggie C; Abicht, Angela; Bulst, Stefanie; Corti, Stefania; Moggio, Maurizio; Bresolin, Nereo; Nigro, Vincenzo; Comi, Giacomo Pietro

2018-04-13

Limb girdle muscular dystrophy (LGMD) type 2G is a rare form of muscle disease, described only in a few patients worldwide, caused by mutations in TCAP gene, encoding the protein telethonin. It is characterised by proximal limb muscle weakness associated with distal involvement of lower limbs, starting in the first or second decade of life. We describe the case of a 37-year-old woman of Greek origin, affected by disto-proximal lower limb weakness. No cardiac or respiratory involvement was detected. Muscle biopsy showed myopathic changes with type I fibre hypotrophy, cytoplasmic vacuoles, lipid overload, multiple central nuclei and fibre splittings; ultrastructural examination showed metabolic abnormalities. Next generation sequencing analysis detected a homozygous frameshift mutation in the TCAP gene (c.90_91del), previously described in one Turkish family. Immunostaining and Western blot analysis showed complete absence of telethonin. Interestingly, Single Nucleotide Polymorphism analysis of the 10 Mb genomic region containing the TCAP gene showed a shared homozygous haplotype of both the Greek and the Turkish patients, thus suggesting a possible founder effect of TCAP gene c.90_91del mutation in this part of the Mediterranean area. Copyright © 2018 Elsevier B.V. All rights reserved.

Microarray Analysis of microRNA Expression during Axolotl Limb Regeneration

PubMed Central

Holman, Edna C.; Campbell, Leah J.; Hines, John; Crews, Craig M.

2012-01-01

Among vertebrates, salamanders stand out for their remarkable capacity to quickly regrow a myriad of tissues and organs after injury or amputation. The limb regeneration process in axolotls (Ambystoma mexicanum) has been well studied for decades at the cell-tissue level. While several developmental genes are known to be reactivated during this epimorphic process, less is known about the role of microRNAs in urodele amphibian limb regeneration. Given the compelling evidence that many microRNAs tightly regulate cell fate and morphogenetic processes through development and adulthood by modulating the expression (or re-expression) of developmental genes, we investigated the possibility that microRNA levels change during limb regeneration. Using two different microarray platforms to compare the axolotl microRNA expression between mid-bud limb regenerating blastemas and non-regenerating stump tissues, we found that miR-21 was overexpressed in mid-bud blastemas compared to stump tissue. Mature A. mexicanum (“Amex”) miR-21 was detected in axolotl RNA by Northern blot and differential expression of Amex-miR-21 in blastema versus stump was confirmed by quantitative RT-PCR. We identified the Amex Jagged1 as a putative target gene for miR-21 during salamander limb regeneration. We cloned the full length 3′UTR of Amex-Jag1, and our in vitro assays demonstrated that its single miR-21 target recognition site is functional and essential for the response of the Jagged1 gene to miR-21 levels. Our findings pave the road for advanced in vivo functional assays aimed to clarify how microRNAs such as miR-21, often linked to pathogenic cell growth, might be modulating the redeployment of developmental genes such as Jagged1 during regenerative processes. PMID:23028429

Intra-articular decorin influences the fibrosis genetic expression profile in a rabbit model of joint contracture.

PubMed

Abdel, M P; Morrey, M E; Barlow, J D; Grill, D E; Kolbert, C P; An, K N; Steinmann, S P; Morrey, B F; Sanchez-Sotelo, J

2014-01-01

The goal of this study was to determine whether intra-articular administration of the potentially anti-fibrotic agent decorin influences the expression of genes involved in the fibrotic cascade, and ultimately leads to less contracture, in an animal model. A total of 18 rabbits underwent an operation on their right knees to form contractures. Six limbs in group 1 received four intra-articular injections of decorin; six limbs in group 2 received four intra-articular injections of bovine serum albumin (BSA) over eight days; six limbs in group 3 received no injections. The contracted limbs of rabbits in group 1 were biomechanically and genetically compared with the contracted limbs of rabbits in groups 2 and 3, with the use of a calibrated joint measuring device and custom microarray, respectively. There was no statistical difference in the flexion contracture angles between those limbs that received intra-articular decorin versus those that received intra-articular BSA (66° vs 69°; p = 0.41). Likewise, there was no statistical difference between those limbs that received intra-articular decorin versus those who had no injection (66° vs 72°; p = 0.27). When compared with BSA, decorin led to a statistically significant increase in the mRNA expression of 12 genes (p < 0.01). In addition, there was a statistical change in the mRNA expression of three genes, when compared with those without injection. In this model, when administered intra-articularly at eight weeks, 2 mg of decorin had no significant effect on joint contractures. However, our genetic analysis revealed a significant alteration in several fibrotic genes. Cite this article: Bone Joint Res 2014;3:82-8.

A conditional allele of Rspo3 reveals redundant function of R-spondins during mouse limb development.

PubMed

Neufeld, Stanley; Rosin, Jessica M; Ambasta, Anshula; Hui, Kristen; Shaneman, Venessa; Crowder, Ray; Vickerman, Lori; Cobb, John

2012-10-01

R-spondins are secreted ligands that bind cell surface receptors and activate Wnt/β-catenin signaling. Human mutations and gene inactivation studies in mice have revealed a role for these four proteins (RSPO1-4) in diverse developmental processes ranging from sex determination to limb development. Among the genes coding for R-spondins, only inactivation of Rspo3 shows early embryonic lethality (E10.5 in mice). Therefore, a conditional allele of this gene is necessary to understand the function of R-spondins throughout murine development. To address this need, we have produced an allele in which loxP sites flank exons 2-4 of Rspo3, allowing tissue-specific deletion of these exons in the presence of Cre recombinase. We used these mice to investigate the role of Rspo3 during limb development and found that limbs ultimately developed normally in the absence of Rspo3 function. However, severe hindlimb truncations resulted when Rspo3 and Rspo2 mutations were combined, demonstrating redundant function of these genes. Copyright © 2012 Wiley Periodicals, Inc.

Are human hands and feet affected by climate? A test of Allen's rule.

PubMed

Betti, Lia; Lycett, Stephen J; von Cramon-Taubadel, Noreen; Pearson, Osbjorn M

2015-09-01

In recent years, several studies have shown that populations from cold, high-latitude regions tend to have relatively shorter limbs than populations from tropical regions, with most of the difference due to the relative length of the zeugopods (i.e., radius, ulna, tibia, fibula). This pattern has been explained either as the consequence of long-term climatic selection or of phenotypic plasticity, with temperature having a direct effect on bone growth during development. The aims of this study were to test whether this pattern of intra-limb proportions extended to the bones of the hands and feet, and to determine whether the pattern remained significant after taking into account the effects of neutral evolutionary processes related to population history. Measurements of the limb bones, including the first metatarsal and metacarpal, were collected for 393 individuals from 10 globally distributed human populations. The relationship between intra-limb indices and minimum temperature was tested using generalized least squares regression, correcting for spatial autocorrelation. The results confirmed previous observations of a temperature-related gradient in intra-limb proportions, even accounting for population history. This pattern extends to the hands, with populations from cold regions displaying a relatively shorter and stockier first metacarpal; however, the first metatarsal appears to be wider but not shorter in cold-adapted populations. The results suggest that climatic adaptation played a role in shaping variation in limb proportions between human populations. The different patterns shown by the hands and feet might be due to the presence of evolutionary constraints on the foot to maintain efficient bipedal locomotion. © 2015 Wiley Periodicals, Inc.

HAND2 Targets Define a Network of Transcriptional Regulators that Compartmentalize the Early Limb Bud Mesenchyme

DOE PAGES

Osterwalder, Marco; Speziale, Dario; Shoukry, Malak; ...

2014-11-10

The genetic networks that govern vertebrate development are well studied, but how the interactions of trans-acting factors with cis-regulatory modules (CRMs) are integrated into spatiotemporal regulation of gene expression is not clear. The transcriptional regulator HAND2 is required during limb, heart, and branchial arch development. Here, we identify the genomic regions enriched in HAND2 chromatin complexes from mouse embryos and limb buds. Then we analyze the HAND2 target CRMs in the genomic landscapes encoding transcriptional regulators required in early limb buds. HAND2 controls the expression of genes functioning in the proximal limb bud and orchestrates the establishment of anterior andmore » posterior polarity of the nascent limb bud mesenchyme by impacting Gli3 and Tbx3 expression. TBX3 is required downstream of HAND2 to refine the posterior Gli3 expression boundary. In conclusion, our analysis uncovers the transcriptional circuits that function in establishing distinct mesenchymal compartments downstream of HAND2 and upstream of SHH signaling.« less

Circadian gene expression regulates pulsatile gonadotropin-releasing hormone (GnRH) secretory patterns in the hypothalamic GnRH-secreting GT1-7 cell line.

PubMed

Chappell, Patrick E; White, Rachel S; Mellon, Pamela L

2003-12-03

Although it has long been established that episodic secretion of gonadotropin-releasing hormone (GnRH) from the hypothalamus is required for normal gonadotropin release, the molecular and cellular mechanisms underlying the synchronous release of GnRH are primarily unknown. We used the GT1-7 mouse hypothalamic cell line as a model for GnRH secretion, because these cells release GnRH in a pulsatile pattern similar to that observed in vivo. To explore possible molecular mechanisms governing secretory timing, we investigated the role of the molecular circadian clock in regulation of GnRH secretion. GT1-7 cells express many known core circadian clock genes, and we demonstrate that oscillations of these components can be induced by stimuli such as serum and the adenylyl cyclase activator forskolin, similar to effects observed in fibroblasts. Strikingly, perturbation of circadian clock function in GT1-7 cells by transient expression of the dominant-negative Clock-Delta19 gene disrupts normal ultradian patterns of GnRH secretion, significantly decreasing mean pulse frequency. Additionally, overexpression of the negative limb clock gene mCry1 in GT1-7 cells substantially increases GnRH pulse amplitude without a commensurate change in pulse frequency, demonstrating that an endogenous biological clock is coupled to the mechanism of neurosecretion in these cells and can regulate multiple secretory parameters. Finally, mice harboring a somatic mutation in the Clock gene are subfertile and exhibit a substantial increase in estrous cycle duration as revealed by examination of vaginal cytology. This effect persists in normal light/dark (LD) cycles, suggesting that a suprachiasmatic nucleus-independent endogenous clock in GnRH neurons is required for eliciting normal pulsatile patterns of GnRH secretion.

Evolutionary trajectories of snake genes and genomes revealed by comparative analyses of five-pacer viper

PubMed Central

Yin, Wei; Wang, Zong-ji; Li, Qi-ye; Lian, Jin-ming; Zhou, Yang; Lu, Bing-zheng; Jin, Li-jun; Qiu, Peng-xin; Zhang, Pei; Zhu, Wen-bo; Wen, Bo; Huang, Yi-jun; Lin, Zhi-long; Qiu, Bi-tao; Su, Xing-wen; Yang, Huan-ming; Zhang, Guo-jie; Yan, Guang-mei; Zhou, Qi

2016-01-01

Snakes have numerous features distinctive from other tetrapods and a rich history of genome evolution that is still obscure. Here, we report the high-quality genome of the five-pacer viper, Deinagkistrodon acutus, and comparative analyses with other representative snake and lizard genomes. We map the evolutionary trajectories of transposable elements (TEs), developmental genes and sex chromosomes onto the snake phylogeny. TEs exhibit dynamic lineage-specific expansion, and many viper TEs show brain-specific gene expression along with their nearby genes. We detect signatures of adaptive evolution in olfactory, venom and thermal-sensing genes and also functional degeneration of genes associated with vision and hearing. Lineage-specific relaxation of functional constraints on respective Hox and Tbx limb-patterning genes supports fossil evidence for a successive loss of forelimbs then hindlimbs during snake evolution. Finally, we infer that the ZW sex chromosome pair had undergone at least three recombination suppression events in the ancestor of advanced snakes. These results altogether forge a framework for our deep understanding into snakes' history of molecular evolution. PMID:27708285

RETURN TO RUNNING FOLLOWING A KNEE DISARTICULATION AMPUTATION: A CASE REPORT

PubMed Central

Diebal-Lee, Angela R.; Kuenzi, Robert S.; Rábago, Christopher A.

2017-01-01

Background and Purpose The evolution of running-specific prostheses has empowered athletes with lower extremity amputations to run farther and faster than previously thought possible; but running with proper mechanics is still paramount to an injury-free, active lifestyle. The purpose of this case report was to describe the successful alteration of intact limb mechanics from a Rearfoot Striking (RFS) to a Non-Rearfoot Striking (NRFS) pattern in an individual with a knee disarticulation amputation, the associated reduction in Average Vertical Loading Rate (AVLR), and the improvement in functional performance following the intervention. Case description A 30 year-old male with a traumatic right knee disarticulation amputation reported complaints of residual limb pain with running distances greater than 5 km, limiting his ability to train toward his goal of participating in triathlons. Qualitative assessment of his running mechanics revealed a RFS pattern with his intact limb and a NRFS pattern with his prosthetic limb. A full body kinematic and kinetic running analysis using 3D motion capture and force plates was performed. The average intact limb loading rate was four-times greater (112 body weights/s) than in his prosthetic limb which predisposed him to possible injury. He underwent a three week running intervention with a certified running specialist to learn a NRFS pattern with his intact limb. Outcomes Immediately following the running intervention, he was able to run distances of over 10 km without pain. On a two-mile fitness test, he decreased his run time from 19:54 min to 15:14 min. Additionally, the intact limb loading rate was dramatically reduced to 27 body weights/s, nearly identical to the prosthetic limb (24 body weights/s). Discussion This case report outlines a detailed return to run program that targets proprioceptive and neuromuscular components, injury prevention, and specificity of training strategies. The outcomes of this case report are promising as they may spur additional research toward understanding how to eliminate potential injury risk factors associated with running after limb loss. Level of Evidence 4 PMID:28900572

Recessive variants of MuSK are associated with late onset CMS and predominant limb girdle weakness.

PubMed

Owen, David; Töpf, Ana; Preethish-Kumar, Veeramani; Lorenzoni, Paulo José; Vroling, Bas; Scola, Rosana Herminia; Dias-Tosta, Elza; Geraldo, Argemiro; Polavarapu, Kiran; Nashi, Saraswati; Cox, Daniel; Evangelista, Teresinha; Dawson, John; Thompson, Rachel; Senderek, Jan; Laurie, Steven; Beltran, Sergi; Gut, Marta; Gut, Ivo; Nalini, Atchayaram; Lochmüller, Hanns

2018-04-28

Congenital myasthenic syndrome (CMS) is a heterogeneous disorder that causes fatigable muscle weakness. CMS has been associated with variants in the MuSK gene and, to date, 16 patients have been reported. MuSK-CMS patients present a different phenotypic pattern of limb girdle weakness. Here, we describe four additional patients and discuss the phenotypic and clinical relationship with those previously reported. Two novel damaging missense variants are described: c.1742T > A; p.I581N found in homozygosis, and c.1634T > C; p.L545P found in compound heterozygosis with p.R166*. The reported patients had predominant limb girdle weakness with symptom onset at 12, 17, 18, and 30 years of age, and the majority exhibited a good clinical response to Salbutamol therapy, but not to esterase inhibitors. Meta-analysis including previously reported variants revealed an increased likelihood of a severe, respiratory phenotype with null alleles. Missense variants exclusively affecting the kinase domain, but not the catalytic site, are associated with late onset. These data refine the phenotype associated with MuSK-related CMS. © 2018 Wiley Periodicals, Inc.

Using temporal mining to examine the development of lymphedema in breast cancer survivors.

PubMed

Green, Jason M; Paladugu, Sowjanya; Shuyu, Xu; Stewart, Bob R; Shyu, Chi-Ren; Armer, Jane M

2013-01-01

Secondary lymphedema is a lifetime risk for breast cancer survivors and can severely affect quality of life. Early detection and treatment are crucial for successful lymphedema management. Limb volume measurements can be utilized not only to diagnose lymphedema but also to track progression of limb volume changes before lymphedema, which has the potential to provide insight into the development of this condition. This study aims to identify commonly occurring patterns in limb volume changes in breast cancer survivors before the development of lymphedema and to determine if there were differences in these patterns between certain patient subgroups. Furthermore, pattern differences were studied between patients who developed lymphedema quickly and those whose onset was delayed. A temporal data mining technique was used to identify and compare common patterns in limb volume measurements in patient subgroups of study participants (n = 232). Patterns were filtered initially by support and confidence values, and then t tests were used to determine statistical significance of the remaining patterns. Higher body mass index and the presence of postoperative swelling are supported as risk factors for lymphedema. In addition, a difference in trajectory to the lymphedema state was observed. The results have potential to guide clinical guidelines for assessment of latent and early-onset lymphedema.

Transcriptomic analysis of Portunus trituberculatus reveals a critical role for WNT4 and WNT signalling in limb regeneration.

PubMed

Liu, Lei; Fu, Yuanyuan; Zhu, Fang; Mu, Changkao; Li, Ronghua; Song, Weiwei; Shi, Ce; Ye, Yangfang; Wang, Chunlin

2018-06-05

The swimming crab (Portunus trituberculatus) is among the most economically important seawater crustacean species in Asia. Despite its commercial importance and being well-studied status, genomic and transcriptomic data are scarce for this crab species. In the present study, limb bud tissue was collected at different developmental stages post amputation for transcriptomic analysis. Illumina RNA-sequencing was applied to characterise the limb regeneration transcriptome and identify the most characteristic genes. A total of 289,018 transcripts were obtained by clustering and assembly of clean reads, producing 150,869 unigenes with an average length of 956 bp. Subsequent analysis revealed WNT signalling as the key pathway involved in limb regeneration, with WNT4 a key mediator. Overall, limb regeneration appears to be regulated by multiple signalling pathways, with numerous cell differentiation, muscle growth, moult, metabolism, and immune-related genes upregulated, including WNT4, LAMA, FIP2, FSTL5, TNC, HUS1, SWI5, NCGL, SLC22, PLA2, Tdc2, SMOX, GDH, and SMPD4. This is the first experimental study done on regenerating claws of P. trituberculatus. These findings expand existing sequence resources for crab species, and will likely accelerate research into regeneration and development in crustaceans, particularly functional studies on genes involved in limb regeneration. Copyright © 2018 Elsevier B.V. All rights reserved.

The fin-to-limb transition as the re-organization of a Turing pattern

PubMed Central

Onimaru, Koh; Marcon, Luciano; Musy, Marco; Tanaka, Mikiko; Sharpe, James

2016-01-01

A Turing mechanism implemented by BMP, SOX9 and WNT has been proposed to control mouse digit patterning. However, its generality and contribution to the morphological diversity of fins and limbs has not been explored. Here we provide evidence that the skeletal patterning of the catshark Scyliorhinus canicula pectoral fin is likely driven by a deeply conserved Bmp–Sox9–Wnt Turing network. In catshark fins, the distal nodular elements arise from a periodic spot pattern of Sox9 expression, in contrast to the stripe pattern in mouse digit patterning. However, our computer model shows that the Bmp–Sox9–Wnt network with altered spatial modulation can explain the Sox9 expression in catshark fins. Finally, experimental perturbation of Bmp or Wnt signalling in catshark embryos produces skeletal alterations which match in silico predictions. Together, our results suggest that the broad morphological diversity of the distal fin and limb elements arose from the spatial re-organization of a deeply conserved Turing mechanism. PMID:27211489

Morphological diversity of the avian foot is related with the pattern of msx gene expression in the developing autopod.

PubMed

Gañan, Y; Macias, D; Basco, R D; Merino, R; Hurle, J M

1998-04-01

The formation of the digits in amniota embryos is accompanied by apoptotic cell death of the interdigital mesoderm triggered through BMP signaling. Differences in the intensity of this apoptotic process account for the establishment of the different morphological types of feet observed in amniota (i.e., free-digits, webbed digits, lobulated digits). The molecular basis accounting for the differential pattern of interdigital cell death remains uncertain since the reduction of cell death in species with webbed digits is not accompanied by a parallel reduction in the pattern of expression of bmp genes in the interdigital regions. In this study we show that the duck interdigital web mesoderm exhibits an attenuated response to both BMP-induced apoptosis and TGFbeta-induced chondrogenesis in comparison with species with free digits. The attenuated response to these signals is accompanied by a reduced pattern of expression of msx-1 and msx-2 genes. Local application of FGF in the duck interdigit expands the domain of msx-2 expression but not the domain of msx-1 expression. This change in the expression of msx-2 is followed by a parallel increase in spontaneous and exogenous BMP-induced interdigital cell death, while the chondrogenic response to TGFbetas is unchanged. The regression of AER, as deduced by the pattern of extinction of fgf-8 expression, takes place in a similar fashion in the chick and duck regardless of the differences in interdigital cell death and msx gene expression. Implantation of BMP-beads in the distal limb mesoderm induces AER regression in both the chick and duck. This finding suggests an additional role for BMPs in the physiological regression of the AER. It is proposed that the formation of webbed vs free-digit feet in amniota results from a premature differentiation of the interdigital mesoderm into connective tissue caused by a reduced expression of msx genes in the developing autopod. Copyright 1998 Academic Press.

Differentiation of cartilaginous anlagen in entire embryonic mouse limbs cultured in a rotating bioreactor

NASA Astrophysics Data System (ADS)

Montufar-Solis, D.; Oakley, C. R.; Jefferson, Y.; Duke, P. J.

2003-10-01

Mechanisms involved in development of the embryonic limb have remained the same throughout eons of genetic and environmental evolution under Earth gravity (lg). During the spaceflight era it has been of interest to explore the ancient theory that form of the skeleton develops in response to gravity, and that changes in gravitational forces can change the developmental pattern of the limb. This has been shown in vivo and in vitro, allowing the hypergravity of centrifugation and microgravity of space to be used as tools to increase our knowledge of limb development. In recapitulations of spaceflight experiments, premetatarsals were cultured in suspension in a bioreactor, and found to be shorter and less differentiated than those cultured in standard culture dishes. This study only measured length of the metatarsals, and did not account for possible changes due to the skeletal elements having a more in vivo 3D shape while in suspension vs. flattened tissues compressed by their own weight. A culture system with an outcome closer to in vivo and that supports growth of younger limb buds than traditional systems will allow studies of early Hox gene expression, and contribute to the understanding of very early stages of development. The purpose of the current experiment was to determine if entire limb buds could be cultured in the bioreactor, and to compare the growth and differentiation with that of culturing in a culture dish system. Fore and hind limbs from E11-E13 ICR mouse embryos were cultured for six days, either in the bioreactor or in center-well organ culture dishes, fixed, and embedded for histology. E13 specimens grown in culture dishes were flat, while bioreactor culture specimens had a more in vivo-like 3D limb shape. Sections showed excellent cartilage differentiation in both culture systems, with more cell maturation, and hypertrophy in the specimens cultured in the bioreactor. Younger limb buds fused together during culture, so an additional set of El 1.5 limb buds was cultured with and without encapsulation in alginate prior to culturing in the bioreactor. Encapsulated limbs grown in the bioreactor did not fuse together, but developed only the more proximal elements while limbs grown in culture dishes formed proximal and distal elements. Alginate encapsulation may have reduced oxygenation to the progress zone of the developing limb bud resulting in lack of development of the more distal elements. These results show that the bioreactor supports growth and differentiation of skeletal elements in entire E13 limb buds, and that a method to culture younger limb buds without fusing together needs to be developed if any morphometric analysis is to be performed.

LncRNA-HIT Functions as an Epigenetic Regulator of Chondrogenesis through Its Recruitment of p100/CBP Complexes.

PubMed

Carlson, Hanqian L; Quinn, Jeffrey J; Yang, Yul W; Thornburg, Chelsea K; Chang, Howard Y; Stadler, H Scott

2015-12-01

Gene expression profiling in E 11 mouse embryos identified high expression of the long noncoding RNA (lncRNA), LNCRNA-HIT in the undifferentiated limb mesenchyme, gut, and developing genital tubercle. In the limb mesenchyme, LncRNA-HIT was found to be retained in the nucleus, forming a complex with p100 and CBP. Analysis of the genome-wide distribution of LncRNA-HIT-p100/CBP complexes by ChIRP-seq revealed LncRNA-HIT associated peaks at multiple loci in the murine genome. Ontological analysis of the genes contacted by LncRNA-HIT-p100/CBP complexes indicate a primary role for these loci in chondrogenic differentiation. Functional analysis using siRNA-mediated reductions in LncRNA-HIT or p100 transcripts revealed a significant decrease in expression of many of the LncRNA-HIT-associated loci. LncRNA-HIT siRNA treatments also impacted the ability of the limb mesenchyme to form cartilage, reducing mesenchymal cell condensation and the formation of cartilage nodules. Mechanistically the LncRNA-HIT siRNA treatments impacted pro-chondrogenic gene expression by reducing H3K27ac or p100 activity, confirming that LncRNA-HIT is essential for chondrogenic differentiation in the limb mesenchyme. Taken together, these findings reveal a fundamental epigenetic mechanism functioning during early limb development, using LncRNA-HIT and its associated proteins to promote the expression of multiple genes whose products are necessary for the formation of cartilage.

LncRNA-HIT Functions as an Epigenetic Regulator of Chondrogenesis through Its Recruitment of p100/CBP Complexes

PubMed Central

Carlson, Hanqian L.; Quinn, Jeffrey J.; Yang, Yul W.; Thornburg, Chelsea K.; Chang, Howard Y.; Stadler, H. Scott

2015-01-01

Gene expression profiling in E 11 mouse embryos identified high expression of the long noncoding RNA (lncRNA), LNCRNA-HIT in the undifferentiated limb mesenchyme, gut, and developing genital tubercle. In the limb mesenchyme, LncRNA-HIT was found to be retained in the nucleus, forming a complex with p100 and CBP. Analysis of the genome-wide distribution of LncRNA-HIT-p100/CBP complexes by ChIRP-seq revealed LncRNA-HIT associated peaks at multiple loci in the murine genome. Ontological analysis of the genes contacted by LncRNA-HIT-p100/CBP complexes indicate a primary role for these loci in chondrogenic differentiation. Functional analysis using siRNA-mediated reductions in LncRNA-HIT or p100 transcripts revealed a significant decrease in expression of many of the LncRNA-HIT-associated loci. LncRNA-HIT siRNA treatments also impacted the ability of the limb mesenchyme to form cartilage, reducing mesenchymal cell condensation and the formation of cartilage nodules. Mechanistically the LncRNA-HIT siRNA treatments impacted pro-chondrogenic gene expression by reducing H3K27ac or p100 activity, confirming that LncRNA-HIT is essential for chondrogenic differentiation in the limb mesenchyme. Taken together, these findings reveal a fundamental epigenetic mechanism functioning during early limb development, using LncRNA-HIT and its associated proteins to promote the expression of multiple genes whose products are necessary for the formation of cartilage. PMID:26633036

The effect of a hybrid assistive limb® on sit-to-stand and standing patterns of stroke patients

PubMed Central

Kasai, Rie; Takeda, Sunao

2016-01-01

[Purpose] The Hybrid Assistive Limb® (HAL®) robot suit is a powered exoskeleton that can assist a user’s lower limb movement. The purpose of this study was to assess the effectiveness of HAL® in stroke rehabilitation, focusing on the change of the sit-to-stand (STS) movement pattern and standing posture. [Subjects and Methods] Five stroke patients participated in this study. Single leg HAL® was attached to each subject’s paretic lower limb. The subjects performed STS three times both with and without HAL® use. A tri-axial accelerometer was used to assess the STS movement pattern. Forward-tilt angle (FTA) and the time required for STS were measured with and without HAL® use. Surface electromyography (EMG) of STS and standing were recorded to assess the vastus medialis muscle activities of the paretic limb. [Results] The average FTA without HAL® use was 35° and it improved to 43° with HAL® use. The time required for STS was longer for all subjects with HAL® use (without HAL® use: 3.42 s, with HAL® use: 5.11 s). The integrated EMGs of HAL® use compared to those without HAL®, were 83.6% and 66.3% for STS and standing, respectively. [Conclusion] HAL® may be effective in improving STS and standing patterns of stroke patients. PMID:27390416

Three-dimensional contrast-enhanced magnetic resonance angiography for anterolateral thigh flap outlining: A retrospective case series of 68 patients.

PubMed

Jiang, Chunjing; Lin, Ping; Fu, Xiaoyan; Shu, Jiner; Li, Huimin; Hu, Xiaogang; He, Jianrong; Ding, Mingxing

2016-08-01

Flap transfer is increasingly used for repairing limb defects secondary to trauma or tumor, and appropriate preoperative planning plays a critical role. The present study aimed to examine the use of three-dimensional (3D) contrast-enhanced magnetic resonance angiography (CE-MRA) in evaluating the blood supply distribution and perforating branch pattern of anterolateral thigh (ALT) flaps. Bilateral donor lower limbs were scanned in 68 patients (136 limbs) using a Siemens Avanto 1.5 T magnetic resonance imaging scanner with a 3D fast low-angle shot sequence, following the thin-slab maximum intensity projection (TS-MIP) technique. The lateral femoral circumflex artery (LFCA) was visualized in all patients: 101 limbs (101/136, 74.3%) were type I; 20 limbs (20/136, 14.7%) were type II; 3 limbs (3/136, 2.2%) were type III; and 12 limbs (12/136, 8.8%) were type IV. Tertiary branches were identified in 94 limbs (94/136, 69.1%). Donor flaps were outlined according to MRA TS-MIP findings in 4 patients. All flaps survived uneventfully following the transfer. In donor flap outlining, 3D CE-MRA with the TS-MIP technique allowed an accurate, direct visualization of the branching pattern and distribution profile of the LFCA supplying the ALT flap.

Alternate pathways of body shape evolution translate into common patterns of locomotor evolution in two clades of lizards.

PubMed

Bergmann, Philip J; Irschick, Duncan J

2010-06-01

Body shape has a fundamental impact on organismal function, but it is unknown how functional morphology and locomotor performance and kinematics relate across a diverse array of body shapes. We showed that although patterns of body shape evolution differed considerably between lizards of the Phrynosomatinae and Lerista, patterns of locomotor evolution coincided between clades. Specifically, we found that the phrynosomatines evolved a stocky phenotype through body widening and limb shortening, whereas Lerista evolved elongation through body lengthening and limb shortening. In both clades, relative limb length played a key role in locomotor evolution and kinematic strategies, with long-limbed species moving faster and taking longer strides. In Lerista, the body axis also influenced locomotor evolution. Similar patterns of locomotor evolution were likely due to constraints on how the body can move. However, these common patterns of locomotor evolution between the two clades resulted in different kinematic strategies and levels of performance among species because of their morphological differences. Furthermore, we found no evidence that distinct body shapes are adaptations to different substrates, as locomotor kinematics did not change on loose or solid substrates. Our findings illustrate the importance of studying kinematics to understand the mechanisms of locomotor evolution and phenotype-function relationships.

Collagen reconstitution is inversely correlated with induction of limb regeneration in Ambystoma mexicanum.

PubMed

Satoh, Akira; Hirata, Ayako; Makanae, Aki

2012-03-01

Amphibians can regenerate missing body parts, including limbs. The regulation of collagen has been considered to be important in limb regeneration. Collagen deposition is suppressed during limb regeneration, so we investigated collagen deposition and apical epithelial cap (AEC) formation during axolotl limb regeneration. The accessory limb model (ALM) has been developed as an alternative model for studying limb regeneration. Using this model, we investigated the relationship between nerves, epidermis, and collagen deposition. We found that Sp-9, an AEC marker gene, was upregulated by direct interaction between nerves and epidermis. However, collagen deposition hindered this interaction, and resulted in the failure of limb regeneration. During wound healing, an increase in deposition of collagen caused a decrease in the blastema induction rate in ALM. Wound healing and limb regeneration are alternate processes.

Effects of postural changes of the upper limb on reflex transmission in the lower limb. Cervicolumbar reflex interactions in man.

PubMed

Delwaide, P J; Figiel, C; Richelle, C

1977-06-01

The influence of passive changes in upper limb position on the excitability of three myotatic arc reflexes (soleus, quadriceps, and biceps femoris) of the lower limb has been explored on 42 volunteers. The results indicate that the excitability of the three myotatic arcs can be influenced at a distance by postural modifications of the upper limb. When the ipsilateral upper limb is forwards or the contralateral backwards, a facilitation of both soleus and quadriceps tendon reflexes is observed while the biceps femoris reflexes are reduced. This pattern of facilitation and inhibition is reversed when the ipsilateral upper limb is backwards or the contralateral forwards. The facilitations as well as inhibitions of proximal myotatic arc reflexes are quantitatively more marked than that of the soleus reflex. Facilitation and inhibition are not linearly related to the angle of the arm with the trunk. Effects begin at a considerable angle, become maximal at 45 degrees, and progressively disappear for greater values. It is suggested that the distinct pattern of facilitation and inhibition which is exerted in reciprocal fashion on extensor and flexor motor nuclei might depend on the long propriospinal neurones connecting cervical and lumbar enlargements.

A review of supernumerary and absent limbs and digits of the upper limb.

PubMed

Klaassen, Zachary; Choi, Monica; Musselman, Ruth; Eapen, Deborah; Tubbs, R Shane; Loukas, Marios

2012-03-01

For years people have been enamored by anomalies of the human limbs, particularly supernumerary and absent limbs and digits. Historically, there are a number of examples of such anomalies, including royal families of ancient Chaldea, tribes from Arabia, and examples from across nineteenth century Europe. The development of the upper limbs in a growing embryo is still being elucidated with the recent advent of homeobox genes, but researchers agree that upper limbs develop between stages 12-23 through a complex embryological process. Maternal thalidomide intake during limb development is known to cause limb reduction and subsequent amelia or phocomelia. Additionally, a number of clinical reports have illustrated different limb anomaly cases, with each situation unique in phenotype and developmental abnormality. Supernumerary and absent limbs and digits are not unique to humans, and a number of animal cases have also been reported. This review of the literature illustrates the historical, anatomical, and clinical aspects of supernumerary and absent limbs and digits for the upper limb.

Cartilage and bone cells do not participate in skeletal regeneration in Ambystoma mexicanum limbs.

PubMed

McCusker, Catherine D; Diaz-Castillo, Carlos; Sosnik, Julian; Q Phan, Anne; Gardiner, David M

2016-08-01

The Mexican Axolotl is one of the few tetrapod species that is capable of regenerating complete skeletal elements in injured adult limbs. Whether the skeleton (bone and cartilage) plays a role in the patterning and contribution to the skeletal regenerate is currently unresolved. We tested the induction of pattern formation, the effect on cell proliferation, and contributions of skeletal tissues (cartilage, bone, and periosteum) to the regenerating axolotl limb. We found that bone tissue grafts from transgenic donors expressing GFP fail to induce pattern formation and do not contribute to the newly regenerated skeleton. Periosteum tissue grafts, on the other hand, have both of these activities. These observations reveal that skeletal tissue does not contribute to the regeneration of skeletal elements; rather, these structures are patterned by and derived from cells of non-skeletal connective tissue origin. Copyright © 2016 Elsevier Inc. All rights reserved.

Macrophages and fibroblasts during inflammation and tissue repair in models of organ regeneration

PubMed Central

2017-01-01

Abstract This review provides a concise summary of the changing phenotypes of macrophages and fibroblastic cells during the local inflammatory response, the onset of tissue repair, and the resolution of inflammation which follow injury to an organ. Both cell populations respond directly to damage and present coordinated sequences of activation states which determine the reparative outcome, ranging from true regeneration of the organ to fibrosis and variable functional deficits. Recent work with mammalian models of organ regeneration, including regeneration of full‐thickness skin, hair follicles, ear punch tissues, and digit tips, is summarized and the roles of local immune cells in these systems are discussed. New investigations of the early phase of amphibian limb and tail regeneration, including the effects of pro‐inflammatory and anti‐inflammatory agents, are then briefly discussed, focusing on the transition from the normally covert inflammatory response to the initiation of the regeneration blastema by migrating fibroblasts and the expression of genes for limb patterning. PMID:28616244

Neural mechanism of optimal limb coordination in crustacean swimming

PubMed Central

Zhang, Calvin; Guy, Robert D.; Mulloney, Brian; Zhang, Qinghai; Lewis, Timothy J.

2014-01-01

A fundamental challenge in neuroscience is to understand how biologically salient motor behaviors emerge from properties of the underlying neural circuits. Crayfish, krill, prawns, lobsters, and other long-tailed crustaceans swim by rhythmically moving limbs called swimmerets. Over the entire biological range of animal size and paddling frequency, movements of adjacent swimmerets maintain an approximate quarter-period phase difference with the more posterior limbs leading the cycle. We use a computational fluid dynamics model to show that this frequency-invariant stroke pattern is the most effective and mechanically efficient paddling rhythm across the full range of biologically relevant Reynolds numbers in crustacean swimming. We then show that the organization of the neural circuit underlying swimmeret coordination provides a robust mechanism for generating this stroke pattern. Specifically, the wave-like limb coordination emerges robustly from a combination of the half-center structure of the local central pattern generating circuits (CPGs) that drive the movements of each limb, the asymmetric network topology of the connections between local CPGs, and the phase response properties of the local CPGs, which we measure experimentally. Thus, the crustacean swimmeret system serves as a concrete example in which the architecture of a neural circuit leads to optimal behavior in a robust manner. Furthermore, we consider all possible connection topologies between local CPGs and show that the natural connectivity pattern generates the biomechanically optimal stroke pattern most robustly. Given the high metabolic cost of crustacean swimming, our results suggest that natural selection has pushed the swimmeret neural circuit toward a connection topology that produces optimal behavior. PMID:25201976

Planar Covariation of Hindlimb and Forelimb Elevation Angles during Terrestrial and Aquatic Locomotion of Dogs

PubMed Central

Catavitello, Giovanna; Ivanenko, Yuri P.; Lacquaniti, Francesco

2015-01-01

The rich repertoire of locomotor behaviors in quadrupedal animals requires flexible inter-limb and inter-segmental coordination. Here we studied the kinematic coordination of different gaits (walk, trot, gallop, and swim) of six dogs (Canis lupus familiaris) and, in particular, the planar covariation of limb segment elevation angles. The results showed significant variations in the relative duration of rearward limb movement, amplitude of angular motion, and inter-limb coordination, with gait patterns ranging from a lateral sequence of footfalls during walking to a diagonal sequence in swimming. Despite these differences, the planar law of inter-segmental coordination was maintained across different gaits in both forelimbs and hindlimbs. Notably, phase relationships and orientation of the covariation plane were highly limb specific, consistent with the functional differences in their neural control. Factor analysis of published muscle activity data also demonstrated differences in the characteristic timing of basic activation patterns of the forelimbs and hindlimbs. Overall, the results demonstrate that the planar covariation of inter-segmental coordination has emerged for both fore- and hindlimbs and all gaits, although in a limb-specific manner. PMID:26218076

Motor neurons with limb-innervating character in the cervical spinal cord are sculpted by apoptosis based on the Hox code in chick embryo.

PubMed

Mukaigasa, Katsuki; Sakuma, Chie; Okada, Tomoaki; Homma, Shunsaku; Shimada, Takako; Nishiyama, Keiji; Sato, Noboru; Yaginuma, Hiroyuki

2017-12-15

In the developing chick embryo, a certain population of motor neurons (MNs) in the non-limb-innervating cervical spinal cord undergoes apoptosis between embryonic days 4 and 5. However, the characteristics of these apoptotic MNs remain undefined. Here, by examining the spatiotemporal profiles of apoptosis and MN subtype marker expression in normal or apoptosis-inhibited chick embryos, we found that this apoptotic population is distinguishable by Foxp1 expression. When apoptosis was inhibited, the Foxp1 + MNs survived and showed characteristics of lateral motor column (LMC) neurons, which are of a limb-innervating subtype, suggesting that cervical Foxp1 + MNs are the rostral continuation of the LMC. Knockdown and misexpression of Foxp1 did not affect apoptosis progression, but revealed the role of Foxp1 in conferring LMC identity on the cervical MNs. Furthermore, ectopic expression of Hox genes that are normally expressed in the brachial region prevented apoptosis, and directed Foxp1 + MNs to LMC neurons at the cervical level. These results indicate that apoptosis in the cervical spinal cord plays a role in sculpting Foxp1 + MNs committed to LMC neurons, depending on the Hox expression pattern. © 2017. Published by The Company of Biologists Ltd.

Towards limb position invariant myoelectric pattern recognition using time-dependent spectral features.

PubMed

Khushaba, Rami N; Takruri, Maen; Miro, Jaime Valls; Kodagoda, Sarath

2014-07-01

Recent studies in Electromyogram (EMG) pattern recognition reveal a gap between research findings and a viable clinical implementation of myoelectric control strategies. One of the important factors contributing to the limited performance of such controllers in practice is the variation in the limb position associated with normal use as it results in different EMG patterns for the same movements when carried out at different positions. However, the end goal of the myoelectric control scheme is to allow amputees to control their prosthetics in an intuitive and accurate manner regardless of the limb position at which the movement is initiated. In an attempt to reduce the impact of limb position on EMG pattern recognition, this paper proposes a new feature extraction method that extracts a set of power spectrum characteristics directly from the time-domain. The end goal is to form a set of features invariant to limb position. Specifically, the proposed method estimates the spectral moments, spectral sparsity, spectral flux, irregularity factor, and signals power spectrum correlation. This is achieved through using Fourier transform properties to form invariants to amplification, translation and signal scaling, providing an efficient and accurate representation of the underlying EMG activity. Additionally, due to the inherent temporal structure of the EMG signal, the proposed method is applied on the global segments of EMG data as well as the sliced segments using multiple overlapped windows. The performance of the proposed features is tested on EMG data collected from eleven subjects, while implementing eight classes of movements, each at five different limb positions. Practical results indicate that the proposed feature set can achieve significant reduction in classification error rates, in comparison to other methods, with ≈8% error on average across all subjects and limb positions. A real-time implementation and demonstration is also provided and made available as a video supplement (see Appendix A). Copyright © 2014 Elsevier Ltd. All rights reserved.

A Reevaluation of X-Irradiation Induced Phocomelia and Proximodistal Limb Patterning

PubMed Central

Galloway, Jenna L.; Delgado, Irene; Ros, Maria A.; Tabin, Clifford J.

2009-01-01

Phocomelia is a devastating, rare congenital limb malformation in which the long bones are shorter than normal, with the upper portion of the limb being most severely affected. In extreme cases, the hands or fingers are attached directly to the shoulder and the most proximal elements (those closest to the shoulder) are entirely missing. This disorder, previously known in both autosomal recessive and sporadic forms, showed a dramatic increase in incidence in the early 1960’s due to the tragic toxicological effects of the drug thalidomide, which had been prescribed as a mild sedative1, 2. This human birth defect is mimicked in developing chick limb buds exposed to X-irradiation3-5. Both X-irradiation5 and thalidomide-induced phocomelia5, 6 have been interpreted as patterning defects in the context of the Progress Zone Model, which states that a cell’s proximodistal (PD) identity is determined by the length of time spent in a distal limb region termed the “Progress Zone” 7. Indeed, studies of X-irradiation induced phocomelia have served as one of the two major experimental lines of evidence supporting the validity of the Progress Zone Model. Here, using a combination of molecular analysis and lineage tracing, we show that X-irradiation-induced phocomelia is fundamentally not a patterning defect, but rather results from a time-dependent loss of skeletal progenitors. As skeletal condensation proceeds from the shoulder to fingers (in a proximal to distal direction), the proximal elements are differentially affected in limb buds exposed to radiation at early stages. This conclusion changes the framework for considering the effect of thalidomide and other forms of phocomelia, suggesting the possibility that the etiology lies not in a defect in the patterning process, but rather in progenitor cell survival and differentiation. Moreover, molecular evidence that PD patterning is unaffected following X-irradiation does not support the predictions of the Progress Zone Model. PMID:19553938

A reevaluation of X-irradiation-induced phocomelia and proximodistal limb patterning.

PubMed

Galloway, Jenna L; Delgado, Irene; Ros, Maria A; Tabin, Clifford J

2009-07-16

Phocomelia is a devastating, rare congenital limb malformation in which the long bones are shorter than normal, with the upper portion of the limb being most severely affected. In extreme cases, the hands or fingers are attached directly to the shoulder and the most proximal elements (those closest to the shoulder) are entirely missing. This disorder, previously known in both autosomal recessive and sporadic forms, showed a marked increase in incidence in the early 1960s due to the tragic toxicological effects of the drug thalidomide, which had been prescribed as a mild sedative. This human birth defect is mimicked in developing chick limb buds exposed to X-irradiation. Both X-irradiation and thalidomide-induced phocomelia have been interpreted as patterning defects in the context of the progress zone model, which states that a cell's proximodistal identity is determined by the length of time spent in a distal limb region termed the 'progress zone'. Indeed, studies of X-irradiation-induced phocomelia have served as one of the two major experimental lines of evidence supporting the validity of the progress zone model. Here, using a combination of molecular analysis and lineage tracing in chick, we show that X-irradiation-induced phocomelia is fundamentally not a patterning defect, but rather results from a time-dependent loss of skeletal progenitors. Because skeletal condensation proceeds from the shoulder to fingers (in a proximal to distal direction), the proximal elements are differentially affected in limb buds exposed to radiation at early stages. This conclusion changes the framework for considering the effect of thalidomide and other forms of phocomelia, suggesting the possibility that the aetiology lies not in a defect in the patterning process, but rather in progenitor cell survival and differentiation. Moreover, molecular evidence that proximodistal patterning is unaffected after X-irradiation does not support the predictions of the progress zone model.

The c.429_452 duplication of the ARX gene: a unique developmental-model of limb kinetic apraxia.

PubMed

Curie, Aurore; Nazir, Tatjana; Brun, Amandine; Paulignan, Yves; Reboul, Anne; Delange, Karine; Cheylus, Anne; Bertrand, Sophie; Rochefort, Fanny; Bussy, Gérald; Marignier, Stéphanie; Lacombe, Didier; Chiron, Catherine; Cossée, Mireille; Leheup, Bruno; Philippe, Christophe; Laugel, Vincent; De Saint Martin, Anne; Sacco, Silvia; Poirier, Karine; Bienvenu, Thierry; Souville, Isabelle; Gilbert-Dussardier, Brigitte; Bieth, Eric; Kauffmann, Didier; Briot, Philippe; de Fréminville, Bénédicte; Prieur, Fabienne; Till, Michel; Rooryck-Thambo, Caroline; Mortemousque, Isabelle; Bobillier-Chaumont, Isabelle; Toutain, Annick; Touraine, Renaud; Sanlaville, Damien; Chelly, Jamel; Freeman, Sonya; Kong, Jian; Hadjikhani, Nouchine; Gollub, Randy L; Roy, Alice; des Portes, Vincent

2014-02-14

The c.429_452dup24 of the ARX gene is a rare genetic anomaly, leading to X-Linked Intellectual Disability without brain malformation. While in certain cases c.429_452dup24 has been associated with specific clinical patterns such as Partington syndrome, the consequence of this mutation has been also often classified as "non-specific Intellectual Disability". The present work aims at a more precise description of the clinical features linked to the c.429_452dup24 mutation. We clinically reviewed all affected patients identified in France over a five-year period, i.e. 27 patients from 12 different families. Detailed cognitive, behavioural, and motor evaluation, as well as standardized videotaped assessments of oro-lingual and gestural praxis, were performed. In a sub-group of 13 ARX patients, kinematic and MRI studies were further accomplished to better characterize the motor impairment prevalent in the ARX patients group. To ensure that data were specific to the ARX gene mutation and did not result from low-cognitive functioning per se, a group of 27 age- and IQ-matched Down syndrome patients served as control. Neuropsychological and motor assessment indicated that the c.429_452dup24 mutation constitutes a recognizable clinical syndrome: ARX patients exhibiting Intellectual Disability, without primary motor impairment, but with a very specific upper limb distal motor apraxia associated with a pathognomonic hand-grip. Patients affected with the so-called Partington syndrome, which involves major hand dystonia and orolingual apraxia, exhibit the most severe symptoms of the disorder. The particular "reach and grip" impairment which was observed in all ARX patients, but not in Down syndrome patients, was further characterized by the kinematic data: (i) loss of preference for the index finger when gripping an object, (ii) major impairment of fourth finger deftness, and (iii) a lack of pronation movements. This lack of distal movement coordination exhibited by ARX patients is associated with the loss of independent digital dexterity and is similar to the distortion of individual finger movements and posture observed in Limb Kinetic Apraxia. These findings suggest that the ARX c.429_452dup24 mutation may be a developmental model for Limb Kinetic Apraxia.

Mutations in MITF and PAX3 cause "splashed white" and other white spotting phenotypes in horses.

PubMed

Hauswirth, Regula; Haase, Bianca; Blatter, Marlis; Brooks, Samantha A; Burger, Dominik; Drögemüller, Cord; Gerber, Vincent; Henke, Diana; Janda, Jozef; Jude, Rony; Magdesian, K Gary; Matthews, Jacqueline M; Poncet, Pierre-André; Svansson, Vilhjálmur; Tozaki, Teruaki; Wilkinson-White, Lorna; Penedo, M Cecilia T; Rieder, Stefan; Leeb, Tosso

2012-01-01

During fetal development neural-crest-derived melanoblasts migrate across the entire body surface and differentiate into melanocytes, the pigment-producing cells. Alterations in this precisely regulated process can lead to white spotting patterns. White spotting patterns in horses are a complex trait with a large phenotypic variance ranging from minimal white markings up to completely white horses. The "splashed white" pattern is primarily characterized by an extremely large blaze, often accompanied by extended white markings at the distal limbs and blue eyes. Some, but not all, splashed white horses are deaf. We analyzed a Quarter Horse family segregating for the splashed white coat color. Genome-wide linkage analysis in 31 horses gave a positive LOD score of 1.6 in a region on chromosome 6 containing the PAX3 gene. However, the linkage data were not in agreement with a monogenic inheritance of a single fully penetrant mutation. We sequenced the PAX3 gene and identified a missense mutation in some, but not all, splashed white Quarter Horses. Genome-wide association analysis indicated a potential second signal near MITF. We therefore sequenced the MITF gene and found a 10 bp insertion in the melanocyte-specific promoter. The MITF promoter variant was present in some splashed white Quarter Horses from the studied family, but also in splashed white horses from other horse breeds. Finally, we identified two additional non-synonymous mutations in the MITF gene in unrelated horses with white spotting phenotypes. Thus, several independent mutations in MITF and PAX3 together with known variants in the EDNRB and KIT genes explain a large proportion of horses with the more extreme white spotting phenotypes.

Mutations in MITF and PAX3 Cause “Splashed White” and Other White Spotting Phenotypes in Horses

PubMed Central

Blatter, Marlis; Brooks, Samantha A.; Burger, Dominik; Drögemüller, Cord; Gerber, Vincent; Henke, Diana; Janda, Jozef; Jude, Rony; Magdesian, K. Gary; Matthews, Jacqueline M.; Poncet, Pierre-André; Svansson, Vilhjálmur; Tozaki, Teruaki; Wilkinson-White, Lorna; Penedo, M. Cecilia T.; Rieder, Stefan; Leeb, Tosso

2012-01-01

During fetal development neural-crest-derived melanoblasts migrate across the entire body surface and differentiate into melanocytes, the pigment-producing cells. Alterations in this precisely regulated process can lead to white spotting patterns. White spotting patterns in horses are a complex trait with a large phenotypic variance ranging from minimal white markings up to completely white horses. The “splashed white” pattern is primarily characterized by an extremely large blaze, often accompanied by extended white markings at the distal limbs and blue eyes. Some, but not all, splashed white horses are deaf. We analyzed a Quarter Horse family segregating for the splashed white coat color. Genome-wide linkage analysis in 31 horses gave a positive LOD score of 1.6 in a region on chromosome 6 containing the PAX3 gene. However, the linkage data were not in agreement with a monogenic inheritance of a single fully penetrant mutation. We sequenced the PAX3 gene and identified a missense mutation in some, but not all, splashed white Quarter Horses. Genome-wide association analysis indicated a potential second signal near MITF. We therefore sequenced the MITF gene and found a 10 bp insertion in the melanocyte-specific promoter. The MITF promoter variant was present in some splashed white Quarter Horses from the studied family, but also in splashed white horses from other horse breeds. Finally, we identified two additional non-synonymous mutations in the MITF gene in unrelated horses with white spotting phenotypes. Thus, several independent mutations in MITF and PAX3 together with known variants in the EDNRB and KIT genes explain a large proportion of horses with the more extreme white spotting phenotypes. PMID:22511888

The flipflop orphan genes are required for limb bud eversion in the Tribolium embryo.

PubMed

Thümecke, Susanne; Beermann, Anke; Klingler, Martin; Schröder, Reinhard

2017-01-01

Unlike Drosophila but similar to other arthropod and vertebrate embryos, the flour beetle Tribolium castaneum develops everted limb buds during embryogenesis. However, the molecular processes directing the evagination of epithelia are only poorly understood. Here we show that the newly discovered genes Tc-flipflop1 and Tc-flipflop2 are involved in regulating the directional budding of appendages. RNAi-knockdown of Tc-flipflop results in a variety of phenotypic traits. Most prominently, embryonic limb buds frequently grow inwards rather than out, leading to the development of inverted appendages inside the larval body. Moreover, affected embryos display dorsal closure defects. The Tc-flipflop genes are evolutionarily non-conserved, and their molecular function is not evident. We further found that Tc-RhoGEF2 , a highly-conserved gene known to be involved in actomyosin-dependent cell movement and cell shape changes, shows a Tc-flipflop -like RNAi-phenotype. The similarity of the inverted appendage phenotype in both the flipflop - and the RhoGEF2 RNAi gene knockdown led us to conclude that the Tc-flipflop orphan genes act in a Rho-dependent pathway that is essential for the early morphogenesis of polarised epithelial movements. Our work describes one of the few examples of an orphan gene playing a crucial role in an important developmental process.

Mechanisms of urodele limb regeneration

PubMed Central

2017-01-01

Abstract This review explores the historical and current state of our knowledge about urodele limb regeneration. Topics discussed are (1) blastema formation by the proteolytic histolysis of limb tissues to release resident stem cells and mononucleate cells that undergo dedifferentiation, cell cycle entry and accumulation under the apical epidermal cap. (2) The origin, phenotypic memory, and positional memory of blastema cells. (3) The role played by macrophages in the early events of regeneration. (4) The role of neural and AEC factors and interaction between blastema cells in mitosis and distalization. (5) Models of pattern formation based on the results of axial reversal experiments, experiments on the regeneration of half and double half limbs, and experiments using retinoic acid to alter positional identity of blastema cells. (6) Possible mechanisms of distalization during normal and intercalary regeneration. (7) Is pattern formation is a self‐organizing property of the blastema or dictated by chemical signals from adjacent tissues? (8) What is the future for regenerating a human limb? PMID:29299322

Comparative architectural properties of limb muscles in Crocodylidae and Alligatoridae and their relevance to divergent use of asymmetrical gaits in extant Crocodylia.

PubMed

Allen, Vivian; Molnar, Julia; Parker, William; Pollard, Andrea; Nolan, Grant; Hutchinson, John R

2014-12-01

Crocodiles and their kin (Crocodylidae) use asymmetrical (bounding and galloping) gaits when moving rapidly. Despite being morphologically and ecologically similar, it seems alligators and their kin (Alligatoridae) do not. To investigate a possible anatomical basis for this apparent major difference in locomotor capabilities, we measured relative masses and internal architecture (fascicle lengths and physiological cross-sectional areas) of muscles of the pectoral and pelvic limbs of 40 individuals from six representative species of Crocodylidae and Alligatoridae. We found that, relative to body mass, Crocodylidae have significantly longer muscle fascicles (increased working range), particularly in the pectoral limb, and generally smaller muscle physiological cross-sectional areas (decreased force-exerting capability) than Alligatoridae. We therefore hypothesise that the ability of some crocodylians to use asymmetrical gaits may be limited more by the ability to make large, rapid limb motions (especially in the pectoral limb) than the ability to exert large limb forces. Furthermore, analysis of scaling patterns in muscle properties shows that limb anatomy in the two clades becomes more divergent during ontogeny. Limb muscle masses, fascicle lengths and physiological cross-sectional areas scale with significantly larger coefficients in Crocodylidae than Alligatoridae. This combination of factors suggests that inter-clade disparity in maximal limb power is highest in adult animals. Therefore, despite their apparent morphological similarities, both mean values and scaling patterns suggest that considerable diversity exists in the locomotor apparatus of extant Crocodylia. © 2014 Anatomical Society.

Update on embryology of the upper limb.

PubMed

Al-Qattan, Mohammad M; Kozin, Scott H

2013-09-01

Current concepts in the steps of upper limb development and the way the limb is patterned along its 3 spatial axes are reviewed. Finally, the embryogenesis of various congenital hand anomalies is delineated with an emphasis on the pathogenetic basis for each anomaly. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Characterization of interfacial socket pressure in transhumeral prostheses: A case series.

PubMed

Schofield, Jonathon S; Schoepp, Katherine R; Williams, Heather E; Carey, Jason P; Marasco, Paul D; Hebert, Jacqueline S

2017-01-01

One of the most important factors in successful upper limb prostheses is the socket design. Sockets must be individually fabricated to arrive at a geometry that suits the user's morphology and appropriately distributes the pressures associated with prosthetic use across the residual limb. In higher levels of amputation, such as transhumeral, this challenge is amplified as prosthetic weight and the physical demands placed on the residual limb are heightened. Yet, in the upper limb, socket fabrication is largely driven by heuristic practices. An analytical understanding of the interactions between the socket and residual limb is absent in literature. This work describes techniques, adapted from lower limb prosthetic research, to empirically characterize the pressure distribution occurring between the residual limb and well-fit transhumeral prosthetic sockets. A case series analyzing the result of four participants with transhumeral amputation is presented. A Tekscan VersaTek pressure measurement system and FaroArm Edge coordinate measurement machine were employed to capture socket-residual limb interface pressures and geometrically register these values to the anatomy of participants. Participants performed two static poses with their prosthesis under two separate loading conditions. Surface pressure maps were constructed from the data, highlighting pressure distribution patterns, anatomical locations bearing maximum pressure, and the relative pressure magnitudes. Pressure distribution patterns demonstrated unique characteristics across the four participants that could be traced to individual socket design considerations. This work presents a technique that implements commercially available tools to quantitatively characterize upper limb socket-residual limb interactions. This is a fundamental first step toward improved socket designs developed through informed, analytically-based design tools.

Characterization of interfacial socket pressure in transhumeral prostheses: A case series

PubMed Central

Schoepp, Katherine R.; Williams, Heather E.; Carey, Jason P.; Marasco, Paul D.

2017-01-01

One of the most important factors in successful upper limb prostheses is the socket design. Sockets must be individually fabricated to arrive at a geometry that suits the user’s morphology and appropriately distributes the pressures associated with prosthetic use across the residual limb. In higher levels of amputation, such as transhumeral, this challenge is amplified as prosthetic weight and the physical demands placed on the residual limb are heightened. Yet, in the upper limb, socket fabrication is largely driven by heuristic practices. An analytical understanding of the interactions between the socket and residual limb is absent in literature. This work describes techniques, adapted from lower limb prosthetic research, to empirically characterize the pressure distribution occurring between the residual limb and well-fit transhumeral prosthetic sockets. A case series analyzing the result of four participants with transhumeral amputation is presented. A Tekscan VersaTek pressure measurement system and FaroArm Edge coordinate measurement machine were employed to capture socket-residual limb interface pressures and geometrically register these values to the anatomy of participants. Participants performed two static poses with their prosthesis under two separate loading conditions. Surface pressure maps were constructed from the data, highlighting pressure distribution patterns, anatomical locations bearing maximum pressure, and the relative pressure magnitudes. Pressure distribution patterns demonstrated unique characteristics across the four participants that could be traced to individual socket design considerations. This work presents a technique that implements commercially available tools to quantitatively characterize upper limb socket-residual limb interactions. This is a fundamental first step toward improved socket designs developed through informed, analytically-based design tools. PMID:28575012

Ectopic Fgf signaling induces the intercalary response in developing chicken limb buds.

PubMed

Makanae, Aki; Satoh, Akira

2018-01-01

Intercalary pattern formation is an important regulatory step in amphibian limb regeneration. Amphibian limb regeneration is composed of multiple steps, including wounding, blastema formation, and intercalary pattern formation. Attempts have been made to transfer insights from regeneration-competent animals to regeneration-incompetent animalsat each step in the regeneration process. In the present study, we focused on the intercalary mechanism in chick limb buds. In amphibian limb regeneration, a proximodistal axis is organized as soon as a regenerating blastema is induced. Intermediate structures are subsequently induced (intercalated) between the established proximal and distal identities. Intercalary tissues are derived from proximal tissues. Fgf signaling mediates the intercalary response in amphibian limb regeneration. We attempted to transfer insights into intercalary regeneration from amphibian models to the chick limb bud. The zeugopodial part was dissected out, and the distal and proximal parts were conjunct at st. 24. Delivering ectopic Fgf2 + Fgf8 between the distal and proximal parts resulted in induction of zeugopodial elements. Examination of HoxA11 expression, apoptosis, and cell proliferation provides insights to compare with those in the intercalary mechanism of amphibian limb regeneration. Furthermore, the cellular contribution was investigated in both the chicken intercalary response and that of axolotl limb regeneration. We developed new insights into cellular contribution in amphibian intercalary regeneration, and found consistency between axolotl and chicken intercalary responses. Our findings demonstrate that the same principal of limb regeneration functions between regeneration-competent and -incompetent animals. In this context, we propose the feasibility of the induction of the regeneration response in amniotes.

Mechanics of limb bone loading during terrestrial locomotion in the green iguana (Iguana iguana) and American alligator (Alligator mississippiensis).

PubMed

Blob, R W; Biewener, A A

2001-03-01

In vivo measurements of strain in the femur and tibia of Iguana iguana (Linnaeus) and Alligator mississippiensis (Daudin) have indicated three ways in which limb bone loading in these species differs from patterns observed in most birds and mammals: (i) the limb bones of I. iguana and A. mississippiensis experience substantial torsion, (ii) the limb bones of I. iguana and A. mississippiensis have higher safety factors than those of birds or mammals, and (iii) load magnitudes in the limb bones of A. mississippiensis do not decrease uniformly with the use of a more upright posture. To verify these patterns, and to evaluate the ground and muscle forces that produce them, we collected three-dimensional kinematic and ground reaction force data from subadult I. iguana and A. mississippiensis using a force platform and high-speed video. The results of these force/kinematic studies generally confirm the loading regimes inferred from in vivo strain measurements. The ground reaction force applies a torsional moment to the femur and tibia in both species; for the femur, this moment augments the moment applied by the caudofemoralis muscle, suggesting large torsional stresses. In most cases, safety factors in bending calculated from force/video data are lower than those determined from strain data, but are as high or higher than the safety factors of bird and mammal limb bones in bending. Finally, correlations between limb posture and calculated stress magnitudes in the femur of I. iguana confirm patterns observed during direct bone strain recordings from A. mississippiensis: in more upright steps, tensile stresses on the anterior cortex decrease, but peak compressive stresses on the dorsal cortex increase. Equilibrium analyses indicate that bone stress increases as posture becomes more upright in saurians because the ankle and knee extensor muscles exert greater forces during upright locomotion. If this pattern of increased bone stress with the use of a more upright posture is typical of taxa using non-parasagittal kinematics, then similar increases in load magnitudes were probably experienced by lineages that underwent evolutionary shifts to a non-sprawling posture. High limb bone safety factors and small body size in these lineages could have helped to accommodate such increases in limb bone stress.

The axolotl limb blastema: cellular and molecular mechanisms driving blastema formation and limb regeneration in tetrapods

PubMed Central

McCusker, Catherine; Bryant, Susan V.

2015-01-01

Abstract The axolotl is one of the few tetrapods that are capable of regenerating complicated biological structures, such as complete limbs, throughout adulthood. Upon injury the axolotl generates a population of regeneration‐competent limb progenitor cells known as the blastema, which will grow, establish pattern, and differentiate into the missing limb structures. In this review we focus on the crucial early events that occur during wound healing, the neural−epithelial interactions that drive the formation of the early blastema, and how these mechanisms differ from those of other species that have restricted regenerative potential, such as humans. We also discuss how the presence of cells from the different axes of the limb is required for the continued growth and establishment of pattern in the blastema as described in the polar coordinate model, and how this positional information is reprogrammed in blastema cells during regeneration. Multiple cell types from the mature limb stump contribute to the blastema at different stages of regeneration, and we discuss the contribution of these types to the regenerate with reference to whether they are “pattern‐forming” or “pattern‐following” cells. Lastly, we explain how an engineering approach will help resolve unanswered questions in limb regeneration, with the goal of translating these concepts to developing better human regenerative therapies. PMID:27499868

There's more than one way to climb a tree: Limb length and microhabitat use in lizards with toe pads.

PubMed

Hagey, Travis J; Harte, Scott; Vickers, Mathew; Harmon, Luke J; Schwarzkopf, Lin

2017-01-01

Ecomorphology links microhabitat and morphology. By comparing ecomorphological associations across clades, we can investigate the extent to which evolution can produce similar solutions in response to similar challenges. While Anolis lizards represent a well-studied example of repeated convergent evolution, very few studies have investigated the ecomorphology of geckos. Similar to anoles, gekkonid lizards have independently evolved adhesive toe pads and many species are scansorial. We quantified gecko and anole limb length and microhabitat use, finding that geckos tend to have shorter limbs than anoles. Combining these measurements with microhabitat observations of geckos in Queensland, Australia, we observed geckos using similar microhabitats as reported for anoles, but geckos with relatively longer limbs were using narrower perches, differing from patterns observed in anoles and other lizards. We also observed arboreal geckos with relatively shorter proximal limb segments as compared to rock-dwelling and terrestrial geckos, similar to patterns observed for other lizards. We conclude that although both geckos and anoles have adhesive pads and use similar microhabitats, their locomotor systems likely complement their adhesive pads in unique ways and result in different ecomorphological patterns, reinforcing the idea that species with convergent morphologies still have idiosyncratic characteristics due to their own separate evolutionary histories.

There’s more than one way to climb a tree: Limb length and microhabitat use in lizards with toe pads

PubMed Central

Harte, Scott; Vickers, Mathew; Harmon, Luke J.; Schwarzkopf, Lin

2017-01-01

Ecomorphology links microhabitat and morphology. By comparing ecomorphological associations across clades, we can investigate the extent to which evolution can produce similar solutions in response to similar challenges. While Anolis lizards represent a well-studied example of repeated convergent evolution, very few studies have investigated the ecomorphology of geckos. Similar to anoles, gekkonid lizards have independently evolved adhesive toe pads and many species are scansorial. We quantified gecko and anole limb length and microhabitat use, finding that geckos tend to have shorter limbs than anoles. Combining these measurements with microhabitat observations of geckos in Queensland, Australia, we observed geckos using similar microhabitats as reported for anoles, but geckos with relatively longer limbs were using narrower perches, differing from patterns observed in anoles and other lizards. We also observed arboreal geckos with relatively shorter proximal limb segments as compared to rock-dwelling and terrestrial geckos, similar to patterns observed for other lizards. We conclude that although both geckos and anoles have adhesive pads and use similar microhabitats, their locomotor systems likely complement their adhesive pads in unique ways and result in different ecomorphological patterns, reinforcing the idea that species with convergent morphologies still have idiosyncratic characteristics due to their own separate evolutionary histories. PMID:28953920

Activation of germline-specific genes is required for limb regeneration in the Mexican axolotl

PubMed Central

Zhu, Wei; Pao, Gerald M; Satoh, Akira; Cummings, Gillian; Monaghan, James R; Harkins, Timothy T; Bryant, Susan V; Voss, S Randal; Gardiner, David M; Hunter, Tony

2013-01-01

The capacity for tissue and organ regeneration in humans is dwarfed by comparison to that of salamanders. Emerging evidence suggests that mechanisms learned from the early phase of salamander limb regeneration – wound healing, cellular dedifferentiation and blastemal formation – will reveal therapeutic approaches for tissue regeneration in humans. Here we describe a unique transcriptional fingerprint of regenerating limb tissue in the Mexican axolotl (Ambystoma mexicanum) that is indicative of cellular reprogramming of differentiated cells to a germline-like state. Two genes that are required for self-renewal of germ cells in mice and flies, Piwi-like 1 (PL1) and Piwi-like 2 (PL2), are expressed in limb blastemal cells, the basal layer keratinocytes and the thickened apical epithelial cap in the wound epidermis in the regenerating limb. Depletion of PL1 and PL2 by morpholino oligonucleotides decreased cell proliferation and increased cell death in the blastema leading to a significant retardation of regeneration. Examination of key molecules that are known to be required for limb development or regeneration further revealed that FGF8 is transcriptionally downregulated in the presence of the morpholino oligos, indicating PL1 and PL2 might participate in FGF signaling during limb regeneration. Given the requirement for FGF signaling in limb development and regeneration, the results suggest that PL1 and PL2 function to establish a unique germline-like state that is associated with successful regeneration. PMID:22841627

EZH2 Modulates Angiogenesis In Vitro and in a Mouse Model of Limb Ischemia

PubMed Central

Mitić, Tijana; Caporali, Andrea; Floris, Ilaria; Meloni, Marco; Marchetti, Micol; Urrutia, Raul; Angelini, Gianni D; Emanueli, Costanza

2015-01-01

Epigenetic mechanisms may regulate the expression of pro-angiogenic genes, thus affecting reparative angiogenesis in ischemic limbs. The enhancer of zest homolog-2 (EZH2) induces thtrimethylation of lysine 27 on histone H3 (H3K27me3), which represses gene transcription. We explored (i) if EZH2 expression is regulated by hypoxia and ischemia; (ii) the impact of EZH2 on the expression of two pro-angiogenic genes: eNOS and BDNF; (iii) the functional effect of EZH2 inhibition on cultured endothelial cells (ECs); (iv) the therapeutic potential of EZH2 inhibition in a mouse model of limb ischemia (LI). EZH2 expression was increased in cultured ECs exposed to hypoxia (control: normoxia) and in ECs extracted from mouse ischemic limb muscles (control: absence of ischemia). EZH2 increased the H3K27me3 abundance onto regulatory regions of eNOS and BDNF promoters. In vitro RNA silencing or pharmacological inhibition by 3-deazaneplanocin (DZNep) of EZH2 increased eNOS and BDNF mRNA and protein levels and enhanced functional capacities (migration, angiogenesis) of ECs under either normoxia or hypoxia. In mice with experimentally induced LI, DZNep increased angiogenesis in ischaemic muscles, the circulating levels of pro-angiogenic hematopoietic cells and blood flow recovery. Targeting EZH2 for inhibition may open new therapeutic avenues for patients with limb ischemia. PMID:25189741

Application of Comparative Functional Genomics to Identify Regeneration-Specific Genes

DTIC Science & Technology

2014-08-25

The first objective will extend an ongoing study of the transcriptional basis of limb regeneration in the Mexican axolotl (Ambystoma mexicanum) to...Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 Limb Regeneration, Transcriptome, Salamander, Axolotl REPORT...transcriptional basis of limb regeneration in the Mexican axolotl (Ambystoma mexicanum) to three additional salamander species (A. tigrinum, A. maculatum, and

Sex and the single (-eared) female: leg function, limb autotomy and mating history trade-offs in field crickets (Gryllus bimaculatus)

PubMed Central

Bateman, Philip W; Fleming, Patricia A

2005-01-01

Both male and female field crickets (Gryllus bimaculatus) autotomize front (tympanal) limbs more slowly than hind limbs. Arguably, this pattern could reflect possible differences in the mechanism of limb autotomy. However, we demonstrate that, for females, limb autotomy is also dependent on their mating status: virgin females autotomize front legs significantly more slowly than mated females. This response suggests a central control for leg autotomy in these animals, and less readiness to autotomize a front leg, possibly because the tympanum is crucial for mate location. PMID:17148319

Effect of long-term bedrest on lower leg muscle activation patterns during quiet standing.

PubMed

Miyoshi, T; Sato, T; Sekiguchi, H; Yamanaka, K; Miyazaki, M; Igawa, S; Komeda, T; Nakazawa, K; Yano, H

2001-07-01

It has been well known that balance instabilities after long-term exposure to microgravity (e.g., Anderson et al. 1986) or bedrest (BR) can be related to alterations and/or adaptations to postural control strategies. Little is known, however, how the reduced muscular activity affects the activation pattern of the lower limb muscles during quiet standing (QS). The purpose of this study was to investigate whether or not any changes in the lower limb muscle activation patterns during QS would occur after BR.

Limb Dominance and Its Effects on the Benefits of Intralimb Transfer of Learning: A Visuomotor Aiming Task.

PubMed

Aiken, Christopher A; Pan, Zhujun; Van Gemmert, Arend W A

2015-01-01

Research has attempted to address what characteristics benefit from transfer of learning; however, it is still unclear which characteristics are effector dependent or independent. Furthermore, it is not clear if intralimb transfer shows, similarly to interlimb transfer, an asymmetry of benefits between the upper limbs. The purpose of the current study is to examine if effector independence effects emerge, as observed in interlimb transfer studies, when transfer to new effector group within the same limb occurs, and whether the pattern of intralimb transfer benefits differ between the limbs. Our results suggest that a visuomotor task transfers within both limbs, even though the transfer benefits within the limbs seem to differ. This was supported by more transfer occurring in the dominant limb than the nondominant limb. Potential control mechanisms used for intralimb transfer are discussed.

Hair patterns of the lower limb in Central Indian males.

PubMed

Chaurasia, B D

1977-08-01

The distribution of hair of the right lower limb has been studied in a random sample of 220 healthy Central Indian males 17 to 45 years of age. The common hair patterns observed are the proximal phalangeal hair in all toes in 55.45%, the middle phalangeal hair in the third toe in 8.18%, the tibial on the dorsum of foot in 69.55%, and the pedo-cruro-femoral in the lower limb in 70.00% subjects. Comparison of these findings with those of the right upper limb shows that hairiness of the two limbs is correlated, that the dorsum of foot is less hairy than the dorsum of hand, and that the third and second toes are comparable with the fourth and third fingers, respectively, as regards their middle phalangeal hair. Comparison with the available literature shows that the Central Indian males resemble the Whites in having greater frequency of middle phalangeal hair than those of the Negroes, that the dorsum of feet of this population is less hairy than the White and more hairy than the Negroes, and that the general hairiness of the lower limb is more or less equal in the three groups of persons.

Enhancer elements upstream of the SHOX gene are active in the developing limb.

PubMed

Durand, Claudia; Bangs, Fiona; Signolet, Jason; Decker, Eva; Tickle, Cheryll; Rappold, Gudrun

2010-05-01

Léri-Weill Dyschondrosteosis (LWD) is a dominant skeletal disorder characterized by short stature and distinct bone anomalies. SHOX gene mutations and deletions of regulatory elements downstream of SHOX resulting in haploinsufficiency have been found in patients with LWD. SHOX encodes a homeodomain transcription factor and is known to be expressed in the developing limb. We have now analyzed the regulatory significance of the region upstream of the SHOX gene. By comparative genomic analyses, we identified several conserved non-coding elements, which subsequently were tested in an in ovo enhancer assay in both chicken limb bud and cornea, where SHOX is also expressed. In this assay, we found three enhancers to be active in the developing chicken limb, but none were functional in the developing cornea. A screening of 60 LWD patients with an intact SHOX coding and downstream region did not yield any deletion of the upstream enhancer region. Thus, we speculate that SHOX upstream deletions occur at a lower frequency because of the structural organization of this genomic region and/or that SHOX upstream deletions may cause a phenotype that differs from the one observed in LWD.

Enhancer elements upstream of the SHOX gene are active in the developing limb

PubMed Central

Durand, Claudia; Bangs, Fiona; Signolet, Jason; Decker, Eva; Tickle, Cheryll; Rappold, Gudrun

2010-01-01

Léri-Weill Dyschondrosteosis (LWD) is a dominant skeletal disorder characterized by short stature and distinct bone anomalies. SHOX gene mutations and deletions of regulatory elements downstream of SHOX resulting in haploinsufficiency have been found in patients with LWD. SHOX encodes a homeodomain transcription factor and is known to be expressed in the developing limb. We have now analyzed the regulatory significance of the region upstream of the SHOX gene. By comparative genomic analyses, we identified several conserved non-coding elements, which subsequently were tested in an in ovo enhancer assay in both chicken limb bud and cornea, where SHOX is also expressed. In this assay, we found three enhancers to be active in the developing chicken limb, but none were functional in the developing cornea. A screening of 60 LWD patients with an intact SHOX coding and downstream region did not yield any deletion of the upstream enhancer region. Thus, we speculate that SHOX upstream deletions occur at a lower frequency because of the structural organization of this genomic region and/or that SHOX upstream deletions may cause a phenotype that differs from the one observed in LWD. PMID:19997128

Differential expression of growth factors at the cellular level in virus-infected brain

PubMed Central

Prosniak, Mikhail; Zborek, Anna; Scott, Gwen S.; Roy, Anirban; Phares, Timothy W.; Koprowski, Hilary; Hooper, D. Craig

2003-01-01

The contribution of host factors to rabies virus (RV) transcription/replication and axonal/transsynaptic spread is largely unknown. We previously identified several host genes that are up-regulated in the mouse brain during RV infection, including neuroleukin, which is involved in neuronal growth and survival, cell motility, and differentiation, and fibroblast growth factor homologous factor 4 (FHF4), which has been implicated in limb and nervous system development. In this study, we used real-time quantitative RT-PCR to assess the expression of mRNAs specific for neuroleukin, the two isoforms of FHF4 (FHF4-1a and -1b) encoded by the FHF4 gene, and N protein of RV in neurons and astrocytes isolated by laser capture microdissection from mouse brains infected with the laboratory-adapted RV strain CVS-N2c or with a street RV of silver-haired bat origin. Differences in the gene expression patterns suggest that the capacity of RV strains to infect nonneuronal cells and differentially modulate host gene expression may be important in virus replication and spread in the CNS. PMID:12736376

Pax-3 expression in segmental mesoderm marks early stages in myogenic cell specification.

PubMed

Williams, B A; Ordahl, C P

1994-04-01

Specification of the myogenic lineage begins prior to gastrulation and culminates in the emergence of determined myogenic precursor cells from the somites. The myoD family (MDF) of transcriptional activators controls late step(s) in myogenic specification that are closely followed by terminal muscle differentiation. Genes expressed in myogenic specification at stages earlier than MDFs are unknown. The Pax-3 gene is expressed in all the cells of the caudal segmental plate, the early mesoderm compartment that contains the precursors of skeletal muscle. As somites form from the segmental plate and mature, Pax-3 expression is progressively modulated. Beginning at the time of segmentation, Pax-3 becomes repressed in the ventral half of the somite, leaving Pax-3 expression only in the dermomyotome. Subsequently, differential modulation of Pax-3 expression levels delineates the medial and lateral halves of the dermomyotome, which contain precursors of axial (back) muscle and limb muscle, respectively. Pax-3 expression is then repressed as dermomyotome-derived cells activate MDFs. Quail-chick chimera and ablation experiments confirmed that the migratory precursors of limb muscle continue to express Pax-3 during migration. Since limb muscle precursors do not activate MDFs until 2 days after they leave the somite, Pax-3 represents the first molecular marker for this migratory cell population. A null mutation of the mouse Pax-3 gene, Splotch, produces major disruptions in early limb muscle development (Franz, T., Kothary, R., Surani, M. A. H., Halata, Z. and Grim, M. (1993) Anat. Embryol. 187, 153-160; Goulding, M., Lumsden, A. and Paquette, A. (1994) Development 120, 957-971). We conclude, therefore, that Pax-3 gene expression in the paraxial mesoderm marks earlier stages in myogenic specification than MDFs and plays a crucial role in the specification and/or migration of limb myogenic precursors.

Intra-session repeatability of lower limb muscles activation pattern during pedaling.

PubMed

Dorel, Sylvain; Couturier, Antoine; Hug, François

2008-10-01

Assessment of intra-session repeatability of muscle activation pattern is of considerable relevance for research settings, especially when used to determine changes over time. However, the repeatability of lower limb muscles activation pattern during pedaling is not fully established. Thus, we tested the intra-session repeatability of the activation pattern of 10 lower limb muscles during a sub-maximal cycling exercise. Eleven triathletes participated to this study. The experimental session consisted in a reference sub-maximal cycling exercise (i.e. 150 W) performed before and after a 53-min simulated training session (mean power output=200+/-12 W). Repeatability of EMG patterns was assessed in terms of muscle activity level (i.e. RMS of the mean pedaling cycle and burst) and muscle activation timing (i.e. onset and offset of the EMG burst) for the 10 following lower limb muscles: gluteus maximus (GMax), semimembranosus (SM), Biceps femoris (BF), vastus medialis (VM), rectus femoris (RF), vastus lateralis (VL), gastrocnemius medianus (GM) and lateralis (GL), soleus (SOL) and tibialis anterior (TA). No significant differences concerning the muscle activation level were found between test and retest for all the muscles investigated. Only VM, SOL and TA showed significant differences in muscle activation timing parameters. Whereas ICC and SEM values confirmed this weak repeatability, cross-correlation coefficients suggest a good repeatability of the activation timing parameters for all the studied muscles. Overall, the main finding of this work is the good repeatability of the EMG pattern during pedaling both in term of muscle activity level and muscle activation timing.

Event-Related Beta EEG Changes During Active, Passive Movement and Functional Electrical Stimulation of the Lower Limb.

PubMed

Qiu, Shuang; Yi, Weibo; Xu, Jiapeng; Qi, Hongzhi; Du, Jingang; Wang, Chunfang; He, Feng; Ming, Dong

2016-02-01

A number of electroencephalographic (EEG) studies have reported on event-related desynchronization/synchronization (ERD/ERS) during active movements, passive movements, and the movements induced by functional electrical stimulation (FES). However, the quantitative differences in ERD values and affected frequency bands associated with the lower limb have not been discussed. The goal of this paper was to quantitatively compare the ERD patterns during active movement, passive movement and FES-induced movement of the lower limb. 64-channel EEG signals were recorded to investigate the brain oscillatory patterns during active movement, passive movement and FES-induced movement of the lower limb in twelve healthy subjects. And passive movement and FES-induced movement were also performed in a hemiplegic stroke patient. For healthy subjects, FES-induced movement presented significantly higher characteristic frequency of central beta ERD while there was no significant difference in ERD values compared with active or passive movement. Meanwhile, beta ERD values of FES-induced movement were significantly correlated with those of active movement, and spatial distribution of beta ERD pattern for FES-induced movement was more correlated with that for active movement. In addition, the stroke patient presented central ERD patterns during FES-induced movement, while no ERD with similar frequencies could be found during passive movement. This work implies that the EEG oscillatory pattern under FES-induced movement tends more towards active movement instead of passive movement. The quantification of ERD patterns could be expected as a potential technique to evaluate the brain response during FES-induced movement.

Sonic hedgehog controls growth of external genitalia by regulating cell cycle kinetics

PubMed Central

Seifert, Ashley W.; Zheng, Zhengui; Ormerod, Brandi K.; Cohn, Martin J.

2010-01-01

During embryonic development, cells are instructed which position to occupy, they interpret these cues as differentiation programmes, and expand these patterns by growth. Sonic hedgehog (Shh) specifies positional identity in many organs; however, its role in growth is not well understood. In this study, we show that inactivation of Shh in external genitalia extends the cell cycle from 8.5 to 14.4 h, and genital growth is reduced by ∼75%. Transient Shh signalling establishes pattern in the genital tubercle; however, transcriptional levels of G1 cell cycle regulators are reduced. Consequently, G1 length is extended, leading to fewer progenitor cells entering S-phase. Cell cycle genes responded similarly to Shh inactivation in genitalia and limbs, suggesting that Shh may regulate growth by similar mechanisms in different organ systems. The finding that Shh regulates cell number by controlling the length of specific cell cycle phases identifies a novel mechanism by which Shh elaborates pattern during appendage development. PMID:20975695

Electromyographic Analysis of the Lower Limb Muscles in Low- and High-Handicap Golfers

ERIC Educational Resources Information Center

Marta, Sérgio; Silva, Luís; Vaz, João R.; Castro, Maria António; Reinaldo, Gustavo; Pezarat-Correia, Pedro

2016-01-01

Purpose: The aim of this study was to compare the electromyographic patterns of the lower limb muscles during a golf swing performed by low- and high-handicap golfers. Method: Ten golfers (5 low- and 5 high-handicap) performed 8 swings using a 7-iron. Surface electromyography (EMG) was recorded for the following lower limb muscles on both sides:…

V1 and V2b interneurons secure the alternating flexor-extensor motor activity mice require for limbed locomotion

PubMed Central

Zhang, Jingming; Lanuza, Guillermo M.; Britz, Olivier; Wang, Zhi; Siembab, Valerie C.; Zhang, Ying; Velasquez, Tomoko; Alvarez, Francisco J.; Frank, Eric; Goulding, Martyn

2014-01-01

SUMMARY The reciprocal activation of flexor and extensor muscles constitutes the fundamental mechanism that tetrapod vertebrates use for locomotion and limb-driven reflex behaviors. This aspect of motor coordination is controlled by inhibitory neurons in the spinal cord; however, the identity of the spinal interneurons that serve this function is not known. Here we show that the production of an alternating flexor-extensor motor rhythm depends on the composite activities of two classes of ventrally-located inhibitory neurons, V1 and V2b interneurons (INs). Abrogating V1 and V2b IN-derived neurotransmission in the isolated spinal cord results in a synchronous pattern of L2 flexor-related and L5 extensor-related locomotor activity. Mice lacking V1 and V2b inhibition are unable to articulate their limb joints and display marked deficits in limb-driven reflex movements. Taken together, these findings identify V1- and V2b-derived neurons as the core interneuronal components of the limb central pattern generator (CPG) that coordinate flexor-extensor motor activity. PMID:24698273

Anchoring in a novel bimanual coordination pattern.

PubMed

Maslovat, Dana; Lam, Melanie Y; Brunke, Kirstin M; Chua, Romeo; Franks, Ian M

2009-02-01

Anchoring in cyclical movements has been defined as regions of reduced spatial or temporal variability [Beek, P. J. (1989). Juggling dynamics. PhD thesis. Amsterdam: Free University Press] that are typically found at movement reversal points. For in-phase and anti-phase movements, synchronizing reversal points with a metronome pulse has resulted in decreased anchor point variability and increased pattern stability [Byblow, W. D., Carson, R. G., & Goodman, D. (1994). Expressions of asymmetries and anchoring in bimanual coordination. Human Movement Science, 13, 3-28; Fink, P. W., Foo, P., Jirsa, V. K., & Kelso, J. A. S. (2000). Local and global stabilization of coordination by sensory information. Experimental Brain Research, 134, 9-20]. The present experiment examined anchoring during acquisition, retention, and transfer of a 90 degrees phase-offset continuous bimanual coordination pattern (whereby the right limb lags the left limb by one quarter cycle), involving horizontal flexion about the elbow. Three metronome synchronization strategies were imposed: participants either synchronized maximal flexion of the right arm (i.e., single metronome), both flexion and extension of the right arm (i.e., double metronome within-limb), or flexion of each arm (i.e., double metronome between-limb) to an auditory metronome. In contrast to simpler in-phase and anti-phase movements, synchronization of additional reversal points to the metronome did not reduce reversal point variability or increase pattern stability. Furthermore, practicing under different metronome synchronization strategies did not appear to have a significant effect on the rate of acquisition of the pattern.

Lower limb injuries caused by improvised explosive devices: proposed 'Bastion classification' and prospective validation.

PubMed

Jacobs, N; Rourke, K; Rutherford, J; Hicks, A; Smith, S R C; Templeton, P; Adams, S A; Jansen, J O

2014-09-01

Complex lower limb injury caused by improvised explosive devices (IEDs) has become the signature wounding pattern of the conflict in Afghanistan. Current classifications neither describe this injury pattern well, nor correlate with management. There is need for a new classification, to aid communication between clinicians, and help evaluate interventions and outcomes. We propose such a classification, and present the results of an initial prospective evaluation. The classification was developed by a panel of military surgeons whilst deployed to Camp Bastion, Afghanistan. Injuries were divided into five classes, by anatomic level. Segmental injuries were recognised as a distinct entity. Associated injuries to the intraperitoneal abdomen, genitalia and perineum, pelvic ring, and upper limbs, which impact on clinical management and resources, were also accounted for. Between 1 November 2010 and 20 February 2011, 179 IED-related lower limb injuries in 103 consecutive casualties were classified, and their subsequent vascular and musculoskeletal treatment recorded. 69% of the injuries were traumatic amputations, and the remainder segmental injuries. 49% of casualties suffered bilateral lower limb amputation. The most common injury was class 3 (involving proximal lower leg or thigh, permitting effective above-knee tourniquet application, 49%), but more proximal patterns (class 4 or 5, preventing effective tourniquet application) accounted for 18% of injuries. Eleven casualties had associated intraperitoneal abdominal injuries, 41 suffered genital or perineal injuries, 9 had pelvic ring fractures, and 66 had upper limb injuries. The classification was easy to apply and correlated with management. The 'Bastion classification' is a pragmatic yet clinically relevant injury categorisation, which describes current injury patterns well, and should facilitate communication between clinicians, and the evaluation of interventions and outcomes. The validation cohort confirms that the injury burden from IEDs in the Helmand Province of Afghanistan remains high, with most casualties sustaining amputation through or above the knee. The rates of associated injury to the abdomen, perineum, pelvis and upper limbs are high. These findings have important implications for the training of military surgeons, staffing and resourcing of medical treatment facilities, to ensure an adequate skill mix to manage these complex and challenging injuries. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Origins location of the outflow tract ventricular arrhythmias exhibiting qrS pattern or QS pattern with a notch on the descending limb in lead V1.

PubMed

Lin, Cong; Zheng, Cheng; Zhou, De-Pu; Li, Xiao-Wei; Wu, Shu-Jie; Lin, Jia-Feng

2017-05-15

Ventricular outflow tract(VOT) ventricular arrhythmias(VAs) presenting qrS pattern or QS pattern with a notch on the descending limb in lead V1 were consistently thought of arising from the commissure between left and right coronary cusp (L-RCC) by previous studies. However, we found they could originate from other anatomic structures in VOT. This study aimed to investigate the exact origin of this kind VAs. Forty-nine patients of VOT premature ventricular contrations/ventricular tachycardia(PVCs/VT) with lead V1 presenting qrS pattern or QS pattern with a notch on the descending limb undergoing successful radiofrequency catheter ablation(RFCA) in our center were analyzed. 12-lead electrocardiogram(ECG) of these PVCs/VT were summarized. Among these PVCs/VT, 37 cases exhibited qrS morphology in lead V1, 12 cases presented QS pattern with a notch on the descending limb in the same lead. Based on the successful ablation sites, these PVCs/VT were divided into 2 groups: (1)Right ventricular outflow tract(RVOT) group (26 cases), and (2) Left ventricular outflow tract (LVOT) group(23 cases, 4 cases originating from the left coronary cusp(LCC), 2 from the right coronary cusp(RCC), 16 from the L-RCC, 1 from the area inferior to LCC(ILCC)). The ECG characteristics of each PVCs/VT were analyzed. Among these PVCs/VT, applying the precordial transitional zone index(TZ index) < 0 to predict LVOT origin was demonstrated with sensitivity of 95.65%, specificity of 96.15%, positive predicting value(PPV) of 95.65% and negative predicting value(NPV) of 96.15%. In LVOT group, further applying the r, R, m,or Rs morphology in lead I to predict L-RCC and RCC origin was demonstrated with sensitivity of 94.44%, specificity of 60.00%, PPV of 89.47% and NPV of 75.00%. Ventricular outflow tract PVCs/VT with lead V1 presenting qrS pattern or QS pattern with a notch on descending limb not only arising from L-RCC, but also RVOT, LCC, RCC and ILCC. Combining TZ index and QRS morphology in lead I to predict origin site of these kind VAs is a convenient, simple and reliable method and facilitates the RFCA procedure.

Limb Girdle Muscular Dystrophy Type 2E Due to a Novel Large Deletion in SGCB Gene.

PubMed

Ghafouri-Fard, Soudeh; Hashemi-Gorji, Feyzollah; Fardaei, Majid; Miryounesi, Mohammad

2017-01-01

Autosomal recessive limb-girdle muscular dystrophies (LGMD type 2) are a group of clinically and genetically heterogeneous diseases with the main characteristics of weakness and wasting of the pelvic and shoulder girdle muscles. Among them are sarcoglycanopathies caused by mutations in at least four genes named SGCA, SGCB, SGCG and SGCD. Here we report a consanguineous Iranian family with two children affected with LGMD type 2E. Mutation analysis revealed a novel homozygous exon 2 deletion of SGCB gene in the patients with the parents being heterozygous for this deletion. This result presents a novel underlying genetic mechanism for LGMD type 2E.

Clinical studies on teenage Brazilian victims of thalidomide.

PubMed

Schmidt, M; Salzano, F M

1983-07-01

Ninety-three Brazilian teenagers with thalidomide embryopathy were studied. The pattern of distribution of their most significant defect was: upper limbs, 66; lower limbs, 8; all four limbs, 12; head, 7. Only 10 individuals presented the major defect unilaterally. In 30 of 83 with bilateral defects there were differences in severity between the two sides. Of the 31 patients whose spines had been X-rayed, 16 showed defects, the most common being spina bifida occulta at S1. Gynecomasty was found in three of the patients having major upper limb defects.

The Evolution of Lineage-Specific Regulatory Activities in the Human Embryonic Limb

PubMed Central

Cotney, Justin; Leng, Jing; Yin, Jun; Reilly, Steven K.; DeMare, Laura E.; Emera, Deena; Ayoub, Albert E.; Rakic, Pasko; Noonan, James P.

2013-01-01

SUMMARY The evolution of human anatomical features likely involved changes in gene regulation during development. However, the nature and extent of human-specific developmental regulatory functions remain unknown. We obtained a genome-wide view of cis-regulatory evolution in human embryonic tissues by comparing the histone modification H3K27ac, which provides a quantitative readout of promoter and enhancer activity, during human, rhesus, and mouse limb development. Based on increased H3K27ac, we find that 13% of promoters and 11% of enhancers have gained activity on the human lineage since the human-rhesus divergence. These gains largely arose by modification of ancestral regulatory activities in the limb or potential co-option from other tissues and are likely to have heterogeneous genetic causes. Most enhancers that exhibit gain of activity in humans originated in mammals. Gains at promoters and enhancers in the human limb are associated with increased gene expression, suggesting they include molecular drivers of human morphological evolution. PMID:23827682

Comparative Anatomy of the Hind Limb Vessels of the Bearded Capuchins (Sapajus libidinosus) with Apes, Baboons, and Cebus capucinus: With Comments on the Vessels' Role in Bipedalism

PubMed Central

Aversi-Ferreira, Roqueline A. G. M. F.; de Abreu, Tainá; Pfrimer, Gabriel A.; Silva, Sylla F.; Ziermann, Janine M.; Carneiro-e-Silva, Frederico O.; Tomaz, Carlos; Tavares, Maria Clotilde H.; Maior, Rafael S.; Aversi-Ferreira, Tales A.

2013-01-01

Capuchin monkeys are known to exhibit sporadic bipedalism while performing specific tasks, such as cracking nuts. The bipedal posture and locomotion cause an increase in the metabolic cost and therefore increased blood supply to lower limbs is necessary. Here, we present a detailed anatomical description of the capuchin arteries and veins of the pelvic limb of Sapajus libidinosus in comparison with other primates. The arterial pattern of the bearded capuchin hind limb is more similar to other quadrupedal Cebus species. Similarities were also found to the pattern observed in the quadruped Papio, which is probably due to a comparable pelvis and the presence of the tail. Sapajus' traits show fewer similarities when compared to great apes and modern humans. Moreover, the bearded capuchin showed unique patterns for the femoral and the short saphenous veins. Although this species switches easily from quadrupedal to bipedal postures, our results indicate that the bearded capuchin has no specific or differential features that support extended bipedal posture and locomotion. Thus, the explanation for the behavioral differences found among capuchin genera probably includes other aspects of their physiology. PMID:24396829

Comparative anatomy of the hind limb vessels of the bearded capuchins (Sapajus libidinosus) with apes, baboons, and Cebus capucinus: with comments on the vessels' role in bipedalism.

PubMed

Aversi-Ferreira, Roqueline A G M F; de Abreu, Tainá; Pfrimer, Gabriel A; Silva, Sylla F; Ziermann, Janine M; Carneiro-E-Silva, Frederico O; Tomaz, Carlos; Tavares, Maria Clotilde H; Maior, Rafael S; Aversi-Ferreira, Tales A

2013-01-01

Capuchin monkeys are known to exhibit sporadic bipedalism while performing specific tasks, such as cracking nuts. The bipedal posture and locomotion cause an increase in the metabolic cost and therefore increased blood supply to lower limbs is necessary. Here, we present a detailed anatomical description of the capuchin arteries and veins of the pelvic limb of Sapajus libidinosus in comparison with other primates. The arterial pattern of the bearded capuchin hind limb is more similar to other quadrupedal Cebus species. Similarities were also found to the pattern observed in the quadruped Papio, which is probably due to a comparable pelvis and the presence of the tail. Sapajus' traits show fewer similarities when compared to great apes and modern humans. Moreover, the bearded capuchin showed unique patterns for the femoral and the short saphenous veins. Although this species switches easily from quadrupedal to bipedal postures, our results indicate that the bearded capuchin has no specific or differential features that support extended bipedal posture and locomotion. Thus, the explanation for the behavioral differences found among capuchin genera probably includes other aspects of their physiology.

Regulation of Axolotl (Ambystoma mexicanum) Limb Blastema Cell Proliferation by Nerves and BMP2 in Organotypic Slice Culture.

PubMed

Lehrberg, Jeffrey; Gardiner, David M

2015-01-01

We have modified and optimized the technique of organotypic slice culture in order to study the mechanisms regulating growth and pattern formation in regenerating axolotl limb blastemas. Blastema cells maintain many of the behaviors that are characteristic of blastemas in vivo when cultured as slices in vitro, including rates of proliferation that are comparable to what has been reported in vivo. Because the blastema slices can be cultured in basal medium without fetal bovine serum, it was possible to test the response of blastema cells to signaling molecules present in serum, as well as those produced by nerves. We also were able to investigate the response of blastema cells to experimentally regulated changes in BMP signaling. Blastema cells responded to all of these signals by increasing the rate of proliferation and the level of expression of the blastema marker gene, Prrx-1. The organotypic slice culture model provides the opportunity to identify and characterize the spatial and temporal co-regulation of pathways in order to induce and enhance a regenerative response.

Regulation of Axolotl (Ambystoma mexicanum) Limb Blastema Cell Proliferation by Nerves and BMP2 in Organotypic Slice Culture

PubMed Central

Lehrberg, Jeffrey; Gardiner, David M.

2015-01-01

We have modified and optimized the technique of organotypic slice culture in order to study the mechanisms regulating growth and pattern formation in regenerating axolotl limb blastemas. Blastema cells maintain many of the behaviors that are characteristic of blastemas in vivo when cultured as slices in vitro, including rates of proliferation that are comparable to what has been reported in vivo. Because the blastema slices can be cultured in basal medium without fetal bovine serum, it was possible to test the response of blastema cells to signaling molecules present in serum, as well as those produced by nerves. We also were able to investigate the response of blastema cells to experimentally regulated changes in BMP signaling. Blastema cells responded to all of these signals by increasing the rate of proliferation and the level of expression of the blastema marker gene, Prrx-1. The organotypic slice culture model provides the opportunity to identify and characterize the spatial and temporal co-regulation of pathways in order to induce and enhance a regenerative response. PMID:25923915

Modulation of phase durations, phase variations, and temporal coordination of the four limbs during quadrupedal split-belt locomotion in intact adult cats

PubMed Central

D'Angelo, Giuseppe; Thibaudier, Yann; Telonio, Alessandro; Hurteau, Marie-France; Kuczynski, Victoria; Dambreville, Charline

2014-01-01

Stepping along curvilinear paths produces speed differences between the inner and outer limb(s). This can be reproduced experimentally by independently controlling left and right speeds with split-belt locomotion. Here we provide additional details on the pattern of the four limbs during quadrupedal split-belt locomotion in intact cats. Six cats performed tied-belt locomotion (same speed bilaterally) and split-belt locomotion where one side (constant side) stepped at constant treadmill speed while the other side (varying side) stepped at several speeds. Cycle, stance, and swing durations changed in parallel in homolateral limbs with shorter and longer stance and swing durations on the fast side, respectively, compared with the slow side. Phase variations were quantified in all four limbs by measuring the slopes of the regressions between stance and cycle durations (rSTA) and between swing and cycle durations (rSW). For a given limb, rSTA and rSW were not significantly different from one another on the constant side whereas on the varying side rSTA increased relative to tied-belt locomotion while rSW became more negative. Phase variations were similar for homolateral limbs. Increasing left-right speed differences produced a large increase in homolateral double support on the slow side, while triple-support periods decreased. Increasing left-right speed differences altered homologous coupling, homolateral coupling on the fast side, and coupling between the fast hindlimb and slow forelimb. Results indicate that homolateral limbs share similar control strategies, only certain features of the interlimb pattern adjust, and spinal locomotor networks of the left and right sides are organized symmetrically. PMID:25031257

Design and test of a Microsoft Kinect-based system for delivering adaptive visual feedback to stroke patients during training of upper limb movement.

PubMed

Simonsen, Daniel; Popovic, Mirjana B; Spaich, Erika G; Andersen, Ole Kæseler

2017-11-01

The present paper describes the design and test of a low-cost Microsoft Kinect-based system for delivering adaptive visual feedback to stroke patients during the execution of an upper limb exercise. Eleven sub-acute stroke patients with varying degrees of upper limb function were recruited. Each subject participated in a control session (repeated twice) and a feedback session (repeated twice). In each session, the subjects were presented with a rectangular pattern displayed on a vertical mounted monitor embedded in the table in front of the patient. The subjects were asked to move a marker inside the rectangular pattern by using their most affected hand. During the feedback session, the thickness of the rectangular pattern was changed according to the performance of the subject, and the color of the marker changed according to its position, thereby guiding the subject's movements. In the control session, the thickness of the rectangular pattern and the color of the marker did not change. The results showed that the movement similarity and smoothness was higher in the feedback session than in the control session while the duration of the movement was longer. The present study showed that adaptive visual feedback delivered by use of the Kinect sensor can increase the similarity and smoothness of upper limb movement in stroke patients.

Quantifying frontal plane knee motion during single limb squats: reliability and validity of 2-dimensional measures.

PubMed

Gwynne, Craig R; Curran, Sarah A

2014-12-01

Clinical assessment of lower limb kinematics during dynamic tasks may identify individuals who demonstrate abnormal movement patterns that may lead to etiology of exacerbation of knee conditions such as patellofemoral joint (PFJt) pain. The purpose of this study was to determine the reliability, validity and associated measurement error of a clinically appropriate two-dimensional (2-D) procedure of quantifying frontal plane knee alignment during single limb squats. Nine female and nine male recreationally active subjects with no history of PFJt pain had frontal plane limb alignment assessed using three-dimensional (3-D) motion analysis and digital video cameras (2-D analysis) while performing single limb squats. The association between 2-D and 3-D measures was quantified using Pearson's product correlation coefficients. Intraclass correlation coefficients (ICCs) were determined for within- and between-session reliability of 2-D data and standard error of measurement (SEM) was used to establish measurement error. Frontal plane limb alignment assessed with 2-D analysis demonstrated good correlation compared with 3-D methods (r = 0.64 to 0.78, p < 0.001). Within-session (0.86) and between-session ICCs (0.74) demonstrated good reliability for 2-D measures and SEM scores ranged from 2° to 4°. 2-D measures have good consistency and may provide a valid measure of lower limb alignment when compared to existing 3-D methods. Assessment of lower limb kinematics using 2-D methods may be an accurate and clinically useful alternative to 3-D motion analysis when identifying individuals who demonstrate abnormal movement patterns associated with PFJt pain. 2b.

Where one hand meets the other: limb-specific and action-dependent movement plans decoded from preparatory signals in single human frontoparietal brain areas.

PubMed

Gallivan, Jason P; McLean, D Adam; Flanagan, J Randall; Culham, Jody C

2013-01-30

Planning object-directed hand actions requires successful integration of the movement goal with the acting limb. Exactly where and how this sensorimotor integration occurs in the brain has been studied extensively with neurophysiological recordings in nonhuman primates, yet to date, because of limitations of non-invasive methodologies, the ability to examine the same types of planning-related signals in humans has been challenging. Here we show, using a multivoxel pattern analysis of functional MRI (fMRI) data, that the preparatory activity patterns in several frontoparietal brain regions can be used to predict both the limb used and hand action performed in an upcoming movement. Participants performed an event-related delayed movement task whereby they planned and executed grasp or reach actions with either their left or right hand toward a single target object. We found that, although the majority of frontoparietal areas represented hand actions (grasping vs reaching) for the contralateral limb, several areas additionally coded hand actions for the ipsilateral limb. Notable among these were subregions within the posterior parietal cortex (PPC), dorsal premotor cortex (PMd), ventral premotor cortex, dorsolateral prefrontal cortex, presupplementary motor area, and motor cortex, a region more traditionally implicated in contralateral movement generation. Additional analyses suggest that hand actions are represented independently of the intended limb in PPC and PMd. In addition to providing a unique mapping of limb-specific and action-dependent intention-related signals across the human cortical motor system, these findings uncover a much stronger representation of the ipsilateral limb than expected from previous fMRI findings.

Planar covariance of upper and lower limb elevation angles during hand-foot crawling in healthy young adults.

PubMed

MacLellan, M J; Catavitello, G; Ivanenko, Y P; Lacquaniti, F

2017-11-01

Habitual quadrupeds have been shown to display a planar covariance of segment elevation angle waveforms in the fore and hind limbs during many forms of locomotion. The purpose of the current study was to determine if humans generate similar patterns in the upper and lower limbs during hand-foot crawling. Nine healthy young adults performed hand-foot crawling on a treadmill at speeds of 1, 2, and 3 km/h. A principal component analysis (PCA) was applied to the segment elevation angle waveforms for the upper (upper arm, lower arm, and hand) and lower (thigh, shank, and foot) limbs separately. The planarity of the elevation angle waveforms was determined using the sum of the variance explained by the first two PCs and the orientation of the covariance plane was quantified using the direction cosines of the eigenvector orthogonal to the plane, projected upon each of the segmental semi-axes. Results showed that planarity of segment elevation angles was maintained in the upper and lower limbs (explained variance >97%), although a slight decrease was present in the upper limb when crawling at 3 km/h. The orientation of the covariance plane was highly limb-specific, consistent with animal studies and possibly related to the functional neural control differences between the upper and lower limbs. These results may suggest that the motor patterns stored in the central nervous system for quadrupedal locomotion may be retained through evolution and may still be exploited when humans perform such tasks.

Limb-state information encoded by peripheral and central somatosensory neurons: Implications for an afferent interface

PubMed Central

Weber, Douglas J.; London, Brian M.; Hokanson, James A.; Ayers, Christopher A.; Gaunt, Robert A.; Torres, Ricardo R.; Zaaimi, Boubker; Miller, Lee E.

2013-01-01

A major issue to be addressed in the development of neural interfaces for prosthetic control is the need for somatosensory feedback. Here, we investigate two possible strategies: electrical stimulation of either dorsal root ganglia (DRG) or primary somatosensory cortex (S1). In each approach, we must determine a model that reflects the representation of limb state in terms of neural discharge. This model can then be used to design stimuli that artificially activate the nervous system to convey information about limb state to the subject. Electrically activating DRG neurons using naturalistic stimulus patterns, modeled on recordings made during passive limb movement, evoked activity in S1 that was similar to that of the original movement. We also found that S1 neural populations could accurately discriminate different patterns of DRG stimulation across a wide range of stimulus pulse-rates. In studying the neural coding of limb-state in S1, we also decoded the kinematics of active limb movement using multi-electrode recordings in the monkey. Neurons having both proprioceptive and cutaneous receptive fields contributed equally to this decoding. Some neurons were most informative of limb state in the recent past, but many others appeared to signal upcoming movements suggesting that they also were modulated by an efference copy signal. Finally, we show that a monkey was able to detect stimulation through a large percentage of electrodes implanted in area 2. We discuss the design of appropriate stimulus paradigms for conveying time-varying limb state information, and the relative merits and limitations of central and peripheral approaches. PMID:21878419

Feasibility and safety of early lower limb robot-assisted training in sub-acute stroke patients: a pilot study.

PubMed

Gandolfi, Marialuisa; Geroin, Christian; Tomelleri, Christopher; Maddalena, Isacco; Kirilova Dimitrova, Eleonora; Picelli, Alessandro; Smania, Nicola; Waldner, Andreas

2017-12-01

So far, the development of robotic devices for the early lower limb mobilization in the sub-acute phase after stroke has received limited attention. To explore the feasibility of a newly robotic-stationary gait training in sub-acute stroke patients. To report the training effects on lower limb function and muscle activation. A pilot study. Rehabilitation ward. Two sub-acute stroke inpatients and ten age-matched healthy controls were enrolled. Healthy controls served as normative data. Patients underwent 10 robot-assisted training sessions (20 minutes, 5 days/week) in alternating stepping movements (500 repetitions/session) on a hospital bed in addition to conventional rehabilitation. Feasibility outcome measures were compliance, physiotherapist time, and responses to self-report questionnaires. Efficacy outcomes were bilateral lower limb muscle activation pattern as measured by surface electromyography (sEMG), Motricity Index (MI), Medical Research Council (MRC) grade, and Ashworth Scale (AS) scores before and after training. No adverse events occurred. No significant differences in sEMG activity between patients and healthy controls were observed. Post-training improvement in MI and MRC scores, but no significant changes in AS scores, were recorded. Post-treatment sEMG analysis of muscle activation patterns showed a significant delay in rectus femoris offset (P=0.02) and prolonged duration of biceps femoris (P=0.04) compared to pretreatment. The robot-assisted training with our device was feasible and safe. It induced physiological muscle activations pattern in both stroke patients and healthy controls. Full-scale studies are needed to explore its potential role in post-stroke recovery. This robotic device may enrich early rehabilitation in subacute stroke patients by inducing physiological muscle activation patterns. Future studies are warranted to evaluate its effects on promoting restorative mechanisms involved in lower limb recovery after stroke.

Functional analysis of limb enhancers in the developing fin

PubMed Central

Booker, Betty M.; Murphy, Karl K.

2013-01-01

Despite diverging ~365 million years ago, tetrapod limbs and pectoral fins express similar genes that could be regulated by shared regulatory elements. In this study, we set out to analyze the ability of enhancers to maintain tissue specificity in these two divergent structures. We tested 22 human sequences that were previously reported as mouse limb enhancers for their enhancer activity in zebrafish (Danio rerio). Using a zebrafish enhancer assay, we found that 10/22 (45 %) were positive for pectoral fin activity. Analysis of the various criteria that correlated with positive fin activity found that both spatial limb activity and evolutionary conservation are not good predictors of fin enhancer activity. These results suggest that zebrafish enhancer assays may be limited in detecting human limb enhancers, and this limitation does not improve by the use of limb spatial expression or evolutionary conservation. PMID:24068387

Morphogenesis and evolution of vertebrate appendicular muscle

PubMed Central

HAINES, LYNN; CURRIE, PETER D.

2001-01-01

Two different modes are utilised by vertebrate species to generate the appendicular muscle present within fins and limbs. Primitive Chondricthyan or cartilaginous fishes use a primitive mode of muscle formation to generate the muscle of the fins. Direct epithelial myotomal extensions invade the fin and generate the fin muscles while remaining in contact with the myotome. Embryos of amniotes such as chick and mouse use a similar mechanism to that deployed in the bony teleost species, zebrafish. Migratory mesenchymal myoblasts delaminate from fin/limb level somites, migrate to the fin/limb field and differentiate entirely within the context of the fin/limb bud. Migratory fin and limb myoblasts express identical genes suggesting that they possess both morphogenetic and molecular identity. We conclude that the mechanisms controlling tetrapod limb muscle formation arose prior to the Sarcopterygian or tetrapod radiation. PMID:11523824

An assessment of postcranial indices, ratios, and body mass versus eco-geographical variables of prehistoric Jomon, Yayoi agriculturalists, and Kumejima Islanders of Japan.

PubMed

Seguchi, Noriko; Quintyn, Conrad B; Yonemoto, Shiori; Takamuku, Hirofumi

2017-09-10

We explore variations in body and limb proportions of the Jomon hunter-gatherers (14,000-2500 BP), the Yayoi agriculturalists (2500-1700 BP) of Japan, and the Kumejima Islanders of the Ryukyus (1600-1800 AD) with 11 geographically diverse skeletal postcranial samples from Africa, Europe, Asia, Australia, and North America using brachial-crural indices, femur head-breadth-to-femur length ratio, femur head-breadth-to-lower-limb-length ratio, and body mass as indicators of phenotypic climatic adaptation. Specifically, we test the hypothesis that variation in limb proportions seen in Jomon, Yayoi, and Kumejima is a complex interaction of genetic adaptation; development and allometric constraints; selection, gene flow and genetic drift with changing cultural factors (i.e., nutrition) and climate. The skeletal data (1127 individuals) were subjected to principle components analysis, Manly's permutation multiple regression tests, and Relethford-Blangero analysis. The results of Manly's tests indicate that body proportions and body mass are significantly correlated with latitude, and minimum and maximum temperatures while limb proportions were not significantly correlated with these climatic variables. Principal components plots separated "climatic zones:" tropical, temperate, and arctic populations. The indigenous Jomon showed cold-adapted body proportions and warm-adapted limb proportions. Kumejima showed cold-adapted body proportions and limbs. The Yayoi adhered to the Allen-Bergmann expectation of cold-adapted body and limb proportions. Relethford-Blangero analysis showed that Kumejima experienced gene flow indicated by high observed variances while Jomon experienced genetic drift indicated by low observed variances. The complex interaction of evolutionary forces and development/nutritional constraints are implicated in the mismatch of limb and body proportions. © 2017 Wiley Periodicals, Inc.

Strength Asymmetry and Landing Mechanics at Return to Sport after ACL Reconstruction

PubMed Central

Schmitt, Laura C.; Paterno, Mark V.; Ford, Kevin R.; Myer, Gregory D.; Hewett, Timothy E.

2014-01-01

Purpose Evidence-based quadriceps femoris muscle (QF) strength guidelines for return to sport following anterior cruciate ligament (ACL) reconstruction are lacking. This study investigated the impact of QF strength asymmetry on knee landing biomechanics at the time of return to sport following ACL reconstruction. Methods Seventy-seven individuals (17.4 years) at the time of return to sport following primary ACL reconstruction (ACLR group) and 47 uninjured control individuals (17.0 years) (CTRL group) participated. QF strength was assessed and Quadriceps Index calculated (QI = [involved strength/uninvolved strength]*100%). The ACLR group was sub-divided based on QI: High Quadriceps (HQ, QI≥90%) and Low-Quadriceps (LQ, QI<85%). Knee kinematic and kinetic variables were collected during a drop vertical jump maneuver. Limb symmetry during landing, and discrete variables were compared among the groups with multivariate analysis of variance and linear regression analyses. Results The LQ group demonstrated worse asymmetry in all kinetic and ground reaction force variables compared to the HQ and CTRL groups, including reduced involved limb peak knee external flexion moments (p<.001), reduced involved limb (p=.003) and increased uninvolved limb (p=.005) peak vertical ground reaction forces, and higher uninvolved limb peak loading rates (p<.004). There were no differences in the landing patterns between the HQ and CTRL groups on any variable (p>.05). In the ACLR group, QF strength estimated limb symmetry during landing after controlling for graft type, meniscus injury, knee pain and symptoms. Conclusion At the time of return to sport, individuals post-ACL reconstruction with weaker QF demonstrate altered landing patterns. Conversely, those with nearly symmetrical QF strength demonstrate landing patterns similar to uninjured individuals. Consideration of an objective QF strength measure may aid clinical decision-making to optimize sports participation following ACL reconstruction. PMID:25373481

The effects of an adopted narrow gait on the external adduction moment at the knee joint during level walking: evidence of asymmetry.

PubMed

Street, Brian D; Gage, William

2013-04-01

The external knee adduction moment is an accurate estimation of the load distribution of the knee and is a valid predictor for the presence, severity and progression rate of medial compartment knee osteoarthritis. Gait modification strategies have been shown to be an effective means of reducing the external adduction moment. The purpose of this study was to test narrow gait as a mechanism to reduce the external adduction moment and investigate if limb dominance affects this pattern. Fifteen healthy male participants (mean age: 23.8 (SD=3.1) years, mean height: 1.8 (SD=0.1) m, and mean body mass: 82.9 (SD=16.1 kg) took part in this study. Five walking trials were performed for each of the three different gait conditions: normal gait, toe-out gait, and narrow gait. Adoption of the narrow gait strategy significantly reduced the early stance phase external knee adduction moment compared to normal and toe-out gait (p<.002). However, it was observed that this reduction only occurred in the non-dominant limb. Gait modification can reduce the external knee adduction moment. However, asymmetrical patterns between the dominant and non-dominant limbs, specifically during gait modification, may attenuate the effectiveness of this intervention. The mechanism of limb dominance and the specific roles of each limb during gait may account for an asymmetrical pattern in the moment arm and center of mass displacement during stance. This new insight into how limb-dominance effects gait modification strategies will be useful in the clinical setting when identifying appropriate patients, when indicating a gait modification strategy and in future research methodology. Copyright © 2013 Elsevier B.V. All rights reserved.

Characterization of in vitro transcriptional responses of dorsal root ganglia cultured in the presence and absence of blastema cells from regenerating salamander limbs

PubMed Central

Athippozhy, Antony; Lehrberg, Jeffrey; Monaghan, James R.; Gardiner, David M.

2014-01-01

Abstract During salamander limb regeneration, nerves provide signals that induce the formation of a mass of proliferative cells called the blastema. To better understand these signals, we developed a blastema−dorsal root ganglia (DRG) co‐culture model system to test the hypothesis that nerves differentially express genes in response to cues provided by the blastema. DRG with proximal and distal nerve trunks were isolated from axolotls (Ambystoma mexicanum), cultured for 5 days, and subjected to microarray analysis. Relative to freshly isolated DRG, 1541 Affymetrix probe sets were identified as differentially expressed and many of the predicted genes are known to function in injury and neurodevelopmental responses observed for mammalian DRG. We then cultured 5‐day DRG explants for an additional 5 days with or without co‐cultured blastema cells. On day 10, we identified 27 genes whose expression in cultured DRG was significantly affected by the presence or absence of blastema cells. Overall, our study established a DRG−blastema in vitro culture system and identified candidate genes for future investigations of axon regrowth, nerve−blastema signaling, and neural regulation of limb regeneration. PMID:25750744

Hunter-gatherer postcranial robusticity relative to patterns of mobility, climatic adaptation, and selection for tissue economy.

PubMed

Stock, J T

2006-10-01

Human skeletal robusticity is influenced by a number of factors, including habitual behavior, climate, and physique. Conflicting evidence as to the relative importance of these factors complicates our ability to interpret variation in robusticity in the past. It remains unclear how the pattern of robusticity in the skeleton relates to adaptive constraints on skeletal morphology. This study investigates variation in robusticity in claviculae, humeri, ulnae, femora, and tibiae among human foragers, relative to climate and habitual behavior. Cross-sectional geometric properties of the diaphyses are compared among hunter-gatherers from southern Africa (n = 83), the Andaman Islands (n = 32), Tierra del Fuego (n = 34), and the Great Lakes region (n = 15). The robusticity of both proximal and distal limb segments correlates negatively with climate and positively with patterns of terrestrial and marine mobility among these groups. However, the relative correspondence between robusticity and these factors varies throughout the body. In the lower limb, partial correlations between polar second moment of area (J(0.73)) and climate decrease from proximal to distal section locations, while this relationship increases from proximal to distal in the upper limb. Patterns of correlation between robusticity and mobility, either terrestrial or marine, generally increase from proximal to distal in the lower and upper limbs, respectively. This suggests that there may be a stronger relationship between observed patterns of diaphyseal hypertrophy and behavioral differences between populations in distal elements. Despite this trend, strength circularity indices at the femoral midshaft show the strongest correspondence with terrestrial mobility, particularly among males.

Neural mechanisms of single corrective steps evoked in the standing rabbit

PubMed Central

Hsu, L.-J.; Zelenin, P. V.; Lyalka, V. F.; Vemula, M. G.; Orlovsky, G. N.; Deliagina, T. G.

2017-01-01

Single steps in different directions are often used for postural corrections. However, our knowledge about the neural mechanisms underlying their generation is scarce. This study was aimed to characterize the corrective steps generated in response to disturbances of the basic body configuration caused by forward, backward or outward displacement of the hindlimb, as well as to reveal location in the CNS of the corrective step generating mechanisms. Video recording of the motor response to translation of the supporting surface under the hindlimb along with contact forces and activity of back and limb muscles was performed in freely standing intact and in fixed postmammillary rabbits. In intact rabbits, displacement of the hindlimb in any direction caused a lateral trunk movement towards the contralateral hindlimb, and then a corrective step in the direction opposite to the initial displacement. The time difference between onsets of these two events varied considerably. The EMG pattern in the supporting hindlimb was similar for all directions of corrective steps. It caused the increase in the limb stiffness. EMG pattern in the stepping limb differed in steps with different directions. In postmammillary rabbits the corrective stepping movements, as well as EMG patterns in both stepping and standing hindlimbs were similar to those observed in intact rabbits. This study demonstrates that the corrective trunk and limb movements are generated by separate mechanisms activated by sensory signals from the deviated limb. The neuronal networks generating postural corrective steps reside in the brainstem, cerebellum, and spinal cord. PMID:28215990

Ectopic expression of Msx-2 in posterior limb bud mesoderm impairs limb morphogenesis while inducing BMP-4 expression, inhibiting cell proliferation, and promoting apoptosis.

PubMed

Ferrari, D; Lichtler, A C; Pan, Z Z; Dealy, C N; Upholt, W B; Kosher, R A

1998-05-01

During early stages of chick limb development, the homeobox-containing gene Msx-2 is expressed in the mesoderm at the anterior margin of the limb bud and in a discrete group of mesodermal cells at the midproximal posterior margin. These domains of Msx-2 expression roughly demarcate the anterior and posterior boundaries of the progress zone, the highly proliferating posterior mesodermal cells underneath the apical ectodermal ridge (AER) that give rise to the skeletal elements of the limb and associated structures. Later in development as the AER loses its activity, Msx-2 expression expands into the distal mesoderm and subsequently into the interdigital mesenchyme which demarcates the developing digits. The domains of Msx-2 expression exhibit considerably less proliferation than the cells of the progress zone and also encompass several regions of programmed cell death including the anterior and posterior necrotic zones and interdigital mesenchyme. We have thus suggested that Msx-2 may be in a regulatory network that delimits the progress zone by suppressing the morphogenesis of the regions of the limb mesoderm in which it is highly expressed. In the present study we show that ectopic expression of Msx-2 via a retroviral expression vector in the posterior mesoderm of the progress zone from the time of initial formation of the limb bud severely impairs limb morphogenesis. Msx-2-infected limbs are typically very narrow along the anteroposterior axis, are occasionally truncated, and exhibit alterations in the pattern of formation of skeletal elements, indicating that as a consequence of ectopic Msx-2 expression the morphogenesis of large portions of the posterior mesoderm has been suppressed. We further show that Msx-2 impairs limb morphogenesis by reducing cell proliferation and promoting apoptosis in the regions of the posterior mesoderm in which it is ectopically expressed. The domains of ectopic Msx-2 expression in the posterior mesoderm also exhibit ectopic expression of BMP-4, a secreted signaling molecule that is coexpressed with Msx-2 during normal limb development in the anterior limb mesoderm, the posterior necrotic zone, and interdigital mesenchyme. This indicates that Msx-2 regulates BMP-4 expression and that the suppressive effects of Msx-2 on limb morphogenesis might be mediated in part by BMP-4. These studies indicate that during normal limb development Msx-2 is a key component of a regulatory network that delimits the boundaries of the progress zone by suppressing the morphogenesis of the regions of the limb mesoderm in which it is highly expressed, thus restricting the outgrowth and formation of skeletal elements and associated structures to the progress zone. We also report that rather large numbers of apoptotic cells as well as proliferating cells are present throughout the AER during all stages of normal limb development we have examined, indicating that many of the cells of the AER are continuously undergoing programmed cell death at the same time that new AER cells are being generated by cell proliferation. Thus, a balance between cell proliferation and programmed cell death may play a very important role in maintaining the activity of the AER. Copyright 1998 Academic Press.

Detection of new paternal dystrophin gene mutations in isolated cases of dystrophinopathy in females

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pegoraro, E.; Wessel, H.B.; Schwartz, L.

1994-06-01

Duchenne muscular dystrophy is one of the most common lethal monogenic disorders and is caused by dystrophin deficiency. The disease is transmitted as an X-linked recessive trait; however, recent biochemical and clinical studies have shown that many girls and women with a primary myopathy have an underlying dystrophinopathy, despite a negative family history for Duchenne dystrophy. These isolated female dystrophinopathy patients carried ambiguous diagnoses with presumed autosomal recessive inheritance (limb-girdle muscular dystrophy) prior to biochemical detection of dystrophin abnormalities in their muscle biopsy. It has been assumed that these female dystrophinopathy patients are heterozygous carries who show preferential inactivation ofmore » the X chromosome harboring the normal dystrophin gene, although this has been shown for only a few X:autosome translocations and for two cases of discordant monozygotic twin female carriers. Here the authors study X-inactivation patterns of 13 female dystrophinopathy patients - 10 isolated cases and 3 cases with a positive family history for Duchenne dystrophy in males. They show that all cases have skewed X-inactivation patterns in peripheral blood DNA. Of the nine isolated cases informative in the assay, eight showed inheritance of the dystrophin gene mutation from the paternal germ line. Only a single case showed maternal inheritance. The 10-fold higher incidence of paternal transmission of dystrophin gene mutations in these cases is at 30-fold variance with Bayesian predictions and gene mutation rates. Thus, the results suggest some mechanistic interaction between new dystrophin gene mutations, paternal inheritance, and skewed X inactivation. The results provide both empirical risk data and a molecular diagnostic test method, which permit genetic counseling and prenatal diagnosis of this new category of patients. 58 refs., 7 figs., 2 tabs.« less

Effects of ladder parameters on asymmetric patterns of force exertion during below-knee amputees climbing ladders.

PubMed

Li, Weidong; Li, Shiqi; Fu, Yan; Chen, Jacon

2017-03-01

Different from walking, ladder climbing requires four-limb coordination and more energy exertion for below-knee amputees (BKAs). We hypothesized that functional deficiency of a disabled limb shall be compensated by the other three intact limbs, showing an asymmetry pattern among limbs. Hand and foot forces of six below-knee amputees and six able-bodied people were collected. Hand, foot and hand/foot sum force variances between groups (non-BKA, intact side and prosthetic side) were carefully examined. Our hypothesis was validated that there is asymmetry between prosthetic and intact side. Results further showed that the ipsilateral hand of the prosthetic leg is stronger than the hand on the intact side, compensating weakness of the prosthetic leg. Effects of ladder rung separations and ladder slant on asymmetric force distribution of BKAs were evaluated, indicating that rung separation has a more significant interactive effect on hand/foot force of BKAs than ladder slant.

Imparting regenerative capacity to limbs by progenitor cell transplantation

PubMed Central

Lin, Gufa; Chen, Ying; Slack, Jonathan M.W.

2012-01-01

Summary The frog Xenopus can normally regenerate its limbs at early developmental stages but loses the ability during metamorphosis. This behavior provides a potential gain-of-function model for measures that can enhance limb regeneration. Here we show that frog limbs can be caused to form multidigit regenerates after receiving transplants of larval limb progenitor cells. It is necessary to activate Wnt/β -catenin signaling in the cells, and to add Sonic hedgehog, FGF10 and thymosin β4. These factors promote survival and growth of the grafted cells and also provide pattern information. The eventual regenerates are not composed solely of donor tissue; the host cells also make a substantial contribution despite their lack of regeneration-competence. Cells from adult frog legs or from regenerating tadpole tails do not promote limb regeneration, demonstrating the necessity for limb progenitor cells. These findings have obvious implications for the development of a technology to promote limb regeneration in mammals. PMID:23273877

Abnormal landing strategies after ACL reconstruction.

PubMed

Gokeler, A; Hof, A L; Arnold, M P; Dijkstra, P U; Postema, K; Otten, E

2010-02-01

The objective was to analyze muscle activity and movement patterns during landing of a single leg hop for distance after anterior cruciate ligament (ACL) reconstruction. Nine (six males, three females) ACL-reconstructed patients 6 months after surgery and 11 (eight males, three females) healthy control subjects performed the hop task. Electromyographic signals from lower limb muscles were analyzed to determine onset time before landing. Biomechanical data were collected using an Optotrak Motion Analysis System and force plate. Matlab was used to calculate kinetics and joint kinematics. Side-to-side differences in ACL-reconstructed patients and healthy subjects as well as differences between the patients and control group were analyzed. In ACL-reconstructed limbs, significantly earlier onset times were found for all muscles, except vastus medialis, compared with the uninvolved side. The involved limbs had significantly reduced knee flexion during the take-off and increased plantarflexion at initial contact. The knee extension moment was significantly lower in the involved limb. In the control group, significantly earlier onset times were found for the semitendinosus, vastus lateralis and medial gastrocnemius of the non-dominant side compared with the dominant side. Muscle onset times are earlier and movement patterns are altered in the involved limb 6 months after ACL reconstruction.

Electromyographic Analysis of the Lower Limb Muscles in Low- and High-Handicap Golfers.

PubMed

Marta, Sérgio; Silva, Luís; Vaz, João R; Castro, Maria António; Reinaldo, Gustavo; Pezarat-Correia, Pedro

2016-09-01

The aim of this study was to compare the electromyographic patterns of the lower limb muscles during a golf swing performed by low- and high-handicap golfers. Ten golfers (5 low- and 5 high-handicap) performed 8 swings using a 7-iron. Surface electromyography (EMG) was recorded for the following lower limb muscles on both sides: biceps femoris, semitendinosus, gluteus maximus, vastus medialis and lateralis, rectus femoris, tibialis anterior, peroneus longus, and gastrocnemius medialis and lateralis. The golf-swing phases were determined by 3-dimensional high-speed video analysis. Compared with the high-handicap golfers, the low-handicap golfers performed the forward swing with a shorter duration of the swing phases, with the exception of the late follow-through, where they exhibited longer duration. Considering the EMG patterns, the low-handicap golfers showed a tendency for the studied muscles to reach an activation peak earlier and presented statistically significant higher muscle activity in some of the lower limb muscles, mainly from the left side. Differences between low- and high-handicap golfers were found in the average duration of swing phases and in the activation level of the lower limbs, with more evidence on muscles from the left side.

Did saber-tooth kittens grow up musclebound? A study of postnatal limb bone allometry in felids from the Pleistocene of Rancho La Brea.

PubMed

Long, Katherine; Prothero, Donald; Madan, Meena; Syverson, Valerie J P

2017-01-01

Previous studies have demonstrated that the Pleistocene saber-toothed cat Smilodon fatalis had many forelimb adaptations for increased strength, presumably to grapple with and subdue prey. The Rancho La Brea tar pits yield large samples of juvenile limb bones forming a growth series that allow us to examine how Smilodon kittens grew up. Almost all available juvenile limb bones were measured, and reduced major axis fits were calculated to determine the allometric growth trends. Contrary to expectations based on their robust limbs, Smilodon kittens show the typical pattern of growth found in other large felids (such as the Ice Age lion, Panthera atrox, as well as living tigers, cougars, servals, and wildcats) where the limb grows longer and more slender faster than they grow thick. This adaptation is thought to give felids greater running speed. Smilodon kittens do not grow increasingly more robust with age. Instead, they start out robust and follow the ancestral felid growth pattern, while maintaining their robustness compared to other felids. Apparently, the growth of felid forelimbs is highly canalized and their ontogeny is tightly constrained.

V1 and v2b interneurons secure the alternating flexor-extensor motor activity mice require for limbed locomotion.

PubMed

Zhang, Jingming; Lanuza, Guillermo M; Britz, Olivier; Wang, Zhi; Siembab, Valerie C; Zhang, Ying; Velasquez, Tomoko; Alvarez, Francisco J; Frank, Eric; Goulding, Martyn

2014-04-02

Reciprocal activation of flexor and extensor muscles constitutes the fundamental mechanism that tetrapod vertebrates use for locomotion and limb-driven reflex behaviors. This aspect of motor coordination is controlled by inhibitory neurons in the spinal cord; however, the identity of the spinal interneurons that serve this function is not known. Here, we show that the production of an alternating flexor-extensor motor rhythm depends on the composite activities of two classes of ventrally located inhibitory neurons, V1 and V2b interneurons (INs). Abrogating V1 and V2b IN-derived neurotransmission in the isolated spinal cord results in a synchronous pattern of L2 flexor-related and L5 extensor-related locomotor activity. Mice lacking V1 and V2b inhibition are unable to articulate their limb joints and display marked deficits in limb-driven reflex movements. Taken together, these findings identify V1- and V2b-derived neurons as the core interneuronal components of the limb central pattern generator (CPG) that coordinate flexor-extensor motor activity. Copyright © 2014 Elsevier Inc. All rights reserved.

The murine homeobox gene Msx-3 shows highly restricted expression in the developing neural tube.

PubMed

Shimeld, S M; McKay, I J; Sharpe, P T

1996-04-01

The mouse homeobox-genes Msx-1 and Msx-2 are expressed in several areas of the developing embryo, including the neural tube, neural crest, facial processes and limb buds. Here we report the characterisation of a third mouse Msx gene, which we designate Msx-3. The embryonic expression of Msx-3 was found to differ from that of Msx-1 and -2 in that it was confined to the dorsal neural tube. In embryos with 5-8 somites a segmental pattern of expression was observed in the hindbrain, with rhombomeres 3 and 5 lacking Msx-3 while other rhombomeres expressed Msx-3. This pattern was transient, however, such that in embryos with 18 or more somites expression was continuous throughout the dorsal hindbrain and anterior dorsal spinal cord. Differentiation of dorsal cell types in the neural tube can be induced by addition of members of the Tgf-beta family. Additionally, Msx-1 and -2 have been shown to be activated by addition of the Tgf-beta family member Bmp-4. To determine if Bmp-4 could activate Msx-3, we incubated embryonic hindbrain explants with exogenous Bmp-4. The dorsal expression of Msx-3 was seen to expand into more ventral regions of the neurectoderm in Bmp-4-treated cultures, implying that Bmp-4 may be able to mimic an in vivo signal that induces Msx-3.

Limbs are moving: where are they going?

PubMed

Schwabe, J W; Rodriguez-Esteban, C; Izpisúa Belmonte, J C

1998-06-01

The past decade has witnessed many changes in the way in which biologists study vertebrate development. Like curious children, we have progressed from merely watching and playing with our toys to the more exciting activity of taking them apart. This progression is mainly due to the application of a number of new techniques that allow us not only to ablate gene function, but also to induce gene activity inappropriately in time and space. Through the use of these techniques we can now disassemble our 'toys' and begin to understand how the pieces fit together and, thus, we are beginning to understand how the vertebrate embryo develops. Additionally, the analysis and comparison of limb development in diverse species has provided much insight into the evolutionary mechanisms through which changes in developmental pathways have led to the extraordinary diversity of limbs.

Network based transcription factor analysis of regenerating axolotl limbs

PubMed Central

2011-01-01

Background Studies on amphibian limb regeneration began in the early 1700's but we still do not completely understand the cellular and molecular events of this unique process. Understanding a complex biological process such as limb regeneration is more complicated than the knowledge of the individual genes or proteins involved. Here we followed a systems biology approach in an effort to construct the networks and pathways of protein interactions involved in formation of the accumulation blastema in regenerating axolotl limbs. Results We used the human orthologs of proteins previously identified by our research team as bait to identify the transcription factor (TF) pathways and networks that regulate blastema formation in amputated axolotl limbs. The five most connected factors, c-Myc, SP1, HNF4A, ESR1 and p53 regulate ~50% of the proteins in our data. Among these, c-Myc and SP1 regulate 36.2% of the proteins. c-Myc was the most highly connected TF (71 targets). Network analysis showed that TGF-β1 and fibronectin (FN) lead to the activation of these TFs. We found that other TFs known to be involved in epigenetic reprogramming, such as Klf4, Oct4, and Lin28 are also connected to c-Myc and SP1. Conclusions Our study provides a systems biology approach to how different molecular entities inter-connect with each other during the formation of an accumulation blastema in regenerating axolotl limbs. This approach provides an in silico methodology to identify proteins that are not detected by experimental methods such as proteomics but are potentially important to blastema formation. We found that the TFs, c-Myc and SP1 and their target genes could potentially play a central role in limb regeneration. Systems biology has the potential to map out numerous other pathways that are crucial to blastema formation in regeneration-competent limbs, to compare these to the pathways that characterize regeneration-deficient limbs and finally, to identify stem cell markers in regeneration. PMID:21418574

Symmetrical upper limb peromelia and lower limb phocomelia associated with a de novo apparently balanced reciprocal translocation: 46,XX,t(2; 12)(p25.1;q24.1).

PubMed

Murray, R S; Keeling, J W; Ellis, P M; FitzPatrick, D R

2002-04-01

We report a female fetus of 20 weeks gestation with severe symmetrical deformity affecting all four limbs. These deformities were unusual in that there was upper limb peromelia and lower limb phocomelia. No additional major malformations were identified on postmortem examination. In particular there was no evidence of splenogonadal fusion or micrognathia and hypoglossia. The limb malformations in this case are associated with a de novo apparently balanced reciprocal translocation 46,XX,t(2;12)(p25.1;q24.1). The cytogenetic features of Roberts-SC phocomelia syndrome were not detected. Unfortunately, the fibroblast line died and no FISH or DNA analysis could be carried out. In spite of this, the case is presented as it may be useful to other researchers in the selection of candidate genes for mendelian forms of peromelia and phocomelia.

Proteomic analysis of fibroblastema formation in regenerating hind limbs of Xenopus laevis froglets and comparison to axolotl

PubMed Central

2014-01-01

Background To gain insight into what differences might restrict the capacity for limb regeneration in Xenopus froglets, we used High Performance Liquid Chromatography (HPLC)/double mass spectrometry to characterize protein expression during fibroblastema formation in the amputated froglet hindlimb, and compared the results to those obtained previously for blastema formation in the axolotl limb. Results Comparison of the Xenopus fibroblastema and axolotl blastema revealed several similarities and significant differences in proteomic profiles. The most significant similarity was the strong parallel down regulation of muscle proteins and enzymes involved in carbohydrate metabolism. Regenerating Xenopus limbs differed significantly from axolotl regenerating limbs in several ways: deficiency in the inositol phosphate/diacylglycerol signaling pathway, down regulation of Wnt signaling, up regulation of extracellular matrix (ECM) proteins and proteins involved in chondrocyte differentiation, lack of expression of a key cell cycle protein, ecotropic viral integration site 5 (EVI5), that blocks mitosis in the axolotl, and the expression of several patterning proteins not seen in the axolotl that may dorsalize the fibroblastema. Conclusions We have characterized global protein expression during fibroblastema formation after amputation of the Xenopus froglet hindlimb and identified several differences that lead to signaling deficiency, failure to retard mitosis, premature chondrocyte differentiation, and failure of dorsoventral axial asymmetry. These differences point to possible interventions to improve blastema formation and pattern formation in the froglet limb. PMID:25063185

Development and Implementation of an End-Effector Upper Limb Rehabilitation Robot for Hemiplegic Patients with Line and Circle Tracking Training

PubMed Central

Li, Chong; Bi, Sheng; Zhang, Xuemin; Huo, Jianfei

2017-01-01

Numerous robots have been widely used to deliver rehabilitative training for hemiplegic patients to improve their functional ability. Because of the complexity and diversity of upper limb motion, customization of training patterns is one key factor during upper limb rehabilitation training. Most of the current rehabilitation robots cannot intelligently provide adaptive training parameters, and they have not been widely used in clinical rehabilitation. This article proposes a new end-effector upper limb rehabilitation robot, which is a two-link robotic arm with two active degrees of freedom. This work investigated the kinematics and dynamics of the robot system, the control system, and the realization of different rehabilitation therapies. We also explored the influence of constraint in rehabilitation therapies on interaction force and muscle activation. The deviation of the trajectory of the end effector and the required trajectory was less than 1 mm during the tasks, which demonstrated the movement accuracy of the robot. Besides, results also demonstrated the constraint exerted by the robot provided benefits for hemiplegic patients by changing muscle activation in the way similar to the movement pattern of the healthy subjects, which indicated that the robot can improve the patient's functional ability by training the normal movement pattern. PMID:29065614

Development and Implementation of an End-Effector Upper Limb Rehabilitation Robot for Hemiplegic Patients with Line and Circle Tracking Training.

PubMed

Liu, Yali; Li, Chong; Ji, Linhong; Bi, Sheng; Zhang, Xuemin; Huo, Jianfei; Ji, Run

2017-01-01

Numerous robots have been widely used to deliver rehabilitative training for hemiplegic patients to improve their functional ability. Because of the complexity and diversity of upper limb motion, customization of training patterns is one key factor during upper limb rehabilitation training. Most of the current rehabilitation robots cannot intelligently provide adaptive training parameters, and they have not been widely used in clinical rehabilitation. This article proposes a new end-effector upper limb rehabilitation robot, which is a two-link robotic arm with two active degrees of freedom. This work investigated the kinematics and dynamics of the robot system, the control system, and the realization of different rehabilitation therapies. We also explored the influence of constraint in rehabilitation therapies on interaction force and muscle activation. The deviation of the trajectory of the end effector and the required trajectory was less than 1 mm during the tasks, which demonstrated the movement accuracy of the robot. Besides, results also demonstrated the constraint exerted by the robot provided benefits for hemiplegic patients by changing muscle activation in the way similar to the movement pattern of the healthy subjects, which indicated that the robot can improve the patient's functional ability by training the normal movement pattern.

Remote Ischemic Preconditioning Enhances the Expression of Genes Encoding Antioxidant Enzymes and Endoplasmic Reticulum Stress-Related Proteins in Rat Skeletal Muscle.

PubMed

Park, Ui Jun; Kim, Hyoung Tae; Cho, Won Hyun; Park, Jae Hyoung; Jung, Hye Ra; Kim, Min Young

2016-12-01

Ischemic preconditioning (IPC), including remote IPC (rIPC) and direct IPC (dIPC), is a promising method to decrease ischemia-reperfusion (IR) injury. This study tested the effect of both rIPC and dIPC on the genes for antioxidant enzymes and endoplasmic reticulum (ER) stress-related proteins. Twenty rats were randomly divided into the control and study groups. In the control group (n=10), the right hind limb was sham-operated. The left hind limb (IscR) of the control group underwent IR injury without IPC. In the study group (n=10), the right hind limb received IR injury after 3 cycles of rIPC. The IscR received IR injury after 3 cycles of dIPC. Gene expression was analyzed by Quantitative real-time polymerase chain reaction from the anterior tibialis muscle. The expression of the antioxidant enzyme genes including glutathione peroxidase (GPx), superoxide dismutase (SOD) 1 and catalase (CAT) were significantly reduced in IscR compared with sham treatment. In comparison with IscR, rIPC enhanced the expression of GPx, SOD2, and CAT genes. dIPC enhanced the expression of SOD2 and CAT genes. The expression of SOD2 genes was consistently higher in rIPC than in dIPC, but the difference was only significant for SOD2. The expression of genes for ER stress-related proteins tended to be reduced in IscR in comparison with sham treatment. However, the difference was only significant for C/EBP homologous protein (CHOP). In comparison with IscR, rIPC significantly up-regulated activating transcription factor 4 and CHOP, whereas dIPC up-regulated CHOP. Both rIPC and dIPC enhanced expression of genes for antioxidant enzymes and ER stress-related proteins.

The Role of Spatially Controlled Cell Proliferation in Limb Bud Morphogenesis

PubMed Central

Boehm, Bernd; Westerberg, Henrik; Lesnicar-Pucko, Gaja; Raja, Sahdia; Rautschka, Michael; Cotterell, James; Swoger, Jim; Sharpe, James

2010-01-01

Although the vertebrate limb bud has been studied for decades as a model system for spatial pattern formation and cell specification, the cellular basis of its distally oriented elongation has been a relatively neglected topic by comparison. The conventional view is that a gradient of isotropic proliferation exists along the limb, with high proliferation rates at the distal tip and lower rates towards the body, and that this gradient is the driving force behind outgrowth. Here we test this hypothesis by combining quantitative empirical data sets with computer modelling to assess the potential role of spatially controlled proliferation rates in the process of directional limb bud outgrowth. In particular, we generate two new empirical data sets for the mouse hind limb—a numerical description of shape change and a quantitative 3D map of cell cycle times—and combine these with a new 3D finite element model of tissue growth. By developing a parameter optimization approach (which explores spatial patterns of tissue growth) our computer simulations reveal that the observed distribution of proliferation rates plays no significant role in controlling the distally extending limb shape, and suggests that directional cell activities are likely to be the driving force behind limb bud outgrowth. This theoretical prediction prompted us to search for evidence of directional cell orientations in the limb bud mesenchyme, and we thus discovered a striking highly branched and extended cell shape composed of dynamically extending and retracting filopodia, a distally oriented bias in Golgi position, and also a bias in the orientation of cell division. We therefore provide both theoretical and empirical evidence that limb bud elongation is achieved by directional cell activities, rather than a PD gradient of proliferation rates. PMID:20644711

5-AZA-2'-DEOXYCYTIDINE INDUCED CYTOTOXICITY AND LONG BONE REDUCTION DEFECTS IN THE MURINE LIMB

EPA Science Inventory

The antineoplastic drug 5-aza-2'-deoxycytidine (dAZA) is a DNA hypomethylating agent that can be used to induce hind limb phocomelia in the offspring of CD-1 Swiss Webster mice. Previously, our laboratory investigated the possibility that dAZA induced alterations in gene express...

Relative high frequency of the c.255delA parkin gene mutation in Spanish patients with autosomal recessive parkinsonism

PubMed Central

Munoz, E; Tolosa, E; Pastor, P; Marti, M; Valldeoriola, F; Campdelacreu, J; Oliva, R

2002-01-01

Objectives: To search for the presence of parkin gene mutations in Spanish patients with Parkinson's disease (PD) and characterise the phenotype associated with these mutations. Methods: Thirty seven PD patients with either early onset or autosomal recessive pattern of inheritance were selected for genetic study. Results: Mutations were identified in seven index patients (19%). Homozygous mutations were detected in six patients and a heterozygous mutation in one. The age at onset was lower in patients with mutations than in patients without mutations. Dystonia at onset was present in two patients with parkin gene mutations. The disease began in two patients with postural tremor in the upper limbs mimicking essential tremor. Four patients exhibited a long term response to dopamine agonists. The c.255delA mutation was identified in four unrelated families. This is a frameshift mutation leading to protein truncation. Conclusions: Parkin gene mutations are present in Spanish patients with early onset and/or an autosomal recessive parkinsonism. The c.255delA is the most frequent mutation found, suggesting a relative high prevalence in the Spanish population. PMID:12397156

Muscle-specific androgen receptor deletion shows limited actions in myoblasts but not in myofibers in different muscles in vivo.

PubMed

Rana, Kesha; Chiu, Maria W S; Russell, Patricia K; Skinner, Jarrod P; Lee, Nicole K L; Fam, Barbara C; Zajac, Jeffrey D; MacLean, Helen E

2016-08-01

The aim of this study was to investigate the direct muscle cell-mediated actions of androgens by comparing two different mouse lines. The cre-loxP system was used to delete the DNA-binding activity of the androgen receptor (AR) in mature myofibers (MCK mAR(ΔZF2)) in one model and the DNA-binding activity of the AR in both proliferating myoblasts and myofibers (α-actin mAR(ΔZF2)) in another model. We found that hind-limb muscle mass was normal in MCK mAR(ΔZF2) mice and that relative mass of only some hind-limb muscles was reduced in α-actin mAR(ΔZF2) mice. This suggests that myoblasts and myofibers are not the major cellular targets mediating the anabolic actions of androgens on male muscle during growth and development. Levator ani muscle mass was decreased in both mouse lines, demonstrating that there is a myofiber-specific effect in this unique androgen-dependent muscle. We found that the pattern of expression of genes including c-myc, Fzd4 and Igf2 is associated with androgen-dependent changes in muscle mass; therefore, these genes are likely to be mediators of anabolic actions of androgens. Further research is required to identify the major targets of androgen actions in muscle, which are likely to include indirect actions via other tissues. © 2016 Society for Endocrinology.

Prevalence of adult Pompe disease in patients with proximal myopathic syndrome and undiagnosed muscle biopsy.

PubMed

Golsari, Amir; Nasimzadah, Arzoo; Thomalla, Götz; Keller, Sarah; Gerloff, Christian; Magnus, Tim

2018-03-01

We examined patients with limb-girdle muscle weakness and/or hyper-CKaemia and undiagnosed muscle biopsy for late onset Pompe disease (LOPD). Patients with an inconclusive limb-girdle muscle weakness who presented at our neuromuscular centre between 2005 and 2015 with undiagnosed muscle biopsies were examined by dry blood spot testing (DBS) including determination of the enzyme activity of acid alpha-glucosidase (GAA). In the case of depressed enzyme activity, additional gene testing of the GAA gene was carried out. Of the 340 evaluated muscle biopsies, 69 patients fulfilled the inclusion criteria and were examined with DBS. Among those patients, 76% showed a limb-girdle muscle weakness and 14% showed a hyper-CKaemia. A diagnosis of LOPD could be established in the case of two patients (2.9%) with reduced GAA enzyme activity and proof of mutations in the GAA gene. One of the two patients presents in the muscle biopsy suggestive features of Pompe disease including vacuoles with positive acid phosphatase reaction. In summary, our results show that a muscle biopsy can be helpful in identifying LOPD patients, but vacuolation with glycogen storage can also be absent. An inconspicuous muscle biopsy does not rule out Pompe disease. Consequently, all patients with limb-girdle muscle weakness should be examined by DBS before conducting a muscle biopsy. Copyright © 2017 Elsevier B.V. All rights reserved.

Zinc finger protein rotund deficiency affects development of the thoracic leg in Bombyx mori.

PubMed

Zhou, Chun-Yan; Zha, Xing-Fu; Liu, Hua-Wei; Xia, Qing-You

2017-06-01

The insect limb develops from the imaginal disc or larval leg during metamorphosis. The molecular mechanisms involved in the development from the larval to the adult leg are poorly understood. Herein, we cloned the full length of a zinc finger gene rotund from Bombyx mori (Bmrn), which contained a 1419 bp open reading frame, and encoded a 473 amino acid protein. Reverse transcription polymerase chain reaction and Western blot analyses demonstrated that Bmrn was expressed at higher levels in the epidermis than in other tissues tested, and it showed a very high expression level during metamorphosis. Knock-down of Bmrn produced defects in the tarsus and pretarsus, including the fusion and reduction of tarsomeres, and the developmental arrest of pretarsus. Our data showed that Bmrn is involved in the formation of the tarsus and pretarsus, whereas its homologous gene in Drosophila has been shown to affect three tarsal segments (t2-t4), suggesting that the remodeling of the leg has involved changes in the patterning of gene regulation during evolution. © 2016 Institute of Zoology, Chinese Academy of Sciences.

Inter-dependent tissue growth and Turing patterning in a model for long bone development

NASA Astrophysics Data System (ADS)

Tanaka, Simon; Iber, Dagmar

2013-10-01

The development of long bones requires a sophisticated spatial organization of cellular signalling, proliferation, and differentiation programs. How such spatial organization emerges on the growing long bone domain is still unresolved. Based on the reported biochemical interactions we developed a regulatory model for the core signalling factors IHH, PTCH1, and PTHrP and included two cell types, proliferating/resting chondrocytes and (pre-)hypertrophic chondrocytes. We show that the reported IHH-PTCH1 interaction gives rise to a Schnakenberg-type Turing kinetics, and that inclusion of PTHrP is important to achieve robust patterning when coupling patterning and tissue dynamics. The model reproduces relevant spatiotemporal gene expression patterns, as well as a number of relevant mutant phenotypes. In summary, we propose that a ligand-receptor based Turing mechanism may control the emergence of patterns during long bone development, with PTHrP as an important mediator to confer patterning robustness when the sensitive Turing system is coupled to the dynamics of a growing and differentiating tissue. We have previously shown that ligand-receptor based Turing mechanisms can also result from BMP-receptor, SHH-receptor, and GDNF-receptor interactions, and that these reproduce the wildtype and mutant patterns during digit formation in limbs and branching morphogenesis in lung and kidneys. Receptor-ligand interactions may thus constitute a general mechanism to generate Turing patterns in nature.

Hox genes, digit identities and the theropod/bird transition.

PubMed

Galis, Frietson; Kundrát, Martin; Metz, Johan A J

2005-05-15

Vargas and Fallon (2005. J Exp Zool (Mol Dev Evol) 304B:86-90) propose that Hox gene expression patterns indicate that the most anterior digit in bird wings is homologous to digit 1 rather than to digit 2 in other amniotes. This interpretation is based on the presence of Hoxd13 expression in combination with the absence of Hoxd12 expression in the second digit condensation from which this digit develops (the first condensation is transiently present). This is a pattern that is similar to that in the developing digit 1 of the chicken foot and the mouse hand and foot. They have tested this new hypothesis by analysing Hoxd12 and Hoxd13 expression patterns in two polydactylous chicken mutants, Silkie and talpid2. They conclude that the data support the notion that the most anterior remaining digit of the bird wing is homologous to digit 1 in other amniotes either in a standard phylogenetic sense, or alternatively in a (limited) developmental sense in agreement with the Frameshift Hypothesis of Wagner and Gautier (1999, i.e., that the developmental pathway is homologous to the one that leads to a digit 1 identity in other amniotes, although it occurs in the second instead of the first digit condensation). We argue that the Hoxd12 and Hoxd13 expression patterns found for these and other limb mutants do not allow distinguishing between the hypothesis of Vargas and Fallon (2005. J Exp Zool (Mol Dev Evol) 304B:86-90) and the alternative one, i.e., the most anterior digit in bird wings is homologous to digit 2 in other amniotes, in a phylogenetic or developmental sense. Therefore, at the moment the data on limb mutants does not present a challenge to the hypothesis, based on other developmental data (Holmgren, 1955. Acta Zool 36:243-328; Hinchliffe, 1984. In: Hecht M, Ostrom JH, Viohl G, Wellnhofer P, editors. The beginnings of birds. Eichstätt: Freunde des Jura-Museum. p 141-147; Burke and Feduccia, 1997. Science 278:666-668; Kundrát et al., 2002. J Exp Zool (Mol Dev Evol) 294B:151-159; Larsson and Wagner, 2002. J Exp Zool (Mol Dev Evol) 294B:146-151; Feduccia and Nowicki, 2002. Naturwissenschaften 89:391-393), that the digits of bird wings are homologous to digits 2,3,4 in amniotes. We recommend further testing of the hypothesis by comparing Hoxd expression patterns in different taxa. Copyright 2005 Wiley-Liss, Inc

The effect of leg dominance and landing height on ACL loading among female athletes.

PubMed

Mokhtarzadeh, Hossein; Ewing, Katie; Janssen, Ina; Yeow, Chen-Hua; Brown, Nicholas; Lee, Peter Vee Sin

2017-07-26

Female athletes are more prone to anterior cruciate ligament (ACL) injury. A neuromuscular imbalance called leg dominance may provide a biomechanical explanation. Therefore, the purpose of this study was to compare the side-to-side lower limb differences in movement patterns, muscle forces and ACL forces during a single-leg drop-landing task from two different heights. We hypothesized that there will be significant differences in lower limb movement patterns (kinematics), muscle forces and ACL loading between the dominant and non-dominant limbs. Further, we hypothesized that significant differences between limbs will be present when participants land from a greater drop-landing height. Eight recreational female participants performed dominant and non-dominant single-leg drop landings from 30 to 60cm. OpenSim software was used to develop participant-specific musculoskeletal models and to calculate muscle forces. We also predicted ACL loading using our previously established method. There were no significant differences between dominant and non-dominant leg landing except in ankle dorsiflexion and GMED muscle forces at peak GRF. Landing from a greater height resulted in significant differences among most kinetics and kinematics variables and ACL forces. Minimal differences in lower-limb muscle forces and ACL loading between the dominant and non-dominant legs during single-leg landing may suggest similar risk of injury across limbs in this cohort. Further research is required to confirm whether limb dominance may play an important role in the higher incidence of ACL injury in female athletes with larger and sport-specific cohorts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Transient Inhibition of FGFR2b-Ligands Signaling Leads to Irreversible Loss of Cellular β-Catenin Organization and Signaling in AER during Mouse Limb Development

PubMed Central

Tabatabai, Reza; Baptista, Sheryl; Tiozzo, Caterina; Carraro, Gianni; Wheeler, Matthew; Barreto, Guillermo; Braun, Thomas; Li, Xiaokun; Hajihosseini, Mohammad K.; Bellusci, Saverio

2013-01-01

The vertebrate limbs develop through coordinated series of inductive, growth and patterning events. Fibroblast Growth Factor receptor 2b (FGFR2b) signaling controls the induction of the Apical Ectodermal Ridge (AER) but its putative roles in limb outgrowth and patterning, as well as in AER morphology and cell behavior have remained unclear. We have investigated these roles through graded and reversible expression of soluble dominant-negative FGFR2b molecules at various times during mouse limb development, using a doxycycline/transactivator/tet(O)-responsive system. Transient attenuation (≤24 hours) of FGFR2b-ligands signaling at E8.5, prior to limb bud induction, leads mostly to the loss or truncation of proximal skeletal elements with less severe impact on distal elements. Attenuation from E9.5 onwards, however, has an irreversible effect on the stability of the AER, resulting in a progressive loss of distal limb skeletal elements. The primary consequences of FGFR2b-ligands attenuation is a transient loss of cell adhesion and down-regulation of P63, β1-integrin and E-cadherin, and a permanent loss of cellular β-catenin organization and WNT signaling within the AER. Combined, these effects lead to the progressive transformation of the AER cells from pluristratified to squamous epithelial-like cells within 24 hours of doxycycline administration. These findings show that FGFR2b-ligands signaling has critical stage-specific roles in maintaining the AER during limb development. PMID:24167544

Genetic regulation of canine skeletal traits: trade-offs between the hind limbs and forelimbs in the fox and dog

PubMed Central

Kharlamova, Anastasia V.; Trut, Lyudmila N.; Carrier, David R.; Chase, Kevin; Lark, Karl G.

2008-01-01

Synopsis Genetic variation in functionally integrated skeletal traits can be maintained over 10 million years despite bottlenecks and stringent selection. Here, we describe an analysis of the genetic architecture of the canid axial skeleton using populations of the Portuguese Water Dog Canis familiaris) and silver fox (Vulpes vulpes). Twenty-one skeletal metrics taken from radiographs of the forelimbs and hind limbs of the fox and dog were used to construct separate anatomical principal component (PC) matrices of the two species. In both species, 15 of the 21 PCs exhibited significant heritability, ranging from 25% to 70%. The second PC, in both species, represents a trade-off in which limb-bone width is inversely correlated with limb-bone length. PC2 accounts for approximately 15% of the observed skeletal variation, ~30% of the variation in shape. Many of the other significant PCs affect very small amounts of variation (e.g., 0.2–2%) along trade-off axes that partition function between the forelimbs and hind limbs. These PCs represent shape axes in which an increase in size of an element of the forelimb is associated with a decrease in size of an element of the hind limb and vice versa. In most cases, these trade-offs are heritable in both species and genetic loci have been identified in the Portuguese Water Dog for many of these. These PCs, present in both the dog and the fox, include ones that affect lengths of the forelimb versus the hind limb, length of the forefoot versus that of the hind foot, muscle moment (i.e., lever) arms of the forelimb versus hind limb, and cortical thickness of the bones of the forelimb versus hind limb. These inverse relationships suggest that genetic regulation of the axial skeleton results, in part, from the action of genes that influence suites of functionally integrated traits. Their presence in both dogs and foxes suggests that the genes controlling the regulation of these PCs of the forelimb versus hind limb may be found in other tetrapod taxa. PMID:18458753

[The use of genetic angiogenesis inductors in surgical treatment of chronic lower limb ischemia].

PubMed

Gavrilenko, A V; Voronov, D A; Bochkov, N P

2013-01-01

The efficacy and safety of gene-engineering recombinant constructions with endothelial growth factor gene and angiogenin for the treatment of the chronic lower limb ischemia were studied. 134 patients were included in prospective controlled study. The main group, who received both traditional treatment and genetic therapy, consisted of 74 patients. The rest 60 patients were included into the control group. Of 74 patients from the main group, genetic therapy was used together with conservative means in 39 patients and with reconstructive vascular operations in 35 patients. The gene-engineering angiogenesis stimulation therapy proved to be effective and safe. The combination of angiogenesis genetic stimulation with reconstructive vascular surgery demonstrated significantly better results, then monotherapy.

Ol-Prx 3, a member of an additional class of homeobox genes, is unimodally expressed in several domains of the developing and adult central nervous system of the medaka (Oryzias latipes)

PubMed Central

Joly, Jean-Stephane; Bourrat, Franck; Nguyen, Van; Chourrout, Daniel

1997-01-01

Large-scale genetic screens for mutations affecting early neurogenesis of vertebrates have recently been performed with an aquarium fish, the zebrafish. Later stages of neural morphogenesis have attracted less attention in small fish species, partly because of the lack of molecular markers of developing structures that may facilitate the detection of discrete structural alterations. In this context, we report the characterization of Ol-Prx 3 (Oryzias latipes-Prx 3). This gene was isolated in the course of a large-scale screen for brain cDNAs containing a highly conserved DNA binding region, the homeobox helix-three. Sequence analysis revealed that this gene belongs to another class of homeobox genes, together with a previously isolated mouse ortholog, called OG-12 [Rovescalli, A. C., Asoh, S. & Nirenberg, M. (1996) Proc. Natl. Acad. Sci. USA 93, 10691–10696] and with the human SHOX gene [Rao, E., Weiss, B., Fukami, M., Rump, A., Niesler, B., et al. (1997) Nat. Genet. 16, 54–62], thought to be involved in the short-stature phenotype of Turner syndrome patients. These three genes exhibit a moderate level of identity in the homeobox with the other genes of the paired-related (PRX) gene family. Ol-Prx 3, as well as the PRX genes, are expressed in various cartilaginous structures of head and limbs. These genes might thus be involved in common regulatory pathways during the morphogenesis of these structures. Moreover, this paper reports a complex and monophasic pattern of Ol-Prx 3 expression in the central nervous system, which differs markedly from the patterns reported for the PRX genes, Prx 3 excluded: this gene begins to be expressed in a variety of central nervous system territories at late neurula stage. Strikingly, it remains turned on in some of the derivatives of each territory during the entire life of the fish. We hope this work will thus help identify common features for the PRX 3 family of homeobox genes. PMID:9371787

Coordinated development of the limb musculoskeletal system: Tendon and muscle patterning and integration with the skeleton.

PubMed

Huang, Alice H

2017-09-15

Functional movement and stability of the limb depends on an organized and fully integrated musculoskeletal system composed of skeleton, muscle, and tendon. Much of our current understanding of musculoskeletal development is based on studies that focused on the development and differentiation of individual tissues. Likewise, research on patterning events have been largely limited to the primary skeletal elements and the mechanisms that regulate soft tissue patterning, the development of the connections between tissues, and their interdependent development are only beginning to be elucidated. This review will therefore highlight recent exciting discoveries in this field, with an emphasis on tendon and muscle patterning and their integrated development with the skeleton and skeletal attachments. Copyright © 2017 Elsevier Inc. All rights reserved.

Influence of genetic variations in platelet glycoproteins and eNOS in the development of arterial ischaemia of lower limbs in type 2 diabetes mellitus patients.

PubMed

Carvalhais, Virginia; Ruivães, Ema; Pina-Cabral, Luis Bernardo; Mesquita, Bárbara; Oliveira, Flávio; Monteiro, Maria Céu; Criado, Maria Begoña

2016-12-01

Endothelial and platelet dysfunction increase the atherothrombotic risk in diabetes mellitus patients. Therefore, arterial ischaemia of lower limbs is an important complication in diabetes mellitus. In the present work, type 2 diabetic patients were classified by a podiatrist into presence or absence of arterial ischaemia of lower limbs. Several polymorphisms in platelet glycoproteins and eNOS genes were evaluated. Our results suggest that the -5CC genotype in Kozak sequence of GPIbα may be associated with a higher risk of developing arterial ischaemia of lower limbs in type 2 diabetes mellitus patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

Clinical, pathological, and genetic features of limb-girdle muscular dystrophy type 2A with new calpain 3 gene mutations in seven patients from three Japanese families.

PubMed

Kawai, H; Akaike, M; Kunishige, M; Inui, T; Adachi, K; Kimura, C; Kawajiri, M; Nishida, Y; Endo, I; Kashiwagi, S; Nishino, H; Fujiwara, T; Okuno, S; Roudaut, C; Richard, I; Beckmann, J S; Miyoshi, K; Matsumoto, T

1998-11-01

We report on the clinical, pathological, and genetic features of 7 patients with limb-girdle muscular dystrophy type 2A (LGMD2A) from three Japanese families. The mean age of onset was 9.7+/-3.1 years (mean+/-SD), and loss of ambulance occurred at 38.5+/-2.1 years. Muscle atrophy was predominant in the pelvic and shoulder girdles, and proximal limb muscles. Muscle pathology revealed dystrophic changes. In two families, an identical G to C mutation at position 1080 the in calpain 3 gene was identified, and a frameshift mutation (1796insA) was found in the third family. The former mutation results in a W360R substitution in the proteolytic site of calpain 3, and the latter in a deletion of the Ca2+-binding domain.

Dynamical mechanisms for skeletal pattern formation in the vertebrate limb.

PubMed Central

Hentschel, H. G. E.; Glimm, Tilmann; Glazier, James A.; Newman, Stuart A.

2004-01-01

We describe a 'reactor-diffusion' mechanism for precartilage condensation based on recent experiments on chondrogenesis in the early vertebrate limb and additional hypotheses. Cellular differentiation of mesenchymal cells into subtypes with different fibroblast growth factor (FGF) receptors occurs in the presence of spatio-temporal variations of FGFs and transforming growth factor-betas (TGF-betas). One class of differentiated cells produces elevated quantities of the extracellular matrix protein fibronectin, which initiates adhesion-mediated preskeletal mesenchymal condensation. The same class of cells also produces an FGF-dependent laterally acting inhibitor that keeps condensations from expanding beyond a critical size. We show that this 'reactor-diffusion' mechanism leads naturally to patterning consistent with skeletal form, and describe simulations of spatio-temporal distribution of these differentiated cell types and the TGF-beta and inhibitor concentrations in the developing limb bud. PMID:15306292

Gallium nitrate: effects on cartilage during limb regeneration in the axolotl, Ambystoma mexicanum.

PubMed

Tassava, Roy A; Mendenhall, Luciara; Apseloff, Glen; Gerber, Nicholas

2002-09-01

Gallium nitrate, a drug shown to have efficacy in Paget's disease of bone, hypercalcemia of malignancy, and a variety of experimental autoimmune diseases, also inhibits the growth of some types of cancer. We examined dose and timing of administration of gallium nitrate on limb regeneration in the Mexican axolotl, Ambystoma mexicanum. Administered by intraperitoneal injection, gallium nitrate inhibited limb regeneration in a dose-dependent manner. Gallium nitrate initially suppressed epithelial wound healing and subsequently distorted both anterior-posterior and proximo-distal chondrogenic patterns. Gallium nitrate given at three days after amputation severely inhibited regeneration at high doses (6.25 mg/axolotl) and altered the normal patterning of the regenerates at low doses (3.75 mg/axolotl). Administration of 6.25 mg of gallium nitrate at four or 14 days prior to amputation also inhibited regeneration. In amputated limbs of gallium-treated axolotls, the chondrocytes were lost from inside the radius/ulna. Limbs that regenerated after gallium treatment was terminated showed blastema formation preferentially over the ulna. New cartilage of the regenerate often attached to the sides of the existing radius/ulna proximally into the stump and less so to the distal cut ends. J. Exp. Zool. 293:384-394, 2002. Copyright 2002 Wiley-Liss, Inc.

Influence of inclination angles on intra- and inter-limb load-sharing during uphill walking.

PubMed

Hong, Shih-Wun; Leu, Tsai-Hsueh; Li, Jia-Da; Wang, Ting-Ming; Ho, Wei-Ping; Lu, Tung-Wu

2014-01-01

Uphill walking is an inevitable part of daily living, placing more challenges on the locomotor system with greater risk of falls than level walking does. The current study aimed to investigate the effects of inclination angles on the inter-joint and inter-limb load-sharing during uphill walking in terms of total support moment and contributions of individual joint moments to the total support moment. Fifteen young adults walked up walkways with 0°, 5°, 10° and 15° of slope while kinematic and kinetic data were collected and analyzed. With increasing inclination angles, the first peak of the total support moment was increased with unaltered individual joint contributions, suggesting an unaltered inter-joint control pattern in the leading limb to meet the increased demands. The second peak of the total support moment remained unchanged with increasing inclination angles primarily through a compensatory redistribution of the hip and knee moments. During DLS, the leading limb shared the majority of the whole body support moments. The current results reveal basic intra- and inter-limb load-sharing patterns of uphill walking, which will be helpful for a better understanding of the control strategies adopted and for subsequent clinical applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Modeling digits. Digit patterning is controlled by a Bmp-Sox9-Wnt Turing network modulated by morphogen gradients.

PubMed

Raspopovic, J; Marcon, L; Russo, L; Sharpe, J

2014-08-01

During limb development, digits emerge from the undifferentiated mesenchymal tissue that constitutes the limb bud. It has been proposed that this process is controlled by a self-organizing Turing mechanism, whereby diffusible molecules interact to produce a periodic pattern of digital and interdigital fates. However, the identities of the molecules remain unknown. By combining experiments and modeling, we reveal evidence that a Turing network implemented by Bmp, Sox9, and Wnt drives digit specification. We develop a realistic two-dimensional simulation of digit patterning and show that this network, when modulated by morphogen gradients, recapitulates the expression patterns of Sox9 in the wild type and in perturbation experiments. Our systems biology approach reveals how a combination of growth, morphogen gradients, and a self-organizing Turing network can achieve robust and reproducible pattern formation. Copyright © 2014, American Association for the Advancement of Science.

Three-dimensional kinematics of the lower limbs during forward ice hockey skating.

PubMed

Upjohn, Tegan; Turcotte, René; Pearsall, David J; Loh, Jonathan

2008-05-01

The objectives of the study were to describe lower limb kinematics in three dimensions during the forward skating stride in hockey players and to contrast skating techniques between low- and high-calibre skaters. Participant motions were recorded with four synchronized digital video cameras while wearing reflective marker triads on the thighs, shanks, and skates. Participants skated on a specialized treadmill with a polyethylene slat bed at a self-selected speed for 1 min. Each participant completed three 1-min skating trials separated by 5 min of rest. Joint and limb segment angles were calculated within the local (anatomical) and global reference planes. Similar gross movement patterns and stride rates were observed; however, high-calibre participants showed a greater range and rate of joint motion in both the sagittal and frontal planes, contributing to greater stride length for high-calibre players. Furthermore, consequent postural differences led to greater lateral excursion during the power stroke in high-calibre skaters. In conclusion, specific kinematic differences in both joint and limb segment angle movement patterns were observed between low- and high-calibre skaters.

Limb Position Tolerant Pattern Recognition for Myoelectric Prosthesis Control with Adaptive Sparse Representations From Extreme Learning.

PubMed

Betthauser, Joseph L; Hunt, Christopher L; Osborn, Luke E; Masters, Matthew R; Levay, Gyorgy; Kaliki, Rahul R; Thakor, Nitish V

2018-04-01

Myoelectric signals can be used to predict the intended movements of an amputee for prosthesis control. However, untrained effects like limb position changes influence myoelectric signal characteristics, hindering the ability of pattern recognition algorithms to discriminate among motion classes. Despite frequent and long training sessions, these deleterious conditional influences may result in poor performance and device abandonment. We present a robust sparsity-based adaptive classification method that is significantly less sensitive to signal deviations resulting from untrained conditions. We compare this approach in the offline and online contexts of untrained upper-limb positions for amputee and able-bodied subjects to demonstrate its robustness compared against other myoelectric classification methods. We report significant performance improvements () in untrained limb positions across all subject groups. The robustness of our suggested approach helps to ensure better untrained condition performance from fewer training conditions. This method of prosthesis control has the potential to deliver real-world clinical benefits to amputees: better condition-tolerant performance, reduced training burden in terms of frequency and duration, and increased adoption of myoelectric prostheses.

Delayed-onset and recurrent limb weakness associated with West Nile virus infection.

PubMed

Sejvar, James J; Davis, Larry E; Szabados, Erica; Jackson, Alan C

2010-02-01

Human neurologic illness following infection with West Nile virus (WNV) may include meningitis, encephalitis, and acute flaccid paralysis (AFP). Most WNV-associated AFP is due to involvement of the spinal motor neurons producing an anterior (polio)myelitis. WNV poliomyelitis is typically characterized by acute and rapidly progressing limb weakness occurring early in the course of illness, which is followed by death or clinical plateauing with subsequent improvement to varying degrees. We describe four cases of WNV poliomyelitis in which the limb weakness was characterized by an atypical temporal pattern, including one case with onset several weeks after illness onset, and three cases developing relapsing or recurrent limb weakness following a period of clinical plateauing or improvement. Delayed onset or recurrent features may be due to persistence of viral infection or delayed neuroinvasion with delayed injury by excitotoxic or other mechanisms, by immune-mediated mechanisms, or a combination thereof. Further clinical and pathogenesis studies are needed to better understand the mechanisms for these phenomena. Clinicians should be aware of these clinical patterns in patients with WNV poliomyelitis.

Maintenance of lateral stability during standing and walking in the cat.

PubMed

Karayannidou, A; Zelenin, P V; Orlovsky, G N; Sirota, M G; Beloozerova, I N; Deliagina, T G

2009-01-01

During free behaviors animals often experience lateral forces, such as collisions with obstacles or interactions with other animals. We studied postural reactions to lateral pulses of force (pushes) in the cat during standing and walking. During standing, a push applied to the hip region caused a lateral deviation of the caudal trunk, followed by a return to the initial position. The corrective hindlimb electromyographic (EMG) pattern included an initial wave of excitation in most extensors of the hindlimb contralateral to push and inhibition of those in the ipsilateral limb. In cats walking on a treadmill with only hindlimbs, application of force also caused lateral deviation of the caudal trunk, with subsequent return to the initial position. The type of corrective movement depended on the pulse timing relative to the step cycle. If the force was applied at the end of the stance phase of one of the limbs or during its swing phase, a lateral component appeared in the swing trajectory of this limb. The corrective step was directed either inward (when the corrective limb was ipsilateral to force application) or outward (when it was contralateral). The EMG pattern in the corrective limb was characterized by considerable modification of the hip abductor and adductor activity in the perturbed step. Thus the basic mechanisms for balance control in these two forms of behavior are different. They perform a redistribution of muscle activity between symmetrical limbs (in standing) and a reconfiguration of the base of support during a corrective lateral step (in walking).

Alanyl-tRNA synthetase mutation in a family with dominant distal hereditary motor neuropathy

PubMed Central

Zhao, Z.; Hashiguchi, A.; Sakiyama, Y.; Okamoto, Y.; Tokunaga, S.; Zhu, L.; Shen, H.; Takashima, H.

2012-01-01

Objective: To identify a new genetic cause of distal hereditary motor neuropathy (dHMN), which is also known as a variant of Charcot-Marie-Tooth disease (CMT), in a Chinese family. Methods: We investigated a Chinese family with dHMN clinically, electrophysiologically, and genetically. We screened for the mutations of 28 CMT or related pathogenic genes using an originally designed microarray resequencing DNA chip. Results: Investigation of the family history revealed an autosomal dominant transmission pattern. The clinical features of the family included mild weakness and wasting of the distal muscles of the lower limb and foot deformity, without clinical sensory involvement. Electrophysiologic studies revealed motor neuropathy. MRI of the lower limbs showed accentuated fatty infiltration of the gastrocnemius and vastus lateralis muscles. All 4 affected family members had a heterozygous missense mutation c.2677G>A (p.D893N) of alanyl-tRNA synthetase (AARS), which was not found in the 4 unaffected members and control subjects. Conclusion: An AARS mutation caused dHMN in a Chinese family. AARS mutations result in not only a CMT phenotype but also a dHMN phenotype. PMID:22573628

The SH3 and cysteine-rich domain 3 (Stac3) gene is important to growth, fiber composition, and calcium release from the sarcoplasmic reticulum in postnatal skeletal muscle.

PubMed

Cong, Xiaofei; Doering, Jonathan; Mazala, Davi A G; Chin, Eva R; Grange, Robert W; Jiang, Honglin

2016-01-01

The SH3 and cysteine-rich domain 3 (Stac3) gene is specifically expressed in the skeletal muscle. Stac3 knockout mice die perinatally. In this study, we determined the potential role of Stac3 in postnatal skeletal muscle growth, fiber composition, and contraction by generating conditional Stac3 knockout mice. We disrupted the Stac3 gene in 4-week-old male mice using the Flp-FRT and tamoxifen-inducible Cre-loxP systems. RT-qPCR and western blotting analyses of the limb muscles of target mice indicated that nearly all Stac3 mRNA and more than 70 % of STAC3 protein were deleted 4 weeks after tamoxifen injection. Postnatal Stac3 deletion inhibited body and limb muscle mass gains. Histological staining and gene expression analyses revealed that postnatal Stac3 deletion decreased the size of myofibers and increased the percentage of myofibers containing centralized nuclei, with no effect on the total myofiber number. Grip strength and grip time tests indicated that postnatal Stac3 deletion decreased limb muscle strength in mice. Muscle contractile tests revealed that postnatal Stac3 deletion reduced electrostimulation-induced but not the ryanodine receptor agonist caffeine-induced maximal force output in the limb muscles. Calcium imaging analysis of single flexor digitorum brevis myofibers indicated that postnatal Stac3 deletion reduced electrostimulation- but not caffeine-induced calcium release from the sarcoplasmic reticulum. This study demonstrates that STAC3 is important to myofiber hypertrophy, myofiber-type composition, contraction, and excitation-induced calcium release from the sarcoplasmic reticulum in the postnatal skeletal muscle.

Vertebrate limb development: moving from classical morphogen gradients to an integrated 4-dimensional patterning system.

PubMed

Bénazet, Jean-Denis; Zeller, Rolf

2009-10-01

A wealth of classical embryological manipulation experiments taking mainly advantage of the chicken limb buds identified the apical ectodermal ridge (AER) and the zone of polarizing activity (ZPA) as the respective ectodermal and mesenchymal key signaling centers coordinating proximodistal (PD) and anteroposterior (AP) limb axis development. These experiments inspired Wolpert's French flag model, which is a classic among morphogen gradient models. Subsequent molecular and genetic analysis in the mouse identified retinoic acid as proximal signal, and fibroblast growth factors (FGFs) and sonic hedgehog (SHH) as the essential instructive signals produced by AER and ZPA, respectively. Recent studies provide good evidence that progenitors are specified early with respect to their PD and AP fates and that morpho-regulatory signaling is also required for subsequent proliferative expansion of the specified progenitor pools. The determination of particular fates seems to occur rather late and depends on additional signals such as bone morphogenetic proteins (BMPs), which indicates that cells integrate signaling inputs over time and space. The coordinate regulation of PD and AP axis patterning is controlled by an epithelial-mesenchymal feedback signaling system, in which transcriptional regulation of the BMP antagonist Gremlin1 integrates inputs from the BMP, SHH, and FGF pathways. Vertebrate limb-bud development is controlled by a 4-dimensional (4D) patterning system integrating positive and negative regulatory feedback loops, rather than thresholds set by morphogen gradients.

Dimeric combinations of MafB, cFos and cJun control the apoptosis-survival balance in limb morphogenesis.

PubMed

Suda, Natsuno; Itoh, Takehiko; Nakato, Ryuichiro; Shirakawa, Daisuke; Bando, Masashige; Katou, Yuki; Kataoka, Kohsuke; Shirahige, Katsuhiko; Tickle, Cheryll; Tanaka, Mikiko

2014-07-01

Apoptosis is an important mechanism for sculpting morphology. However, the molecular cascades that control apoptosis in developing limb buds remain largely unclear. Here, we show that MafB was specifically expressed in apoptotic regions of chick limb buds, and MafB/cFos heterodimers repressed apoptosis, whereas MafB/cJun heterodimers promoted apoptosis for sculpting the shape of the limbs. Chromatin immunoprecipitation sequencing in chick limb buds identified potential target genes and regulatory elements controlled by Maf and Jun. Functional analyses revealed that expression of p63 and p73, key components known to arrest the cell cycle, was directly activated by MafB and cJun. Our data suggest that dimeric combinations of MafB, cFos and cJun in developing chick limb buds control the number of apoptotic cells, and that MafB/cJun heterodimers lead to apoptosis via activation of p63 and p73. © 2014. Published by The Company of Biologists Ltd.

Retrotransposon long interspersed nucleotide element-1 (LINE-1) is activated during salamander limb regeneration

PubMed Central

Zhu, Wei; Kuo, Dwight; Nathanson, Jason; Satoh, Akira; Pao, Gerald M.; Yeo, Gene W.; Bryant, Susan V.; Voss, S. Randal; Gardiner, David M.; Hunter, Tony

2012-01-01

Salamanders possess an extraordinary capacity for tissue and organ regeneration when compared to mammals. In our effort to characterize the unique transcriptional fingerprint emerging during the early phase of salamander limb regeneration, we identified transcriptional activation of some germline-specific genes within the Mexican axolotl (Ambystoma mexicanum) that is indicative of cellular reprogramming of differentiated cells into a germline-like state. In this work, we focus on one of these genes, the long interspersed nucleotide element-1 (LINE-1) retrotransposon, which is usually active in germ cells and silent in most of the somatic tissues in other organisms. LINE-1 was found to be dramatically upregulated during regeneration. In addition, higher genomic LINE-1 content was also detected in the limb regenerate when compared to that before amputation indicating that LINE-1 retrotransposition is indeed active during regeneration. Active LINE-1 retrotransposition has been suggested to have a potentially deleterious impact on genomic integrity. Silencing of activated LINE-1 by small RNAs has been reported to be part of the machinery aiming to maintain genomic integrity. Indeed, we were able to identify putative LINE-1-related piRNAs in the limb blastema. Transposable element-related piRNAs have been identified frequently in the germline in other organisms. Thus, we present here a scenario in which a unique germline-like state is established during axolotl limb regeneration, and the re-activation of LINE-1 may serve as a marker for cellular dedifferentiation in the early-stage of limb regeneration. PMID:22913491

An injectable elastin-based gene delivery platform for dose-dependent modulation of angiogenesis and inflammation for critical limb ischemia.

PubMed

Dash, Biraja C; Thomas, Dilip; Monaghan, Michael; Carroll, Oliver; Chen, Xizhe; Woodhouse, Kimberly; O'Brien, Timothy; Pandit, Abhay

2015-10-01

Critical limb ischemia is a major clinical problem. Despite rigorous treatment regimes, there has been only modest success in reducing the rate of amputations in affected patients. Reduced level of blood flow and enhanced inflammation are the two major pathophysiological changes that occur in the ischemic tissue. The objective of this study was to develop a controlled dual gene delivery system capable of delivering therapeutic plasmid eNOS and IL-10 in a temporal manner. In order to deliver multiple therapeutic genes, an elastin-like polypeptide (ELP) based injectable system was designed. The injectable system was comprised of hollow spheres and an in situ-forming gel scaffold of elastin-like polypeptide capable of carrying gene complexes, with an extended manner release profile. In addition, the ELP based injectable system was used to deliver human eNOS and IL-10 therapeutic genes in vivo. A subcutaneous dose response study showed enhanced blood vessel density in the treatment groups of eNOS (20 μg) and IL-10 (10 μg)/eNOS (20 μg) and reduced inflammation with IL-10 (10 μg) alone. Next, we carried out a hind-limb ischemia model comparing the efficacy of the following interventions; Saline; IL-10, eNOS and IL-10/eNOS. The selected dose of eNOS, exhibited enhanced angiogenesis. IL-10 treatment groups showed reduction in the level of inflammatory cells. Furthermore, we demonstrated that eNOS up-regulated major proangiogenic growth factors such as vascular endothelial growth factors, platelet derived growth factor B, and fibroblast growth factor 1, which may explain the mechanism of this approach. These factors help in formation of a stable vascular network. Thus, ELP injectable system mediating non-viral delivery of human IL10-eNOS is a promising therapy towards treating limb ischemia. Copyright © 2015 Elsevier Ltd. All rights reserved.

Progress on gene therapy, cell therapy, and pharmacological strategies toward the treatment of oculopharyngeal muscular dystrophy.

PubMed

Harish, Pradeep; Malerba, Alberto; Dickson, George; Bachtarzi, Houria

2015-05-01

Oculopharyngeal muscular dystrophy (OPMD) is a muscle-specific, late-onset degenerative disorder whereby muscles of the eyes (causing ptosis), throat (leading to dysphagia), and limbs (causing proximal limb weakness) are mostly affected. The disease is characterized by a mutation in the poly(A)-binding protein nuclear-1 (PABPN1) gene, resulting in a short GCG expansion in the polyalanine tract of PABPN1 protein. Accumulation of filamentous intranuclear inclusions in affected skeletal muscle cells constitutes the pathological hallmark of OPMD. This review highlights the current translational research advances in the treatment of OPMD. In vitro and in vivo disease models are described. Conventional and experimental therapeutic approaches are discussed with emphasis on novel molecular therapies including the use of intrabodies, gene therapy, and myoblast transfer therapy.

Substantive hemodynamic and thermal strain upon completing lower-limb hot-water immersion; comparisons with treadmill running.

PubMed

Thomas, Kate N; van Rij, André M; Lucas, Samuel J E; Gray, Andrew R; Cotter, James D

2016-01-01

Exercise induces arterial flow patterns that promote functional and structural adaptations, improving functional capacity and reducing cardiovascular risk. While heat is produced by exercise, local and whole-body passive heating have recently been shown to generate favorable flow profiles and associated vascular adaptations in the upper limb. Flow responses to acute heating in the lower limbs have not yet been assessed, or directly compared to exercise, and other cardiovascular effects of lower-limb heating have not been fully characterized. Lower-limb heating by hot-water immersion (30 min at 42°C, to the waist) was compared to matched-duration treadmill running (65-75% age-predicted heart rate maximum) in 10 healthy, young adult volunteers. Superficial femoral artery shear rate assessed immediately upon completion was increased to a greater extent following immersion (mean ± SD: immersion +252 ± 137% vs. exercise +155 ± 69%, interaction: p = 0.032), while superficial femoral artery flow-mediated dilation was unchanged in either intervention. Immersion increased heart rate to a lower peak than during exercise (immersion +38 ± 3 beats·min -1 vs. exercise +87 ± 3 beats·min -1 , interaction: p < 0.001), whereas only immersion reduced mean arterial pressure after exposure (-8 ± 3 mmHg, p = 0.012). Core temperature increased twice as much during immersion as exercise (+1.3 ± 0.4°C vs. +0.6 ± 0.4°C, p < 0.001). These data indicate that acute lower-limb hot-water immersion has potential to induce favorable shear stress patterns and cardiovascular responses within vessels prone to atherosclerosis. Whether repetition of lower-limb heating has long-term beneficial effects in such vasculature remains unexplored.

Molecular shifts in limb identity underlie development of feathered feet in two domestic avian species

PubMed Central

Domyan, Eric T; Kronenberg, Zev; Infante, Carlos R; Vickrey, Anna I; Stringham, Sydney A; Bruders, Rebecca; Guernsey, Michael W; Park, Sungdae; Payne, Jason; Beckstead, Robert B; Kardon, Gabrielle; Menke, Douglas B; Yandell, Mark; Shapiro, Michael D

2016-01-01

Birds display remarkable diversity in the distribution and morphology of scales and feathers on their feet, yet the genetic and developmental mechanisms governing this diversity remain unknown. Domestic pigeons have striking variation in foot feathering within a single species, providing a tractable model to investigate the molecular basis of skin appendage differences. We found that feathered feet in pigeons result from a partial transformation from hindlimb to forelimb identity mediated by cis-regulatory changes in the genes encoding the hindlimb-specific transcription factor Pitx1 and forelimb-specific transcription factor Tbx5. We also found that ectopic expression of Tbx5 is associated with foot feathers in chickens, suggesting similar molecular pathways underlie phenotypic convergence between these two species. These results show how changes in expression of regional patterning genes can generate localized changes in organ fate and morphology, and provide viable molecular mechanisms for diversity in hindlimb scale and feather distribution. DOI: http://dx.doi.org/10.7554/eLife.12115.001 PMID:26977633

MOLECULAR CHARACTERISATION AND ANTIMICROBIAL RESISTANCE PATTERNS OF ESCHERICHIA COLI ISOLATES FROM GOATS SLAUGHTERED IN PARTS OF KENYA.

PubMed

Njoroge, S; Muigai, A W T; Njiruh, P N; Kariuki, S

2013-03-01

To determine the antibiotic resistance patterns of pathogenic Escherichia coli on goat meat carcass at Huruma and Kiserian abattoirs in Kenya. Laboratory based study. Huruma and Kiserian abattoirs in Kenya, 400 slaughtered goats inspected by veterinary health officers and approved for human consumption. A Total of 400 slaughtered goats which were inspected by veterinary health officers and approved for human consumption were sampled from Huruma and Kiserian abattoir. Goat carcass swabs were collected by passing each swab tissue on four parts of the carcass mainly neck, right and left forelimbs, right and left hind limbs, and brisket. A total of 54 E. coli isolates were isolated and confirmed to be pathogenic. The percentage of isolates resistant to various microbial agents was recorded as follows: ampicillin (26 %), amoxycillin-clavulanic acid (17%), tetracycline (15%), chroramphenicol (4%), and ceftrixone (2% each). All Escherichia coli isolates were susceptible to gentamicin sulphamethaxazole-trimethomprin, kanamycin, cetriazididine (CAZ, 30pg), ciproxacin, nalidixic acid and chloramphenicol. Isolates were resistant to one or more of the antibiotics tested. Among the drugs tested, resistance was more frequently observed against ampicillin, amoxycillin-clavulanic acid, tetracycline, ceftrixone and chroramphenicol antibiotics. Among the isolates 26(48%) were positive for the stx1 gene, 19(35%) had the eae gene, 10(19%) possessed est gene,while 8(15%) harboured elt gene. Overall five isolates (10%) possessed aspu gene and two (4%) had aggR gene. No isolate possessed ipah gene. This study demonstrated that there is a significant level of antimicrobial resistance in pathogenic E. coli isolated from goat meat from Huruma and Kiserian abattoir. This indicates that goat meat from abattoirs could pose a risk of transmission of pathogenic antibiotic resistant strains to human. Poor hygienic standards and indiscriminate use of antimicrobials are the two main reasons for the presence of resistant pathogens in goat carcasses. Implemention of appropriate hygiene measures to control contamination of meat with pathogenic E. coli.

Bat Accelerated Regions Identify a Bat Forelimb Specific Enhancer in the HoxD Locus

PubMed Central

Mason, Mandy K.; VanderMeer, Julia E.; Zhao, Jingjing; Eckalbar, Walter L.; Logan, Malcolm; Illing, Nicola; Pollard, Katherine S.; Ahituv, Nadav

2016-01-01

The molecular events leading to the development of the bat wing remain largely unknown, and are thought to be caused, in part, by changes in gene expression during limb development. These expression changes could be instigated by variations in gene regulatory enhancers. Here, we used a comparative genomics approach to identify regions that evolved rapidly in the bat ancestor, but are highly conserved in other vertebrates. We discovered 166 bat accelerated regions (BARs) that overlap H3K27ac and p300 ChIP-seq peaks in developing mouse limbs. Using a mouse enhancer assay, we show that five Myotis lucifugus BARs drive gene expression in the developing mouse limb, with the majority showing differential enhancer activity compared to the mouse orthologous BAR sequences. These include BAR116, which is located telomeric to the HoxD cluster and had robust forelimb expression for the M. lucifugus sequence and no activity for the mouse sequence at embryonic day 12.5. Developing limb expression analysis of Hoxd10-Hoxd13 in Miniopterus natalensis bats showed a high-forelimb weak-hindlimb expression for Hoxd10-Hoxd11, similar to the expression trend observed for M. lucifugus BAR116 in mice, suggesting that it could be involved in the regulation of the bat HoxD complex. Combined, our results highlight novel regulatory regions that could be instrumental for the morphological differences leading to the development of the bat wing. PMID:27019019

Expression and function of the zinc finger transcription factor Sp6-9 in the spider Parasteatoda tepidariorum.

PubMed

Königsmann, Tatiana; Turetzek, Natascha; Pechmann, Matthias; Prpic, Nikola-Michael

2017-11-01

Zinc finger transcription factors of the Sp6-9 group are evolutionarily conserved in all metazoans and have important functions in, e.g., limb formation and heart development. The function of Sp6-9-related genes has been studied in a number of vertebrates and invertebrates, but data from chelicerates (spiders and allies) was lacking so far. We have isolated the ortholog of Sp6-9 from the common house spider Parasteatoda tepidariorum and the cellar spider Pholcus phalangioides. We show that the Sp6-9 gene in these spider species is expressed in the developing appendages thus suggesting a conserved role in limb formation. Indeed, RNAi with Sp6-9 in P. tepidariorum leads not only to strong limb defects, but also to the loss of body segments and head defects in more strongly affected animals. Together with a new expression domain in the early embryo, these data suggest that Sp6-9 has a dual role P. tepidariorum. The early role in head and body segment formation is not known from other arthropods, but the role in limb formation is evolutionarily highly conserved.

Gene Expression Profiling in Limb-Girdle Muscular Dystrophy 2A

PubMed Central

Sáenz, Amets; Azpitarte, Margarita; Armañanzas, Rubén; Leturcq, France; Alzualde, Ainhoa; Inza, Iñaki; García-Bragado, Federico; De la Herran, Gaspar; Corcuera, Julián; Cabello, Ana; Navarro, Carmen; De la Torre, Carolina; Gallardo, Eduard; Illa, Isabel; de Munain, Adolfo López

2008-01-01

Limb-girdle muscular dystrophy type 2A (LGMD2A) is a recessive genetic disorder caused by mutations in calpain 3 (CAPN3). Calpain 3 plays different roles in muscular cells, but little is known about its functions or in vivo substrates. The aim of this study was to identify the genes showing an altered expression in LGMD2A patients and the possible pathways they are implicated in. Ten muscle samples from LGMD2A patients with in which molecular diagnosis was ascertained were investigated using array technology to analyze gene expression profiling as compared to ten normal muscle samples. Upregulated genes were mostly those related to extracellular matrix (different collagens), cell adhesion (fibronectin), muscle development (myosins and melusin) and signal transduction. It is therefore suggested that different proteins located or participating in the costameric region are implicated in processes regulated by calpain 3 during skeletal muscle development. Genes participating in the ubiquitin proteasome degradation pathway were found to be deregulated in LGMD2A patients, suggesting that regulation of this pathway may be under the control of calpain 3 activity. As frizzled-related protein (FRZB) is upregulated in LGMD2A muscle samples, it could be hypothesized that β-catenin regulation is also altered at the Wnt signaling pathway, leading to an incorrect myogenesis. Conversely, expression of most transcription factor genes was downregulated (MYC, FOS and EGR1). Finally, the upregulation of IL-32 and immunoglobulin genes may induce the eosinophil chemoattraction explaining the inflammatory findings observed in presymptomatic stages. The obtained results try to shed some light on identification of novel therapeutic targets for limb-girdle muscular dystrophies. PMID:19015733

Sarcolemmal alpha and gamma sarcoglycan protein deficiencies in Turkish siblings with a novel missense mutation in the alpha sarcoglycan gene.

PubMed

Diniz, Gulden; Tosun Yildirim, Hulya; Akinci, Gulcin; Hazan, Filiz; Ozturk, Aysel; Yararbas, Kanay; Tukun, Ajlan

2014-06-01

The sarcoglycan alpha gene, also known as the adhalin gene, is located on chromosome 17q21; mutations in this gene are associated with limb-girdle muscular dystrophy type 2D. We describe two Turkish siblings with findings consistent with limb-girdle muscular dystrophy type 2D. The evaluation excluded a dystrophinopathy, which is the most common form of muscular dystrophy. Both siblings had very high levels of creatinine phosphokinase and negative molecular tests for deletions and duplications of the dystrophin gene. The older boy presented at 8 years of age with an inability to climb steps and an abnormal gait. His younger brother was 5 years old and had similar symptoms. The muscle biopsy evaluation was performed only in the older brother. The muscle biopsy showed dystrophic features as well as a deficiency in the expression of two different glycoproteins: the alpha sarcoglycan and the gamma sarcoglycan. Sarcolemmal expressions of dystrophin and other sarcoglycans (beta and delta) were diffusely present. DNA analysis demonstrated the presence of previously unknown homozygous mutations [c.226 C > T (p.L76 F)] in exon 3 in the sarcoglycan alpha genes of both siblings. Similar heterozygous point mutations at the same locus were found in both parents, but the genes of beta, delta, and gamma sarcoglycan were normal in the remaining family members. We describe two siblings with limb-girdle muscular dystrophy type 2D with a novel missense mutation. These patients illustrate that the differential diagnosis of muscular dystrophies is impossible with clinical findings alone. Therefore, a muscle biopsy and DNA analysis remain essential methods for diagnosis of muscle diseases. Copyright © 2014 Elsevier Inc. All rights reserved.

Genetics Home Reference: hand-foot-genital syndrome

MedlinePlus

... article on PubMed Central Goodman FR, Scambler PJ. Human HOX gene mutations. Clin Genet. 2001 Jan;59(1):1- ... on PubMed Goodman FR. Limb malformations and the human HOX genes. Am J Med Genet. 2002 Oct 15;112( ...

Blood Oxygenation Level-Dependent Functional Magnetic Resonance Imaging in Early Days: Correlation between Passive Activation and Motor Recovery After Unilateral Striatocapsular Cerebral Infarction.

PubMed

Zhou, Long-Jiang; Wang, Wei; Zhao, Yi; Liu, Chun-Feng; Zhang, Xin-Jiang; Liu, Zhen-Sheng; Li, Hua-Dong

2017-11-01

This study aimed to investigate the correlation between the functional magnetic resonance imaging (fMRI) pattern and the motor function recovery of an affected limb during the passive movement of the affected limb at an early stage of the striatocapsular infarction (SCI). A total of 17 patients with an acute stage of SCI and 3 healthy volunteers as controls were included in this study. fMRI scans of passive movement were performed on the affected limbs of stroke patients within 1 week of onset. Follow-ups were carried out for the motor functions of the affected limbs (before fMRI scan, 1 month, and 3 months after the scan). The control group showed that the activation was mainly located in the contralateral sensorimotor cortex (SMC) and the bilateral supplementary motor area (SMA). The fMRI scan region of interest for stroke patients can be divided into 3 types: type I includes mainly the affected side, bilateral SMC, and SMA with activation; type II includes SMC on the affected side and SMA with activation; type III includes only SMC on the affected side or M1 with activation. The recovery of type I patients was better and faster, while the recovery of type II patients was better but slower, but recovery of type III patients was poorer and slower. Multiple cortical activation patterns were noted during the passive movement of the affected limbs at an early stage of SCI, and a correlation was found between the different activation patterns and the clinical prognosis of patients. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

The pattern and diagnostic criteria of sensory neuronopathy: a case–control study

PubMed Central

Camdessanché, Jean-Philippe; Jousserand, Guillemette; Ferraud, Karine; Vial, Christophe; Petiot, Philippe; Honnorat, Jérôme

2009-01-01

Acquired sensory neuronopathies encompass a group of paraneoplastic, dysimmune, toxic or idiopathic disorders characterized by degeneration of peripheral sensory neurons in dorsal root ganglia. As dorsal root ganglia cannot easily be explored, the clinical diagnosis of these disorders may be difficult. The question as to whether there exists a common clinical pattern of sensory neuronopathies, allowing the establishment of validated and easy-to-use diagnostic criteria, has not yet been addressed. In this study, logistic regression was used to construct diagnostic criteria on a retrospective study population of 78 patients with sensory neuronopathies and 56 with other sensory neuropathies. For this, sensory neuronopathy was provisionally considered as unambiguous in 44 patients with paraneoplastic disorder or cisplatin treatment and likely in 34 with a dysimmune or idiopathic setting who may theoretically have another form of neuropathy. To test the homogeneity of the sensory neuronopathy population, likely candidates were compared with unambiguous cases and then the whole population was compared with the other sensory neuropathies population. Criteria accuracy was checked on 37 prospective patients referred for diagnosis of sensory neuropathy. In the study population, sensory neuronopathy showed a common clinical and electrophysiological pattern that was independent of the underlying cause, including unusual forms with only patchy sensory loss, mild electrical motor nerve abnormalities and predominant small fibre or isolated lower limb involvement. Logistic regression allowed the construction of a set of criteria that gave fair results with the following combination: ataxia in the lower or upper limbs + asymmetrical distribution + sensory loss not restricted to the lower limbs + at least one sensory action potential absent or three sensory action potentials <30% of the lower limit of normal in the upper limbs + less than two nerves with abnormal motor nerve conduction study in the lower limbs. PMID:19506068

Classification of Posture in Poststroke Upper Limb Spasticity: A Potential Decision Tool for Botulinum Toxin A Treatment?

ERIC Educational Resources Information Center

Hefter, Harald; Jost, Wolfgang H.; Reissig, Andrea; Zakine, Benjamin; Bakheit, Abdel Magid; Wissel, Jorg

2012-01-01

A significant percentage of patients suffering from a stroke involving motor-relevant central nervous system regions will develop a spastic movement disorder. Hyperactivity of different muscle combinations forces the limbs affected into abnormal postures or movement patterns. As muscular hyperactivity can effectively and safely be treated with…

Spatial interactions during bimanual coordination patterns: the effect of directional compatibility.

PubMed

Bogaerts, H; Swinnen, S P

2001-04-01

Whereas previous bimanual coordination research has predominantly focused on the constraining role of timing, the present study addressed the role of spatial (i.e., directional) constraints during the simultaneous production of equilateral triangles with both upper limbs. In addition to coordination modes in which mirror-image and isodirectional movements were performed (compatible patterns), new modes were tested in which the left limb lagged with respect to the right by one triangle side (non-compatible patterns). This resulted in the experimental manipulation of directional compatibility between the limbs. In addition, triangles with either horizontal or vertical orientations were to be drawn in order to assess the role of static images on movement production. Results supported the important role of directional constraints in bimanual coordination. Furthermore, triangles in vertical orientations (with a vertical symmetry axis, i.e., one apex pointing up) were drawn more successfully than those in horizontal orientations (with a horizontal symmetry axis, i.e., one apex pointing left or right), suggesting that the static aspects of a geometric form may affect movement dynamics. Finally, evidence suggested that cognitive processes related to integration of the submovements into a unified plan mediate the performance of new coordination patterns. The implications of the present finding for clinical populations are discussed

ITRAQ-based quantitative proteomic analysis of Cynops orientalis limb regeneration.

PubMed

Tang, Jie; Yu, Yuan; Zheng, Hanxue; Yin, Lu; Sun, Mei; Wang, Wenjun; Cui, Jihong; Liu, Wenguang; Xie, Xin; Chen, Fulin

2017-09-22

Salamanders regenerate their limbs after amputation. However, the molecular mechanism of this unique regeneration remains unclear. In this study, isobaric tags for relative and absolute quantification (iTRAQ) coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS) was employed to quantitatively identify differentially expressed proteins in regenerating limbs 3, 7, 14, 30 and 42 days post amputation (dpa). Of 2636 proteins detected in total, 253 proteins were differentially expressed during different regeneration stages. Among these proteins, Asporin, Cadherin-13, Keratin, Collagen alpha-1(XI) and Titin were down-regulated. CAPG, Coronin-1A, AnnexinA1, Cathepsin B were up-regulated compared with the control. The identified proteins were further analyzed to obtain information about their expression patterns and functions in limb regeneration. Functional analysis indicated that the differentially expressed proteins were associated with wound healing, immune response, cellular process, metabolism and binding. This work indicated that significant proteome alternations occurred during salamander limb regeneration. The results may provide fundamental knowledge to understand the mechanism of limb regeneration.

Comparison of the Kinematic Patterns of Kick Between Brazilian and Japanese Young Soccer Players

PubMed Central

Pereira Santiago, Paulo Roberto; Palucci Vieira, Luiz Henrique; Barbieri, Fabio Augusto; Moura, Felipe Arruda; Exel Santana, Juliana; de Andrade, Vitor Luiz; de Souza Bedo, Bruno Luiz; Cunha, Sergio Augusto

2016-01-01

Background Kicking performance is the most studied technical action in soccer and lower limbs kinematics is closely related to success in kicking, mainly because they are essential in imparting high velocity to the ball. Previous studies demonstrated that soccer leagues in different countries exhibit different physical demands and technical requirements during the matches. However, evidencewhether nationality has any influence in the kinematics of soccer-related skills has not yet been reported. The nationality of the players is an aspect that might be also relevant to the performance in kicking. Objectives The aim of this study was to compare the lower limbs kinematic patterns during kicking, between Brazilian and Japanese young top soccer players. Patients and Methods Seven Brazilian (GA) and seven Japanese (GB) U-17 players performed 15 side-foot kicks each, with a distance of 20 m away from the goal, aiming a target of 1 × 1 m in upper corner, constrained by a defensive wall (1.8 × 2 m). Four digital video cameras (120 Hz) recorded the performance for further 3D reconstruction of thigh, shank and foot segments of both kicking and support limbs. The selected kicking cycle was characterized by the toe-off of the kicking limb to the end of the kicking foot when it came in contact with the ball. Stereographical projection of each segment was applied to obtain the representative curves of kicking as function of time for each participant in each trial. Cluster analysis was performed to identify the mean GA and GB curves for each segment. Silhouette coefficient (SC) was calculated, in order to determine the degree of separation between the two groups’ curves. Results Comparison between the median confidence intervals of the SC showed no differences between groups as regards lower limb patterns of movements. Task accuracy was determined by the relative frequency that the ball reached the target for all attempts and no differences were found (GA: 10.48 ± 14.33%; GB: 9.52 ± 6.51%; P = 0.88). Conclusions We conclude that lower limb kinematic patterns, in support and ball contact phases, are similar in young Brazilian and Japanese soccer players during free kicks when adopting the side-foot kick style. PMID:27625761

Allometry and apparent paradoxes in human limb proportions: Implications for scaling factors.

PubMed

Auerbach, Benjamin M; Sylvester, Adam D

2011-03-01

It has been consistently demonstrated that human proximal limb elements exhibit negative allometry, while distal elements scale with positive allometry. Such scaling implies that longer limbs will have higher intralimb indices, a phenomenon not borne out by empirical analyses. This, therefore, creates a paradox within the limb allometry literature. This study shows that these apparently conflicting results are the product of two separate phenomena. First, the use of the geometric mean of limb elements produces allometry coefficients that are not independent, and that when using ordinary least squares regression must yield an average slope of one. This phenomenon argues against using the geometric mean as a size variable when examining limb allometry. While the employment of relevant dimensions independent of those under analysis to calculate the geometric mean--as suggested by Coleman (Am J Phys Anthropol 135 (2008) 404-415)--may be a partial method for resolving the problem, an empirically determined, independent and biologically relevant size variable is advocated. If stature is used instead of the geometric mean as an independent size variable, all major limb elements scale with positive allometry. Second, while limb allometry coefficients do indicate differential allometry in limb elements, and thus should lead to some intralimb index allometry, this pattern appears to be attenuated by other sources of limb element length variation. Copyright © 2010 Wiley-Liss, Inc.

The king cobra genome reveals dynamic gene evolution and adaptation in the snake venom system.

PubMed

Vonk, Freek J; Casewell, Nicholas R; Henkel, Christiaan V; Heimberg, Alysha M; Jansen, Hans J; McCleary, Ryan J R; Kerkkamp, Harald M E; Vos, Rutger A; Guerreiro, Isabel; Calvete, Juan J; Wüster, Wolfgang; Woods, Anthony E; Logan, Jessica M; Harrison, Robert A; Castoe, Todd A; de Koning, A P Jason; Pollock, David D; Yandell, Mark; Calderon, Diego; Renjifo, Camila; Currier, Rachel B; Salgado, David; Pla, Davinia; Sanz, Libia; Hyder, Asad S; Ribeiro, José M C; Arntzen, Jan W; van den Thillart, Guido E E J M; Boetzer, Marten; Pirovano, Walter; Dirks, Ron P; Spaink, Herman P; Duboule, Denis; McGlinn, Edwina; Kini, R Manjunatha; Richardson, Michael K

2013-12-17

Snakes are limbless predators, and many species use venom to help overpower relatively large, agile prey. Snake venoms are complex protein mixtures encoded by several multilocus gene families that function synergistically to cause incapacitation. To examine venom evolution, we sequenced and interrogated the genome of a venomous snake, the king cobra (Ophiophagus hannah), and compared it, together with our unique transcriptome, microRNA, and proteome datasets from this species, with data from other vertebrates. In contrast to the platypus, the only other venomous vertebrate with a sequenced genome, we find that snake toxin genes evolve through several distinct co-option mechanisms and exhibit surprisingly variable levels of gene duplication and directional selection that correlate with their functional importance in prey capture. The enigmatic accessory venom gland shows a very different pattern of toxin gene expression from the main venom gland and seems to have recruited toxin-like lectin genes repeatedly for new nontoxic functions. In addition, tissue-specific microRNA analyses suggested the co-option of core genetic regulatory components of the venom secretory system from a pancreatic origin. Although the king cobra is limbless, we recovered coding sequences for all Hox genes involved in amniote limb development, with the exception of Hoxd12. Our results provide a unique view of the origin and evolution of snake venom and reveal multiple genome-level adaptive responses to natural selection in this complex biological weapon system. More generally, they provide insight into mechanisms of protein evolution under strong selection.

Directional constraint of endpoint force emerges from hindlimb anatomy.

PubMed

Bunderson, Nathan E; McKay, J Lucas; Ting, Lena H; Burkholder, Thomas J

2010-06-15

Postural control requires the coordination of force production at the limb endpoints to apply an appropriate force to the body. Subjected to horizontal plane perturbations, quadruped limbs stereotypically produce force constrained along a line that passes near the center of mass. This phenomenon, referred to as the force constraint strategy, may reflect mechanical constraints on the limb or body, a specific neural control strategy or an interaction among neural controls and mechanical constraints. We used a neuromuscular model of the cat hindlimb to test the hypothesis that the anatomical constraints restrict the mechanical action of individual muscles during stance and constrain the response to perturbations to a line independent of perturbation direction. In a linearized neuromuscular model of the cat hindlimb, muscle lengthening directions were highly conserved across 10,000 different muscle activation patterns, each of which produced an identical, stance-like endpoint force. These lengthening directions were closely aligned with the sagittal plane and reveal an anatomical structure for directionally constrained force responses. Each of the 10,000 activation patterns was predicted to produce stable stance based on Lyapunov stability analysis. In forward simulations of the nonlinear, seven degree of freedom model under the action of 200 random muscle activation patterns, displacement of the endpoint from its equilibrium position produced restoring forces, which were also biased toward the sagittal plane. The single exception was an activation pattern based on minimum muscle stress optimization, which produced destabilizing force responses in some perturbation directions. The sagittal force constraint increased during simulations as the system shifted from an inertial response during the acceleration phase to a viscoelastic response as peak velocity was obtained. These results qualitatively match similar experimental observations and suggest that the force constraint phenomenon may result from the anatomical arrangement of the limb.

Directional constraint of endpoint force emerges from hindlimb anatomy

PubMed Central

Bunderson, Nathan E.; McKay, J. Lucas; Ting, Lena H.; Burkholder, Thomas J.

2010-01-01

Postural control requires the coordination of force production at the limb endpoints to apply an appropriate force to the body. Subjected to horizontal plane perturbations, quadruped limbs stereotypically produce force constrained along a line that passes near the center of mass. This phenomenon, referred to as the force constraint strategy, may reflect mechanical constraints on the limb or body, a specific neural control strategy or an interaction among neural controls and mechanical constraints. We used a neuromuscular model of the cat hindlimb to test the hypothesis that the anatomical constraints restrict the mechanical action of individual muscles during stance and constrain the response to perturbations to a line independent of perturbation direction. In a linearized neuromuscular model of the cat hindlimb, muscle lengthening directions were highly conserved across 10,000 different muscle activation patterns, each of which produced an identical, stance-like endpoint force. These lengthening directions were closely aligned with the sagittal plane and reveal an anatomical structure for directionally constrained force responses. Each of the 10,000 activation patterns was predicted to produce stable stance based on Lyapunov stability analysis. In forward simulations of the nonlinear, seven degree of freedom model under the action of 200 random muscle activation patterns, displacement of the endpoint from its equilibrium position produced restoring forces, which were also biased toward the sagittal plane. The single exception was an activation pattern based on minimum muscle stress optimization, which produced destabilizing force responses in some perturbation directions. The sagittal force constraint increased during simulations as the system shifted from an inertial response during the acceleration phase to a viscoelastic response as peak velocity was obtained. These results qualitatively match similar experimental observations and suggest that the force constraint phenomenon may result from the anatomical arrangement of the limb. PMID:20511528

An equilibrium-point model for fast, single-joint movement: I. Emergence of strategy-dependent EMG patterns.

PubMed

Latash, M L; Gottlieb, G L

1991-09-01

We describe a model for the regulation of fast, single-joint movements, based on the equilibrium-point hypothesis. Limb movement follows constant rate shifts of independently regulated neuromuscular variables. The independently regulated variables are tentatively identified as thresholds of a length sensitive reflex for each of the participating muscles. We use the model to predict EMG patterns associated with changes in the conditions of movement execution, specifically, changes in movement times, velocities, amplitudes, and moments of limb inertia. The approach provides a theoretical neural framework for the dual-strategy hypothesis, which considers certain movements to be results of one of two basic, speed-sensitive or speed-insensitive strategies. This model is advanced as an alternative to pattern-imposing models based on explicit regulation of timing and amplitudes of signals that are explicitly manifest in the EMG patterns.

Reorganisation of Hoxd regulatory landscapes during the evolution of a snake-like body plan.

PubMed

Guerreiro, Isabel; Gitto, Sandra; Novoa, Ana; Codourey, Julien; Nguyen Huynh, Thi Hanh; Gonzalez, Federico; Milinkovitch, Michel C; Mallo, Moises; Duboule, Denis

2016-08-01

Within land vertebrate species, snakes display extreme variations in their body plan, characterized by the absence of limbs and an elongated morphology. Such a particular interpretation of the basic vertebrate body architecture has often been associated with changes in the function or regulation of Hox genes. Here, we use an interspecies comparative approach to investigate different regulatory aspects at the snake HoxD locus. We report that, unlike in other vertebrates, snake mesoderm-specific enhancers are mostly located within the HoxD cluster itself rather than outside. In addition, despite both the absence of limbs and an altered Hoxd gene regulation in external genitalia, the limb-associated bimodal HoxD chromatin structure is maintained at the snake locus. Finally, we show that snake and mouse orthologous enhancer sequences can display distinct expression specificities. These results show that vertebrate morphological evolution likely involved extensive reorganisation at Hox loci, yet within a generally conserved regulatory framework.

Late-onset Pompe disease: what is the prevalence of limb-girdle muscular weakness presentation?

PubMed

Lorenzoni, Paulo José; Kay, Cláudia Suemi Kamoi; Higashi, Nádia Sugano; D'Almeida, Vânia; Werneck, Lineu Cesar; Scola, Rosana Herminia

2018-04-01

Pompe disease is an inherited disease caused by acid alpha-glucosidase (GAA) deficiency. A single center observational study aimed at assessing the prevalence of late-onset Pompe disease in a high-risk Brazilian population, using the dried blood spot test to detect GAA deficiency as a main screening tool. Dried blood spots were collected for GAA activity assay from 24 patients with "unexplained" limb-girdle muscular weakness without vacuolar myopathy in their muscle biopsy. Samples with reduced enzyme activity were also investigated for GAA gene mutations. Of the 24 patients with dried blood spots, one patient (4.2%) showed low GAA enzyme activity (NaG/AaGIA: 40.42; %INH: 87.22%). In this patient, genetic analysis confirmed two heterozygous mutations in the GAA gene (c.-32-13T>G/p.Arg854Ter). Our data confirm that clinicians should look for late-onset Pompe disease in patients whose clinical manifestation is an "unexplained" limb-girdle weakness even without vacuolar myopathy in muscle biopsy.

Reorganisation of Hoxd regulatory landscapes during the evolution of a snake-like body plan

PubMed Central

Guerreiro, Isabel; Gitto, Sandra; Novoa, Ana; Codourey, Julien; Nguyen Huynh, Thi Hanh; Gonzalez, Federico; Milinkovitch, Michel C; Mallo, Moises; Duboule, Denis

2016-01-01

Within land vertebrate species, snakes display extreme variations in their body plan, characterized by the absence of limbs and an elongated morphology. Such a particular interpretation of the basic vertebrate body architecture has often been associated with changes in the function or regulation of Hox genes. Here, we use an interspecies comparative approach to investigate different regulatory aspects at the snake HoxD locus. We report that, unlike in other vertebrates, snake mesoderm-specific enhancers are mostly located within the HoxD cluster itself rather than outside. In addition, despite both the absence of limbs and an altered Hoxd gene regulation in external genitalia, the limb-associated bimodal HoxD chromatin structure is maintained at the snake locus. Finally, we show that snake and mouse orthologous enhancer sequences can display distinct expression specificities. These results show that vertebrate morphological evolution likely involved extensive reorganisation at Hox loci, yet within a generally conserved regulatory framework. DOI: http://dx.doi.org/10.7554/eLife.16087.001 PMID:27476854

Divergent Hox Coding and Evasion of Retinoid Signaling Specifies Motor Neurons Innervating Digit Muscles

PubMed Central

Mendelsohn, Alana I.; Dasen, Jeremy S.; Jessell, Thomas M.

2017-01-01

Summary The establishment of spinal motor neuron subclass diversity is achieved through developmental programs that are aligned with the organization of muscle targets in the limb. The evolutionary emergence of digits represents a specialized adaptation of limb morphology, yet it remains unclear how the specification of digit-innervating motor neuron subtypes parallels the elaboration of digits. We show that digit-innervating motor neurons can be defined by selective gene markers and distinguished from other LMC neurons by the expression of a variant Hox gene repertoire and by the failure to express a key enzyme involved in retinoic acid synthesis. This divergent developmental program is sufficient to induce the specification of digit-innervating motor neurons, emphasizing the specialized status of digit control in the evolution of skilled motor behaviors. Our findings suggest that the emergence of digits in the limb is matched by distinct mechanisms for specifying motor neurons that innervate digit muscles. PMID:28190640

Increasing morphological complexity in multiple parallel lineages of the Crustacea

PubMed Central

Adamowicz, Sarah J.; Purvis, Andy; Wills, Matthew A.

2008-01-01

The prospect of finding macroevolutionary trends and rules in the history of life is tremendously appealing, but very few pervasive trends have been found. Here, we demonstrate a parallel increase in the morphological complexity of most of the deep lineages within a major clade. We focus on the Crustacea, measuring the morphological differentiation of limbs. First, we show a clear trend of increasing complexity among 66 free-living, ordinal-level taxa from the Phanerozoic fossil record. We next demonstrate that this trend is pervasive, occurring in 10 or 11 of 12 matched-pair comparisons (across five morphological diversity indices) between extinct Paleozoic and related Recent taxa. This clearly differentiates the pattern from the effects of lineage sorting. Furthermore, newly appearing taxa tend to have had more types of limbs and a higher degree of limb differentiation than the contemporaneous average, whereas those going extinct showed higher-than-average limb redundancy. Patterns of contemporary species diversity partially reflect the paleontological trend. These results provide a rare demonstration of a large-scale and probably driven trend occurring across multiple independent lineages and influencing both the form and number of species through deep time and in the present day. PMID:18347335

Pattern of Injuries from Road Traffic Accidents Presented at a Rural Teaching Institution of Karachi.

PubMed

Shamim, Muhammad

2017-08-01

The aim of the study is to study the pattern of injuries from road traffic accidents presented at the emergency department of a rural teaching institution in Karachi. This descriptive case series was conducted prospectively in the Emergency Department of Fatima Hospital and Baqai Medical University from 1 January 2012 to 21 March 2013. There were 385 patients in the series. All of the patients with recent injuries from road traffic accidents were included. Cases with injuries more than 72 h old were excluded. The majority of patients had lower limb injuries 172 (44.7%), followed by head and neck injuries 107 (27.8%), multiple injuries 62 (16.1%), upper limb injuries 22 (5.7%), abdominoperineal injuries 19 (5%), and chest injuries 3 (0.8%). Majority (229, 59.5%) of patients were given first aid treatment and discharged, while 151 (39.3%) patients were either admitted or referred to better equipped hospitals. Three patients were brought dead, and two patients left against medical advice. The lower limb injuries were the commonest road traffic accidental injuries, followed by head and neck injuries, multiple injuries, upper limb injuries, abdominoperineal injuries, and chest injuries.

Role of Brain-Derived Neurotrophic Factor in Beneficial Effects of Repetitive Transcranial Magnetic Stimulation for Upper Limb Hemiparesis after Stroke.

PubMed

Niimi, Masachika; Hashimoto, Kenji; Kakuda, Wataru; Miyano, Satoshi; Momosaki, Ryo; Ishima, Tamaki; Abo, Masahiro

2016-01-01

Repetitive transcranial magnetic stimulation (rTMS) can improve upper limb hemiparesis after stroke but the mechanism underlying its efficacy remains elusive. rTMS seems to alter brain-derived neurotrophic factor (BDNF) and such effect is influenced by BDNF gene polymorphism. To investigate the molecular effects of rTMS on serum levels of BDNF, its precursor proBDNF and matrix metalloproteinase-9 (MMP-9) in poststroke patients with upper limb hemiparesis. Poststroke patients with upper limb hemiparesis were studied. Sixty-two patients underwent rehabilitation plus rTMS combination therapy and 33 patients underwent rehabilitation monotherapy without rTMS for 14 days at our hospital. One Hz rTMS was applied over the motor representation of the first dorsal interosseous muscle on the non-lesional hemisphere. Fugl-Meyer Assessment and Wolf Motor Function (WMFT) were used to evaluate motor function on the affected upper limb before and after intervention. Blood samples were collected for analysis of BDNF polymorphism and measurement of BDNF, proBDNF and MMP-9 levels. Two-week combination therapy increased BDNF and MMP-9 serum levels, but not serum proBDNF. Serum BDNF and MMP-9 levels did not correlate with motor function improvement, though baseline serum proBDNF levels correlated negatively and significantly with improvement in WMFT (ρ = -0.422, p = 0.002). The outcome of rTMS therapy was not altered by BDNF gene polymorphism. The combination therapy of rehabilitation plus low-frequency rTMS seems to improve motor function in the affected limb, by activating BDNF processing. BDNF and its precursor proBDNF could be potentially suitable biomarkers for poststroke motor recovery.

Deletion in the EVC2 gene causes chondrodysplastic dwarfism in Tyrolean Grey cattle.

PubMed

Murgiano, Leonardo; Jagannathan, Vidhya; Benazzi, Cinzia; Bolcato, Marilena; Brunetti, Barbara; Muscatello, Luisa Vera; Dittmer, Keren; Piffer, Christian; Gentile, Arcangelo; Drögemüller, Cord

2014-01-01

During the summer of 2013 seven Italian Tyrolean Grey calves were born with abnormally short limbs. Detailed clinical and pathological examination revealed similarities to chondrodysplastic dwarfism. Pedigree analysis showed a common founder, assuming autosomal monogenic recessive transmission of the defective allele. A positional cloning approach combining genome wide association and homozygosity mapping identified a single 1.6 Mb genomic region on BTA 6 that was associated with the disease. Whole genome re-sequencing of an affected calf revealed a single candidate causal mutation in the Ellis van Creveld syndrome 2 (EVC2) gene. This gene is known to be associated with chondrodysplastic dwarfism in Japanese Brown cattle, and dwarfism, abnormal nails and teeth, and dysostosis in humans with Ellis-van Creveld syndrome. Sanger sequencing confirmed the presence of a 2 bp deletion in exon 19 (c.2993_2994ACdel) that led to a premature stop codon in the coding sequence of bovine EVC2, and was concordant with the recessive pattern of inheritance in affected and carrier animals. This loss of function mutation confirms the important role of EVC2 in bone development. Genetic testing can now be used to eliminate this form of chondrodysplastic dwarfism from Tyrolean Grey cattle.

Deletion in the EVC2 Gene Causes Chondrodysplastic Dwarfism in Tyrolean Grey Cattle

PubMed Central

Murgiano, Leonardo; Jagannathan, Vidhya; Benazzi, Cinzia; Bolcato, Marilena; Brunetti, Barbara; Muscatello, Luisa Vera; Dittmer, Keren; Piffer, Christian; Gentile, Arcangelo; Drögemüller, Cord

2014-01-01

During the summer of 2013 seven Italian Tyrolean Grey calves were born with abnormally short limbs. Detailed clinical and pathological examination revealed similarities to chondrodysplastic dwarfism. Pedigree analysis showed a common founder, assuming autosomal monogenic recessive transmission of the defective allele. A positional cloning approach combining genome wide association and homozygosity mapping identified a single 1.6 Mb genomic region on BTA 6 that was associated with the disease. Whole genome re-sequencing of an affected calf revealed a single candidate causal mutation in the Ellis van Creveld syndrome 2 (EVC2) gene. This gene is known to be associated with chondrodysplastic dwarfism in Japanese Brown cattle, and dwarfism, abnormal nails and teeth, and dysostosis in humans with Ellis-van Creveld syndrome. Sanger sequencing confirmed the presence of a 2 bp deletion in exon 19 (c.2993_2994ACdel) that led to a premature stop codon in the coding sequence of bovine EVC2, and was concordant with the recessive pattern of inheritance in affected and carrier animals. This loss of function mutation confirms the important role of EVC2 in bone development. Genetic testing can now be used to eliminate this form of chondrodysplastic dwarfism from Tyrolean Grey cattle. PMID:24733244

PhEXPA1, a Petunia hybrida expansin, is involved in cell wall metabolism and in plant architecture specification.

PubMed

Dal Santo, Silvia; Fasoli, Marianna; Cavallini, Erika; Tornielli, Giovanni Battista; Pezzotti, Mario; Zenoni, Sara

2011-12-01

Expansins are wall-loosening proteins that induce wall stress relaxation and irreversible wall extension in a pH-dependent manner. Despite a substantial body of work has been performed on the characterization of many expansins genes in different plant species, the knowledge about their precise biological roles during plant development remains scarce. To yield insights into the expansion process in Petunia hybrida, PhEXPA1, an expansin gene preferentially expressed in petal limb, has been characterized. The constitutive overexpression of PhEXPA1 significantly increased expansin activity, cells size and organ dimensions. Moreover, 35S::PhEXPA1 transgenic plants exhibited an altered cell wall polymer composition and a precocious timing of axillary meristem development compared with wild-type plants. These findings supported a previous hypothesis that expansins are not merely structural proteins involved in plant cell wall metabolism but they also take part in many plant development processes. Here, to support this expansins dual role, we discuss about differential cell wall-related genes expressed in PhEXPA1 expression mutants and gradients of altered petunia branching pattern. © 2011 Landes Bioscience

Myozenin: An α-actinin- and γ-filamin-binding protein of skeletal muscle Z lines

PubMed Central

Takada, Fumio; Woude, Douglas L. Vander; Tong, Hui-Qi; Thompson, Terri G.; Watkins, Simon C.; Kunkel, Louis M.; Beggs, Alan H.

2001-01-01

To better understand the structure and function of Z lines, we used sarcomeric isoforms of α-actinin and γ-filamin to screen a human skeletal muscle cDNA library for interacting proteins by using the yeast two-hybrid system. Here we describe myozenin (MYOZ), an α-actinin- and γ-filamin-binding Z line protein expressed predominantly in skeletal muscle. Myozenin is predicted to be a 32-kDa, globular protein with a central glycine-rich domain flanked by α-helical regions with no strong homologies to any known genes. The MYOZ gene has six exons and maps to human chromosome 10q22.1-q22.2. Northern blot analysis demonstrated that this transcript is expressed primarily in skeletal muscle with significantly lower levels of expression in several other tissues. Antimyozenin antisera stain skeletal muscle in a sarcomeric pattern indistinguishable from that seen by using antibodies for α-actinin, and immunogold electron microscopy confirms localization specifically to Z lines. Thus, myozenin is a skeletal muscle Z line protein that may be a good candidate gene for limb-girdle muscular dystrophy or other neuromuscular disorders. PMID:11171996

The apical ectodermal ridge of the mouse model of ectrodactyly Dlx5;Dlx6−/− shows altered stratification and cell polarity, which are restored by exogenous Wnt5a ligand

PubMed Central

Conte, Daniele; Garaffo, Giulia; Lo Iacono, Nadia; Mantero, Stefano; Piccolo, Stefano; Cordenonsi, Michelangelo; Perez-Morga, David; Orecchia, Valeria; Poli, Valeria; Merlo, Giorgio R.

2016-01-01

The congenital malformation split hand/foot (SHFM) is characterized by missing central fingers and dysmorphology or fusion of the remaining ones. Type-1 SHFM is linked to deletions/rearrangements of the DLX5–DLX6 locus and point mutations in the DLX5 gene. The ectrodactyly phenotype is reproduced in mice by the double knockout (DKO) of Dlx5 and Dlx6. During limb development, the apical ectodermal ridge (AER) is a key-signaling center responsible for early proximal–distal growth and patterning. In Dlx5;6 DKO hindlimbs, the central wedge of the AER loses multilayered organization and shows down-regulation of FGF8 and Dlx2. In search for the mechanism, we examined the non-canonical Wnt signaling, considering that Dwnt-5 is a target of distalless in Drosophila and the knockout of Wnt5, Ryk, Ror2 and Vangl2 in the mouse causes severe limb malformations. We found that in Dlx5;6 DKO limbs, the AER expresses lower levels of Wnt5a, shows scattered β-catenin responsive cells and altered basolateral and planar cell polarity (PCP). The addition of Wnt5a to cultured embryonic limbs restored the expression of AER markers and its stratification. Conversely, the inhibition of the PCP molecule c-jun N-terminal kinase caused a loss of AER marker expression. In vitro, the addition of Wnt5a on mixed primary cultures of embryonic ectoderm and mesenchyme was able to confer re-polarization. We conclude that the Dlx-related ectrodactyly defect is associated with the loss of basoapical and PCP, due to reduced Wnt5a expression and that the restoration of the Wnt5a level is sufficient to partially reverts AER misorganization and dysmorphology. PMID:26685160

Blastema induction in aneurogenic state and Prrx-1 regulation by MMPs and FGFs in Ambystoma mexicanum limb regeneration.

PubMed

Satoh, Akira; makanae, Aki; Hirata, Ayako; Satou, Yutaka

2011-07-15

Urodele amphibians can regenerate amputated limbs. It has been considered that differentiated dermal tissues generate multipotent and undifferentiated cells called blastema cells during limb regeneration. In early phases of limb regeneration, blastema cells are induced by nerves and the apical epithelial cap (AEC). We had previously investigated the role of neurotrophic factors in blastema or blastema-like formation consisting of Prrx-1 positive cells. A new system suitable for investigating early phases of limb regeneration, called the accessory limb model (ALM), was recently developed. In this study, we performed a comparative transcriptome analysis between a blastema and wound using ALM. Matrix metalloproteinase (MMP) and fibroblast growth factor (FGF) signaling components were observed to be predominantly expressed in ALM blastema cells. Furthermore, we found that MMP activity induced a blastema marker gene, Prrx-1, in vitro, and FGF signaling pathways worked in coordination to maintain Prrx-1 expression and ALM blastema formation. Furthermore, we demonstrated that these two activities were sufficient to induce an ALM blastema in the absence of a nerve in vivo. Copyright © 2011 Elsevier Inc. All rights reserved.

Gene therapy for therapeutic angiogenesis in peripheral arterial disease - a systematic review and meta-analysis of randomized, controlled trials.

PubMed

Hammer, Alexandra; Steiner, Sabine

2013-09-01

Beyond pharmacological, endovascular and surgical treatment strategies for peripheral arterial disease (PAD), therapeutic angiogenesis has been advocated to relieve symptoms and support limb salvage, in particular in patients with critical limb ischemia. We aimed to systematically review randomized controlled trials (RCTs) of gene therapy in PAD. A systematic search of electronic databases was performed to identify RCTs studying local administration of pro-angiogenic growth factors (VEGF, FGF, HGF, Del-1, HIF-1alpha) using plasmid or viral gene transfer by intra-arterial or intra-muscular injections. Outcomes of interest comprised all-cause mortality, amputations, ulcer healing, walking distance and ankle-brachial index. If feasible, standard meta-analysis should be performed with subgroup analysis for claudicants and patients with critical limb ischemia (CLI). The systematic search yielded 12 RCTs for analysis from 1163 citations. In total, 1494 patients (29 % females) were included with the majority suffering from CLI (64 %). Various endpoints were improved by single studies, but none by a majority of studies. Meta-analysis showed neither a significant benefit nor harm for gene therapy when synthesizing data for all-cause mortality (OR 0.88, 95 % CI 0.62 - 1.26) amputations (OR 0.64, 95 % CI 0.31 - 1.31) or ulcer healing (OR 1.79, 95 % CI 0.8 - 4.01). No differences were seen between patients with intermittent claudication or CLI. Despite promising results in single studies, no clear benefit could be identified for gene therapy in PAD patients, irrespective of disease severity.

Biomechanical effects of robot assisted walking on knee joint kinematics and muscle activation pattern.

PubMed

Thangavel, Pavithra; Vidhya, S; Li, Junhua; Chew, Effie; Bezerianos, Anastasios; Yu, Haoyong

2017-07-01

Since manual rehabilitation therapy can be taxing for both the patient and the physiotherapist, a gait rehabilitation robot has been built to reduce the physical strain and increase the efficacy of the rehabilitation therapy. The prototype of the gait rehabilitation robot is designed to provide assistance while walking for patients with abnormal gait pattern and it can also be used for rehabilitation therapy to restore an individual's normal gait pattern by aiding motor recovery. The Gait Rehabilitation Robot uses gait event based synchronization, which enables the exoskeleton to provide synchronous assistance during walking that aims to reduce the lower-limb muscle activation. This study emphasizes on the biomechanical effects of assisted walking on the lower limb by analyzing the EMG signal, knee joint kinematics data that was collected from the right leg during the various experimental conditions. The analysis of the measured data shows an improved knee joint trajectory and reduction in muscle activity with assistance. The result of this study does not only assess the functionality of the exoskeleton but also provides a profound understanding of the human-robot interaction by studying the effects of assistance on the lower limb.

Genomic Identification and Analysis of Shared Cis-regulator Elements in a Developmentally Critical homeobox Cluster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chris Amemiya

2003-04-01

The goals of this project were to isolate, characterize, and sequence the Dlx3/Dlx7 bigene cluster from twelve different species of mammals. The Dlx3 and Dlx7 genes are known to encode homeobox transcription factors involved in patterning of structures in the vertebrate jaw as well as vertebrate limbs. Genomic sequences from the respective taxa will subsequently be compared in order to identify conserved non-coding sequences that are potential cis-regulatory elements. Based on the comparisons they will fashion transgenic mouse experiments to functionally test the strength of the potential cis-regulatory elements. A goal of the project is to attempt to identify thosemore » elements that may function in coordinately regulating both Dlx3 and Dlx7 functions.« less

Embryonic timing, axial stem cells, chromatin dynamics, and the Hox clock

PubMed Central

Deschamps, Jacqueline; Duboule, Denis

2017-01-01

Collinear regulation of Hox genes in space and time has been an outstanding question ever since the initial work of Ed Lewis in 1978. Here we discuss recent advances in our understanding of this phenomenon in relation to novel concepts associated with large-scale regulation and chromatin structure during the development of both axial and limb patterns. We further discuss how this sequential transcriptional activation marks embryonic stem cell-like axial progenitors in mammals and, consequently, how a temporal genetic system is further translated into spatial coordinates via the fate of these progenitors. In this context, we argue the benefit and necessity of implementing this unique mechanism as well as the difficulty in evolving an alternative strategy to deliver this critical positional information. PMID:28860158

Reciprocal Expression of lin-41 and the microRNAs let-7 and mir-125 During Mouse Embryogenesis

PubMed Central

Schulman, Betsy R. Maller; Esquela-Kerscher, Aurora; Slack, Frank J.

2008-01-01

In C. elegans, heterochronic genes control the timing of cell fate determination during development. Two heterochronic genes, let-7 and lin-4, encode microRNAs (miRNAs) that down-regulate a third heterochronic gene lin-41 by binding to complementary sites in its 3’UTR. let-7 and lin-4 are conserved in mammals. Here we report the cloning and sequencing of mammalian lin-41 orthologs. We find that mouse and human lin-41 genes contain predicted conserved complementary sites for let-7 and the lin-4 ortholog, mir-125, in their 3’UTRs. Mouse lin-41 (Mlin-41) is temporally expressed in developing mouse embryos, most dramatically in the limb buds. Mlin-41 is down-regulated during mid-embryogenesis at the time when mouse let-7c and mir-125 RNA levels are up-regulated. Our results suggest that mammalian lin-41 is temporally regulated by miRNAs in order to direct key developmental events such as limb formation. PMID:16247770

Highly efficient targeted mutagenesis in one-cell mouse embryos mediated by the TALEN and CRISPR/Cas systems.

PubMed

Yasue, Akihiro; Mitsui, Silvia Naomi; Watanabe, Takahito; Sakuma, Tetsushi; Oyadomari, Seiichi; Yamamoto, Takashi; Noji, Sumihare; Mito, Taro; Tanaka, Eiji

2014-07-16

Since the establishment of embryonic stem (ES) cell lines, the combined use of gene targeting with homologous recombination has aided in elucidating the functions of various genes. However, the ES cell technique is inefficient and time-consuming. Recently, two new gene-targeting technologies have been developed: the transcription activator-like effector nuclease (TALEN) system, and the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein (Cas) system. In addition to aiding researchers in solving conventional problems, these technologies can be used to induce site-specific mutations in various species for which ES cells have not been established. Here, by targeting the Fgf10 gene through RNA microinjection in one-cell mouse embryos with the TALEN and CRISPR/Cas systems, we produced the known limb-defect phenotypes of Fgf10-deficient embryos at the F0 generation. Compared to the TALEN system, the CRISPR/Cas system induced the limb-defect phenotypes with a strikingly higher efficiency. Our results demonstrate that although both gene-targeting technologies are useful, the CRISPR/Cas system more effectively elicits single-step biallelic mutations in mice.

The influence of applying additional weight to the affected leg on gait patterns during aquatic treadmill walking in people poststroke.

PubMed

Jung, Taeyou; Lee, Dokyeong; Charalambous, Charalambos; Vrongistinos, Konstantinos

2010-01-01

Jung T, Lee D, Charalambous C, Vrongistinos K. The influence of applying additional weight to the affected leg on gait patterns during aquatic treadmill walking in people poststroke. To investigate how the application of additional weights to the affected leg influences gait patterns of people poststroke during aquatic treadmill walking. Comparative gait analysis. University-based aquatic therapy center. Community-dwelling volunteers (n=22) with chronic hemiparesis caused by stroke. Not applicable. Spatiotemporal and kinematic gait parameters. The use of an ankle weight showed an increase in the stance phase percentage of gait cycle (3%, P=.015) when compared with no weight. However, the difference was not significant after a Bonferroni adjustment was applied for a more stringent statistical analysis. No significant differences were found in cadence and stride length. The use of an ankle weight showed a significant decrease of the peak hip flexion (7.9%, P=.001) of the affected limb as compared with no weight condition. This decrease was marked as the reduction of unwanted limb flotation because people poststroke typically show excessive hip flexion of the paretic leg in the late swing phase followed by fluctuating hip movements during aquatic treadmill walking. The frontal and transverse plane hip motions did not show any significant differences but displayed a trend of a decrease in the peak hip abduction during the swing phase with additional weights. The use of additional weight did not alter sagittal plane kinematics of the knee and ankle joints. The use of applied weight on the affected limb can reduce unwanted limb flotation on the paretic side during aquatic treadmill walking. It can also assist the stance stability by increasing the stance phase percentage closer to 60% of gait cycle. Both findings can contribute to the development of more efficient motor patterns in gait training for people poststroke. The use of a cuff weight does not seem to reduce the limb circumduction during aquatic treadmill walking. Copyright (c) 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Neurotrophic regulation of epidermal dedifferentiation during wound healing and limb regeneration in the axolotl (Ambystoma mexicanum).

PubMed

Satoh, A; Graham, G M C; Bryant, S V; Gardiner, D M

2008-07-15

Adult urodeles (salamanders) are unique in their ability to regenerate complex organs perfectly. The recently developed Accessory Limb Model (ALM) in the axolotl provides an opportunity to identify and characterize the essential signaling events that control the early steps in limb regeneration. The ALM demonstrates that limb regeneration progresses in a stepwise fashion that is dependent on signals from the wound epidermis, nerves and dermal fibroblasts from opposite sides of the limb. When all the signals are present, a limb is formed de novo. The ALM thus provides an opportunity to identify and characterize the signaling pathways that control blastema morphogenesis and limb regeneration. In the present study, we have utilized the ALM to identity the buttonhead-like zinc-finger transcription factor, Sp9, as being involved in the formation of the regeneration epithelium. Sp9 expression is induced in basal keratinocytes of the apical blastema epithelium in a pattern that is comparable to its expression in developing limb buds, and it thus is an important marker for dedifferentiation of the epidermis. Induction of Sp9 expression is nerve-dependent, and we have identified KGF as an endogenous nerve factor that induces expression of Sp9 in the regeneration epithelium.

Studies of limb-dislodging forces acting on an ejection seat occupant.

PubMed

Schneck, D J

1980-03-01

A mathematical theory is being developed in order to calculate the aerodynamic loading to which a pilot is exposed during high-speed ejections. Neglecting the initial effects of flow separation, results thus far indicate that a pilot's musculoskeletal system is not likely to withstand the tendency for limb-flailing if he is ejecting at Mach numbers in excess of about 0.7. This tendency depends very strongly upon the angle at which the pilot's limbs intercept a high-speed flow; the forces that cause limb dislodgement increase dramatically with speed of ejection. Examining the time-course of limb-dislodging forces after the initial onset of windblast, the theory further predicts the generation of a double vortex street pattern on the downstream side of the limbs of an ejection seat occupant. This results in the corresponding appearance of oscillating forces tending to cause lateral motion (vibration) of the limbs. The amplitude and frequency of these oscillating forces are also very dependent on the Mach number of ejection and the angle at which the pilot's limbs intercept the flow. However, even at moderate Mach numbers, the frequency can be as high as 100 cycles per second, and the amplitude rapidly exceeds a pilot's musculo-skeletal resistive powers for Mach numbers above 0.7.

Are muscle activation patterns altered during shod and barefoot running with a forefoot footfall pattern?

PubMed

Ervilha, Ulysses Fernandes; Mochizuki, Luis; Figueira, Aylton; Hamill, Joseph

2017-09-01

This study aimed to investigate the activation of lower limb muscles during barefoot and shod running with forefoot or rearfoot footfall patterns. Nine habitually shod runners were asked to run straight for 20 m at self-selected speed. Ground reaction forces and thigh and shank muscle surface electromyographic (EMG) were recorded. EMG outcomes (EMG intensity [iEMG], latency between muscle activation and ground reaction force, latency between muscle pairs and co-activation index between muscle pairs) were compared across condition (shod and barefoot), running cycle epochs (pre-strike, strike, propulsion) and footfall (rearfoot and forefoot) by ANOVA. Condition affected iEMG at pre-strike epoch. Forefoot and rearfoot strike patterns induced different EMG activation time patterns affecting co-activation index for pairs of thigh and shank muscles. All these timing changes suggest that wearing shoes or not is less important for muscle activation than the way runners strike the foot on the ground. In conclusion, the guidance for changing external forces applied on lower limbs should be pointed to the question of rearfoot or forefoot footfall patterns.

Surgical trauma induces overgrowth in lower limb gigantism: regulation with use of rapamycin is promising.

PubMed

Pinto, Rohan Sebastian; Harrison, William David; Graham, Kenneth; Nayagam, Durai

2018-01-04

We describe an unclassified overgrowth syndrome characterised by unregulated growth of dermal fibroblasts in the lower limbs of a 35-year-old woman. A PIK3CA gene mutation resulted in lower limb gigantism. Below the waist, she weighed 117 kg with each leg measuring over 100 cm in circumference. Her total adiposity was 50% accounted for by her legs mainly. Liposuction and surgical debulking were performed to reduce the size of the limbs but had exacerbated the overgrowth in her lower limbs. Systemic sepsis from an infected foot ulcer necessitated treatment by an above-knee amputation. Postoperatively, the stump increased in size by 19 kg. A trial of rapamycin to reverse the growth of the stump has shown promise. We discuss the clinical and genetic features of this previously unclassified disorder and the orthopaedic considerations involved. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Scapula development is governed by genetic interactions of Pbx1 with its family members and with Emx2 via their cooperative control of Alx1

PubMed Central

Capellini, Terence D.; Vaccari, Giulia; Ferretti, Elisabetta; Fantini, Sebastian; He, Mu; Pellegrini, Massimo; Quintana, Laura; Di Giacomo, Giuseppina; Sharpe, James; Selleri, Licia; Zappavigna, Vincenzo

2010-01-01

The genetic pathways underlying shoulder blade development are largely unknown, as gene networks controlling limb morphogenesis have limited influence on scapula formation. Analysis of mouse mutants for Pbx and Emx2 genes has suggested their potential roles in girdle development. In this study, by generating compound mutant mice, we examined the genetic control of scapula development by Pbx genes and their functional relationship with Emx2. Analyses of Pbx and Pbx1;Emx2 compound mutants revealed that Pbx genes share overlapping functions in shoulder development and that Pbx1 genetically interacts with Emx2 in this process. Here, we provide a biochemical basis for Pbx1;Emx2 genetic interaction by showing that Pbx1 and Emx2 can bind specific DNA sequences as heterodimers. Moreover, the expression of genes crucial for scapula development is altered in these mutants, indicating that Pbx genes act upstream of essential pathways for scapula formation. In particular, expression of Alx1, an effector of scapula blade patterning, is absent in all compound mutants. We demonstrate that Pbx1 and Emx2 bind in vivo to a conserved sequence upstream of Alx1 and cooperatively activate its transcription via this potential regulatory element. Our results establish an essential role for Pbx1 in genetic interactions with its family members and with Emx2 and delineate novel regulatory networks in shoulder girdle development. PMID:20627960

Sit-To-Stand Biomechanics Before and After Total Hip Arthroplasty

PubMed Central

Abujaber, Sumayeh B.; Marmon, Adam R.; Pozzi, Federico; Rubano, James J.; Zeni, Joseph A.

2015-01-01

The purpose of this study was to evaluate changes in movement patterns during a sit-to-stand (STS) task before and after total hip arthroplasty (THA), and to compare biomechanical outcomes after THA to a control group. Forty-five subjects who underwent THA and twenty-three healthy control subjects participated in three-dimensional motion analysis. Pre-operatively, subjects exhibited inter-limb movement asymmetries with lower vertical ground reaction force (VGRF) and smaller moments on the operated limb. Although there were significant improvements in movement symmetry 3 months after THA, patients continued to demonstrate lower VGRF and smaller moments on the operated limb compared to non-operated and to control limbs. Future studies should identify the contributions of physical impairments and the influence of surgical approach on STS biomechanics. PMID:26117068

Sparsely-distributed organization of face and limb activations in human ventral temporal cortex

PubMed Central

Weiner, Kevin S.; Grill-Spector, Kalanit

2011-01-01

Functional magnetic resonance imaging (fMRI) has identified face- and body part-selective regions, as well as distributed activation patterns for object categories across human ventral temporal cortex (VTC), eliciting a debate regarding functional organization in VTC and neural coding of object categories. Using high-resolution fMRI, we illustrate that face- and limb-selective activations alternate in a series of largely nonoverlapping clusters in lateral VTC along the inferior occipital gyrus (IOG), fusiform gyrus (FG), and occipitotemporal sulcus (OTS). Both general linear model (GLM) and multivoxel pattern (MVP) analyses show that face- and limb-selective activations minimally overlap and that this organization is consistent across experiments and days. We provide a reliable method to separate two face-selective clusters on the middle and posterior FG (mFus and pFus), and another on the IOG using their spatial relation to limb-selective activations and retinotopic areas hV4, VO-1/2, and hMT+. Furthermore, these activations show a gradient of increasing face selectivity and decreasing limb selectivity from the IOG to the mFus. Finally, MVP analyses indicate that there is differential information for faces in lateral VTC (containing weakly- and highly-selective voxels) relative to non-selective voxels in medial VTC. These findings suggest a sparsely-distributed organization where sparseness refers to the presence of several face- and limb-selective clusters in VTC, and distributed refers to the presence of different amounts of information in highly-, weakly-, and non-selective voxels. Consequently, theories of object recognition should consider the functional and spatial constraints of neural coding across a series of nonoverlapping category-selective clusters that are themselves distributed. PMID:20457261

Towards the resolution of a long-standing evolutionary question: muscle identity and attachments are mainly related to topological position and not to primordium or homeotic identity of digits.

PubMed

Diogo, Rui; Walsh, Sean; Smith, Christopher; Ziermann, Janine M; Abdala, Virginia

2015-06-01

Signaling for limb bone development usually precedes that for muscle development, such that cartilage is generally present before muscle formation. It remains obscure, however, if: (i) tetrapods share a general, predictable spatial correlation between bones and muscles; and, if that is the case, if (ii) such a correlation would reflect an obligatory association between the signaling involved in skeletal and muscle morphogenesis. We address these issues here by using the results of a multidisciplinary analysis of the appendicular muscles of all major tetrapod groups integrating dissections, muscle antibody stainings, regenerative and ontogenetic analyses of fluorescently-labeled (GFP) animals, and studies of non-pentadactyl human limbs related to birth defects. Our synthesis suggests that there is a consistent, surprising anatomical pattern in both normal and abnormal phenotypes, in which the identity and attachments of distal limb muscles are mainly related to the topological position, and not to the developmental primordium (anlage) or even the homeotic identity, of the digits to which they are attached. This synthesis is therefore a starting point towards the resolution of a centuries-old question raised by authors such as Owen about the specific associations between limb bones and muscles. This question has crucial implications for evolutionary and developmental biology, and for human medicine because non-pentadactyly is the most common birth defect in human limbs. In particular, this synthesis paves the way for future developmental experimental and mechanistic studies, which are needed to clarify the processes that may be involved in the elaboration of the anatomical patterns described here, and to specifically test the hypothesis that distal limb muscle identity/attachment is mainly related to digit topology. © 2015 Anatomical Society.

Impact of long-term corticosteroid therapy on the distribution pattern of lower limb atherosclerosis.

PubMed

Willenberg, T; Diehm, N; Zwahlen, M; Kalka, C; Do, D-D; Gretener, S; Ortmann, J; Baumgartner, I

2010-04-01

Ectopic calcification and mediacalcinosis can be promoted by corticosteroid use. Aim of the present investigation is to describe macrovascular disease features in patients with long-term corticosteroid therapy and symptomatic lower limb peripheral arterial occlusive disease (PAD). A consecutive series of 2783 patients undergoing clinical and angiographic work-up of PAD were screened for long-term (>5 years) corticosteroid use (group A). Comparison was performed to a randomly selected age-, sex- and risk factor-matched PAD control cohort from the same series without corticosteroid use (group B). Patients with diabetes mellitus or severe renal failure were excluded. Arterial calcification was evaluated by qualitative assessment on radiographic images. Severity of atherosclerotic lesions was analysed from angiographic images using a semi-quantitative score (Bollinger score). In general, 12 patients (5 males, mean age 78.5 +/- 9.0 years) with 15 ischaemic limbs qualified to be enrolled in group A and were compared to 23 matching control patients (6 2 males, mean age 79.5 +/- 6 years) with 32 ischaemic limbs. Incompressibility of ankle arteries determined by measurement of the ankle-brachial index was seen in 12 limbs (80%) in group A compared to 3 limbs (9%) in group B (p = 0.0009). No significant difference was found comparing group A and B for segmental calcification, whereas comparison of the atherosclerotic burden using the angiographic severity score showed a significantly higher score at the infragenicular arterial level in group A (p = 0.001). Findings suggest that the long-term corticosteroid therapy is associated with a distally accentuated, calcifying peripheral atherosclerosis inducing arterial incompressibility. This occlusion pattern is comparable to patients with renal failure or diabetes. Further research is required to support our observations.

Bone growth, limb proportions and non-specific stress in archaeological populations from Croatia.

PubMed

Pinhasi, R; Timpson, A; Thomas, M; Slaus, M

2014-01-01

The effect of environmental factors and, in particular, non-specific stress on the growth patterns of limbs and other body dimensions of children from past populations is not well understood. This study assesses whether growth of mediaeval and post-mediaeval children aged between 0-11.5 years from Adriatic (coastal) and continental Croatia varies by region and by the prevalence and type of non-specific stress. Dental ages were estimated using the Moorrees, Fanning and Hunt (MFH) scoring method. Growth of long bone diaphyses (femur, tibia, humerus, radius and ulna) was assessed by using a composite Z-score statistic (CZS). Clavicular length was measured as a proxy for upper trunk width, distal metaphyseal width of the femur was measured as a proxy for body mass and upper and lower intra-limb indices were calculated. Differences between sub-sets sampled by (a) region and (b) active vs healed non-specific stress indicators and (c) intra-limb indices were tested by Mann--Whitney U-tests and Analysis of Covariance (ANCOVA). Adriatic children attained larger dimensions-per-age than continental children. Children with healed stress lesions had larger dimensions-per-age than those with active lesions. No inter-regional difference was found in intra-limb indices. These findings highlight the complexity of growth patterns in past populations and indicate that variation in environmental conditions such as diet and differences in the nature of non-specific stress lesions both exert a significant effect on long bone growth.

Locomotor variation and bending regimes of capuchin limb bones.

PubMed

Demes, Brigitte; Carlson, Kristian J

2009-08-01

Primates are very versatile in their modes of progression, yet laboratory studies typically capture only a small segment of this variation. In vivo bone strain studies in particular have been commonly constrained to linear locomotion on flat substrates, conveying the potentially biased impression of stereotypic long bone loading patterns. We here present substrate reaction forces (SRF) and limb postures for capuchin monkeys moving on a flat substrate ("terrestrial"), on an elevated pole ("arboreal"), and performing turns. The angle between the SRF vector and longitudinal axes of the forearm or leg is taken as a proxy for the bending moment experienced by these limb segments. In both frontal and sagittal planes, SRF vectors and distal limb segments are not aligned, but form discrepant angles; that is, forces act on lever arms and exert bending moments. The positions of the SRF vectors suggest bending around oblique axes of these limb segments. Overall, the leg is exposed to greater moments than the forearm. Simulated arboreal locomotion and turns introduce variation in the discrepancy angles, thus confirming that expanding the range of locomotor behaviors studied will reveal variation in long bone loading patterns that is likely characteristic of natural locomotor repertoires. "Arboreal" locomotion, even on a linear noncompliant branch, is characterized by greater variability of force directions and discrepancy angles than "terrestrial" locomotion (significant for the forearm only), partially confirming the notion that life in trees is associated with greater variation in long bone loading. Directional changes broaden the range of external bending moments even further.

Ambulatory activity classification with dendogram-based support vector machine: Application in lower-limb active exoskeleton.

PubMed

Mazumder, Oishee; Kundu, Ananda Sankar; Lenka, Prasanna Kumar; Bhaumik, Subhasis

2016-10-01

Ambulatory activity classification is an active area of research for controlling and monitoring state initiation, termination, and transition in mobility assistive devices such as lower-limb exoskeletons. State transition of lower-limb exoskeletons reported thus far are achieved mostly through the use of manual switches or state machine-based logic. In this paper, we propose a postural activity classifier using a 'dendogram-based support vector machine' (DSVM) which can be used to control a lower-limb exoskeleton. A pressure sensor-based wearable insole and two six-axis inertial measurement units (IMU) have been used for recognising two static and seven dynamic postural activities: sit, stand, and sit-to-stand, stand-to-sit, level walk, fast walk, slope walk, stair ascent and stair descent. Most of the ambulatory activities are periodic in nature and have unique patterns of response. The proposed classification algorithm involves the recognition of activity patterns on the basis of the periodic shape of trajectories. Polynomial coefficients extracted from the hip angle trajectory and the centre-of-pressure (CoP) trajectory during an activity cycle are used as features to classify dynamic activities. The novelty of this paper lies in finding suitable instrumentation, developing post-processing techniques, and selecting shape-based features for ambulatory activity classification. The proposed activity classifier is used to identify the activity states of a lower-limb exoskeleton. The DSVM classifier algorithm achieved an overall classification accuracy of 95.2%. Copyright © 2016 Elsevier B.V. All rights reserved.

Human Locomotion under Reduced Gravity Conditions: Biomechanical and Neurophysiological Considerations

PubMed Central

Sylos-Labini, Francesca; Ivanenko, Yuri P.

2014-01-01

Reduced gravity offers unique opportunities to study motor behavior. This paper aims at providing a review on current issues of the known tools and techniques used for hypogravity simulation and their effects on human locomotion. Walking and running rely on the limb oscillatory mechanics, and one way to change its dynamic properties is to modify the level of gravity. Gravity has a strong effect on the optimal rate of limb oscillations, optimal walking speed, and muscle activity patterns, and gait transitions occur smoothly and at slower speeds at lower gravity levels. Altered center of mass movements and interplay between stance and swing leg dynamics may challenge new forms of locomotion in a heterogravity environment. Furthermore, observations in the lack of gravity effects help to reveal the intrinsic properties of locomotor pattern generators and make evident facilitation of nonvoluntary limb stepping. In view of that, space neurosciences research has participated in the development of new technologies that can be used as an effective tool for gait rehabilitation. PMID:25247179

Different nerve ultrasound patterns in charcot-marie-tooth types and hereditary neuropathy with liability to pressure palsies.

PubMed

Padua, Luca; Coraci, Daniele; Lucchetta, Marta; Paolasso, Ilaria; Pazzaglia, Costanza; Granata, Giuseppe; Cacciavillani, Mario; Luigetti, Marco; Manganelli, Fiore; Pisciotta, Chiara; Piscosquito, Giuseppe; Pareyson, Davide; Briani, Chiara

2018-01-01

Nerve ultrasound in Charcot-Marie-Tooth (CMT) disease has focused mostly on the upper limbs. We performed an evaluation of a large cohort of CMT patients in which we sonographically characterized nerve abnormalities in different disease types, ages, and nerves. Seventy patients affected by different CMT types and hereditary neuropathy with liability to pressure palsies (HNPP) were evaluated, assessing median, ulnar, fibular, tibial, and sural nerves bilaterally. Data were correlated with age. Nerve dimensions were correlated with CMT type, age, and nerve site. Nerves were larger in demyelinating than in axonal neuropathies. Nerve involvement was symmetric. CMT1 patients had larger nerves than did patients with other CMT types. Patients with HNPP showed enlargement at entrapment sites. Our study confirms the general symmetry of ultrasound nerve patterns in CMT. When compared with ultrasound studies of nerves of the upper limbs, evaluation of the lower limbs did not provide additional information. Muscle Nerve 57: E18-E23, 2018. © 2017 Wiley Periodicals, Inc.

Treatment of phantom limb pain (PLP) based on augmented reality and gaming controlled by myoelectric pattern recognition: a case study of a chronic PLP patient

PubMed Central

Ortiz-Catalan, Max; Sander, Nichlas; Kristoffersen, Morten B.; Håkansson, Bo; Brånemark, Rickard

2014-01-01

A variety of treatments have been historically used to alleviate phantom limb pain (PLP) with varying efficacy. Recently, virtual reality (VR) has been employed as a more sophisticated mirror therapy. Despite the advantages of VR over a conventional mirror, this approach has retained the use of the contralateral limb and is therefore restricted to unilateral amputees. Moreover, this strategy disregards the actual effort made by the patient to produce phantom motions. In this work, we investigate a treatment in which the virtual limb responds directly to myoelectric activity at the stump, while the illusion of a restored limb is enhanced through augmented reality (AR). Further, phantom motions are facilitated and encouraged through gaming. The proposed set of technologies was administered to a chronic PLP patient who has shown resistance to a variety of treatments (including mirror therapy) for 48 years. Individual and simultaneous phantom movements were predicted using myoelectric pattern recognition and were then used as input for VR and AR environments, as well as for a racing game. The sustained level of pain reported by the patient was gradually reduced to complete pain-free periods. The phantom posture initially reported as a strongly closed fist was gradually relaxed, interestingly resembling the neutral posture displayed by the virtual limb. The patient acquired the ability to freely move his phantom limb, and a telescopic effect was observed where the position of the phantom hand was restored to the anatomically correct distance. More importantly, the effect of the interventions was positively and noticeably perceived by the patient and his relatives. Despite the limitation of a single case study, the successful results of the proposed system in a patient for whom other medical and non-medical treatments have been ineffective justifies and motivates further investigation in a wider study. PMID:24616655

Treatment of phantom limb pain (PLP) based on augmented reality and gaming controlled by myoelectric pattern recognition: a case study of a chronic PLP patient.

PubMed

Ortiz-Catalan, Max; Sander, Nichlas; Kristoffersen, Morten B; Håkansson, Bo; Brånemark, Rickard

2014-01-01

A variety of treatments have been historically used to alleviate phantom limb pain (PLP) with varying efficacy. Recently, virtual reality (VR) has been employed as a more sophisticated mirror therapy. Despite the advantages of VR over a conventional mirror, this approach has retained the use of the contralateral limb and is therefore restricted to unilateral amputees. Moreover, this strategy disregards the actual effort made by the patient to produce phantom motions. In this work, we investigate a treatment in which the virtual limb responds directly to myoelectric activity at the stump, while the illusion of a restored limb is enhanced through augmented reality (AR). Further, phantom motions are facilitated and encouraged through gaming. The proposed set of technologies was administered to a chronic PLP patient who has shown resistance to a variety of treatments (including mirror therapy) for 48 years. Individual and simultaneous phantom movements were predicted using myoelectric pattern recognition and were then used as input for VR and AR environments, as well as for a racing game. The sustained level of pain reported by the patient was gradually reduced to complete pain-free periods. The phantom posture initially reported as a strongly closed fist was gradually relaxed, interestingly resembling the neutral posture displayed by the virtual limb. The patient acquired the ability to freely move his phantom limb, and a telescopic effect was observed where the position of the phantom hand was restored to the anatomically correct distance. More importantly, the effect of the interventions was positively and noticeably perceived by the patient and his relatives. Despite the limitation of a single case study, the successful results of the proposed system in a patient for whom other medical and non-medical treatments have been ineffective justifies and motivates further investigation in a wider study.

Age-related variations of varicose veins anatomy.

PubMed

Caggiati, Alberto; Rosi, Caterina; Heyn, Rosemarie; Franceschini, Marco; Acconcia, Maria Cristina

2006-12-01

Primary varicose veins are commonly considered a progressive disease starting from the saphenous junctions and extending to tributaries in a retrograde fashion along the saphenous trunks. This theory has been criticized by studies indicating different patterns of development and progression of varicose veins. To contribute to the understanding of the pathogenesis of the disease, the anatomy of the venous bed was comparatively evaluated by duplex sonography in patients with varicose veins with a marked difference in age. The study included 100 varicose limbs in 82 patients aged < 30 years and 238 limbs in 183 patients aged > 60 years. Veins were designated as saphenous veins (SVs), tributaries of the SVs (STVs), and veins not connected with the SVs (NSVs). Four main anatomic patterns were comparatively evaluated: (1) varicose changes only along SVs, (2) varicose changes along SVs and STVs, (3) varicose changes only in STVs, and (4) varicose changes only in NSVs. SVs were normal in 44% of varicose limbs. In most limbs from young subjects, varicose changes afflicted only SVTs (25%) and NSVs (36%). Varicose SVs were more frequent in the older group (62%) than in younger one (39%) owing to a higher prevalence of limbs with combined SV and STV varicosities (respectively, 59% and 37%). In the older group, varicosities in the STVs were more frequently observed in association with incompetence of the SV trunks. The frequent occurrence of normal SVs in varicose limbs of all patients does not support the crucial role commonly credited to SVs in the pathogenesis of primary varicosities. Moreover, the SV trunks were normal in most varicose limbs from young patients. These findings suggest that varicose disease may progressively extend in an antegrade fashion, spreading from the STVs to the SVs. This hypothesis suggests that the saphenous trunks could be spared in the treatment of a relevant number of varicose legs. Prospective longitudinal studies with serial duplex evaluations of large series of extremities are necessary to confirm this hypothesis.

Attenuation of bone morphogenetic protein signaling during amphibian limb development results in the generation of stage-specific defects.

PubMed

Jones, Tamsin E M; Day, Robert C; Beck, Caroline W

2013-11-01

The vertebrate limb is one of the most intensively studied organs in the field of developmental biology. Limb development in tetrapod vertebrates is highly conserved and dependent on the interaction of several important molecular pathways. The bone morphogenetic protein (BMP) signaling cascade is one of these pathways and has been shown to be crucial for several aspects of limb development. Here, we have used a Xenopus laevis transgenic line, in which expression of the inhibitor Noggin is under the control of the heat-shock promoter hsp70 to examine the effects of attenuation of BMP signaling at different stages of limb development. Remarkably different phenotypes were produced at different stages, illustrating the varied roles of BMP in development of the limb. Very early limb buds appeared to be refractory to the effects of BMP attenuation, developing normally in most cases. Ectopic limbs were produced by overexpression of Noggin corresponding to a brief window of limb development at about stage 49/50, as recently described by Christen et al. (2012). Attenuation of BMP signaling in stage 51 or 52 tadpoles lead to a reduction in the number of digits formed, resulting in hypodactyly or ectrodactyly, as well as occasional defects in the more proximal tibia-fibula. Finally, inhibition at stage 54 (paddle stage) led to the formation of dramatically shortened digits resulting from loss of distal phalanges. Transcriptome analysis has revealed the possibility that more Noggin-sensitive members of the BMP family could be involved in limb development than previously suspected. Our analysis demonstrates the usefulness of heat-shock-driven gene expression as an effective method for inhibiting a developmental pathway at different times during limb development. © 2013 Anatomical Society.

Sonic Hedgehog Signaling in Limb Development

PubMed Central

Tickle, Cheryll; Towers, Matthew

2017-01-01

The gene encoding the secreted protein Sonic hedgehog (Shh) is expressed in the polarizing region (or zone of polarizing activity), a small group of mesenchyme cells at the posterior margin of the vertebrate limb bud. Detailed analyses have revealed that Shh has the properties of the long sought after polarizing region morphogen that specifies positional values across the antero-posterior axis (e.g., thumb to little finger axis) of the limb. Shh has also been shown to control the width of the limb bud by stimulating mesenchyme cell proliferation and by regulating the antero-posterior length of the apical ectodermal ridge, the signaling region required for limb bud outgrowth and the laying down of structures along the proximo-distal axis (e.g., shoulder to digits axis) of the limb. It has been shown that Shh signaling can specify antero-posterior positional values in limb buds in both a concentration- (paracrine) and time-dependent (autocrine) fashion. Currently there are several models for how Shh specifies positional values over time in the limb buds of chick and mouse embryos and how this is integrated with growth. Extensive work has elucidated downstream transcriptional targets of Shh signaling. Nevertheless, it remains unclear how antero-posterior positional values are encoded and then interpreted to give the particular structure appropriate to that position, for example, the type of digit. A distant cis-regulatory enhancer controls limb-bud-specific expression of Shh and the discovery of increasing numbers of interacting transcription factors indicate complex spatiotemporal regulation. Altered Shh signaling is implicated in clinical conditions with congenital limb defects and in the evolution of the morphological diversity of vertebrate limbs. PMID:28293554

Computer simulations of neural mechanisms explaining upper and lower limb excitatory neural coupling

PubMed Central

2010-01-01

Background When humans perform rhythmic upper and lower limb locomotor-like movements, there is an excitatory effect of upper limb exertion on lower limb muscle recruitment. To investigate potential neural mechanisms for this behavioral observation, we developed computer simulations modeling interlimb neural pathways among central pattern generators. We hypothesized that enhancement of muscle recruitment from interlimb spinal mechanisms was not sufficient to explain muscle enhancement levels observed in experimental data. Methods We used Matsuoka oscillators for the central pattern generators (CPG) and determined parameters that enhanced amplitudes of rhythmic steady state bursts. Potential mechanisms for output enhancement were excitatory and inhibitory sensory feedback gains, excitatory and inhibitory interlimb coupling gains, and coupling geometry. We first simulated the simplest case, a single CPG, and then expanded the model to have two CPGs and lastly four CPGs. In the two and four CPG models, the lower limb CPGs did not receive supraspinal input such that the only mechanisms available for enhancing output were interlimb coupling gains and sensory feedback gains. Results In a two-CPG model with inhibitory sensory feedback gains, only excitatory gains of ipsilateral flexor-extensor/extensor-flexor coupling produced reciprocal upper-lower limb bursts and enhanced output up to 26%. In a two-CPG model with excitatory sensory feedback gains, excitatory gains of contralateral flexor-flexor/extensor-extensor coupling produced reciprocal upper-lower limb bursts and enhanced output up to 100%. However, within a given excitatory sensory feedback gain, enhancement due to excitatory interlimb gains could only reach levels up to 20%. Interconnecting four CPGs to have ipsilateral flexor-extensor/extensor-flexor coupling, contralateral flexor-flexor/extensor-extensor coupling, and bilateral flexor-extensor/extensor-flexor coupling could enhance motor output up to 32%. Enhancement observed in experimental data exceeded 32%. Enhancement within this symmetrical four-CPG neural architecture was more sensitive to relatively small interlimb coupling gains. Excitatory sensory feedback gains could produce greater output amplitudes, but larger gains were required for entrainment compared to inhibitory sensory feedback gains. Conclusions Based on these simulations, symmetrical interlimb coupling can account for much, but not all of the excitatory neural coupling between upper and lower limbs during rhythmic locomotor-like movements. PMID:21143960

Prx-1 expression in Xenopus laevis scarless skin-wound healing and its resemblance to epimorphic regeneration.

PubMed

Yokoyama, Hitoshi; Maruoka, Tamae; Aruga, Akio; Amano, Takanori; Ohgo, Shiro; Shiroishi, Toshihiko; Tamura, Koji

2011-12-01

Despite a strong clinical need for inducing scarless wound healing, the molecular factors required to accomplish it are unknown. Although skin-wound healing in adult mammals often results in scarring, some amphibians can regenerate injured body parts, even an amputated limb, without it. To understand the mechanisms of perfect skin-wound healing in regenerative tetrapods, we studied the healing process in young adult Xenopus "froglets" after experimental skin excision. We found that the excision wound healed completely in Xenopus froglets, without scarring. Mononuclear cells expressing a homeobox gene, prx1, accumulated under the new epidermis of skin wounds on the limb and trunk and at the regenerating limb. In transgenic Xenopus froglets expressing a reporter for the mouse prx1 limb-specific enhancer, activity was seen in the healing skin and in the regenerating limb. Comparable activity did not accompany skin-wound healing in adult mice. Our results suggest that scarless skin-wound healing may require activation of the prx1 limb enhancer, and competence to activate the enhancer is probably a prerequisite for epimorphic regeneration, such as limb regeneration. Finally, the induction of this prx1 enhancer activity may be useful as a reliable marker for therapeutically induced scarless wound healing in mammals.

Melatonin Promotes Cheliped Regeneration, Digestive Enzyme Function, and Immunity Following Autotomy in the Chinese Mitten Crab, Eriocheir sinensis

PubMed Central

Zhang, Cong; Yang, Xiao-zhen; Xu, Min-jie; Huang, Gen-yong; Zhang, Qian; Cheng, Yong-xu; He, Long; Ren, Hong-yu

2018-01-01

In the pond culture of juvenile Eriocheir sinensis, a high limb-impairment rate seriously affects the culture success. Therefore, it is particularly important to artificially promote limb regeneration. This study evaluated the effects of melatonin on cheliped regeneration, digestive ability, and immunity, as well as its relationship with the eyestalk. It was found that the injection of melatonin significantly increased the limb regeneration rate compared with the saline group (P < 0.05). The qRT-PCR results of growth-related genes showed that the level of EcR-mRNA (ecdysteroid receptor) and Chi-mRNA (chitinase) expression was significantly increased following the melatonin injection, while the expression of MIH-mRNA (molt-inhibiting hormone) was significantly decreased (P < 0.05). Melatonin significantly increased lipase activity (P < 0.05). We observed that the survival rates of limb-impaired and unilateral eyestalk-ablated crabs were substantially improved following melatonin treatment, whereas the survival of the unilateral eyestalk-ablated crabs was significantly decreased compared with the control group (P < 0.05). Furthermore, the results of serum immune and antioxidant capacity revealed that melatonin significantly increased the total hemocyte counts (THC), hemocyanin content, total antioxidant capacity (T-AOC), acid phosphatase (ACP), and glutathione peroxidase activity (GSH-Px), whereas the immune-related parameters were significantly decreased in eyestalk-ablated crabs (P < 0.05). Therefore, these findings indicate that melatonin exerts a protective effect on organism injury, which could promote limb regeneration by up-regulating the expression of growth-related genes, improve digestive enzyme activity, and strengthen the immune response, particularly antioxidant capacity. PMID:29623051

GH/IGF-I Transgene Expression on Muscle Homeostasis

NASA Technical Reports Server (NTRS)

Schwartz, Robert J.

1999-01-01

We propose to test the hypothesis that the growth hormone/ insulin like growth factor-I axis through autocrine/paracrine mechanisms may provide long term muscle homeostasis under conditions of prolonged weightlessness. As a key alternative to hormone replacement therapy, ectopic production of hGH, growth hormone releasing hormone (GHRH), and IGF-I will be studied for its potential on muscle mass impact in transgenic mice under simulated microgravity. Expression of either hGH or IGF-I would provide a chronic source of a growth-promoting protein whose biosynthesis or secretion is shut down in space. Muscle expression of the IGF-I transgene has demonstrated about a 20% increase in hind limb muscle mass over control nontransgenic litter mates. These recent experiments, also establish the utility of hind-limb suspension in mice as a workable model to study atrophy in weight bearing muscles. Thus, transgenic mice will be used in hind-limb suspension models to determine the role of GH/IGF-I on maintenance of muscle mass and whether concentric exercises might act in synergy with hormone treatment. As a means to engineer and ensure long-term protein production that would be workable in humans, gene therapy technology will be used by to monitor muscle mass preservation during hind-limb suspension, after direct intramuscular injection of a genetically engineered muscle-specific vector expressing GHRH. Effects of this gene-based therapy will be assessed in both fast twitch (medial gastrocnemius) and slow twitch muscle (soleus). End-points include muscle size, ultrastructure, fiber type, and contractile function, in normal animals, hind limb suspension, and reambutation.

In vivo locomotor strain in the hindlimb bones of alligator mississippiensis and iguana iguana: implications for the evolution of limb bone safety factor and non-sprawling limb posture

PubMed

Blob; Biewener

1999-05-01

Limb postures of terrestrial tetrapods span a continuum from sprawling to fully upright; however, most experimental investigations of locomotor mechanics have focused on mammals and ground-dwelling birds that employ parasagittal limb kinematics, leaving much of the diversity of tetrapod locomotor mechanics unexplored. This study reports measurements of in vivo locomotor strain from the limb bones of lizard (Iguana iguana) and crocodilian (Alligator mississippiensis) species, animals from previously unsampled phylogenetic lineages with non-parasagittal limb posture and kinematics. Principal strain orientations and shear strain magnitudes indicate that the limb bones of these species experience considerable torsion during locomotion. This contrasts with patterns commonly observed in mammals, but matches predictions from kinematic observations of axial rotation in lizard and crocodilian limbs. Comparisons of locomotor load magnitudes with the mechanical properties of limb bones in Alligator and Iguana indicate that limb bone safety factors in bending for these species range from 5.5 to 10.8, as much as twice as high as safety factors previously calculated for mammals and birds. Limb bone safety factors in shear (3.9-5.4) for Alligator and Iguana are also moderately higher than safety factors to yield in bending for birds and mammals. Finally, correlations between limb posture and strain magnitudes in Alligator show that at some recording locations limb bone strains can increase during upright locomotion, in contrast to expectations based on size-correlated changes in posture among mammals that limb bone strains should decrease with the use of an upright posture. These data suggest that, in some lineages, strain magnitudes may not have been maintained at constant levels through the evolution of a non-sprawling posture unless the postural change was accompanied by a shift to parasagittal kinematics or by an evolutionary decrease in body size.

Duplications of BHLHA9 are associated with ectrodactyly and tibia hemimelia inherited in non-Mendelian fashion.

PubMed

Klopocki, Eva; Lohan, Silke; Doelken, Sandra C; Stricker, Sigmar; Ockeloen, Charlotte W; Soares Thiele de Aguiar, Renata; Lezirovitz, Karina; Mingroni Netto, Regina Celia; Jamsheer, Aleksander; Shah, Hitesh; Kurth, Ingo; Habenicht, Rolf; Warman, Matthew; Devriendt, Koenraad; Kordass, Ulrike; Hempel, Maja; Rajab, Anna; Mäkitie, Outi; Naveed, Mohammed; Radhakrishna, Uppala; Antonarakis, Stylianos E; Horn, Denise; Mundlos, Stefan

2012-02-01

Split-hand/foot malformation (SHFM)-also known as ectrodactyly-is a congenital disorder characterised by severe malformations of the distal limbs affecting the central rays of hands and/or feet. A distinct entity termed SHFLD presents with SHFM and long bone deficiency. Mouse models suggest that a defect of the central apical ectodermal ridge leads to the phenotype. Although six different loci/mutations (SHFM1-6) have been associated with SHFM, the underlying cause in a large number of cases is still unresolved. High resolution array comparative genomic hybridisation (CGH) was performed in patients with SHFLD to detect copy number changes. Candidate genes were further evaluated for expression and function during limb development by whole mount in situ hybridisation and morpholino knock-down experiments. Array CGH showed microduplications on chromosome 17p13.3, a locus previously associated with SHFLD. Detailed analysis of 17 families revealed that this copy number variation serves as a susceptibility factor for a highly variable phenotype with reduced penetrance, particularly in females. Compared to other known causes for SHFLD 17p duplications appear to be the most frequent cause of SHFLD. A ~11.8 kb minimal critical region was identified encompassing a single gene, BHLHA9, a putative basic loop helix transcription factor. Whole mount in situ hybridisation showed expression restricted to the limb bud mesenchyme underlying the apical ectodermal ridge in mouse and zebrafish embryos. Knock down of bhlha9 in zebrafish resulted in shortening of the pectoral fins. Genomic duplications encompassing BHLHA9 are associated with SHFLD and non-Mendelian inheritance characterised by a high degree of non-penetrance with sex bias. Knock-down of bhlha9 in zebrafish causes severe reduction defects of the pectoral fin, indicating a role for this gene in limb development.

A Novel Intronic Single Nucleotide Polymorphism in the Myosin heavy polypeptide 4 Gene Is Responsible for the Mini-Muscle Phenotype Characterized by Major Reduction in Hind-Limb Muscle Mass in Mice

PubMed Central

Kelly, Scott A.; Bell, Timothy A.; Selitsky, Sara R.; Buus, Ryan J.; Hua, Kunjie; Weinstock, George M.; Garland, Theodore; Pardo-Manuel de Villena, Fernando; Pomp, Daniel

2013-01-01

Replicated artificial selection for high levels of voluntary wheel running in an outbred strain of mice favored an autosomal recessive allele whose primary phenotypic effect is a 50% reduction in hind-limb muscle mass. Within the High Runner (HR) lines of mice, the numerous pleiotropic effects (e.g., larger hearts, reduced total body mass and fat mass, longer hind-limb bones) of this hypothesized adaptive allele include functional characteristics that facilitate high levels of voluntary wheel running (e.g., doubling of mass-specific muscle aerobic capacity, increased fatigue resistance of isolated muscles, longer hind-limb bones). Previously, we created a backcross population suitable for mapping the responsible locus. We phenotypically characterized the population and mapped the Minimsc locus to a 2.6-Mb interval on MMU11, a region containing ∼100 known or predicted genes. Here, we present a novel strategy to identify the genetic variant causing the mini-muscle phenotype. Using high-density genotyping and whole-genome sequencing of key backcross individuals and HR mice with and without the mini-muscle mutation, from both recent and historical generations of the HR lines, we show that a SNP representing a C-to-T transition located in a 709-bp intron between exons 11 and 12 of the Myosin heavy polypeptide 4 (Myh4) skeletal muscle gene (position 67,244,850 on MMU11; assembly, December 2011, GRCm38/mm10; ENSMUSG00000057003) is responsible for the mini-muscle phenotype, Myh4Minimsc. Using next-generation sequencing, our approach can be extended to identify causative mutations arising in mouse inbred lines and thus offers a great avenue to overcome one of the most challenging steps in quantitative genetics. PMID:24056412

A novel intronic single nucleotide polymorphism in the myosin heavy polypeptide 4 gene is responsible for the mini-muscle phenotype characterized by major reduction in hind-limb muscle mass in mice.

PubMed

Kelly, Scott A; Bell, Timothy A; Selitsky, Sara R; Buus, Ryan J; Hua, Kunjie; Weinstock, George M; Garland, Theodore; Pardo-Manuel de Villena, Fernando; Pomp, Daniel

2013-12-01

Replicated artificial selection for high levels of voluntary wheel running in an outbred strain of mice favored an autosomal recessive allele whose primary phenotypic effect is a 50% reduction in hind-limb muscle mass. Within the High Runner (HR) lines of mice, the numerous pleiotropic effects (e.g., larger hearts, reduced total body mass and fat mass, longer hind-limb bones) of this hypothesized adaptive allele include functional characteristics that facilitate high levels of voluntary wheel running (e.g., doubling of mass-specific muscle aerobic capacity, increased fatigue resistance of isolated muscles, longer hind-limb bones). Previously, we created a backcross population suitable for mapping the responsible locus. We phenotypically characterized the population and mapped the Minimsc locus to a 2.6-Mb interval on MMU11, a region containing ∼100 known or predicted genes. Here, we present a novel strategy to identify the genetic variant causing the mini-muscle phenotype. Using high-density genotyping and whole-genome sequencing of key backcross individuals and HR mice with and without the mini-muscle mutation, from both recent and historical generations of the HR lines, we show that a SNP representing a C-to-T transition located in a 709-bp intron between exons 11 and 12 of the Myosin heavy polypeptide 4 (Myh4) skeletal muscle gene (position 67,244,850 on MMU11; assembly, December 2011, GRCm38/mm10; ENSMUSG00000057003) is responsible for the mini-muscle phenotype, Myh4(Minimsc). Using next-generation sequencing, our approach can be extended to identify causative mutations arising in mouse inbred lines and thus offers a great avenue to overcome one of the most challenging steps in quantitative genetics.

The king cobra genome reveals dynamic gene evolution and adaptation in the snake venom system

PubMed Central

Vonk, Freek J.; Casewell, Nicholas R.; Henkel, Christiaan V.; Heimberg, Alysha M.; Jansen, Hans J.; McCleary, Ryan J. R.; Kerkkamp, Harald M. E.; Vos, Rutger A.; Guerreiro, Isabel; Calvete, Juan J.; Wüster, Wolfgang; Woods, Anthony E.; Logan, Jessica M.; Harrison, Robert A.; Castoe, Todd A.; de Koning, A. P. Jason; Pollock, David D.; Yandell, Mark; Calderon, Diego; Renjifo, Camila; Currier, Rachel B.; Salgado, David; Pla, Davinia; Sanz, Libia; Hyder, Asad S.; Ribeiro, José M. C.; Arntzen, Jan W.; van den Thillart, Guido E. E. J. M.; Boetzer, Marten; Pirovano, Walter; Dirks, Ron P.; Spaink, Herman P.; Duboule, Denis; McGlinn, Edwina; Kini, R. Manjunatha; Richardson, Michael K.

2013-01-01

Snakes are limbless predators, and many species use venom to help overpower relatively large, agile prey. Snake venoms are complex protein mixtures encoded by several multilocus gene families that function synergistically to cause incapacitation. To examine venom evolution, we sequenced and interrogated the genome of a venomous snake, the king cobra (Ophiophagus hannah), and compared it, together with our unique transcriptome, microRNA, and proteome datasets from this species, with data from other vertebrates. In contrast to the platypus, the only other venomous vertebrate with a sequenced genome, we find that snake toxin genes evolve through several distinct co-option mechanisms and exhibit surprisingly variable levels of gene duplication and directional selection that correlate with their functional importance in prey capture. The enigmatic accessory venom gland shows a very different pattern of toxin gene expression from the main venom gland and seems to have recruited toxin-like lectin genes repeatedly for new nontoxic functions. In addition, tissue-specific microRNA analyses suggested the co-option of core genetic regulatory components of the venom secretory system from a pancreatic origin. Although the king cobra is limbless, we recovered coding sequences for all Hox genes involved in amniote limb development, with the exception of Hoxd12. Our results provide a unique view of the origin and evolution of snake venom and reveal multiple genome-level adaptive responses to natural selection in this complex biological weapon system. More generally, they provide insight into mechanisms of protein evolution under strong selection. PMID:24297900

Intra- and interspecies gene expression models for predicting drug response in canine osteosarcoma.

PubMed

Fowles, Jared S; Brown, Kristen C; Hess, Ann M; Duval, Dawn L; Gustafson, Daniel L

2016-02-19

Genomics-based predictors of drug response have the potential to improve outcomes associated with cancer therapy. Osteosarcoma (OS), the most common primary bone cancer in dogs, is commonly treated with adjuvant doxorubicin or carboplatin following amputation of the affected limb. We evaluated the use of gene-expression based models built in an intra- or interspecies manner to predict chemosensitivity and treatment outcome in canine OS. Models were built and evaluated using microarray gene expression and drug sensitivity data from human and canine cancer cell lines, and canine OS tumor datasets. The "COXEN" method was utilized to filter gene signatures between human and dog datasets based on strong co-expression patterns. Models were built using linear discriminant analysis via the misclassification penalized posterior algorithm. The best doxorubicin model involved genes identified in human lines that were co-expressed and trained on canine OS tumor data, which accurately predicted clinical outcome in 73 % of dogs (p = 0.0262, binomial). The best carboplatin model utilized canine lines for gene identification and model training, with canine OS tumor data for co-expression. Dogs whose treatment matched our predictions had significantly better clinical outcomes than those that didn't (p = 0.0006, Log Rank), and this predictor significantly associated with longer disease free intervals in a Cox multivariate analysis (hazard ratio = 0.3102, p = 0.0124). Our data show that intra- and interspecies gene expression models can successfully predict response in canine OS, which may improve outcome in dogs and serve as pre-clinical validation for similar methods in human cancer research.

Constraint-induced movement therapy promotes brain functional reorganization in stroke patients with hemiplegia

PubMed Central

Wang, Wenqing; Wang, Aihui; Yu, Limin; Han, Xuesong; Jiang, Guiyun; Weng, Changshui; Zhang, Hongwei; Zhou, Zhiqiang

2012-01-01

Stroke patients with hemiplegia exhibit flexor spasms in the upper limb and extensor spasms in the lower limb, and their movement patterns vary greatly. Constraint-induced movement therapy is an upper limb rehabilitation technique used in stroke patients with hemiplegia; however, studies of lower extremity rehabilitation are scarce. In this study, stroke patients with lower limb hemiplegia underwent conventional Bobath therapy for 4 weeks as baseline treatment, followed by constraint-induced movement therapy for an additional 4 weeks. The 10-m maximum walking speed and Berg balance scale scores significantly improved following treatment, and lower extremity motor function also improved. The results of functional MRI showed that constraint-induced movement therapy alleviates the reduction in cerebral functional activation in patients, which indicates activation of functional brain regions and a significant increase in cerebral blood perfusion. These results demonstrate that constraint-induced movement therapy promotes brain functional reorganization in stroke patients with lower limb hemiplegia. PMID:25337108

Development of an assist controller with robot suit HAL for hemiplegic patients using motion data on the unaffected side.

PubMed

Kawamoto, Hiroaki; Kandone, Hideki; Sakurai, Takeru; Ariyasu, Ryohei; Ueno, Yukiko; Eguchi, Kiyoshi; Sankai, Yoshiyuki

2014-01-01

Among several characteristics seen in gait of hemiplegic patients after stroke, symmetry is known to be an indicator of the degree of impairment of walking ability. This paper proposes a control method for a wearable type lower limb motion assist robot to realize spontaneous symmetric gait for these individuals. This control method stores the motion of the unaffected limb during swing and then provides motion support on the affected limb during the subsequent swing using the stored pattern to realize symmetric gait based on spontaneous limb swing. This method is implemented on the robot suit HAL (Hybrid Assistive Limbs). Clinical tests were conducted in order to assess the feasibility of the control method. Our case study involved participation of one chronic stroke patient who was not able to flex his right knee. As a result, the walking support for hemiplegic leg provided by the HAL improved the subject's gait symmetry. The feasibility study showed promising basis for the future clinical study.

Chronic inflammatory pure sensory polyradiculoneuropathy: a rare CIDP variant with unusual electrophysiology.

PubMed

Rajabally, Yusuf A; Wong, Siew L

2012-03-01

We describe a patient presenting with progressive upper limb numbness and sensory ataxia of the 4 limbs. Motor nerve conduction studies were completely normal. Sensory electrophysiology showed reduced/absent upper limb sensory action potentials (SAPs). In the lower limbs, SAPs were mostly normal. Sensory conduction velocities were normal. Forearm sensory conduction blocks were present for both median nerves on antidromic testing. The maximal recordable sural SAP was preserved in comparison to maximal recordable radial SAP, consistent with an "abnormal radial normal sural" pattern. Somatosensory evoked potentials were unrecordable for tibial and median nerves. Cerebrospinal fluid protein was raised (0.99 g/L). The patient worsened on oral corticosteroids but subsequently made substantial functional recovery on intravenous immunoglobulins. This case is different to those previously reported of sensory chronic inflammatory demyelinating polyradiculoneuropathy, given its exclusive sensory electrophysiologic presentation, presence of predominant upper limb reduced sensory amplitudes, and detection of sensory conduction blocks. These electrophysiologic features were of paramount importance in establishing diagnosis and effective therapy.

The DYT1 gene on 9q34 is responsible for most cases of early limb-onset idiopathic torsion dystonia in non-Jews

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kramer, P.L.; Heiman, G.A.; Leon, D. de

1994-09-01

Idiopathic torsion dystonia (ITD) is characterized by involuntary twisting movements and postures. A gene for this disorder, DYT1, was mapped to chromosome 9q34 in 12 Ashkenazi Jewish (AJ) families and one large non-Jewish kindred. In the AJ population, strong linkage disequilibrium exists between DYT1 and adjacent markers within a 2-cM region. The associated haplotype occurs in >90% of early limb-onset AJ cases. The authors examined seven non-Jewish ITD families of northern European and French Canadian descent to determine the extent to which early-onset ITD in non-Jews maps to DYT1. Results are consistent with linkage to the DYT1 region. Affected individualsmore » in these families are clinically similar to the AJ cases, i.e., the site of onset is predominantly in the limbs and at least one individual in each pedigree had onset before age 12 years. None carries the AJ haplotype; therefore, they probably represent different mutations in the DYT1 gene. The two French Canadian families, however, display the same haplotype. Estimates of penetrance in non-Jewish families range from .40 to .75. They identified disease gene carriers and, with adjustments for age at onset, obtained a direct estimate of penetrance of .46. This is consistent with estimates of 30%-40% in the AJ population. Two other non-Jewish families with atypical ITD (later onset and/or cranial or cervical involvement) are not linked to DYT1, which indicates involvement of other genes in dystonia. 26 refs., 1 fig., 3 tabs.« less

Temporal coding of brain patterns for direct limb control in humans.

PubMed

Müller-Putz, Gernot R; Scherer, Reinhold; Pfurtscheller, Gert; Neuper, Christa

2010-01-01

For individuals with a high spinal cord injury (SCI) not only the lower limbs, but also the upper extremities are paralyzed. A neuroprosthesis can be used to restore the lost hand and arm function in those tetraplegics. The main problem for this group of individuals, however, is the reduced ability to voluntarily operate device controllers. A brain-computer interface provides a non-manual alternative to conventional input devices by translating brain activity patterns into control commands. We show that the temporal coding of individual mental imagery pattern can be used to control two independent degrees of freedom - grasp and elbow function - of an artificial robotic arm by utilizing a minimum number of EEG scalp electrodes. We describe the procedure from the initial screening to the final application. From eight naïve subjects participating online feedback experiments, four were able to voluntarily control an artificial arm by inducing one motor imagery pattern derived from one EEG derivation only.

The draft genomes of soft-shell turtle and green sea turtle yield insights into the development and evolution of the turtle-specific body plan.

PubMed

Wang, Zhuo; Pascual-Anaya, Juan; Zadissa, Amonida; Li, Wenqi; Niimura, Yoshihito; Huang, Zhiyong; Li, Chunyi; White, Simon; Xiong, Zhiqiang; Fang, Dongming; Wang, Bo; Ming, Yao; Chen, Yan; Zheng, Yuan; Kuraku, Shigehiro; Pignatelli, Miguel; Herrero, Javier; Beal, Kathryn; Nozawa, Masafumi; Li, Qiye; Wang, Juan; Zhang, Hongyan; Yu, Lili; Shigenobu, Shuji; Wang, Junyi; Liu, Jiannan; Flicek, Paul; Searle, Steve; Wang, Jun; Kuratani, Shigeru; Yin, Ye; Aken, Bronwen; Zhang, Guojie; Irie, Naoki

2013-06-01

The unique anatomical features of turtles have raised unanswered questions about the origin of their unique body plan. We generated and analyzed draft genomes of the soft-shell turtle (Pelodiscus sinensis) and the green sea turtle (Chelonia mydas); our results indicated the close relationship of the turtles to the bird-crocodilian lineage, from which they split ∼267.9-248.3 million years ago (Upper Permian to Triassic). We also found extensive expansion of olfactory receptor genes in these turtles. Embryonic gene expression analysis identified an hourglass-like divergence of turtle and chicken embryogenesis, with maximal conservation around the vertebrate phylotypic period, rather than at later stages that show the amniote-common pattern. Wnt5a expression was found in the growth zone of the dorsal shell, supporting the possible co-option of limb-associated Wnt signaling in the acquisition of this turtle-specific novelty. Our results suggest that turtle evolution was accompanied by an unexpectedly conservative vertebrate phylotypic period, followed by turtle-specific repatterning of development to yield the novel structure of the shell.

A Rare de novo Interstitial Duplication at 4p15.2 in a Boy with Severe Congenital Heart Defects, Limb Anomalies, Hypogonadism, and Global Developmental Delay.

PubMed

Liang, Liyang; Xie, Yingjun; Shen, Yiping; Yin, Qibin; Yuan, Haiming

2016-01-01

Proximal 4p deletion syndrome is a relatively rare genetic condition characterized by dysmorphic facial features, limb anomalies, minor congenital heart defects, hypogonadism, cafe-au-lait spots, developmental delay, tall and thin habitus, and intellectual disability. At present, over 20 cases of this syndrome have been published. However, duplication of the same region in proximal 4p has never been reported. Here, we describe a 2-year-5-month-old boy with severe congenital heart defects, limb anomalies, hypogonadism, distinctive facial features, pre- and postnatal developmental delay, and mild cognitive impairments. A de novo 4.5-Mb interstitial duplication at 4p15.2p15.1 was detected by chromosomal microarray analysis. Next-generation sequencing was employed and confirmed the duplication, but revealed no additional pathogenic variants. Several candidate genes in this interval responsible for the complex clinical phenotype were identified, such as RBPJ, STIM2, CCKAR, and LGI2. The results suggest a novel contiguous gene duplication syndrome. © 2016 S. Karger AG, Basel.

Size-Related Changes in Foot Impact Mechanics in Hoofed Mammals

PubMed Central

Warner, Sharon Elaine; Pickering, Phillip; Panagiotopoulou, Olga; Pfau, Thilo; Ren, Lei; Hutchinson, John Richard

2013-01-01

Foot-ground impact is mechanically challenging for all animals, but how do large animals mitigate increased mass during foot impact? We hypothesized that impact force amplitude scales according to isometry in animals of increasing size through allometric scaling of related impact parameters. To test this, we measured limb kinetics and kinematics in 11 species of hoofed mammals ranging from 18–3157 kg body mass. We found impact force amplitude to be maintained proportional to size in hoofed mammals, but that other features of foot impact exhibit differential scaling patterns depending on the limb; forelimb parameters typically exhibit higher intercepts with lower scaling exponents than hind limb parameters. Our explorations of the size-related consequences of foot impact advance understanding of how body size influences limb morphology and function, foot design and locomotor behaviour. PMID:23382967

Influence of maturation on instep kick biomechanics in female soccer athletes.

PubMed

Lyle, Mark A; Sigward, Susan M; Tsai, Liang-Ching; Pollard, Christine D; Powers, Christopher M

2011-10-01

The purpose of this study was to compare kicking biomechanics between young female soccer players at two different stages of physical maturation and to identify biomechanical predictors of peak foot velocity. Swing and stance limb kinematics and kinetics were recorded from 20 female soccer players (10 prepubertal, 10 postpubertal) while kicking a soccer ball using an angled two-step approach. Peak foot velocity as well as hip and knee kinematics and kinetics were compared between groups using independent-samples t-tests. Pearson correlation coefficients and stepwise multiple regression were used to identify predictors of peak foot velocity. Peak foot velocity and the peak swing limb net hip flexor moment was significantly greater in the postpubertal group when compared with the prepubertal group (13.4 vs 11.6 m·s(-1), P = 0.003; 1.22 vs 1.07 N·m·kg(-1)·m(-1), P = 0.03). Peak stance limb hip and knee extensor moments were not different between groups. Although the peak swing limb hip and knee flexion angles were similar between groups, the postpubertal group demonstrated significantly less peak stance limb hip and knee flexion angles when compared with the prepubertal group (P < 0.001 and P = 0.045). Using a linear regression model, swing limb peak hip flexor moment and peak swing limb hip extension range of motion combined to explain 65% of the variance in peak foot velocity. Despite a difference in stance limb kinematics, similar swing limb kinematics between groups indicates that the prepubertal female athletes kicked with a mature swing limb kick pattern. The ability to generate a large hip flexor moment of the swing limb seems to be an important factor for improving kicking performance in young female soccer players.

Patterned control of human locomotion

PubMed Central

Lacquaniti, Francesco; Ivanenko, Yuri P; Zago, Myrka

2012-01-01

There is much experimental evidence for the existence of biomechanical constraints which simplify the problem of control of multi-segment movements. In addition, it has been hypothesized that movements are controlled using a small set of basic temporal components or activation patterns, shared by several different muscles and reflecting global kinematic and kinetic goals. Here we review recent studies on human locomotion showing that muscle activity is accounted for by a combination of few basic patterns, each one timed at a different phase of the gait cycle. Similar patterns are involved in walking and running at different speeds, walking forwards or backwards, and walking under different loading conditions. The corresponding weights of distribution to different muscles may change as a function of the condition, allowing highly flexible control. Biomechanical correlates of each activation pattern have been described, leading to the hypothesis that the co-ordination of limb and body segments arises from the coupling of neural oscillators between each other and with limb mechanical oscillators. Muscle activations need only intervene during limited time epochs to force intrinsic oscillations of the system when energy is lost. PMID:22411012

Patterned control of human locomotion.

PubMed

Lacquaniti, Francesco; Ivanenko, Yuri P; Zago, Myrka

2012-05-15

There is much experimental evidence for the existence of biomechanical constraints which simplify the problem of control of multi-segment movements. In addition, it has been hypothesized that movements are controlled using a small set of basic temporal components or activation patterns, shared by several different muscles and reflecting global kinematic and kinetic goals. Here we review recent studies on human locomotion showing that muscle activity is accounted for by a combination of few basic patterns, each one timed at a different phase of the gait cycle. Similar patterns are involved in walking and running at different speeds, walking forwards or backwards, and walking under different loading conditions. The corresponding weights of distribution to different muscles may change as a function of the condition, allowing highly flexible control. Biomechanical correlates of each activation pattern have been described, leading to the hypothesis that the co-ordination of limb and body segments arises from the coupling of neural oscillators between each other and with limb mechanical oscillators. Muscle activations need only intervene during limited time epochs to force intrinsic oscillations of the system when energy is lost.

Vertical head and pelvic movement symmetry at the trot in dogs with induced supporting limb lameness.

PubMed

Gómez Álvarez, C B; Gustås, P; Bergh, A; Rhodin, M

2017-11-01

Compensatory limb loading has been studied in lame dogs; however, little is known about how these compensations relate to motion of the head and pelvis, assessment of which is an important component of lameness examinations. The aim of this study was to describe the patterns of vertical head and pelvic motion symmetry at the trot in dogs with induced supporting limb lameness in the forelimbs or hind limbs. Ten sound dogs were trotted on a treadmill before and after temporary induction of moderate lameness (grade 2/5) in each limb. Reflective markers were located on the head, pelvis and right forelimb, and kinematic data were captured with a motion capture system. Upper body symmetry parameters were calculated, including differences in the highest (HDmax) and in the lowest (HDmin) positions of the head, and in the highest (PDmax) and in the lowest (PDmin) positions of the mid-pelvis, with a value of zero indicating symmetry. The head was lowered more during the sound limb stance phase and lowered less during the lame limb stance phase in supporting forelimb lameness (HDmin: 4.6mm in dogs when sound, -18.3mm when left limb lameness was induced and 20.5mm when right limb lameness was induced). The mid-pelvis was lowered more during the sound limb stance phase and lowered and lifted less during the lame limb stance phase in supporting hind limb lameness (PDmin: 1mm in dogs when sound, -10.1mm in left limb lameness and 8.4mm in right limb lameness). The hip of the lame side, measured at the level of the greater trochanter, had an increased downwards displacement during the lame limb swing phase (-21mm in left hind limb lameness, P=0.005; 23.4mm in right hind limb lameness, P=0.007). Asymmetry in the lowering of the head or mid-pelvis is a more sensitive indicator of supporting forelimb and hind limb lameness, respectively, than asymmetry in the raising of the head. Increased displacement of the hip ('hip drop' of the lame side during its swing phase) is a good indicator of hind limb lameness in dogs. Copyright © 2017. Published by Elsevier Ltd.

Slow- and fast-twitch rat hind limb skeletal muscle phenotypes 8 months after spinal cord transection and olfactory ensheathing glia transplantation

PubMed Central

Negredo, Pilar; Rivero, José-Luis L; González, Beatriz; Ramón-Cueto, Almudena; Manso, Rafael

2008-01-01

Paralysed skeletal muscle of rats with spinal cord injury (SCI) undergoes atrophy and a switch in gene expression pattern which leads to faster, more fatigable phenotypes. Olfactory ensheathing glia (OEG) transplants have been reported to promote axonal regeneration and to restore sensory-motor function in animals with SCI. We hypothesized that OEG transplants could attenuate skeletal muscle phenotypic deterioration and that this effect could underlie the functional recovery observed in behavioural tests. A variety of morphological, metabolic and molecular markers were assessed in soleus (SOL) and extensor digitorum longus (EDL) muscles of spinal cord transected (SCT), OEG-transplanted rats 8 months after the intervention and compared with non-transplanted SCT rats and sham-operated (without SCT) controls (C). A multivariate analysis encompassing all the parameters indicated that OEG-transplanted rats displayed skeletal muscle phenotypes intermediate between non-transplanted and sham-operated controls, but different from both. A high correlation was observed between behaviourally tested sensory-motor functional capacity and expression level of slow- and fast-twitch hind limb skeletal muscle phenotypic markers, particularly the histochemical glycerol-3-phosphate dehydrogenase activity (−0.843, P < 0.0001) and the fraction of variant 2s of the slow regulatory myosin light chain isoform (0.848, P < 0.0001) in SOL. Despite the mean overall effect of OEG transplants in patterning skeletal muscle protein expression towards normal, in 6 out of 9 animals they appeared insufficient to overcome fibre type switching and to support a consistent and generalized long-term maintenance of normal skeletal muscle characteristics. The interplay of OEG and exercise-mediated neurotrophic actions is a plausible mechanism underlying OEG transplantation effects on paralysed skeletal muscle. PMID:18372308

What Explains Patterns of Diversification and Richness among Animal Phyla?

PubMed Central

Jezkova, Tereza; Wiens, John J.

2016-01-01

Animal phyla vary dramatically in species richness (from 1 species to >1.2 million), but the causes of this variation remain largely unknown. Animals have also evolved striking variation in morphology and ecology, including sessile marine taxa lacking heads, eyes, limbs, and complex organs (e.g. sponges), parasitic worms (e.g. nematodes, platyhelminths), and taxa with eyes, skeletons, limbs, and complex organs that dominate terrestrial ecosystems (arthropods, chordates). Relating this remarkable variation in traits to the diversification and richness of animal phyla is a fundamental yet unresolved problem in biology. Here, we test the impacts of 18 traits (including morphology, ecology, reproduction, and development) on diversification and richness of extant animal phyla. Using phylogenetic multiple regression, the best-fitting model includes five traits that explain ~74% of the variation in diversification rates (dioecy, parasitism, eyes/photoreceptors, a skeleton, non-marine habitat). However, a model including just three (skeleton, parasitism, habitat) explains nearly as much variation (~67%). Diversification rates then largely explain richness patterns. Our results also identify many striking traits that have surprisingly little impact on diversification (e.g. head, limbs, and complex circulatory and digestive systems). Overall, our results reveal the key factors that shape large-scale patterns of diversification and richness across >80% of all extant, described species. PMID:28221832

What Explains Patterns of Diversification and Richness among Animal Phyla?

PubMed

Jezkova, Tereza; Wiens, John J

2017-03-01

Animal phyla vary dramatically in species richness (from one species to >1.2 million), but the causes of this variation remain largely unknown. Animals have also evolved striking variation in morphology and ecology, including sessile marine taxa lacking heads, eyes, limbs, and complex organs (e.g., sponges), parasitic worms (e.g., nematodes, platyhelminths), and taxa with eyes, skeletons, limbs, and complex organs that dominate terrestrial ecosystems (arthropods, chordates). Relating this remarkable variation in traits to the diversification and richness of animal phyla is a fundamental yet unresolved problem in biology. Here, we test the impacts of 18 traits (including morphology, ecology, reproduction, and development) on diversification and richness of extant animal phyla. Using phylogenetic multiple regression, the best-fitting model includes five traits that explain ∼74% of the variation in diversification rates (dioecy, parasitism, eyes/photoreceptors, a skeleton, nonmarine habitat). However, a model including just three (skeleton, parasitism, habitat) explains nearly as much variation (∼67%). Diversification rates then largely explain richness patterns. Our results also identify many striking traits that have surprisingly little impact on diversification (e.g., head, limbs, and complex circulatory and digestive systems). Overall, our results reveal the key factors that shape large-scale patterns of diversification and richness across >80% of all extant, described species.

A bioinformatics expert system linking functional data to anatomical outcomes in limb regeneration

PubMed Central

Lobo, Daniel; Feldman, Erica B.; Shah, Michelle; Malone, Taylor J.

2014-01-01

Abstract Amphibians and molting arthropods have the remarkable capacity to regenerate amputated limbs, as described by an extensive literature of experimental cuts, amputations, grafts, and molecular techniques. Despite a rich history of experimental effort, no comprehensive mechanistic model exists that can account for the pattern regulation observed in these experiments. While bioinformatics algorithms have revolutionized the study of signaling pathways, no such tools have heretofore been available to assist scientists in formulating testable models of large‐scale morphogenesis that match published data in the limb regeneration field. Major barriers to preventing an algorithmic approach are the lack of formal descriptions for experimental regenerative information and a repository to centralize storage and mining of functional data on limb regeneration. Establishing a new bioinformatics of shape would significantly accelerate the discovery of key insights into the mechanisms that implement complex regeneration. Here, we describe a novel mathematical ontology for limb regeneration to unambiguously encode phenotype, manipulation, and experiment data. Based on this formalism, we present the first centralized formal database of published limb regeneration experiments together with a user‐friendly expert system tool to facilitate its access and mining. These resources are freely available for the community and will assist both human biologists and artificial intelligence systems to discover testable, mechanistic models of limb regeneration. PMID:25729585

A pilot study to compare the cerebral hemodynamics between patients with obstructive sleep apnea syndrome (OSA) and periodic limb movement syndrome (PLMS) during nocturnal sleep with near-infrared spectroscopy (NIRS)

NASA Astrophysics Data System (ADS)

Zhang, Zhongxing; Schneider, Maja; Laures, Marco; Fritschi, Ursula; Hügli, Gordana; Lehner, Isabella; Qi, Ming; Khatami, Ramin

2014-03-01

Obstructive sleep apnea syndrome (OSA) and periodic limb movement in sleep syndrome (PLMS) are two common sleep disorders. Previous studies showed that OSA and PLMS share common features, such as increased cardio-vascular risk, both apnea events and limb movements occur periodically, they are usually associated with cortical arousals, and both of them can induce declines in peripheral oxygen saturation measured with pulse oximetry. However, the question whether apnea events and limb movements also show similar characteristics in cerebral hemodynamic and oxygenation has never been addressed. In this pilot study, we will first time compare the cerebral hemodynamic changes induced by apnea events and limb movements in patients with OSA (n=4) and PLMS (n=4) with NIRS. In patients with OSA, we found periodic oscillations in HbO2, HHb, and blood volume induced by apnea/hypopnea events, HbO2 and HHb showed reverse changing trends. By contrast, the periodic oscillations linked to limb movements were only found in HbO2 and blood volume in patients with PLMS. These findings of different cerebral hemodynamics patterns between apnea events and limb movements may indicate different regulations of nervous system between these two sleep disorders.

Expression Analysis of Macrodactyly Identifies Pleiotrophin Upregulation

PubMed Central

Lau, Frank H.; Xia, Fang; Kaplan, Adam; Cerrato, Felecia; Greene, Arin K.; Taghinia, Amir; Cowan, Chad A.; Labow, Brian I.

2012-01-01

Macrodactyly is a rare family of congenital disorders characterized by the diffuse enlargement of 1 or more digits. Multiple tissue types within the affected digits are involved, but skeletal patterning and gross morphological features are preserved. Not all tissues are equally involved and there is marked heterogeneity with respect to clinical phenotype. The molecular mechanisms responsible for these growth disturbances offer unique insight into normal limb growth and development, in general. To date, no genes or loci have been implicated in the development of macrodactyly. In this study, we performed the first transcriptional profiling of macrodactyly tissue. We found that pleiotrophin (PTN) was significantly overexpressed across all our macrodactyly samples. The mitogenic functions of PTN correlate closely with the clinical characteristics of macrodactyly. PTN thus represents a promising target for further investigation into the etiology of overgrowth phenotypes. PMID:22848377

Targeted Resequencing of 29 Candidate Genes and Mouse Expression Studies Implicate ZIC3 and FOXF1 in Human VATER/VACTERL Association.

PubMed

Hilger, Alina C; Halbritter, Jan; Pennimpede, Tracie; van der Ven, Amelie; Sarma, Georgia; Braun, Daniela A; Porath, Jonathan D; Kohl, Stefan; Hwang, Daw-Yang; Dworschak, Gabriel C; Hermann, Bernhard G; Pavlova, Anna; El-Maarri, Osman; Nöthen, Markus M; Ludwig, Michael; Reutter, Heiko; Hildebrandt, Friedhelm

2015-12-01

The VATER/VACTERL association describes the combination of congenital anomalies including vertebral defects, anorectal malformations, cardiac defects, tracheoesophageal fistula with or without esophageal atresia, renal malformations, and limb defects. As mutations in ciliary genes were observed in diseases related to VATER/VACTERL, we performed targeted resequencing of 25 ciliary candidate genes as well as disease-associated genes (FOXF1, HOXD13, PTEN, ZIC3) in 123 patients with VATER/VACTERL or VATER/VACTERL-like phenotype. We detected no biallelic mutation in any of the 25 ciliary candidate genes; however, identified an identical, probably disease-causing ZIC3 missense mutation (p.Gly17Cys) in four patients and a FOXF1 de novo mutation (p.Gly220Cys) in a further patient. In situ hybridization analyses in mouse embryos between E9.5 and E14.5 revealed Zic3 expression in limb and prevertebral structures, and Foxf1 expression in esophageal, tracheal, vertebral, anal, and genital tubercle tissues, hence VATER/VACTERL organ systems. These data provide strong evidence that mutations in ZIC3 or FOXF1 contribute to VATER/VACTERL. © 2015 WILEY PERIODICALS, INC.

Specific patterns of canine scavenging in indoor settings.

PubMed

Colard, Thomas; Delannoy, Yann; Naji, Stephan; Gosset, Didier; Hartnett, Kristen; Bécart, Anne

2015-03-01

Postmortem animal mutilations due to domestic dogs in isolated domestic deaths are taphonomic modifications regularly observed by forensic pathologists. They are rarely described in the literature; however, even though they present specific patterns. Through 41 cases, 10 at the forensic institute in Lille (France) and 31 at the New York City Office of Chief Medical Examiner (USA), plus 22 cases from the literature, specific locations and patterns of postmortem scavenging lesions are proposed. These lesions are mainly distributed in three locations: the face, especially the nose and the mouth (73.1%), the neck (43.1%), and the arm (shoulder/upper limb [29.2%], hand [26.8%]). We discuss the time span between death and scavenging, the consequences on identification, and comparison with outdoor settings. Outdoor scavenging lesions are mainly located on the trunk and limbs usually sparing the head, which strongly differs from indoor distribution and imply different animal motivations. © 2015 American Academy of Forensic Sciences.

The Effect of Manipulating Subject Mass on Lower Extremity Torque Patterns During Locomotion

NASA Technical Reports Server (NTRS)

DeWitt, John K.; Cromwell, Ronita L.; Hagan, R. Donald

2007-01-01

During locomotion, humans adapt their motor patterns to maintain coordination despite changing conditions (Reisman et al., 2005). Bernstein (1967) proposed that in addition to the present state of a given joint, other factors, including limb inertia and velocity, must be taken into account to allow proper motion to occur. During locomotion with added mass counterbalanced using vertical suspension to maintain body weight, vertical ground reaction forces (GRF's) increase during walking but decrease during running, suggesting that adaptation may be velocity-specific (De Witt et al., 2006). It is not known, however, how lower extremity joint torques adapt to changes in inertial forces. The purpose of this investigation was to examine the effects of increasing body mass while maintaining body weight upon lower-limb joint torque during walking and running. We hypothesized that adaptations in joint torque patterns would occur with the addition of body mass.

Bilateral versus ipsilesional cortico-subcortical activity patterns in stroke show hemispheric dependence.

PubMed

Vidal, Ana C; Banca, Paula; Pascoal, Augusto G; Cordeiro, Gustavo; Sargento-Freitas, João; Gouveia, Ana; Castelo-Branco, Miguel

2018-01-01

Background Understanding of interhemispheric interactions in stroke patients during motor control is an important clinical neuroscience quest that may provide important clues for neurorehabilitation. In stroke patients bilateral overactivation in both hemispheres has been interpreted as a poor prognostic indicator of functional recovery. In contrast, ipsilesional patterns have been linked with better motor outcomes. Aim We investigated the pathophysiology of hemispheric interactions during limb movement without and with contralateral restraint, to mimic the effects of constraint-induced movement therapy. We used neuroimaging to probe brain activity with such a movement-dependent interhemispheric modulation paradigm. Methods We used a functional magnetic resonance imaging block design during which the plegic/paretic upper limb was recruited/mobilized to perform unilateral arm elevation, as a function of presence versus absence of contralateral limb restriction (n = 20, with balanced left/right lesion sites). Results Analysis of 10 right hemispheric stroke participants yielded bilateral sensorimotor cortex activation in all movement phases in contrast with the unilateral dominance seen in the 10 left hemispheric stroke participants. Superimposition of contralateral restriction led to a prominent shift from activation to deactivation response patterns, in particular in cortical and basal ganglia motor areas in right hemispheric stroke. Left hemispheric stroke was, in general, characterized by reduced activation patterns, even in the absence of restriction, which induced additional cortical silencing. Conclusion The observed hemispheric-dependent activation/deactivation shifts is novel and these pathophysiological observations suggest short-term neuroplasticity that may be useful for hemisphere-tailored neurorehabilitation.

Bilateral versus ipsilesional cortico-subcortical activity patterns in stroke show hemispheric dependence.

PubMed

Vidal, A Cristina; Banca, Paula; Pascoal, Augusto G; Santo, Gustavo C; Sargento-Freitas, João; Gouveia, Ana; Castelo-Branco, Miguel

2017-01-01

Background Understanding of interhemispheric interactions in stroke patients during motor control is an important clinical neuroscience quest that may provide important clues for neurorehabilitation. In stroke patients, bilateral overactivation in both hemispheres has been interpreted as a poor prognostic indicator of functional recovery. In contrast, ipsilesional patterns have been linked with better motor outcomes. Aim We investigated the pathophysiology of hemispheric interactions during limb movement without and with contralateral restraint, to mimic the effects of constraint-induced movement therapy. We used neuroimaging to probe brain activity with such a movement-dependent interhemispheric modulation paradigm. Methods We used an fMRI block design during which the plegic/paretic upper limb was recruited/mobilized to perform unilateral arm elevation, as a function of presence versus absence of contralateral limb restriction ( n = 20, with balanced left/right lesion sites). Results Analysis of 10 right-hemispheric stroke participants yielded bilateral sensorimotor cortex activation in all movement phases in contrast with the unilateral dominance seen in the 10 left-hemispheric stroke participants. Superimposition of contralateral restriction led to a prominent shift from activation to deactivation response patterns, in particular in cortical and basal ganglia motor areas in right-hemispheric stroke. Left-hemispheric stroke was in general characterized by reduced activation patterns, even in the absence of restriction, which induced additional cortical silencing. Conclusion The observed hemispheric-dependent activation/deactivation shifts are novel and these pathophysiological observations suggest short-term neuroplasticity that may be useful for hemisphere-tailored neurorehabilitation.

A genome-wide association study of limb bone length using a Large White × Minzhu intercross population.

PubMed

Zhang, Long-Chao; Li, Na; Liu, Xin; Liang, Jing; Yan, Hua; Zhao, Ke-Bin; Pu, Lei; Shi, Hui-Bi; Zhang, Yue-Bo; Wang, Li-Gang; Wang, Li-Xian

2014-11-04

In pig, limb bone length influences ham yield and body height to a great extent and has important economic implications for pig industry. In this study, an intercross population was constructed between the indigenous Chinese Minzhu pig breed and the western commercial Large White pig breed to examine the genetic basis for variation in limb bone length. The aim of this study was to detect potential genetic variants associated with porcine limb bone length. A total of 571 F2 individuals from a Large White and Minzhu intercross population were genotyped using the Illumina PorcineSNP60K Beadchip, and phenotyped for femur length (FL), humerus length (HL), hipbone length (HIPL), scapula length (SL), tibia length (TL), and ulna length (UL). A genome-wide association study was performed by applying the previously reported approach of genome-wide rapid association using mixed model and regression. Statistical significance of the associations was based on Bonferroni-corrected P-values. A total of 39 significant SNPs were mapped to a 11.93 Mb long region on pig chromosome 7 (SSC7). Linkage analysis of these significant SNPs revealed three haplotype blocks of 495 kb, 376 kb and 492 kb, respectively, in the 11.93 Mb region. Annotation based on the pig reference genome identified 15 genes that were located near or contained the significant SNPs in these linkage disequilibrium intervals. Conditioned analysis revealed that four SNPs, one on SSC2 and three on SSC4, showed significant associations with SL and HL, respectively. Analysis of the 15 annotated genes that were identified in these three haplotype blocks indicated that HMGA1 and PPARD, which are expressed in limbs and influence chondrocyte cell growth and differentiation, could be considered as relevant biological candidates for limb bone length in pig, with potential applications in breeding programs. Our results may also be useful for the study of the mechanisms that underlie human limb length and body height.

Efficient gene knockin in axolotl and its use to test the role of satellite cells in limb regeneration.

PubMed

Fei, Ji-Feng; Schuez, Maritta; Knapp, Dunja; Taniguchi, Yuka; Drechsel, David N; Tanaka, Elly M

2017-11-21

Salamanders exhibit extensive regenerative capacities and serve as a unique model in regeneration research. However, due to the lack of targeted gene knockin approaches, it has been difficult to label and manipulate some of the cell populations that are crucial for understanding the mechanisms underlying regeneration. Here we have established highly efficient gene knockin approaches in the axolotl ( Ambystoma mexicanum ) based on the CRISPR/Cas9 technology. Using a homology-independent method, we successfully inserted both the Cherry reporter gene and a larger membrane-tagged Cherry-ER T2 -Cre-ER T2 (∼5-kb) cassette into axolotl Sox2 and Pax7 genomic loci. Depending on the size of the DNA fragments for integration, 5-15% of the F0 transgenic axolotl are positive for the transgene. Using these techniques, we have labeled and traced the PAX7-positive satellite cells as a major source contributing to myogenesis during axolotl limb regeneration. Our work brings a key genetic tool to molecular and cellular studies of axolotl regeneration.

Lower-Limb Joint Coordination Pattern in Obese Subjects

PubMed Central

Ranavolo, Alberto; Donini, Lorenzo M.; Mari, Silvia; Serrao, Mariano; Silvetti, Alessio; Iavicoli, Sergio; Cava, Edda; Asprino, Rosa; Pinto, Alessandro; Draicchio, Francesco

2013-01-01

The coordinative pattern is an important feature of locomotion that has been studied in a number of pathologies. It has been observed that adaptive changes in coordination patterns are due to both external and internal constraints. Obesity is characterized by the presence of excess mass at pelvis and lower-limb areas, causing mechanical constraints that central nervous system could manage modifying the physiological interjoint coupling relationships. Since an altered coordination pattern may induce joint diseases and falls risk, the aim of this study was to analyze whether and how coordination during walking is affected by obesity. We evaluated interjoint coordination during walking in 25 obese subjects as well as in a control group. The time-distance parameters and joint kinematics were also measured. When compared with the control group, obese people displayed a substantial similarity in joint kinematic parameters and some differences in the time-distance and in the coupling parameters. Obese subjects revealed higher values in stride-to-stride intrasubjects variability in interjoint coupling parameters, whereas the coordinative mean pattern was unaltered. The increased variability in the coupling parameters is associated with an increased risk of falls and thus should be taken into account when designing treatments aimed at restoring a normal locomotion pattern. PMID:23484078

Preaxial Polydactyly in Sost/Sostdc1 Double Knockouts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yee, C M; Collette, N M; Loots, G G

2011-07-29

In the United States, {approx}5% are born with congenital birth defects due to abnormal function of cellular processes and interactions. Sclerosteosis, a rare autosomal recessive disease, causes hyperostosis of the axial and appendicular skeleton, and patients present radial deviation, digit syndactyly, nail dysplasia, and overall high bone mineral density. Sclerosteosis is due to a loss of function of sclerostin (Sost). Sost is a Wnt (abbrev.) antagonist; when mutated, nonfunctional Sost results in hyperactive osteoblast activity which leads to abnormal high bone mass. Previous studies have shown that Sost overexpression in transgenic mice causes reduced bone mineral density and a varietymore » of limb phenotypes ranging from lost, fused, and split phalanges. Consistent with clinical manifestations of Sclerosteosis, Sost knockout mice exhibit increased generalized bone mineral density and syndactyly of the digits. Sostdc1 is a paralog of Sost that has also been described as an antagonist of Wnt signaling, in developing tooth buds. Unlike Sost knockouts, Sostdc1 null mice do not display any limb abnormalities. To determine if Sost and Sostdc1 have redundant functions during limb patterning, we examined Sost; Sostdc1 mice determined that they exhibit a novel preaxial polydactyly phenotype with a low penetrance. LacZ staining, skeletal preparations, and in situ hybridization experiments were used to help characterize this novel phenotype and understand how this phenotype develops. We find Sost and Sostdc1 to have complementary expression patterns during limb development, and the loss of their expression alters the transcription of several key limb regulators, such as Fgf8, Shh and Grem.« less

Quantification of upper limb kinetic asymmetries in front crawl swimming.

PubMed

Morouço, Pedro G; Marinho, Daniel A; Fernandes, Ricardo J; Marques, Mário C

2015-04-01

This study aimed at quantifying upper limb kinetic asymmetries in maximal front crawl swimming and to examine if these asymmetries would affect the contribution of force exertion to swimming performance. Eighteen high level male swimmers with unilateral breathing patterns and sprint or middle distance specialists, volunteered as participants. A load-cell was used to quantify the forces exerted in water by completing a 30s maximal front crawl tethered swimming test and a maximal 50 m free swimming was considered as a performance criterion. Individual force-time curves were obtained to calculate the mean and maximum forces per cycle, for each upper limb. Following, symmetry index was estimated and breathing laterality identified by questionnaire. Lastly, the pattern of asymmetries along the test was estimated for each upper limb using linear regression of peak forces per cycle. Asymmetrical force exertion was observed in the majority of the swimmers (66.7%), with a total correspondence of breathing laterality opposite to the side of the force asymmetry. Forces exerted by the dominant upper limb presented a higher decrease than from the non-dominant. Very strong associations were found between exerted forces and swimming performance, when controlling the isolated effect of symmetry index. Results point that force asymmetries occur in the majority of the swimmers, and that these asymmetries are most evident in the first cycles of a maximum bout. Symmetry index stood up as an influencing factor on the contribution of tethered forces over swimming performance. Thus, to some extent, a certain degree of asymmetry is not critical for short swimming performance. Copyright © 2015 Elsevier B.V. All rights reserved.

The Comparisons of Cerebral Hemodynamics Induced by Obstructive Sleep Apnea with Arousal and Periodic Limb Movement with Arousal: A Pilot NIRS Study

PubMed Central

Zhang, Zhongxing; Schneider, Maja; Laures, Marco; Qi, Ming; Khatami, Ramin

2016-01-01

Obstructive sleep apnea syndrome (OSA) and restless legs syndrome (RLS) with periodic limb movement during sleep (PLMS) are two sleep disorders characterized by repetitive respiratory or movement events associated with cortical arousals. We compared the cerebral hemodynamic changes linked to periodic apneas/hypopneas with arousals (AHA) in four OSA-patients with periodic limb movements (PLMA) with arousals in four patients with RLS-PLMS using near-infrared spectroscopy (NIRS). AHA induced homogenous pattern of periodic fluctuations in oxygenated (HbO2) and deoxygenated (HHb) hemoglobin, i.e., the decrease of HbO2 was accompanied by an increase of HHb during the respiratory event and resolved to reverse pattern when cortical arousal started. Blood volume (BV) showed the same pattern as HHb but with relative smaller amplitude in most of the AHA events.These changing patterns were significant as Wilcoxon signed-rank tests gave p < 0.001 when comparing the area under the curve of these hemodynamic parameters to zero. By contrast, in PLMA limb movements induced periodic increments in HbO2 and BV (Wilcoxon signed-rank tests, p < 0.001), but HHb changed more heterogeneously even during the events coming from the same patient. Heart rate (HR) also showed different patterns between AHA and PLMA. It significantly decreased during the respiratory event (Wilcoxon signed-rank test, p < 0.001) and then increased after the occurrence of cortical arousal (Wilcoxon signed-rank test, p < 0.001); while in PLMA HR first increased preceding the occurrence of cortical arousal (Wilcoxon signed-rank test, p < 0.001) and then decreased. The results of this preliminary study show that both AHA and PLMA induce changes in cerebral hemodynamics. The occurrence of cortical arousal is accompanied by increased HR in both events, but by different BV changes (i.e., decreased/increased BV in AHA/PLMA, respectively). HR changes may partially account for the increased cerebral hemodynamics during PLMA; whereas in AHA probable vasodilatation mediated by hypoxia/hypercapnia is more crucial for the post-arousal hemodynamics. The differences between changes of cerebral hemodynamics and HR may indicate different pathological mechanisms behind these two sleep disorder events. PMID:27630539

The Comparisons of Cerebral Hemodynamics Induced by Obstructive Sleep Apnea with Arousal and Periodic Limb Movement with Arousal: A Pilot NIRS Study.

PubMed

Zhang, Zhongxing; Schneider, Maja; Laures, Marco; Qi, Ming; Khatami, Ramin

2016-01-01

Obstructive sleep apnea syndrome (OSA) and restless legs syndrome (RLS) with periodic limb movement during sleep (PLMS) are two sleep disorders characterized by repetitive respiratory or movement events associated with cortical arousals. We compared the cerebral hemodynamic changes linked to periodic apneas/hypopneas with arousals (AHA) in four OSA-patients with periodic limb movements (PLMA) with arousals in four patients with RLS-PLMS using near-infrared spectroscopy (NIRS). AHA induced homogenous pattern of periodic fluctuations in oxygenated (HbO2) and deoxygenated (HHb) hemoglobin, i.e., the decrease of HbO2 was accompanied by an increase of HHb during the respiratory event and resolved to reverse pattern when cortical arousal started. Blood volume (BV) showed the same pattern as HHb but with relative smaller amplitude in most of the AHA events.These changing patterns were significant as Wilcoxon signed-rank tests gave p < 0.001 when comparing the area under the curve of these hemodynamic parameters to zero. By contrast, in PLMA limb movements induced periodic increments in HbO2 and BV (Wilcoxon signed-rank tests, p < 0.001), but HHb changed more heterogeneously even during the events coming from the same patient. Heart rate (HR) also showed different patterns between AHA and PLMA. It significantly decreased during the respiratory event (Wilcoxon signed-rank test, p < 0.001) and then increased after the occurrence of cortical arousal (Wilcoxon signed-rank test, p < 0.001); while in PLMA HR first increased preceding the occurrence of cortical arousal (Wilcoxon signed-rank test, p < 0.001) and then decreased. The results of this preliminary study show that both AHA and PLMA induce changes in cerebral hemodynamics. The occurrence of cortical arousal is accompanied by increased HR in both events, but by different BV changes (i.e., decreased/increased BV in AHA/PLMA, respectively). HR changes may partially account for the increased cerebral hemodynamics during PLMA; whereas in AHA probable vasodilatation mediated by hypoxia/hypercapnia is more crucial for the post-arousal hemodynamics. The differences between changes of cerebral hemodynamics and HR may indicate different pathological mechanisms behind these two sleep disorder events.

Limb segment vibration modulates spinal reflex excitability and muscle mRNA expression after spinal cord injury

PubMed Central

Chang, Shuo-Hsiu; Tseng, Shih-Chiao; McHenry, Colleen L.; Littmann, Andrew E.; Suneja, Manish; Shields, Richard K.

2012-01-01

Objective We investigated the effect of various doses of vertical oscillation (vibration) on soleus H-reflex amplitude and post-activation depression in individuals with and without SCI. We also explored the acute effect of short-term limb vibration on skeletal muscle mRNA expression of genes associated with spinal plasticity. Methods Six healthy adults and five chronic complete SCI subjects received vibratory stimulation of their tibia over three different gravitational accelerations (0.3g, 0.6g, and 1.2g) at a fixed frequency (30 Hz). Soleus H-reflexes were measured before, during, and after vibration. Two additional chronic complete SCI subjects had soleus muscle biopsies 3 h following a single bout of vibration. Results H-reflex amplitude was depressed over 83% in both groups during vibration. This vibratory-induced inhibition lasted over 2 min in the control group, but not in the SCI group. Post-activation depression was modulated during the long-lasting vibratory inhibition. A single bout of mechanical oscillation altered mRNA expression from selected genes associated with synaptic plasticity. Conclusions Vibration of the lower leg inhibits the H-reflex amplitude, influences post-activation depression, and alters skeletal muscle mRNA expression of genes associated with synaptic plasticity. Significance Limb segment vibration may offer a long term method to reduce spinal reflex excitability after SCI. PMID:21963319

[Clinical analysis and genetic diagnosis of short-limb inherited short stature diseases in children].

PubMed

Li, Fang; Ma, Hong-Wei; Song, Ying; Hu, Man; Ren, Shuang; Yu, Ya-Fen; Zhao, Gui-Jie

2013-11-01

To analyze the clinical manifestations, bone X-ray findings and genetic analysis results of three short-limb inherited short stature diseases: achondroplasia (ACH), hypochondroplasia (HCH) and pseudoachondroplasia (PSACH). The clinical manifestations, bone X-ray findings, and genetic analysis results of 10 children with genetically confirmed short-limb inherited short stature diseases, including 4 cases of ACH 3 cases of HCH, and 3 cases of PSACH, were analyzed. The 10 patients had a mean body height of -3.69±1.79 SD, a mean sitting height/standing height ratio of 0.65±0.03, and a mean finger spacing/body height ratio of 0.93±0.04. Four ACH cases and 3 PSACH cases showed typical bone X-ray findings; one HCH case showed a smaller sciatic notch, and another HCH case showed no widening of interpedicular distance. G380R mutation in FGFR3 gene was detected in 3 of 4 ACH cases, and Y278C mutation in the other ACH case, N540K mutation in FGFR3 gene was detected in 3 HCH cases, and heterozygous mutations in COMP gene were detected in 3 PSACH cases. Children with ACH and PSACH have severer short stature and skeletal deformities than children with HCH, who have mild, atypical clinical manifestations. Bone X-ray and genetic analysis are helpful for the diagnosis and differential diagnosis of the three diseases. The mutational hotspots in two genes are involved in the three diseases, which is conducive to clinical genetic diagnosis.

A heterozygous 21-bp deletion in CAPN3 causes dominantly inherited limb girdle muscular dystrophy.

PubMed

Vissing, John; Barresi, Rita; Witting, Nanna; Van Ghelue, Marijke; Gammelgaard, Lise; Bindoff, Laurence A; Straub, Volker; Lochmüller, Hanns; Hudson, Judith; Wahl, Christoph M; Arnardottir, Snjolaug; Dahlbom, Kathe; Jonsrud, Christoffer; Duno, Morten

2016-08-01

Limb girdle muscular dystrophy type 2A is the most common limb girdle muscular dystrophy form worldwide. Although strict recessive inheritance is assumed, patients carrying a single mutation in the calpain 3 gene (CAPN3) are reported. Such findings are commonly attributed to incomplete mutation screening. In this investigation, we report 37 individuals (age range: 21-85 years, 21 females and 16 males) from 10 families in whom only one mutation in CAPN3 could be identified; a 21-bp, in-frame deletion (c.643_663del21). This mutation co-segregated with evidence of muscle disease and autosomal dominant transmission in several generations. Evidence of muscle disease was indicated by muscle pain, muscle weakness and wasting, significant fat replacement of muscles on imaging, myopathic changes on muscle biopsy and loss of calpain 3 protein on western blotting. Thirty-one of 34 patients had elevated creatine kinase or myoglobin. Muscle weakness was generally milder than observed in limb girdle muscular dystrophy type 2A, but affected the same muscle groups (proximal leg, lumbar paraspinal and medial gastrocnemius muscles). In some cases, the weakness was severely disabling. The 21-bp deletion did not affect mRNA maturation. Calpain 3 expression in muscle, assessed by western blot, was below 15% of normal levels in the nine mutation carriers in whom this could be tested. Haplotype analysis in four families from three different countries suggests that the 21-bp deletion is a founder mutation. This study provides strong evidence that heterozygosity for the c.643_663del21 deletion in CAPN3 results in a dominantly inherited muscle disease. The normal expression of mutated mRNA and the severe loss of calpain 3 on western blotting, suggest a dominant negative effect with a loss-of-function mechanism affecting the calpain 3 homodimer. This renders patients deficient in calpain 3 as in limb girdle muscular dystrophy type 2A, albeit in a milder form in most cases. Based on findings in 10 families, our study indicates that a dominantly inherited pattern of calpainopathy exists, and should be considered in the diagnostic work-up and genetic counselling of patients with calpainopathy and single-allele aberrations in CAPN3. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Myasthenic syndromes due to defects in COL13A1 and in the N-linked glycosylation pathway.

PubMed

Beeson, David; Cossins, Judith; Rodriguez-Cruz, Pedro; Maxwell, Susan; Liu, Wei-Wei; Palace, Jacqueline

2018-02-01

The congenital myasthenic syndromes (CMS) are hereditary disorders of neuromuscular transmission. The number of cases recognized, at around 1:100,000 in the United Kingdom, is increasing with improved diagnosis. The advent of next-generation sequencing has facilitated the discovery of many genes that harbor CMS-associated mutations. An emerging group of CMS, characterized by a limb-girdle pattern of muscle weakness, is caused by mutations in genes that encode proteins involved in the initial steps of the N-linked glycosylation pathway, which is surprising, since this pathway is found in all mammalian cells. However, mutations in these genes may also give rise to multisystem disorders (congenital disorders of glycosylation) or muscle disorders where the myasthenic symptoms constitute only one component within a wider phenotypic spectrum. We also report a CMS due to mutations in COL13A1, which encodes an extracellular matrix protein that is concentrated at the neuromuscular junction and highlights a role for these extracellular matrix proteins in maintaining synaptic stability that is independent of the AGRN/MuSK clustering pathway. Knowledge about the neuromuscular synapse and the different proteins involved in maintaining its structure as well as function enables us to tailor treatments to the underlying pathogenic mechanisms. © 2018 New York Academy of Sciences.

Physical mapping of the torsion dystonia region of human chromosome 9q34

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ozelius, L.J.; Hewett, J.; Shalish, C.

1994-09-01

Torsion dystonia is a syndrome characterized by loss of voluntary movements appearing as sustained muscle contractions and/or abnormal postures. The DYT1 gene is responsible for a subtype of torsion dystonia in which onset of symptoms tends to occur in a limb at an early age (mean 13 years) and to progress to a generalized state. Expression of the disease gene follows an autosomal dominant mode of inheritance with reduced penetrance. We initially mapped this gene to human chromosome 9q34 and have now defined its location to a < 1 cM region near the ASS locus based on historic recombination eventsmore » around a founder mutation in the Ashkenazic Jewish population. Using the CEPH YAC library and a chromosome 9 flow-sorted YAC library, we have generated a YAC contig spanning about 500 kb of this region. These YACs are being used to identify cosmids by direct hybridization to chromosome 9-specific cosmid libraries. Cosmids are being aligned by restriction digest patterns and by hybridization with oligonucleotide repeat probes. In addition, the cosmids are being {open_quotes}trapped{close_quotes} by exon amplification and these exons used to screen cDNA libraries. Thus far we have identified several candidate transcripts in this region.« less

A new titinopathy

PubMed Central

De Cid, Rafael; Ben Yaou, Rabah; Roudaut, Carinne; Charton, Karine; Baulande, Sylvain; Leturcq, France; Romero, Norma Beatriz; Malfatti, Edoardo; Beuvin, Maud; Vihola, Anna; Criqui, Audrey; Nelson, Isabelle; Nectoux, Juliette; Ben Aim, Laurène; Caloustian, Christophe; Olaso, Robert; Udd, Bjarne; Bonne, Gisèle; Eymard, Bruno

2015-01-01

Objective: To identify the genetic defects present in 3 families with muscular dystrophy, contractures, and calpain 3 deficiency. Methods: We performed targeted exome sequencing on one patient presenting a deficiency in calpain 3 on Western blot but for which mutations in the gene had been excluded. The identification of a homozygous truncating mutation in the M-line part of titin prompted us to sequence this region in 2 additional patients presenting similar clinical and biochemical characteristics. Results: The 3 patients shared similar features: coexistence of limb-girdle weakness and early-onset diffuse joint contractures without cardiomyopathy. The biopsies showed rimmed vacuoles, a dystrophic pattern, and secondary reduction in calpain 3. We identified a novel homozygous mutation in the exon Mex3 of the TTN gene in the first patient. At protein level, this mutation introduces a stop codon at the level of Mex3. Interestingly, we identified truncating mutations in both alleles in the same region of the TTN gene in patients from 2 additional families. Molecular protein analyses confirm loss of the C-ter part of titin. Conclusions: Our study broadens the phenotype of titinopathies with the report of a new clinical entity with prominent contractures and no cardiac abnormality and where the recessive mutations lead to truncation of the M-line titin and secondary calpain 3 deficiency. PMID:26581302

[Specific features of Becker Muscular Dystrophy patients and female carriers of Duchenne Muscular Dystrophy].

PubMed

Magot, A; Mercier, S; Péréon, Y

2015-12-01

Becker muscular dystrophy (BMD) was first described in 1955 and linked to the DMD gene in 1987. Compared to Duchenne muscular dystrophy (DMD), clinical onset of BMD usually occurs after the age of 12 and wheelchair is required after the age of 16. BMD is characterized by generalized weakness first affecting limb girdle muscles, hypertrophy of the calves and cardiomyopathy in males. Some patients have only mild symptoms such as cramps or elevated serum creatine kinases (SCK) throughout all their lives. SCK levels are usually elevated. Muscle biopsy (immunohistochemistry or immunoblotting) shows a dystrophic pattern with abnormal dystrophin staining. Diagnosis is confirmed by DMD gene sequencing. Deletions or duplications of one or several exons are identified in the majority of cases. A multidisciplinary approach is recommended for the care management of these patients with a particular attention to the cardiomyopathy, which is typically responsible for death but can be prevented by specific treatment. X-linked dilated cardiomyopathies linked to DMD gene are a phenotypic continuum of BMD. Some female carriers of DMD mutations exhibit clinical symptoms of variable severity, often milder and beginning later than in males. The cardiomyopathy is the most frequent feature that should be especially monitored in these patients. Genetic counselling should be systematically proposed. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

The chicken talpid3 gene encodesa novel protein essentialfor Hedgehog signaling

PubMed Central

Davey, Megan G.; Paton, I. Robert; Yin, Yili; Schmidt, Maike; Bangs, Fiona K.; Morrice, David R.; Smith, Terence Gordon; Buxton, Paul; Stamataki, Despina; Tanaka, Mikiko; Münsterberg, Andrea E.; Briscoe, James; Tickle, Cheryll; Burt, Dave W.

2006-01-01

Talpid3 is a classical chicken mutant with abnormal limb patterning and malformations in other regions of the embryo known to depend on Hedgehog signaling. We combined the ease of manipulating chicken embryos with emerging knowledge of the chicken genome to reveal directly the basis of defective Hedgehog signal transduction in talpid3 embryos and to identify the talpid3 gene. We show in several regions of the embryo that the talpid3 phenotype is completely ligand independent and demonstrate for the first time that talpid3 is absolutely required for the function of both Gli repressor and activator in the intracellular Hedgehog pathway. We map the talpid3 locus to chromosome 5 and find a frameshift mutation in a KIAA0586 ortholog (ENSGALG00000012025), a gene not previously attributed with any known function. We show a direct causal link between KIAA0586 and the mutant phenotype by rescue experiments. KIAA0586 encodes a novel protein, apparently specific to vertebrates, that localizes to the cytoplasm. We show that Gli3 processing is abnormal in talpid3 mutant cells but that Gli3 can still translocate to the nucleus. These results suggest that the talpid3 protein operates in the cytoplasm to regulate the activity of both Gli repressor and activator proteins. PMID:16702409

Fork stalling and template switching as a mechanism for polyalanine tract expansion affecting the DYC mutant of HOXD13, a new murine model of synpolydactyly.

PubMed

Cocquempot, Olivier; Brault, Véronique; Babinet, Charles; Herault, Yann

2009-09-01

Polyalanine expansion diseases are proposed to result from unequal crossover of sister chromatids that increases the number of repeats. In this report we suggest an alternative mechanism we put forward while we investigated a new spontaneous mutant that we named "Dyc" for "Digit in Y and Carpe" phenotype. Phenotypic analysis revealed an abnormal limb patterning similar to that of the human inherited congenital disease synpolydactyly (SPD) and to the mouse mutant model Spdh. Both human SPD and mouse Spdh mutations affect the Hoxd13 gene within a 15-residue polyalanine-encoding repeat in the first exon of the gene, leading to a dominant negative HOXD13. Genetic analysis of the Dyc mutant revealed a trinucleotide expansion in the polyalanine-encoding region of the Hoxd13 gene resulting in a 7-alanine expansion. However, unlike the Spdh mutation, this expansion cannot result from a simple duplication of a short segment. Instead, we propose the fork stalling and template switching (FosTeS) described for generation of nonrecurrent genomic rearrangements as a possible mechanism for the Dyc polyalanine extension, as well as for other polyalanine expansions described in the literature and that could not be explained by unequal crossing over.

Fork Stalling and Template Switching As a Mechanism for Polyalanine Tract Expansion Affecting the DYC Mutant of HOXD13, a New Murine Model of Synpolydactyly

PubMed Central

Cocquempot, Olivier; Brault, Véronique; Babinet, Charles; Herault, Yann

2009-01-01

Polyalanine expansion diseases are proposed to result from unequal crossover of sister chromatids that increases the number of repeats. In this report we suggest an alternative mechanism we put forward while we investigated a new spontaneous mutant that we named “Dyc” for “Digit in Y and Carpe” phenotype. Phenotypic analysis revealed an abnormal limb patterning similar to that of the human inherited congenital disease synpolydactyly (SPD) and to the mouse mutant model Spdh. Both human SPD and mouse Spdh mutations affect the Hoxd13 gene within a 15-residue polyalanine-encoding repeat in the first exon of the gene, leading to a dominant negative HOXD13. Genetic analysis of the Dyc mutant revealed a trinucleotide expansion in the polyalanine-encoding region of the Hoxd13 gene resulting in a 7-alanine expansion. However, unlike the Spdh mutation, this expansion cannot result from a simple duplication of a short segment. Instead, we propose the fork stalling and template switching (FosTeS) described for generation of nonrecurrent genomic rearrangements as a possible mechanism for the Dyc polyalanine extension, as well as for other polyalanine expansions described in the literature and that could not be explained by unequal crossing over. PMID:19546318

Coordination and Symmetry Patterns During the Drop Vertical Jump in People With Chronic Ankle Instability and Lateral Ankle Sprain Copers.

PubMed

Doherty, Cailbhe; Bleakley, Chris; Hertel, Jay; Caulfield, Brian; Ryan, John; Sweeney, Kevin; Patterson, Matthew R; Delahunt, Eamonn

2016-08-01

The drop vertical jump (DVJ) task has previously been used to identify movement patterns associated with a number of injury types. However, no current research exists evaluating people with chronic ankle instability (CAI) compared with people coping with lateral ankle sprain (LAS) (referred to as "LAS copers") during this task. The aim of this study was to identify the coping movement and motor control patterns of LAS copers in comparison with individuals with CAI during the DVJ task. This was a case-control study. Seventy individuals were recruited at convenience within 2-weeks of sustaining a first-time acute LAS injury. One year following recruitment, these individuals were stratified into 2 groups: 28 with CAI and 42 LAS copers. They attended the testing laboratory to complete a DVJ task. Three-dimensional kinematic and sagittal-plane kinetic profiles were plotted for the lower extremity joints of both limbs for the drop jump phase (phase 1) and drop landing phase (phase 2) of the DVJ. The rate of impact modulation relative to body weight during both phases of the DVJ also was determined. Compared with LAS copers, participants with CAI displayed significant increases in hip flexion on their "involved" limb during phase 1 of the DVJ (23° vs 18°) and bilaterally during phase 2 (15° vs 10°). These movement patterns coincided with altered moment-of-force patterns at the hip on the "uninvolved" limb. It is unknown whether these movement and motor control patterns preceded or occurred as a result of the initial LAS injury. Participants with CAI displayed hip-centered changes in movement and motor control patterns during a DVJ task compared with LAS copers. The findings of this study may give an indication of the coping mechanism underlying outcome following initial LAS injury. © 2016 American Physical Therapy Association.

Divergence in male and female manipulative behaviors with the intensification of metallurgy in Central Europe.

PubMed

Macintosh, Alison A; Pinhasi, Ron; Stock, Jay T

2014-01-01

Humeral morphology has been shown to reflect, in part, habitual manipulative behaviors in humans. Among Central European agricultural populations, long-term social change, increasing task specialization, and technological innovation all had the potential to impact patterns of habitual activity and upper limb asymmetry. However, systematic temporal change in the skeletal morphology of agricultural populations in this region has not been well-characterized. This study investigates diachronic patterns in humeral biomechanical properties and lengths among 174 adult Central European agriculturalists through the first ∼ 5400 years of farming in the region. Greater asymmetry in biomechanical properties was expected to accompany the introduction of metallurgy, particularly in males, while upper limb loading patterns were expected to be more similar between the Bronze and Iron Ages. Results revealed a divergence in the lateralization of upper limb biomechanical properties by sex between the Early/Middle Neolithic and Early/Middle Bronze Age. Neolithic females had significantly more variable properties than males in both humeri, while Bronze Age female properties became homogeneous and very symmetrical relative to the right-biased lateralization of contemporaneous males. The Bronze Age to Iron Age transition was associated with morphological change among females, with a significant increase in right-biased asymmetry and a concomitant reduction in sexual dimorphism. Relative to biomechanical properties, humeral length variation and asymmetry were low though some significant sexual dimorphism and temporal change was found. It was among females that the lateralization of humeral biomechanical properties, and variation within them, changed most profoundly through time. This suggests that the introduction of the ard and plow, metallurgical innovation, task specialization, and socioeconomic change through ∼ 5400 years of agriculture impacted upper limb loading in Central European women to a greater extent than men.

Deficiency in Mental Rotation of Upper and Lower-Limbs in Patients With Multiple Sclerosis and Its Relation With Cognitive Functions.

PubMed

Azin, Mahdieh; Zangiabadi, Nasser; Moghadas Tabrizi, Yousef; Iranmanesh, Farhad; Baneshi, Mohammad Reza

2016-08-01

Mental rotation is a cognitive motor process which was impaired in different neurologic disorders. We investigated whether there were deficits in response pattern, reaction time and response accuracy rate of mental rotation in multiple sclerosis (MS) patients compared to healthy subjects and whether cognitive dysfunctions in MS patients were correlated with mental rotation deficits. Moreover, we showed whether there was a difference between upper and lower-limbs mental rotation in MS patients. Thirty-five MS patients and 25 healthy subjects performed hand mental rotation (HMR) and foot mental rotation (FMR) tasks. Visual information processing speed, spatial learning and memory ability, and visuospatial processing were assessed by Symbol Digit Modalities Test (SDMT), Brief Visuospatial Memory Test-Revised (BVMT-R), and Judgment of Line Orientation Test (JLO) respectively in MS patients. Reaction time for both hand and foot stimuli increased, and response accuracy rate for hand stimuli decreased in MS patients compared to healthy subjects, but response pattern of mental rotation in MS patients persisted. Similar to healthy subjects, MS patients performed upper-limbs mental rotation more easily than a lower-limbs mental rotation with more speed and response accuracy rate. Reaction time and response accuracy rate were correlated with the mentioned cognitive functions. MS patients made use of the correct response pattern for problem solving of increasing orientation from upright stimuli. Reaction time and response accuracy rate altered in these patients and this alteration might occur along with impairment in motor planning. Subjects' better responding to hand stimuli was due to more familiarity with hand stimuli. The correlation of mental rotation ability with cognitive functions indicates the possible role of cognitive functions in mental rotation.

Development of the arterial pattern in the upper limb of staged human embryos: normal development and anatomic variations

PubMed Central

RODRÍGUEZ-NIEDENFÜHR, M.; BURTON, G. J.; DEU, J.; SAÑUDO, J. R.

2001-01-01

A total of 112 human embryos (224 upper limbs) between stages 12 and 23 of development were examined. It was observed that formation of the arterial system in the upper limb takes place as a dual process. An initial capillary plexus appears from the dorsal aorta during stage 12 and develops at the same rate as the limb. At stage 13, the capillary plexus begins a maturation process involving the enlargement and differentiation of selected parts. This remodelling process starts in the aorta and continues in a proximal to distal sequence. By stage 15 the differentiation has reached the subclavian and axillary arteries, by stage 17 it has reached the brachial artery as far as the elbow, by stage 18 it has reached the forearm arteries except for the distal part of the radial, and finally by stage 21 the whole arterial pattern is present in its definitive morphology. This differentiation process parallels the development of the skeletal system chronologically. A number of arterial variations were observed, and classified as follows: superficial brachial (7.7%), accessory brachial (0.6%), brachioradial (14%), superficial brachioulnar (4.7%), superficial brachioulnoradial (0.7%), palmar pattern of the median (18.7%) and superficial brachiomedian (0.7%) arteries. They were observed in embryos belonging to stages 17–23 and were not related to a specific stage of development. Statistical comparison with the rates of variations reported in adults did not show significant differences. It is suggested that the variations arise through the persistence, enlargement and differentiation of parts of the initial network which would normally remain as capillaries or even regress. PMID:11693301

A horse’s locomotor signature: COP path determined by the individual limb

PubMed Central

Hobbs, Sarah Jane; Back, Willem

2017-01-01

Introduction Ground reaction forces in sound horses with asymmetric hooves show systematic differences in the horizontal braking force and relative timing of break-over. The Center Of Pressure (COP) path quantifies the dynamic load distribution under the hoof in a moving horse. The objective was to test whether anatomical asymmetry, quantified by the difference in dorsal wall angle between the left and right forelimbs, correlates with asymmetry in the COP path between these limbs. In addition, repeatability of the COP path was investigated. Methods A larger group (n = 31) visually sound horses with various degree of dorsal hoof wall asymmetry trotted three times over a pressure mat. COP path was determined in a hoof-bound coordinate system. A relationship between correlations between left and right COP paths and degree of asymmetry was investigated. Results Using a hoof-bound coordinate system made the COP path highly repeatable and unique for each limb. The craniocaudal patterns are usually highly correlated between left and right, but the mediolateral patterns are not. Some patterns were found between COP path and dorsal wall angle but asymmetry in dorsal wall angle did not necessarily result in asymmetry in COP path and the same could be stated for symmetry. Conclusion This method is a highly sensitive method to quantify the net result of the interaction between all of the forces and torques that occur in the limb and its inertial properties. We argue that changes in motor control, muscle force, inertial properties, kinematics and kinetics can potentially be picked up at an early stage using this method and could therefore be used as an early detection method for changes in the musculoskeletal apparatus. PMID:28196073

Electromiography comparison of distal and proximal lower limb muscle activity patterns during external perturbation in subjects with and without functional ankle instability.

PubMed

Kazemi, Khadijeh; Arab, Amir Massoud; Abdollahi, Iraj; López-López, Daniel; Calvo-Lobo, César

2017-10-01

Ankle sprain is one of the most common injuries among athletes and the general population. Most ankle injuries commonly affect the lateral ligament complex. Changes in postural sway and hip abductor muscle strength may be generated after inversion ankle sprain. Therefore, the consequences of ankle injury may affect proximal structures of the lower limb. The aim is to describe and compare the activity patterns of distal and proximal lower limb muscles following external perturbation in individuals with and without functional ankle instability. The sample consisted of 16 women with functional ankle instability and 18 healthy women were recruited to participate in this research. The external perturbation via body jacket using surface electromyography, amplitude and onset of muscle activity of gluteus maximums, gluteus medius, tibialis anterior, and peroneus longus was recorded and analyzed during external perturbation. There were differences between the onset of muscles activity due to perturbation direction in the two groups (healthy and functional ankle instability). In the healthy group, there were statistically significant differences in amplitude of proximal muscle activity with distal muscle activity during front perturbation with eyes open and closed. In the functional ankle instability group; there were statistically significant differences in amplitude of proximal muscle activity with distal muscle activity during perturbation of the front and back with eyes open. There were statistically significant differences in the onset of muscle activity and amplitude of muscle activity, with-in and between groups (P<0.05). Therefore, in the presence of functional ankle instability, activation patterns of the lower limb proximal muscles may be altered. Copyright © 2017 Elsevier B.V. All rights reserved.

Laser Doppler assessment of skin blood flow in arteriopathic limbs.

PubMed

Allen, P I; Goldman, M

1987-05-01

In severely ischaemic lower limbs, the skin response to changing posture from lying to standing is a diagnostic flush. We investigated this observation by measurements of the microcirculation using the non-invasive laser Doppler technique. Eleven patients with ankle: brachial pressure (A:B) ratios less than 0.7 were compared with 13 age-matched controls (A:B ratios greater than 1). In normal subjects, mean horizontal skin blood flow (SBF) was 30.2 +/- 14.9 (+/- SD), significantly greater than mean SBF in the ischaemic group: 12.4 +/- 9.2 (P less than 0.01, Student's t test). Mean SBF fell in the normal group on dependency to 27.5 +/- 16.4 but this change was not significant. Unexpectedly mean SBF rose in the ischaemic limbs to 20.7 +/- 13.8 (P less than 0.05). The pattern of SBF response to change in posture is different in normal and arteriopathic limbs.

Lower extremity sagittal joint moment production during split-belt treadmill walking

PubMed Central

Roemmich, Ryan T.; Stegemöller, Elizabeth L.; Hass, Chris J.

2012-01-01

The split-belt treadmill (SBT) has recently been used to rehabilitate locomotor asymmetries in clinical populations. However, the joint mechanics produced while walking on a SBT are not well-understood. The purpose of this study was to investigate the lower extremity sagittal joint moments produced by each limb during SBT walking and provide insight as to how these joint moment patterns may be useful in rehabilitating unilateral gait deficits. Thirteen healthy young volunteers walked on the SBT with the belts tied and in a “SPLIT” session in which one belt moved twice as fast as the other. Sagittal lower extremity joint moment and ground reaction force impulses were then calculated over the braking and propulsive phases of the gait cycle. Paired t-tests were performed to analyze magnitude differences between conditions (i.e. the fast and slow limbs during SPLIT vs. the same limb during tied-belt walking) and between the fast and slow limbs during SPLIT. During the SPLIT session, the fast limb produced higher ground reaction force and ankle moment impulses during the propulsive and braking phases, and lower knee moment impulses during the propulsive phase when compared to the slow limb. The knee moment impulse was also significantly higher during braking in the slow limb than in the fast limb. The mechanics of each limb during the SPLIT session also differed from the mechanics observed when the belt speeds were tied. Based on these findings, we suggest that each belt may have intrinsic value in rehabilitating specific unilateral locomotor deficits. PMID:22985473

Predictive Value of Upper Limb Muscles and Grasp Patterns on Functional Outcome in Cervical Spinal Cord Injury.

PubMed

Velstra, Inge-Marie; Bolliger, Marc; Krebs, Jörg; Rietman, Johan S; Curt, Armin

2016-05-01

To determine which single or combined upper limb muscles as defined by the International Standards for the Neurological Classification of Spinal Cord Injury (ISNCSCI); upper extremity motor score (UEMS) and the Graded Redefined Assessment of Strength, Sensibility, and Prehension (GRASSP), best predict upper limb function and independence in activities of daily living (ADLs) and to assess the predictive value of qualitative grasp movements (QlG) on upper limb function in individuals with acute tetraplegia. As part of a Europe-wide, prospective, longitudinal, multicenter study ISNCSCI, GRASSP, and Spinal Cord Independence Measure (SCIM III) scores were recorded at 1 and 6 months after SCI. For prediction of upper limb function and ADLs, a logistic regression model and unbiased recursive partitioning conditional inference tree (URP-CTREE) were used. Results: Logistic regression and URP-CTREE revealed that a combination of ISNCSCI and GRASSP muscles (to a maximum of 4) demonstrated the best prediction (specificity and sensitivity ranged from 81.8% to 96.0%) of upper limb function and identified homogenous outcome cohorts at 6 months. The URP-CTREE model with the QlG predictors for upper limb function showed similar results. Prediction of upper limb function can be achieved through a combination of defined, specific upper limb muscles assessed in the ISNCSCI and GRASSP. A combination of a limited number of proximal and distal muscles along with an assessment of grasping movements can be applied for clinical decision making for rehabilitation interventions and clinical trials. © The Author(s) 2015.

[Coordination patterns assessed by a continuous measure of joints coupling during upper limb repetitive movements].

PubMed

Draicchio, F; Silvetti, A; Ranavolo, A; Iavicoli, S

2008-01-01

We analyzed the coordination patterns between elbow, shoulder and trunk in a motor task consisting of reaching out, picking up a cylinder, and transporting it back by using the Dynamical Systems Theory and calculating the continuous relative phase (CRP), a continuous measure of the coupling between two interacting joints. We used an optoelectronic motion analysis system consisting of eight infra-red ray cameras to detect the movements of nine skin-mounted markers. We calculated the root square of the adjusted coefficient of determination, the coefficient of multiple correlation (CMC), in order to investigate the repeatability of the joints coordination. The data confirm that the CNS establishes both synergic (i.e. coupling between shoulder and trunk on the frontal plane) and hierarchical (i.e. coupling between elbow-shoulder-trunk on the horizontal plane) relationships among the available degrees of freedom to overcome the complexity due to motor redundancy. The present study describes a method to investigate the organization of the kinematic degrees of freedom during upper limb multi-joint motor tasks that can be useful to assess upper limb repetitive movements.

Genome-Wide Profiling of p63 DNA–Binding Sites Identifies an Element that Regulates Gene Expression during Limb Development in the 7q21 SHFM1 Locus

PubMed Central

Oti, Martin; Dutilh, Bas E.; Alonso, M. Eva; de la Calle-Mustienes, Elisa; Smeenk, Leonie; Rinne, Tuula; Parsaulian, Lilian; Bolat, Emine; Jurgelenaite, Rasa; Huynen, Martijn A.; Hoischen, Alexander; Veltman, Joris A.; Brunner, Han G.; Roscioli, Tony; Oates, Emily; Wilson, Meredith; Manzanares, Miguel; Gómez-Skarmeta, José Luis; Stunnenberg, Hendrik G.; Lohrum, Marion; van Bokhoven, Hans; Zhou, Huiqing

2010-01-01

Heterozygous mutations in p63 are associated with split hand/foot malformations (SHFM), orofacial clefting, and ectodermal abnormalities. Elucidation of the p63 gene network that includes target genes and regulatory elements may reveal new genes for other malformation disorders. We performed genome-wide DNA–binding profiling by chromatin immunoprecipitation (ChIP), followed by deep sequencing (ChIP–seq) in primary human keratinocytes, and identified potential target genes and regulatory elements controlled by p63. We show that p63 binds to an enhancer element in the SHFM1 locus on chromosome 7q and that this element controls expression of DLX6 and possibly DLX5, both of which are important for limb development. A unique micro-deletion including this enhancer element, but not the DLX5/DLX6 genes, was identified in a patient with SHFM. Our study strongly indicates disruption of a non-coding cis-regulatory element located more than 250 kb from the DLX5/DLX6 genes as a novel disease mechanism in SHFM1. These data provide a proof-of-concept that the catalogue of p63 binding sites identified in this study may be of relevance to the studies of SHFM and other congenital malformations that resemble the p63-associated phenotypes. PMID:20808887

Msx homeobox gene family and craniofacial development.

PubMed

Alappat, Sylvia; Zhang, Zun Yi; Chen, Yi Ping

2003-12-01

Vertebrate Msx genes are unlinked, homeobox-containing genes that bear homology to the Drosophila muscle segment homeobox gene. These genes are expressed at multiple sites of tissue-tissue interactions during vertebrate embryonic development. Inductive interactions mediated by the Msx genes are essential for normal craniofacial, limb and ectodermal organ morphogenesis, and are also essential to survival in mice, as manifested by the phenotypic abnormalities shown in knockout mice and in humans. This review summarizes studies on the expression, regulation, and functional analysis of Msx genes that bear relevance to craniofacial development in humans and mice. Key words: Msx genes, craniofacial, tooth, cleft palate, suture, development, transcription factor, signaling molecule.

Longitudinal quasi-static stability predicts changes in dog gait on rough terrain

PubMed Central

Reeve, Michelle A.; Haynes, G. Clark; Revzen, Shai; Koditschek, Daniel E.; Spence, Andrew J.

2017-01-01

ABSTRACT Legged animals utilize gait selection to move effectively and must recover from environmental perturbations. We show that on rough terrain, domestic dogs, Canis lupus familiaris, spend more time in longitudinal quasi-statically stable patterns of movement. Here, longitudinal refers to the rostro-caudal axis. We used an existing model in the literature to quantify the longitudinal quasi-static stability of gaits neighbouring the walk, and found that trot-like gaits are more stable. We thus hypothesized that when perturbed, the rate of return to a stable gait would depend on the direction of perturbation, such that perturbations towards less quasi-statically stable patterns of movement would be more rapid than those towards more stable patterns of movement. The net result of this would be greater time spent in longitudinally quasi-statically stable patterns of movement. Limb movement patterns in which diagonal limbs were more synchronized (those more like a trot) have higher longitudinal quasi-static stability. We therefore predicted that as dogs explored possible limb configurations on rough terrain at walking speeds, the walk would shift towards trot. We gathered experimental data quantifying dog gait when perturbed by rough terrain and confirmed this prediction using GPS and inertial sensors (n=6, P<0.05). By formulating gaits as trajectories on the n-torus we are able to make tractable the analysis of gait similarity. These methods can be applied in a comparative study of gait control which will inform the ultimate role of the constraints and costs impacting locomotion, and have applications in diagnostic procedures for gait abnormalities, and in the development of agile legged robots. PMID:28264903

Longitudinal quasi-static stability predicts changes in dog gait on rough terrain.

PubMed

Wilshin, Simon; Reeve, Michelle A; Haynes, G Clark; Revzen, Shai; Koditschek, Daniel E; Spence, Andrew J

2017-05-15

Legged animals utilize gait selection to move effectively and must recover from environmental perturbations. We show that on rough terrain, domestic dogs, Canis lupus familiaris , spend more time in longitudinal quasi-statically stable patterns of movement. Here, longitudinal refers to the rostro-caudal axis. We used an existing model in the literature to quantify the longitudinal quasi-static stability of gaits neighbouring the walk, and found that trot-like gaits are more stable. We thus hypothesized that when perturbed, the rate of return to a stable gait would depend on the direction of perturbation, such that perturbations towards less quasi-statically stable patterns of movement would be more rapid than those towards more stable patterns of movement. The net result of this would be greater time spent in longitudinally quasi-statically stable patterns of movement. Limb movement patterns in which diagonal limbs were more synchronized (those more like a trot) have higher longitudinal quasi-static stability. We therefore predicted that as dogs explored possible limb configurations on rough terrain at walking speeds, the walk would shift towards trot. We gathered experimental data quantifying dog gait when perturbed by rough terrain and confirmed this prediction using GPS and inertial sensors ( n =6, P <0.05). By formulating gaits as trajectories on the n -torus we are able to make tractable the analysis of gait similarity. These methods can be applied in a comparative study of gait control which will inform the ultimate role of the constraints and costs impacting locomotion, and have applications in diagnostic procedures for gait abnormalities, and in the development of agile legged robots. © 2017. Published by The Company of Biologists Ltd.

A comparative study of single-leg ground reaction forces in running lizards.

PubMed

McElroy, Eric J; Wilson, Robbie; Biknevicius, Audrone R; Reilly, Stephen M

2014-03-01

The role of different limbs in supporting and propelling the body has been studied in many species with animals appearing to have either similarity in limb function or differential limb function. Differential hindlimb versus forelimb function has been proposed as a general feature of running with a sprawling posture and as benefiting sprawled postured animals by enhancing maneuvering and minimizing joint moments. Yet only a few species have been studied and thus the generality of differential limb function in running animals with sprawled postures is unknown. We measured the limb lengths of seven species of lizard and their single-limb three-dimensional ground reaction forces during high-speed running. We found that all species relied on the hindlimb for producing accelerative forces. Braking forces were forelimb dominated in four species and equally distributed between limbs in the other three. Vertical forces were dominated by the hindlimb in three species and equally distributed between the forelimb and hindlimb in the other four. Medial forces were dominated by the hindlimb in four species and equally distributed in the other three, with all Iguanians exhibiting hindlimb-biased medial forces. Relative hindlimb to forelimb length of each species was related to variation in hindlimb versus forelimb medial forces; species with relatively longer hindlimbs compared with forelimbs exhibited medial forces that were more biased towards the hindlimbs. These results suggest that the function of individual limbs in lizards varies across species with only a single general pattern (hindlimb-dominated accelerative force) being present.

The functional anatomy of suggested limb paralysis.

PubMed

Deeley, Quinton; Oakley, David A; Toone, Brian; Bell, Vaughan; Walsh, Eamonn; Marquand, Andre F; Giampietro, Vincent; Brammer, Michael J; Williams, Steven C R; Mehta, Mitul A; Halligan, Peter W

2013-02-01

Suggestions of limb paralysis in highly hypnotically suggestible subjects have been employed to successfully model conversion disorders, revealing similar patterns of brain activation associated with attempted movement of the affected limb. However, previous studies differ with regard to the executive regions involved during involuntary inhibition of the affected limb. This difference may have arisen as previous studies did not control for differences in hypnosis depth between conditions and/or include subjective measures to explore the experience of suggested paralysis. In the current study we employed functional magnetic resonance imaging (fMRI) to examine the functional anatomy of left and right upper limb movements in eight healthy subjects selected for high hypnotic suggestibility during (i) hypnosis (NORMAL) and (ii) attempted movement following additional left upper limb paralysis suggestions (PARALYSIS). Contrast of left upper limb motor function during NORMAL relative to PARALYSIS conditions revealed greater activation of contralateral M1/S1 and ipsilateral cerebellum, consistent with the engagement of these regions in the completion of movements. By contrast, two significant observations were noted in PARALYSIS relative to NORMAL conditions. In conjunction with reports of attempts to move the paralysed limb, greater supplementary motor area (SMA) activation was observed, a finding consistent with the role of SMA in motor intention and planning. The anterior cingulate cortex (ACC, BA 24) was also significantly more active in PARALYSIS relative to NORMAL conditions - suggesting that ACC (BA 24) may be implicated in involuntary, as well as voluntary inhibition of prepotent motor responses. Copyright © 2012 Elsevier Ltd. All rights reserved.

Extracting time-frequency feature of single-channel vastus medialis EMG signals for knee exercise pattern recognition.

PubMed

Zhang, Yi; Li, Peiyang; Zhu, Xuyang; Su, Steven W; Guo, Qing; Xu, Peng; Yao, Dezhong

2017-01-01

The EMG signal indicates the electrophysiological response to daily living of activities, particularly to lower-limb knee exercises. Literature reports have shown numerous benefits of the Wavelet analysis in EMG feature extraction for pattern recognition. However, its application to typical knee exercises when using only a single EMG channel is limited. In this study, three types of knee exercises, i.e., flexion of the leg up (standing), hip extension from a sitting position (sitting) and gait (walking) are investigated from 14 healthy untrained subjects, while EMG signals from the muscle group of vastus medialis and the goniometer on the knee joint of the detected leg are synchronously monitored and recorded. Four types of lower-limb motions including standing, sitting, stance phase of walking, and swing phase of walking, are segmented. The Wavelet Transform (WT) based Singular Value Decomposition (SVD) approach is proposed for the classification of four lower-limb motions using a single-channel EMG signal from the muscle group of vastus medialis. Based on lower-limb motions from all subjects, the combination of five-level wavelet decomposition and SVD is used to comprise the feature vector. The Support Vector Machine (SVM) is then configured to build a multiple-subject classifier for which the subject independent accuracy will be given across all subjects for the classification of four types of lower-limb motions. In order to effectively indicate the classification performance, EMG features from time-domain (e.g., Mean Absolute Value (MAV), Root-Mean-Square (RMS), integrated EMG (iEMG), Zero Crossing (ZC)) and frequency-domain (e.g., Mean Frequency (MNF) and Median Frequency (MDF)) are also used to classify lower-limb motions. The five-fold cross validation is performed and it repeats fifty times in order to acquire the robust subject independent accuracy. Results show that the proposed WT-based SVD approach has the classification accuracy of 91.85%±0.88% which outperforms other feature models.

Towards Efficient Decoding of Multiple Classes of Motor Imagery Limb Movements Based on EEG Spectral and Time Domain Descriptors.

PubMed

Samuel, Oluwarotimi Williams; Geng, Yanjuan; Li, Xiangxin; Li, Guanglin

2017-10-28

To control multiple degrees of freedom (MDoF) upper limb prostheses, pattern recognition (PR) of electromyogram (EMG) signals has been successfully applied. This technique requires amputees to provide sufficient EMG signals to decode their limb movement intentions (LMIs). However, amputees with neuromuscular disorder/high level amputation often cannot provide sufficient EMG control signals, and thus the applicability of the EMG-PR technique is limited especially to this category of amputees. As an alternative approach, electroencephalograph (EEG) signals recorded non-invasively from the brain have been utilized to decode the LMIs of humans. However, most of the existing EEG based limb movement decoding methods primarily focus on identifying limited classes of upper limb movements. In addition, investigation on EEG feature extraction methods for the decoding of multiple classes of LMIs has rarely been considered. Therefore, 32 EEG feature extraction methods (including 12 spectral domain descriptors (SDDs) and 20 time domain descriptors (TDDs)) were used to decode multiple classes of motor imagery patterns associated with different upper limb movements based on 64-channel EEG recordings. From the obtained experimental results, the best individual TDD achieved an accuracy of 67.05 ± 3.12% as against 87.03 ± 2.26% for the best SDD. By applying a linear feature combination technique, an optimal set of combined TDDs recorded an average accuracy of 90.68% while that of the SDDs achieved an accuracy of 99.55% which were significantly higher than those of the individual TDD and SDD at p < 0.05. Our findings suggest that optimal feature set combination would yield a relatively high decoding accuracy that may improve the clinical robustness of MDoF neuroprosthesis. The study was approved by the ethics committee of Institutional Review Board of Shenzhen Institutes of Advanced Technology, and the reference number is SIAT-IRB-150515-H0077.

Can an ankle-foot orthosis change hearts and minds?

PubMed

Patzkowski, Jeanne C; Blanck, Ryan V; Owens, Johnny G; Wilken, Jason M; Blair, James A; Hsu, Joseph R

2011-01-01

The current military conflicts of Operation Enduring Freedom and Operation Iraqi Freedom have been characterized by high-energy explosive wounding patterns, with the majority affecting the extremities. While many injuries have resulted in amputation, surgical advances have allowed the orthopaedic surgeon to pursue limb salvage in the face of injuries once considered unsalvageable. The military limb salvage patient is frequently highly active and motivated and expresses significant frustration with the slow nature of limb salvage rehabilitation and continued functional deficits. Inspired by these patients, efforts at this institution began to provide them with a more dynamic orthosis. Utilizing techniques and technology resulting from cerebral palsy, stroke, and amputation research, the Intrepid Dynamic Exoskeletal Orthosis was created. To date, this device has significantly improved the functional capabilities of the limb salvage wounded warrior population when combined with a high-intensity rehabilitation program. Clinical and biomechanical research is currently underway at this institution in order to fully characterize the device, its effect on patients, and what can be done to modify future generations of the device to best serve the combat-wounded limb salvage population.

Prenatal Development of Interlimb Motor Learning in the Rat Fetus

PubMed Central

Robinson, Scott R.; Kleven, Gale A.; Brumley, Michele R.

2010-01-01

The role of sensory feedback in the early ontogeny of motor coordination remains a topic of speculation and debate. On E20 of gestation (the 20th day after conception, 2 days before birth), rat fetuses can alter interlimb coordination after a period of training with an interlimb yoke, which constrains limb movement and promotes synchronized, conjugate movement of the yoked limbs. The aim of this study was to determine how the ability to express this form of motor learning may change during prenatal development. Fetal rats were prepared for in vivo study at 4 ages (E18–21) and tested in a 65-min training-and-testing session examining hind limb motor learning. A significant increase in conjugate hind limb activity was expressed by E19, but not E18 fetuses, with further increases in conjugate hind limb activity on E20 and E21. These findings suggest substantial development of the ability of fetal rats to modify patterns of interlimb coordination in response to kinesthetic feedback during motor training before birth. PMID:20198121

Tissue‐specific reactions to positional discontinuities in the regenerating axolotl limb

PubMed Central

Avila, Daima; Roy, Molly; Seifert, Ashley W.

2015-01-01

Abstract We investigated cellular contributions to intercalary regenerates and 180o supernumerary limbs during axolotl limb regeneration using the cell autonomous green fluorescent protein marker and exchanged blastemas between white and green fluorescent protein animals. After distal blastemas were grafted to proximal levels tissues of the intercalary regenerate behaved independently with regard to the law of distal transformation; graft epidermis was replaced by stump epidermis, muscle‐derived cells, blood vessels, and Schwann cells of the distal blastema moved proximally to the stylopodium and cartilage and dermal cells conformed to the law. After 180o rotation, blastemas showed contributions from stump tissues which failed to alter patterning of the blastema. Supernumerary limbs were composed of stump and graft tissues and extensive contributions of stump tissues generated inversions or duplications of polarity to produce limbs of mixed handedness. Tail skeletal muscle and cardiac muscle broke the law with cells derived from these tissues exhibiting an apparent anteroposterior polarity as they migrated to the anterior side of the blastema. We attribute this behavior to the possible presence of a chemotactic factor from the wound epidermis. PMID:26755943

The Fanconi anemia/BRCA gene network in zebrafish: embryonic expression and comparative genomics.

PubMed

Titus, Tom A; Yan, Yi-Lin; Wilson, Catherine; Starks, Amber M; Frohnmayer, Jonathan D; Bremiller, Ruth A; Cañestro, Cristian; Rodriguez-Mari, Adriana; He, Xinjun; Postlethwait, John H

2009-07-31

Fanconi anemia (FA) is a genetic disease resulting in bone marrow failure, high cancer risks, and infertility, and developmental anomalies including microphthalmia, microcephaly, hypoplastic radius and thumb. Here we present cDNA sequences, genetic mapping, and genomic analyses for the four previously undescribed zebrafish FA genes (fanci, fancj, fancm, and fancn), and show that they reverted to single copy after the teleost genome duplication. We tested the hypothesis that FA genes are expressed during embryonic development in tissues that are disrupted in human patients by investigating fanc gene expression patterns. We found fanc gene maternal message, which can provide Fanc proteins to repair DNA damage encountered in rapid cleavage divisions. Zygotic expression was broad but especially strong in eyes, central nervous system and hematopoietic tissues. In the pectoral fin bud at hatching, fanc genes were expressed specifically in the apical ectodermal ridge, a signaling center for fin/limb development that may be relevant to the radius/thumb anomaly of FA patients. Hatching embryos expressed fanc genes strongly in the oral epithelium, a site of squamous cell carcinomas in FA patients. Larval and adult zebrafish expressed fanc genes in proliferative regions of the brain, which may be related to microcephaly in FA. Mature ovaries and testes expressed fanc genes in specific stages of oocyte and spermatocyte development, which may be related to DNA repair during homologous recombination in meiosis and to infertility in human patients. The intestine strongly expressed some fanc genes specifically in proliferative zones. Our results show that zebrafish has a complete complement of fanc genes in single copy and that these genes are expressed in zebrafish embryos and adults in proliferative tissues that are often affected in FA patients. These results support the notion that zebrafish offers an attractive experimental system to help unravel mechanisms relevant not only to FA, but also to breast cancer, given the involvement of fancj (brip1), fancn (palb2) and fancd1 (brca2) in both conditions.

The Fanconi anemia/BRCA gene network in zebrafish: Embryonic expression and comparative genomics

PubMed Central

Titus, Tom A.; Yan, Yi-Lin; Wilson, Catherine; Starks, Amber M.; Frohnmayer, Jonathan D.; Canestro, Cristian; Rodriguez-Mari, Adriana; He, Xinjun; Postlethwait, John H.

2008-01-01

Fanconi anemia (FA) is a genic disease resulting in bone marrow failure, high cancer risks, and infertility, and developmental anomalies including microphthalmia, microcephaly, hypoplastic radius and thumb. Here we present cDNA sequences, genetic mapping, and genomic analyses for the four previously undescribed zebrafish FA genes (fanci, fancj, fancm, and fancn, and show that they reverted to single copy after the teleost genome duplication. We tested the hypothesis that FA genes are expressed during embryonic development in tissues that are disrupted in human patients by investigating fanc gene expression patterns. We found fanc gene maternal message, which can provide Fanc proteins to repair DNA damage encountered in rapid cleavage divisions. Zygotic expression was broad but especially strong in eyes, central nervous system and hematopoietic tissues. In the pectoral fin bud at hatching, fanc genes were expressed specifically in the apical ectodermal ridge, a signaling center for fin/limb development that may be relevant to the radius/thumb anomaly of FA patients. Hatching embryos expressed fanc genes strongly in the oral epithelium, a site of squamous cell carcinomas in FA patients. Larval and adult zebrafish expressed fanc genes in proliferative regions of the brain, which may be related to microcephaly in FA. Mature ovaries and testes expressed fanc genes in specific stages of oocyte and spermatocyte development, which may be related to DNA repair during homologous recombination in meiosis and to infertility in human patients. The intestine strongly expressed some fanc genes specifically in proliferative zones. Our results show that zebrafish has a complete complement of fanc genes in single copy and that these genes are expressed in zebrafish embryos and adults in proliferative tissues that are often affected in FA patients. These results support the notion that zebrafish offers an attractive experimental system to help unravel mechanisms relevant not only to FA, but also to breast cancer, given the involvement of fancj (brip1), fancn (palb2) and fancd1 (brca2) in both conditions. PMID:19101574

Genetics Home Reference: congenital contractural arachnodactyly

MedlinePlus

... 9 Related Information How are genetic conditions and genes named? Additional Information & Resources MedlinePlus (5 links) Encyclopedia: Arachnodactyly Encyclopedia: Contracture Deformity Encyclopedia: Skeletal Limb Abnormalities Health Topic: Connective Tissue Disorders Health ...

Limb-Enhancer Genie: An accessible resource of accurate enhancer predictions in the developing limb

DOE PAGES

Monti, Remo; Barozzi, Iros; Osterwalder, Marco; ...

2017-08-21

Epigenomic mapping of enhancer-associated chromatin modifications facilitates the genome-wide discovery of tissue-specific enhancers in vivo. However, reliance on single chromatin marks leads to high rates of false-positive predictions. More sophisticated, integrative methods have been described, but commonly suffer from limited accessibility to the resulting predictions and reduced biological interpretability. Here we present the Limb-Enhancer Genie (LEG), a collection of highly accurate, genome-wide predictions of enhancers in the developing limb, available through a user-friendly online interface. We predict limb enhancers using a combination of > 50 published limb-specific datasets and clusters of evolutionarily conserved transcription factor binding sites, taking advantage ofmore » the patterns observed at previously in vivo validated elements. By combining different statistical models, our approach outperforms current state-of-the-art methods and provides interpretable measures of feature importance. Our results indicate that including a previously unappreciated score that quantifies tissue-specific nuclease accessibility significantly improves prediction performance. We demonstrate the utility of our approach through in vivo validation of newly predicted elements. Moreover, we describe general features that can guide the type of datasets to include when predicting tissue-specific enhancers genome-wide, while providing an accessible resource to the general biological community and facilitating the functional interpretation of genetic studies of limb malformations.« less

Hox gene clusters in the Indonesian coelacanth, Latimeria menadoensis

PubMed Central

Koh, Esther G. L.; Lam, Kevin; Christoffels, Alan; Erdmann, Mark V.; Brenner, Sydney; Venkatesh, Byrappa

2003-01-01

The Hox genes encode transcription factors that play a key role in specifying body plans of metazoans. They are organized into clusters that contain up to 13 paralogue group members. The complex morphology of vertebrates has been attributed to the duplication of Hox clusters during vertebrate evolution. In contrast to the single Hox cluster in the amphioxus (Branchiostoma floridae), an invertebrate-chordate, mammals have four clusters containing 39 Hox genes. Ray-finned fishes (Actinopterygii) such as zebrafish and fugu possess more than four Hox clusters. The coelacanth occupies a basal phylogenetic position among lobe-finned fishes (Sarcopterygii), which gave rise to the tetrapod lineage. The lobe fins of sarcopterygians are considered to be the evolutionary precursors of tetrapod limbs. Thus, the characterization of Hox genes in the coelacanth should provide insights into the origin of tetrapod limbs. We have cloned the complete second exon of 33 Hox genes from the Indonesian coelacanth, Latimeria menadoensis, by extensive PCR survey and genome walking. Phylogenetic analysis shows that 32 of these genes have orthologs in the four mammalian HOX clusters, including three genes (HoxA6, D1, and D8) that are absent in ray-finned fishes. The remaining coelacanth gene is an ortholog of hoxc1 found in zebrafish but absent in mammals. Our results suggest that coelacanths have four Hox clusters bearing a gene complement more similar to mammals than to ray-finned fishes, but with an additional gene, HoxC1, which has been lost during the evolution of mammals from lobe-finned fishes. PMID:12547909

Hox gene clusters in the Indonesian coelacanth, Latimeria menadoensis.

PubMed

Koh, Esther G L; Lam, Kevin; Christoffels, Alan; Erdmann, Mark V; Brenner, Sydney; Venkatesh, Byrappa

2003-02-04

The Hox genes encode transcription factors that play a key role in specifying body plans of metazoans. They are organized into clusters that contain up to 13 paralogue group members. The complex morphology of vertebrates has been attributed to the duplication of Hox clusters during vertebrate evolution. In contrast to the single Hox cluster in the amphioxus (Branchiostoma floridae), an invertebrate-chordate, mammals have four clusters containing 39 Hox genes. Ray-finned fishes (Actinopterygii) such as zebrafish and fugu possess more than four Hox clusters. The coelacanth occupies a basal phylogenetic position among lobe-finned fishes (Sarcopterygii), which gave rise to the tetrapod lineage. The lobe fins of sarcopterygians are considered to be the evolutionary precursors of tetrapod limbs. Thus, the characterization of Hox genes in the coelacanth should provide insights into the origin of tetrapod limbs. We have cloned the complete second exon of 33 Hox genes from the Indonesian coelacanth, Latimeria menadoensis, by extensive PCR survey and genome walking. Phylogenetic analysis shows that 32 of these genes have orthologs in the four mammalian HOX clusters, including three genes (HoxA6, D1, and D8) that are absent in ray-finned fishes. The remaining coelacanth gene is an ortholog of hoxc1 found in zebrafish but absent in mammals. Our results suggest that coelacanths have four Hox clusters bearing a gene complement more similar to mammals than to ray-finned fishes, but with an additional gene, HoxC1, which has been lost during the evolution of mammals from lobe-finned fishes.

Remote limb ischemic preconditioning (rIPC) activates antioxidant and antiapoptotic genes and inhibits proinflammatory cytokine genes in renal ischemia/reperfusion injury.

PubMed

Hussein, Abdelaziz M; Harraz, Ahmed M; Awadalla, Amira; Barakat, Nashwa; Khater, Shery; Shokeir, Ahmed A

2016-01-01

The mechanisms underlying the renoprotective effect for remote limb ischemic preconditioning (rIPC) against renal ischemia/reperfusion injury need further elucidation. In our work, one hundred and twenty male Sprague Dawley rats were randomized into 3 groups; sham, I/R group (left renal 45 min ischemia) and rIPC (as I/R group with 3 cycles of left femoral ischemic PC just before renal ischemia). Rats were sacrificed at 2 h, 24 h, 48 h and 7 days. Serum creatinine and urea were measured at the baseline and endpoints. Also, histopathological examination and assessment of the expression of inflammatory cytokines e.g. TNF-α, IL-1β and ICAM-1 and antioxidant genes: Nrf2, HO-1 and NQO-1 and anti-apoptotic gene Bcl-2 in left kidney were done by the end of experiment. The results of this study demonstrated that, rIPC caused significant improvement in serum creatinine and BUN levels and in the expression of antioxidant genes and Bcl-2 antiapoptotic gene with significant attenuation of pro-inflammatory cytokines and histopathological damage score at all-time points compared to I/R group (p ≤ 0.05). In conclusion, inhibition of inflammatory cytokine (TNF-α, IL-1β and ICAM-1) formation and activation of antioxidant genes: Nrf2, HO-1 and NQO-1 and anti-apoptotic gene Bcl-2 could be possible underlying mechanisms for the renoprotective effect of rIPC.

Body proportions in ancient Andeans from high and low altitudes.

PubMed

Weinstein, Karen J

2005-11-01

Living human populations from high altitudes in the Andes exhibit relatively short limbs compared with neighboring groups from lower elevations as adaptations to cold climates characteristic of high-altitude environments. This study compares relative limb lengths and proportions in pre-Contact human skeletons from different altitudes to test whether ecogeographic variation also existed in Andean prehistory. Maximum lengths of the humerus, radius, femur, and tibia, and femoral head breadth are measured in sex-specific groups of adult human skeletons (N = 346) from the central (n = 80) and the south-central (n = 123) Andean coasts, the Atacama Desert at 2,500 m (n = 102), and the southern Peruvian highlands at 2,000-3,800 m (n = 41). To test whether limb lengths vary with altitude, comparisons are made of intralimb proportions, limb lengths against body mass estimates derived from published equations, limb lengths against the geometric mean of all measurements, and principal component analysis. Intralimb proportions do not statistically differ between coastal groups and those from the Atacama Desert, whereas intralimb proportions are significantly shorter in the Peruvian highland sample. Overall body size and limb lengths relative to body size vary along an altitudinal gradient, with larger individuals from coastal environments and smaller individuals with relatively longer limbs for their size from higher elevations. Ecogeographic variation in relation to climate explains the variation in intralimb proportions, and dietary variation may explain the altitudinal cline in body size and limb lengths relative to body size. The potential effects of gene flow on variation in body proportions in Andean prehistory are also explored. Copyright 2005 Wiley-Liss, Inc

Transcriptome analyses based on genetic screens for Pax3 myogenic targets in the mouse embryo

PubMed Central

2010-01-01

Background Pax3 is a key upstream regulator of the onset of myogenesis, controlling progenitor cell survival and behaviour as well as entry into the myogenic programme. It functions in the dermomyotome of the somite from which skeletal muscle derives and in progenitor cell populations that migrate from the somite such as those of the limbs. Few Pax3 target genes have been identified. Identifying genes that lie genetically downstream of Pax3 is therefore an important endeavour in elucidating the myogenic gene regulatory network. Results We have undertaken a screen in the mouse embryo which employs a Pax3GFP allele that permits isolation of Pax3 expressing cells by flow cytometry and a Pax3PAX3-FKHR allele that encodes PAX3-FKHR in which the DNA binding domain of Pax3 is fused to the strong transcriptional activation domain of FKHR. This constitutes a gain of function allele that rescues the Pax3 mutant phenotype. Microarray comparisons were carried out between Pax3GFP/+ and Pax3GFP/PAX3-FKHR preparations from the hypaxial dermomyotome of somites at E9.5 and forelimb buds at E10.5. A further transcriptome comparison between Pax3-GFP positive and negative cells identified sequences specific to myogenic progenitors in the forelimb buds. Potential Pax3 targets, based on changes in transcript levels on the gain of function genetic background, were validated by analysis on loss or partial loss of function Pax3 mutant backgrounds. Sequences that are up- or down-regulated in the presence of PAX3-FKHR are classified as somite only, somite and limb or limb only. The latter should not contain sequences from Pax3 positive neural crest cells which do not invade the limbs. Verification by whole mount in situ hybridisation distinguishes myogenic markers. Presentation of potential Pax3 target genes focuses on signalling pathways and on transcriptional regulation. Conclusions Pax3 orchestrates many of the signalling pathways implicated in the activation or repression of myogenesis by regulating effectors and also, notably, inhibitors of these pathways. Important transcriptional regulators of myogenesis are candidate Pax3 targets. Myogenic determination genes, such as Myf5 are controlled positively, whereas the effect of Pax3 on genes encoding inhibitors of myogenesis provides a potential brake on differentiation. In the progenitor cell population, Pax7 and also Hdac5 which is a potential repressor of Foxc2, are subject to positive control by Pax3. PMID:21143873

Progress toward a non-viral gene therapy protocol for the treatment of anemia

PubMed Central

Sebestyén, Magdolna G.; Hegge, Julia O.; Noble, Mark A.; Lewis, David L.; Herweijer, Hans; Wolff, Jon A.

2008-01-01

Anemia frequently accompanies chronic diseases such as progressive renal failure, AIDS and cancer. Patients are currently treated with erythropoietin (EPO) replacement therapy using various recombinant human EPO protein formulations. Although this treatment is effective, gene therapy could be more economical and more convenient for the long-term management of the disease. The objective of this study was to develop a naked DNA-based gene therapy protocol that could fill this need. The hydrodynamic limb vein technology has been shown to be an effective and safe procedure for delivering naked plasmid DNA (pDNA) into the skeletal muscles of the limb. Using this method, we addressed the major challenge of an EPO-based gene therapy of anemia: maintaining stable, long-term expression at a level that sufficiently promotes erythropoiesis without leading to polycythemia. The results of our study using a rat anemia model provide proof of principle that repeated delivery of small pDNA doses has an additive effect and can gradually lead to the correction of anemia without triggering excessive hemopoiesis. This simple method provides an alternative approach for regulating EPO expression. EPO expression was also proportional to the injected pDNA dose in non-human primates. In addition, long-term (over 450 days) expression was obtained after delivering rhesus EPO cDNA under the transcriptional control of the muscle-specific MCK promoter. In conclusion, these data suggest that the repeated delivery of small doses of EPO expressing pDNA into skeletal muscle is a promising, clinically viable approach to alleviate the symptoms of anemia. Overview summary We delivered various EPO-expressing naked pDNA constructs into the skeletal muscles of the limb by the minimally invasive, hydrodynamic limb vein (HLV) procedure. Serum EPO concentrations and the physiological response were pDNA dose-dependent both in rats and rhesus monkeys. The kinetics and longevity of expression were promoter-dependent. The mouse MCK promoter provided stable expression for well over a year, while the effect of the CMV promoter construct lasted only for 5–7 months. By using repeated, small-dose pDNA injections in a rat anemia model, EPO expression was controlled at the most fundamental level of the delivered gene dose. Our results suggest that this non-viral gene therapy approach provides safe and long-term solution for the treatment of chronic anemia and that it can be tailored to the individual needs of the patient. PMID:17376007

Modeling of the Human Alveolar Rhabdomyosarcoma Pax3-Foxo1 Chromosome Translocation in Mouse Myoblasts Using CRISPR-Cas9 Nuclease

PubMed Central

Lagutina, Irina V.; Valentine, Virginia; Picchione, Fabrizio; Harwood, Frank; Valentine, Marcus B.; Villarejo-Balcells, Barbara; Carvajal, Jaime J.; Grosveld, Gerard C.

2015-01-01

Many recurrent chromosome translocations in cancer result in the generation of fusion genes that are directly implicated in the tumorigenic process. Precise modeling of the effects of cancer fusion genes in mice has been inaccurate, as constructs of fusion genes often completely or partially lack the correct regulatory sequences. The reciprocal t(2;13)(q36.1;q14.1) in human alveolar rhabdomyosarcoma (A-RMS) creates a pathognomonic PAX3-FOXO1 fusion gene. In vivo mimicking of this translocation in mice is complicated by the fact that Pax3 and Foxo1 are in opposite orientation on their respective chromosomes, precluding formation of a functional Pax3-Foxo1 fusion via a simple translocation. To circumvent this problem, we irreversibly inverted the orientation of a 4.9 Mb syntenic fragment on chromosome 3, encompassing Foxo1, by using Cre-mediated recombination of two pairs of unrelated oppositely oriented LoxP sites situated at the borders of the syntenic region. We tested if spatial proximity of the Pax3 and Foxo1 loci in myoblasts of mice homozygous for the inversion facilitated Pax3-Foxo1 fusion gene formation upon induction of targeted CRISPR-Cas9 nuclease-induced DNA double strand breaks in Pax3 and Foxo1. Fluorescent in situ hybridization indicated that fore limb myoblasts show a higher frequency of Pax3/Foxo1 co-localization than hind limb myoblasts. Indeed, more fusion genes were generated in fore limb myoblasts via a reciprocal t(1;3), which expressed correctly spliced Pax3-Foxo1 mRNA encoding Pax3-Foxo1 fusion protein. We conclude that locus proximity facilitates chromosome translocation upon induction of DNA double strand breaks. Given that the Pax3-Foxo1 fusion gene will contain all the regulatory sequences necessary for precise regulation of its expression, we propose that CRISPR-Cas9 provides a novel means to faithfully model human diseases caused by chromosome translocation in mice. PMID:25659124

Relationships of maternal and paternal anthropometry with neonatal body size, proportions and adiposity in an Australian cohort.

PubMed

Pomeroy, Emma; Wells, Jonathan C K; Cole, Tim J; O'Callaghan, Michael; Stock, Jay T

2015-04-01

The patterns of association between maternal or paternal and neonatal phenotype may offer insight into how neonatal characteristics are shaped by evolutionary processes, such as conflicting parental interests in fetal investment and obstetric constraints. Paternal interests are theoretically served by maximizing fetal growth, and maternal interests by managing investment in current and future offspring, but whether paternal and maternal influences act on different components of overall size is unknown. We tested whether parents' prepregnancy height and body mass index (BMI) were related to neonatal anthropometry (birthweight, head circumference, absolute and proportional limb segment and trunk lengths, subcutaneous fat) among 1,041 Australian neonates using stepwise linear regression. Maternal and paternal height and maternal BMI were associated with birthweight. Paternal height related to offspring forearm and lower leg lengths, maternal height and BMI to neonatal head circumference, and maternal BMI to offspring adiposity. Principal components analysis identified three components of variability reflecting neonatal "head and trunk skeletal size," "adiposity," and "limb lengths." Regression analyses of the component scores supported the associations of head and trunk size or adiposity with maternal anthropometry, and limb lengths with paternal anthropometry. Our results suggest that while neonatal fatness reflects environmental conditions (maternal physiology), head circumference and limb and trunk lengths show differing associations with parental anthropometry. These patterns may reflect genetics, parental imprinting and environmental influences in a manner consistent with parental conflicts of interest. Paternal height may relate to neonatal limb length as a means of increasing fetal growth without exacerbating the risk of obstetric complications. © 2014 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.

Relationships of maternal and paternal anthropometry with neonatal body size, proportions and adiposity in an Australian cohort

PubMed Central

Pomeroy, Emma; Wells, Jonathan CK; Cole, Tim J; O'Callaghan, Michael; Stock, Jay T

2015-01-01

The patterns of association between maternal or paternal and neonatal phenotype may offer insight into how neonatal characteristics are shaped by evolutionary processes, such as conflicting parental interests in fetal investment and obstetric constraints. Paternal interests are theoretically served by maximizing fetal growth, and maternal interests by managing investment in current and future offspring, but whether paternal and maternal influences act on different components of overall size is unknown. We tested whether parents' prepregnancy height and body mass index (BMI) were related to neonatal anthropometry (birthweight, head circumference, absolute and proportional limb segment and trunk lengths, subcutaneous fat) among 1,041 Australian neonates using stepwise linear regression. Maternal and paternal height and maternal BMI were associated with birthweight. Paternal height related to offspring forearm and lower leg lengths, maternal height and BMI to neonatal head circumference, and maternal BMI to offspring adiposity. Principal components analysis identified three components of variability reflecting neonatal “head and trunk skeletal size,” “adiposity,” and “limb lengths.” Regression analyses of the component scores supported the associations of head and trunk size or adiposity with maternal anthropometry, and limb lengths with paternal anthropometry. Our results suggest that while neonatal fatness reflects environmental conditions (maternal physiology), head circumference and limb and trunk lengths show differing associations with parental anthropometry. These patterns may reflect genetics, parental imprinting and environmental influences in a manner consistent with parental conflicts of interest. Paternal height may relate to neonatal limb length as a means of increasing fetal growth without exacerbating the risk of obstetric complications. Am J Phys Anthropol 156:625–636, 2015. PMID:25502164

From soil mechanics to chick development.

PubMed

Wolpert, Lewis

2018-01-01

Here, I provide some recollections of my life, starting as a civil engineer in South Africa and how I gradually became interested in biology, particularly pattern formation. In retrospect, I think that my decision to work on chick embryos to study limb development back in 1966 turned out to be the right one. The principles discovered in these 50 years, both by my collaborators and by other colleagues, have established the principles of how the limb develops in higher vertebrates, including humans.

Deregulation of the Protocadherin Gene FAT1 Alters Muscle Shapes: Implications for the Pathogenesis of Facioscapulohumeral Dystrophy

PubMed Central

Caruso, Nathalie; Herberth, Balàzs; Bartoli, Marc; Puppo, Francesca; Dumonceaux, Julie; Zimmermann, Angela; Denadai, Simon; Lebossé, Marie; Roche, Stephane; Geng, Linda; Magdinier, Frederique; Attarian, Shahram; Bernard, Rafaelle; Maina, Flavio; Levy, Nicolas; Helmbacher, Françoise

2013-01-01

Generation of skeletal muscles with forms adapted to their function is essential for normal movement. Muscle shape is patterned by the coordinated polarity of collectively migrating myoblasts. Constitutive inactivation of the protocadherin gene Fat1 uncoupled individual myoblast polarity within chains, altering the shape of selective groups of muscles in the shoulder and face. These shape abnormalities were followed by early onset regionalised muscle defects in adult Fat1-deficient mice. Tissue-specific ablation of Fat1 driven by Pax3-cre reproduced muscle shape defects in limb but not face muscles, indicating a cell-autonomous contribution of Fat1 in migrating muscle precursors. Strikingly, the topography of muscle abnormalities caused by Fat1 loss-of-function resembles that of human patients with facioscapulohumeral dystrophy (FSHD). FAT1 lies near the critical locus involved in causing FSHD, and Fat1 mutant mice also show retinal vasculopathy, mimicking another symptom of FSHD, and showed abnormal inner ear patterning, predictive of deafness, reminiscent of another burden of FSHD. Muscle-specific reduction of FAT1 expression and promoter silencing was observed in foetal FSHD1 cases. CGH array-based studies identified deletion polymorphisms within a putative regulatory enhancer of FAT1, predictive of tissue-specific depletion of FAT1 expression, which preferentially segregate with FSHD. Our study identifies FAT1 as a critical determinant of muscle form, misregulation of which associates with FSHD. PMID:23785297

Segmental heterogeneity in Bcl-2, Bcl-xL and Bax expression in rat tubular epithelium after ischemia-reperfusion.

PubMed

Valdés, Francisco; Pásaro, Eduardo; Díaz, Inmaculada; Centeno, Alberto; López, Eduardo; García-Doval, Sandra; González-Roces, Severino; Alba, Alfonso; Laffon, Blanca

2008-06-01

Studies in rats with bilateral clamping of renal arteries showed transient Bcl-2, Bcl-xL and Bax expression in renal tubular epithelium following ischemia-reperfusion. However, current data on the preferential localization of specific mRNAs or proteins are limited because gene expression was not analysed at segmental level. This study analyses the mRNA expression of Bcl-2, Bcl-xL and Bax in four segments of proximal and distal tubules localized in the renal cortex and outer medulla in rat kidneys with bilateral renal clamping for 30 min and seven reperfusion times versus control animals without clamp. Proximal convoluted tubule (PCT), distal convoluted tubule (DCT), proximal straight tubule (PST) and medullary thick ascending limb (MTAL) were obtained by manual microdissection. RT-PCR was used to analyse mRNA expression at segmental level. Proximal convoluted tubule and MTAL showed early, persistent and balanced up-regulation of Bcl-2, Bcl-xL and Bax, while PST and DCT revealed only Bcl-2 and Bcl-xL, when only Bax was detected in PST. DCT expressed Bcl-xL initially, and persistent Bcl-2 later. These patterns suggest a heterogeneous apoptosis regulatory response in rat renal tubules after ischemia-reperfusion, independently of cortical or medullary location. This heterogeneity of the expression patterns of Bcl-2 genes could explain the different susceptibility to undergo apoptosis, the different threshold to ischemic damage and the different adaptive capacity to injury among these tubular segments.

A case of Vibrio vulnificus infection complicated with fulminant purpura: gene and biotype analysis of the pathogen

PubMed Central

Nakayama, Akifumi; Kitagawa, Daisuke; Fukushima, Hidetada; Asai, Hideki; Kawai, Yasuyuki; Okuchi, Kazuo

2017-01-01

Introduction. Vibrio vulnificus (V. vulnificus) causes a severe infection that develops in the compromised host. Its pathophysiology is classified into three types: (1) primary septicaemia, (2) gastrointestinal illness pattern and (3) wound infection pattern. Of these, primary septicaemia is critical. V. vulnificus can be classified into three biotypes and two genotypes and its pathogenicity is type-dependent. Case presentation. A 47-year-old man presented to a local hospital with chief complaints of fever, bilateral lower limb pain and diarrhoea. He had no history of foreign travel or known medical problems. He was in septic shock and developed fulminant purpura within 24 h of the onset. High-dose vasopressor and antibiotic administration failed to alter his status and he died 3 days after the onset of symptoms. V. vulnificus was isolated from blood, skin and nasal discharge cultures. Biotype and gene analysis of the microbe isolated identified it as Biotype 3, mainly reported in Israel in wound infections, and Genotype E, implicating an environmental isolate. These typing analyses indicated that the microbe isolated could be classified as a type with low pathogenicity. Conclusion. This case highlighted that Biotype 3 and Genotype E can also cause primary septicaemia. Although the majority of reports on Biotype 3 have been from the Middle East, this experience with the present case provided evidence that the habitat of Biotype 3 V. vulnificus has been extending to East Asia as well. PMID:29026623

Exogenous retinoic acid induces digit reduction in opossums (Monodelphis domestica) by disrupting cell death and proliferation, and apical ectodermal ridge and zone of polarizing activity function.

PubMed

Molineaux, Anna C; Maier, Jennifer A; Schecker, Teresa; Sears, Karen E

2015-03-01

Retinoic acid (RA) is a vitamin A derivative. Exposure to exogenous RA generates congenital limb malformations (CLMs) in species from frogs to humans. These CLMs include but are not limited to oligodactyly and long-bone hypoplasia. The processes by which exogenous RA induces CLMs in mammals have been best studied in mouse, but as of yet remain unresolved. We investigated the impact of exogenous RA on the cellular and molecular development of the limbs of a nonrodent model mammal, the opossum Monodelphis domestica. Opossums exposed to exogenous retinoic acid display CLMs including oligodactly, and results are consistent with opossum development being more susceptible to RA-induced disruptions than mouse development. Exposure of developing opossums to exogenous RA leads to an increase in cell death in the limb mesenchyme that is most pronounced in the zone of polarizing activity, and a reduction in cell proliferation throughout the limb mesenchyme. Exogenous RA also disrupts the expression of Shh in the zone of polarizing activity, and Fgf8 in the apical ectodermal ridge, and other genes with roles in the regulation of limb development and cell death. Results are consistent with RA inducing CLMs in opossum limbs by disrupting the functions of the apical ectodermal ridge and zone of polarizing activity, and driving an increase in cell death and reduction of cell proliferation in the mesenchyme of the developing limb. © 2015 Wiley Periodicals, Inc.

Changes in shoulder muscle activity pattern on surface electromyography after breast cancer surgery.

PubMed

Yang, Eun Joo; Kwon, YoungOk

2018-02-01

Alterations in muscle activation and restricted shoulder mobility, which are common in breast cancer patients, have been found to affect upper limb function. The purpose of this study was to determine muscle activity patterns, and to compare the prevalence of abnormal patterns among the type of breast surgery. In total, 274 breast cancer patients were recruited after surgery. Type of breast surgery was divided into mastectomy without reconstruction (Mastectomy), reconstruction with tissue expander/implant (TEI), latissimus dorsi (LD) flap, or transverse rectus abdominis flap (TRAM). Activities of shoulder muscles were measured using surface electromyography. Experimental analysis was conducted using a Gaussian filter smoothing method with regression. Patients demonstrated different patterns of muscle activation, such as normal, lower muscle electrical activity, and tightness. After adjusting for BMI and breast surgery, the odds of lower muscle electrical activity and tightness in the TRAM are 40.2% and 38.4% less than in the Mastectomy only group. The prevalence of abnormal patterns was significantly greater in the ALND than SLNB in all except TRAM. Alterations in muscle activity patterns differed by breast surgery and reconstruction type. For breast cancer patients with ALND, TRAM may be the best choice for maintaining upper limb function. © 2017 Wiley Periodicals, Inc.

Polydactyly in Development, Inheritance, and Evolution.

PubMed

Lange, Axel; Müller, Gerd B

2017-03-01

The occurrence of supernumerary digits or toes in humans and other tetrapods has attracted general interest since antiquity and later influenced scientific theories of development, inheritance, and evolution. Seventeenth-century genealogical studies of polydactyly were at the beginning of an understanding of the rules of inheritance. Features of polydactyly were also part of the classical disputes on the nature of development, including the preformation-versus-epigenesis and the atavism-versus-malformation debates. In the evolutionary domain, polydactyly was used in the criticism of the gradualist account of variation underlying Darwin’s theory. Today, extra digit formation plays a role in the conceptualization of gene regulation and pattern formation in vertebrate limb evolution. Recent genetic, experimental, and modeling accounts of extra digit formation highlight the existence of nongradual transitions in phenotypic states, suggesting a distinction between continuous and discontinuous variation in evolution. Unless otherwise noted, all translations are our own.

The incidence of pelvic fractures with traumatic lower limb amputation in modern warfare due to improvised explosive devices.

PubMed

Cross, A M; Davis, C; Penn-Barwell, J; Taylor, D M; De Mello, W F; Matthews, J J

2014-01-01

A frequently-seen injury pattern in current military experience is traumatic lower limb amputation as a result of improvised explosive devices (IEDs). This injury can coexist with fractures involving the pelvic ring. This study aims to assess the frequency of concomitant pelvic fracture in IED-related lower limb amputation. A retrospective analysis of the trauma charts, medical notes, and digital imaging was undertaken for all patients arriving at the Emergency Department at the UK military field hospital in Camp Bastion, Afghanistan, with a traumatic lower limb amputation in the six months between September 2009 and April 2010, in order to determine the incidence of associated pelvic ring fractures. Of 77 consecutive patients with traumatic lower limb amputations, 17 (22%) had an associated pelvic fracture (eleven with displaced pelvic ring fractures, five undisplaced fractures and one acetabular fracture). Unilateral amputees (n = 31) had a 10% incidence of associated pelvic fracture, whilst 30 % of bilateral amputees (n = 46) had a concurrent pelvic fracture. However, in bilateral, trans-femoral amputations (n = 28) the incidence of pelvic fracture was 39%. The study demonstrates a high incidence of pelvic fractures in patients with traumatic lower limb amputations, supporting the routine pre-hospital application of pelvic binders in this patient group.

Identification of Dh/+ and Dh/Dh embryos through close linkage of Dh and peptidase-3.

PubMed

Holmes, L B

1986-12-01

The close linkage between the genes Dominant hemimelia (Dh) and peptidase-3 (Pep-3) has been determined in 65 informative matings with the recombination frequency of 3.8%. Progeny testing showed that nonpenetrance does occur in Dh/+ adults. The presence of the "slow" and "fast" variants of Pep-3 can be determined in homogenates of kidney tissue as well as in a portion of the day 10 and 11 embryos. In a litter of embryos born to an informative mating, those which are Dh/Dh, Dh/+, and +/+ can be distinguished by the presence of the Pep-3 allele known to be in coupling with the Dh gene. This technique makes it possible to identify and to study the limb malformations and other phenotypic effects of Dh during their development and before the limb deformity is visible.

Intralimb and Interlimb Cutaneous Reflexes during Locomotion in the Intact Cat.

PubMed

Hurteau, Marie-France; Thibaudier, Yann; Dambreville, Charline; Danner, Simon M; Rybak, Ilya A; Frigon, Alain

2018-04-25

When the foot contacts an obstacle during locomotion, cutaneous inputs activate spinal circuits to ensure dynamic balance and forward progression. In quadrupeds, this requires coordinated reflex responses between the four limbs. Here, we investigated the patterns and phasic modulation of cutaneous reflexes in forelimb and hindlimb muscles evoked by inputs from all four limbs. Five female cats were implanted to record muscle activity and to stimulate the superficial peroneal and superficial radial nerves during locomotion. Stimulating these nerves evoked short-, mid-, and longer-latency excitatory and/or inhibitory responses in all four limbs that were phase-dependent. The largest responses were generally observed during the peak activity of the muscle. Cutaneous reflexes during mid-swing were consistent with flexion of the homonymous limb and accompanied by modification of the stance phases of the other three limbs, by coactivating flexors and extensors and/or by delaying push-off. Cutaneous reflexes during mid-stance were consistent with stabilizing the homonymous limb by delaying and then facilitating its push-off and modifying the support phases of the homolateral and diagonal limbs, characterized by coactivating flexors and extensors, reinforcing extensor activity and/or delaying push-off. The shortest latencies of homolateral and diagonal responses were consistent with fast-conducting disynaptic or trisynaptic pathways. Descending homolateral and diagonal pathways from the forelimbs to the hindlimbs had a higher probability of eliciting responses compared with ascending pathways from the hindlimbs to the forelimbs. Thus, in quadrupeds, intralimb and interlimb reflexes activated by cutaneous inputs ensure dynamic coordination of the four limbs, producing a whole-body response. SIGNIFICANCE STATEMENT The skin contains receptors that, when activated, send inputs to spinal circuits, signaling a perturbation. Rapid responses, or reflexes, in muscles of the contacted limb and opposite homologous limb help maintain balance and forward progression. Here, we investigated reflexes during quadrupedal locomotion in the cat by electrically stimulating cutaneous nerves in each of the four limbs. Functionally, responses appear to modify the trajectory or stabilize the movement of the stimulated limb while modifying the support phase of the other limbs. Reflexes between limbs are mediated by fast-conducting pathways that involve excitatory and inhibitory circuits controlling each limb. The comparatively stronger descending pathways from cervical to lumbar circuits controlling the forelimbs and hindlimbs, respectively, could serve a protective function. Copyright © 2018 the authors 0270-6474/18/384104-19$15.00/0.

Hereditary neuropathy with liability to pressure palsy: an investigation in a rare and large Chinese family.

PubMed

He, Yuan; Wu, Qiang; Xu, Zhipeng; Wang, Qianqian; Wang, Weili; Li, Dezhong; Liu, Wanhong; He, Xiaohua

2012-01-01

Hereditary neuropathy with liability to pressure palsy (HNPP), mainly associated with the peripheral myelin protein 22 (PMP22) gene, is generally an autosomal-dominant inherited peripheral neuropathy. The present large family including four generations provides an exciting opportunity to gain important insights into HNPP in China. A large 43-member family with ten members suspected to be affected by HNPP was studied. Neurologic examinations, electrophysiological and neuropathological studies and molecular genetic testing were used for these kindred. Clinically, the proband had limb hyposthenia and atrophy, and his mother showed declined tendon reflexes in the right lower limb. Electrophysiologically, sensory and motor nerve conduction velocities were generalized reduced. Sural nerve biopsy for the proband showed focal thickesning of the myelin sheaths. Furthermore, real-time quantitative PCR demonstrated that the PMP22 gene has a higher Ct value than reference gene in all suspected patients. These results indicated that the family is indeed a rare and large pedigree of HNPP caused by the deletion of PMP22 gene. Given that the suspected patient in the fourth generation is absent, this family is still worthy of further follow-up study. Copyright © 2012 S. Karger AG, Basel.

Mutations in DDR2 gene cause SMED with short limbs and abnormal calcifications.

PubMed

Bargal, Ruth; Cormier-Daire, Valerie; Ben-Neriah, Ziva; Le Merrer, Martine; Sosna, Jacob; Melki, Judith; Zangen, David H; Smithson, Sarah F; Borochowitz, Zvi; Belostotsky, Ruth; Raas-Rothschild, Annick

2009-01-01

The spondylo-meta-epiphyseal dysplasia [SMED] short limb-hand type [SMED-SL] is a rare autosomal-recessive disease, first reported by Borochowitz et al. in 1993.(1) Since then, 14 affected patients have been reported.(2-5) We diagnosed 6 patients from 5 different consanguineous Arab Muslim families from the Jerusalem area with SMED-SL. Additionally, we studied two patients from Algerian and Pakistani ancestry and the parents of the first Jewish patients reported.(1) Using a homozygosity mapping strategy, we located a candidate region on chromosome 1q23 spanning 2.4 Mb. The position of the Discoidin Domain Receptor 2 (DDR2) gene within the candidate region and the similarity of the ddr2 knockout mouse to the SMED patients' phenotype prompted us to study this gene(6). We identified three missense mutations c.2254 C > T [R752C], c. 2177 T > G [I726R], c.2138C > T [T713I] and one splice site mutation [IVS17+1g > a] in the conserved sequence encoding the tyrosine kinase domain of the DDR2 gene. The results of this study will permit an accurate early prenatal diagnosis and carrier screening for families at risk.

Cross-bridge kinetics of fast and slow fibres of cat jaw and limb muscles: correlations with myosin subunit composition.

PubMed

Hoh, Joseph F Y; Li, Zhao-Bo; Qin, Han; Hsu, Michael K H; Rossmanith, Gunther H

2007-01-01

Mechanical properties of the jaw-closing muscles of the cat are poorly understood. These muscles are known to differ in myosin and fibre type compositions from limb muscles. This work aims to correlate mechanical properties of single fibres in cat jaw and limb muscles with their myosin subunit compositions. The stiffness minimum frequency, f(min), which reflects isometric cross-bridge kinetics, was measured in Ca(2+)-activated glycerinated fast and slow fibres from cat jaw and limb muscles for temperatures ranging between 15 and 30 degrees C by mechanical perturbation analysis. At 15 degrees C, f(min) was 0.5 Hz for limb-slow fibres, 4-6 Hz for jaw-slow fibres, and 10-13 Hz for limb-fast and jaw-fast fibres. The activation energy for f(min) obtained from the slope of the Arrhenius plot for limb-slow fibres was 30-40% higher than values for the other three types of fibres. SDS-PAGE and western blotting using highly specific antibodies verified that limb-fast fibres contained IIA or IIX myosin heavy chain (MyHC). Jaw-fast fibres expressed masticatory MyHC while both jaw-fast and jaw-slow fibres expressed masticatory myosin light chains (MLCs). The nucleotide sequences of the 3' ends of the slow MyHC cDNAs isolated from cat masseter and soleus cDNA libraries showed identical coding and 3'-untranslated regions, suggesting that jaw-slow and limb-slow fibres express the same slow MyHC gene. We conclude that the isometric cross-bridge cycling kinetics of jaw-fast and limb-fast fibres detected by f(min) are indistinguishable in spite of differences in MyHC and light chain compositions. However, jaw-slow fibres, in which the same slow MyHCs are found in combination with MLCs of the jaw type, show enhanced cross-bridge cycling kinetics and reduced activation energy for cross-bridge detachment.

Anatomical variations between the sciatic nerve and the piriformis muscle: a contribution to surgical anatomy in piriformis syndrome.

PubMed

Natsis, Konstantinos; Totlis, Trifon; Konstantinidis, George A; Paraskevas, George; Piagkou, Maria; Koebke, Juergen

2014-04-01

To detect the variable relationship between sciatic nerve and piriformis muscle and make surgeons aware of certain anatomical features of each variation that may be useful for the surgical treatment of the piriformis syndrome. The gluteal region of 147 Caucasian cadavers (294 limbs) was dissected. The anatomical relationship between the sciatic nerve and the piriformis muscle was recorded and classified according to the Beaton and Anson classification. The literature was reviewed to summarize the incidence of each variation. The sciatic nerve and piriformis muscle relationship followed the typical anatomical pattern in 275 limbs (93.6 %). In 12 limbs (4.1 %) the common peroneal nerve passed through and the tibial nerve below a double piriformis. In one limb (0.3 %) the common peroneal nerve coursed superior and the tibial nerve below the piriformis. In one limb (0.3 %) both nerves penetrated the piriformis. In one limb (0.3 %) both nerves passed above the piriformis. Four limbs (1.4 %) presented non-classified anatomical variations. When a double piriformis muscle was present, two different arrangements of the two heads were observed. Anatomical variations of the sciatic nerve around the piriformis muscle were present in 6.4 % of the limbs examined. When dissection of the entire piriformis is necessary for adequate sciatic nerve decompression, the surgeon should explore for the possible existence of a second tendon, which may be found either inferior or deep to the first one. Some rare, unclassified variations of the sciatic nerve should be expected during surgical intervention of the region.

Dynamic parameters of three-point crutch gait in female patients after total hip arthroplasty.

PubMed

Murawa, Michał; Dworak, Lechosław B; Kabaciński, Jarosław; Syczewska, Małgorzata; Rzepnicka, Agata

2016-01-01

Patient recovery after a surgical procedure depends, among other factors, on the amount of the body weight with which patient loads lower limb. Research studies report different results of the degree of body weight with which lower limb is loaded during three-point crutch gait. The aim of this study was to evaluate the level of the ground reaction forces (GRF) during crutch gait used by patients after total hip arthroplasty (THA) in the first week after discharge from the orthopaedic units. Ten female patients diagnosed with primary unilateral coxarthrosis participated in a single measurement session. In order to record kinematic and dynamic variables of this gait pattern motion analysis system was used together with two force plates. The static test of body weight distribution between lower limbs was performed on a dual-top stabilometric plate. The average peak values of loading on the operated (O) limb during mid stance and terminal stance of three-point crutch gait were 64.6% and 64.3% of body weight (BW), respectively, whereas in the case of the nonoperated (NO) limb 103.5%BW and 108.8%BW, respectively. The maximum loads on the crutches were significantly higher (by 9%BW) on the NO side as compared to the O side ( p < 0.05). During the static test, average values of body weight distribution on the O and NO limb were 36%BW and 64%BW, respectively. The patients showed surprisingly similar level of loading on the O limb. The weight bearing on the O limb was lower during static trial than during three-point crutch gait.

Toward attenuating the impact of arm positions on electromyography pattern-recognition based motion classification in transradial amputees

PubMed Central

2012-01-01

Background Electromyography (EMG) pattern-recognition based control strategies for multifunctional myoelectric prosthesis systems have been studied commonly in a controlled laboratory setting. Before these myoelectric prosthesis systems are clinically viable, it will be necessary to assess the effect of some disparities between the ideal laboratory setting and practical use on the control performance. One important obstacle is the impact of arm position variation that causes the changes of EMG pattern when performing identical motions in different arm positions. This study aimed to investigate the impacts of arm position variation on EMG pattern-recognition based motion classification in upper-limb amputees and the solutions for reducing these impacts. Methods With five unilateral transradial (TR) amputees, the EMG signals and tri-axial accelerometer mechanomyography (ACC-MMG) signals were simultaneously collected from both amputated and intact arms when performing six classes of arm and hand movements in each of five arm positions that were considered in the study. The effect of the arm position changes was estimated in terms of motion classification error and compared between amputated and intact arms. Then the performance of three proposed methods in attenuating the impact of arm positions was evaluated. Results With EMG signals, the average intra-position and inter-position classification errors across all five arm positions and five subjects were around 7.3% and 29.9% from amputated arms, respectively, about 1.0% and 10% low in comparison with those from intact arms. While ACC-MMG signals could yield a similar intra-position classification error (9.9%) as EMG, they had much higher inter-position classification error with an average value of 81.1% over the arm positions and the subjects. When the EMG data from all five arm positions were involved in the training set, the average classification error reached a value of around 10.8% for amputated arms. Using a two-stage cascade classifier, the average classification error was around 9.0% over all five arm positions. Reducing ACC-MMG channels from 8 to 2 only increased the average position classification error across all five arm positions from 0.7% to 1.0% in amputated arms. Conclusions The performance of EMG pattern-recognition based method in classifying movements strongly depends on arm positions. This dependency is a little stronger in intact arm than in amputated arm, which suggests that the investigations associated with practical use of a myoelectric prosthesis should use the limb amputees as subjects instead of using able-body subjects. The two-stage cascade classifier mode with ACC-MMG for limb position identification and EMG for limb motion classification may be a promising way to reduce the effect of limb position variation on classification performance. PMID:23036049

Neurobiological degeneracy and affordance perception support functional intra-individual variability of inter-limb coordination during ice climbing.

PubMed

Seifert, Ludovic; Wattebled, Léo; Herault, Romain; Poizat, Germain; Adé, David; Gal-Petitfaux, Nathalie; Davids, Keith

2014-01-01

This study investigated the functional intra-individual movement variability of ice climbers differing in skill level to understand how icefall properties were used by participants as affordances to adapt inter-limb coordination patterns during performance. Seven expert climbers and seven beginners were observed as they climbed a 30 m icefall. Movement and positioning of the left and right hand ice tools, crampons and the climber's pelvis over the first 20 m of the climb were recorded and digitized using video footage from a camera (25 Hz) located perpendicular to the plane of the icefall. Inter-limb coordination, frequency and types of action and vertical axis pelvis displacement exhibited by each climber were analysed for the first five minutes of ascent. Participant perception of climbing affordances was assessed through: (i) calculating the ratio between exploratory movements and performed actions, and (ii), identifying, by self-confrontation interviews, the perceptual variables of environmental properties, which were significant to climbers for their actions. Data revealed that experts used a wider range of upper and lower limb coordination patterns, resulting in the emergence of different types of action and fewer exploratory movements, suggesting that effective holes in the icefall provided affordances to regulate performance. In contrast, beginners displayed lower levels of functional intra-individual variability of motor organization, due to repetitive swinging of ice tools and kicking of crampons to achieve and maintain a deep anchorage, suggesting lack of perceptual attunement and calibration to environmental properties to support climbing performance.

Elevated Fibroblast Growth Factor Signaling Is Critical for the Pathogenesis of the Dwarfism in Evc2/Limbin Mutant Mice.

PubMed

Zhang, Honghao; Kamiya, Nobuhiro; Tsuji, Takehito; Takeda, Haruko; Scott, Greg; Rajderkar, Sudha; Ray, Manas K; Mochida, Yoshiyuki; Allen, Benjamin; Lefebvre, Veronique; Hung, Irene H; Ornitz, David M; Kunieda, Tetsuo; Mishina, Yuji

2016-12-01

Ellis-van Creveld (EvC) syndrome is a skeletal dysplasia, characterized by short limbs, postaxial polydactyly, and dental abnormalities. EvC syndrome is also categorized as a ciliopathy because of ciliary localization of proteins encoded by the two causative genes, EVC and EVC2 (aka LIMBIN). While recent studies demonstrated important roles for EVC/EVC2 in Hedgehog signaling, there is still little known about the pathophysiological mechanisms underlying the skeletal dysplasia features of EvC patients, and in particular why limb development is affected, but not other aspects of organogenesis that also require Hedgehog signaling. In this report, we comprehensively analyze limb skeletogenesis in Evc2 mutant mice and in cell and tissue cultures derived from these mice. Both in vivo and in vitro data demonstrate elevated Fibroblast Growth Factor (FGF) signaling in Evc2 mutant growth plates, in addition to compromised but not abrogated Hedgehog-PTHrP feedback loop. Elevation of FGF signaling, mainly due to increased Fgf18 expression upon inactivation of Evc2 in the perichondrium, critically contributes to the pathogenesis of limb dwarfism. The limb dwarfism phenotype is partially rescued by inactivation of one allele of Fgf18 in the Evc2 mutant mice. Taken together, our data uncover a novel pathogenic mechanism to understand limb dwarfism in patients with Ellis-van Creveld syndrome.

Elevated Fibroblast Growth Factor Signaling Is Critical for the Pathogenesis of the Dwarfism in Evc2/Limbin Mutant Mice

PubMed Central

Zhang, Honghao; Kamiya, Nobuhiro; Tsuji, Takehito; Takeda, Haruko; Scott, Greg; Ray, Manas K.; Mochida, Yoshiyuki; Lefebvre, Veronique; Hung, Irene H.; Kunieda, Tetsuo; Mishina, Yuji

2016-01-01

Ellis-van Creveld (EvC) syndrome is a skeletal dysplasia, characterized by short limbs, postaxial polydactyly, and dental abnormalities. EvC syndrome is also categorized as a ciliopathy because of ciliary localization of proteins encoded by the two causative genes, EVC and EVC2 (aka LIMBIN). While recent studies demonstrated important roles for EVC/EVC2 in Hedgehog signaling, there is still little known about the pathophysiological mechanisms underlying the skeletal dysplasia features of EvC patients, and in particular why limb development is affected, but not other aspects of organogenesis that also require Hedgehog signaling. In this report, we comprehensively analyze limb skeletogenesis in Evc2 mutant mice and in cell and tissue cultures derived from these mice. Both in vivo and in vitro data demonstrate elevated Fibroblast Growth Factor (FGF) signaling in Evc2 mutant growth plates, in addition to compromised but not abrogated Hedgehog-PTHrP feedback loop. Elevation of FGF signaling, mainly due to increased Fgf18 expression upon inactivation of Evc2 in the perichondrium, critically contributes to the pathogenesis of limb dwarfism. The limb dwarfism phenotype is partially rescued by inactivation of one allele of Fgf18 in the Evc2 mutant mice. Taken together, our data uncover a novel pathogenic mechanism to understand limb dwarfism in patients with Ellis-van Creveld syndrome. PMID:28027321

Definitions of state variables and state space for brain-computer interface : Part 2. Extraction and classification of feature vectors.

PubMed

Freeman, Walter J

2007-06-01

The hypothesis is proposed that the central dynamics of the action-perception cycle has five steps: emergence from an existing macroscopic brain state of a pattern that predicts a future goal state; selection of a mesoscopic frame for action control; execution of a limb trajectory by microscopic spike activity; modification of microscopic cortical spike activity by sensory inputs; construction of mesoscopic perceptual patterns; and integration of a new macroscopic brain state. The basis is the circular causality between microscopic entities (neurons) and the mesoscopic and macroscopic entities (populations) self-organized by axosynaptic interactions. Self-organization of neural activity is bidirectional in all cortices. Upwardly the organization of mesoscopic percepts from microscopic spike input predominates in primary sensory areas. Downwardly the organization of spike outputs that direct specific limb movements is by mesoscopic fields constituting plans to achieve predicted goals. The mesoscopic fields in sensory and motor cortices emerge as frames within macroscopic activity. Part 1 describes the action-perception cycle and its derivative reflex arc qualitatively. Part 2 describes the perceptual limb of the arc from microscopic MSA to mesoscopic wave packets, and from these to macroscopic EEG and global ECoG fields that express experience-dependent knowledge in successive states. These macroscopic states are conceived to embed and control mesoscopic frames in premotor and motor cortices that are observed in local ECoG and LFP of frontoparietal areas. The fields sampled by ECoG and LFP are conceived as local patterns of neural activity in which trajectories of multiple spike activities (MSA) emerge that control limb movements. Mesoscopic frames are located by use of the analytic signal from the Hilbert transform after band pass filtering. The state variables in frames are measured to construct feature vectors by which to describe and classify frame patterns. Evidence is cited to justify use of linear analysis. The aim of the review is to enable researchers to conceive and identify goal-oriented states in brain activity for use as commands, in order to relegate the details of execution to adaptive control devices outside the brain.

The draft genomes of soft–shell turtle and green sea turtle yield insights into the development and evolution of the turtle–specific body plan

PubMed Central

Niimura, Yoshihito; Huang, Zhiyong; Li, Chunyi; White, Simon; Xiong, Zhiqiang; Fang, Dongming; Wang, Bo; Ming, Yao; Chen, Yan; Zheng, Yuan; Kuraku, Shigehiro; Pignatelli, Miguel; Herrero, Javier; Beal, Kathryn; Nozawa, Masafumi; Li, Qiye; Wang, Juan; Zhang, Hongyan; Yu, Lili; Shigenobu, Shuji; Wang, Junyi; Liu, Jiannan; Flicek, Paul; Searle, Steve; Wang, Jun; Kuratani, Shigeru; Yin, Ye; Aken, Bronwen; Zhang, Guojie; Irie, Naoki

2014-01-01

The unique anatomical features of turtles have raised unanswered questions about the origin of their unique body plan. We generated and analyzed draft genomes of the soft-shell turtle (Pelodiscus sinensis) and the green sea turtle (Chelonia mydas); our results indicated the close relationship of the turtles to the bird-crocodilian lineage, from which they split ~267.9–248.3 million years ago (Upper Permian to Triassic). We also found extensive expansion of olfactory receptor genes in these turtles. Embryonic gene expression analysis identified an hourglass-like divergence of turtle and chicken embryogenesis, with maximal conservation around the vertebrate phylotypic period, rather than at later stages that show the amniote-common pattern. Wnt5a expression was found in the growth zone of the dorsal shell, supporting the possible co-option of limb-associated Wnt signaling in the acquisition of this turtle-specific novelty. Our results suggest that turtle evolution was accompanied by an unexpectedly conservative vertebrate phylotypic period, followed by turtle-specific repatterning of development to yield the novel structure of the shell. PMID:23624526

Tetrapod axial evolution and developmental constraints; Empirical underpinning by a mouse model

PubMed Central

Woltering, Joost M.; Duboule, Denis

2015-01-01

The tetrapod vertebral column has become increasingly complex during evolution as an adaptation to a terrestrial life. At the same time, the evolution of the vertebral formula became subject to developmental constraints acting on the size of the cervical and thoraco-lumbar regions. In the course of our studies concerning the evolution of Hox gene regulation, we produced a transgenic mouse model expressing fish Hox genes, which displayed a reduced number of thoraco-lumbar vertebrae and concurrent sacral homeotic transformations. Here, we analyze this mutant stock and conclude that the ancestral, pre-tetrapodial Hox code already possessed the capacity to induce vertebrae with sacral characteristics. This suggests that alterations in the interpretation of the Hox code may have participated to the evolution of this region in tetrapods, along with potential modifications of the HOX proteins themselves. With its reduced vertebral number, this mouse stock violates a previously described developmental constraint, which applies to the thoraco-lumbar region. The resulting offset between motor neuron morphology, vertebral patterning and the relative positioning of hind limbs illustrates that the precise orchestration of the Hox-clock in parallel with other ontogenetic pathways places constraints on the evolvability of the body plan. PMID:26238020

Efficacy of a hybrid assistive limb in post-stroke hemiplegic patients: a preliminary report

PubMed Central

2011-01-01

Background Robotic devices are expected to be widely used in various applications including support for the independent mobility of the elderly with muscle weakness and people with impaired motor function as well as support for nursing care that involves heavy laborious work. We evaluated the effects of a hybrid assistive limb robot suit on the gait of stroke patients undergoing rehabilitation. Methods The study group comprised 16 stroke patients with severe hemiplegia. All patients underwent gait training. Four patients required assistance, and 12 needed supervision while walking. The stride length, walking speed and physiological cost index on wearing the hybrid assistive limb suit and a knee-ankle-foot orthosis were compared. Results The hybrid assistive limb suit increased the stride length and walking speed in 4 of 16 patients. The patients whose walking speed decreased on wearing the hybrid assistive limb suit either had not received sufficient gait training or had an established gait pattern with a knee-ankle-foot orthosis using a quad cane. The physiological cost index increased after wearing the hybrid assistive limb suit in 12 patients, but removal of the suit led to a decrease in the physiological cost index values to equivalent levels prior to the use of the suit. Conclusions Although the hybrid assistive limb suit is not useful for all hemiplegic patients, it may increase the walking speed and affect the walking ability. Further investigation would clarify its indication for the possibility of gait training. PMID:21943320

Progressive Loss of Function in a Limb Enhancer during Snake Evolution.

PubMed

Kvon, Evgeny Z; Kamneva, Olga K; Melo, Uirá S; Barozzi, Iros; Osterwalder, Marco; Mannion, Brandon J; Tissières, Virginie; Pickle, Catherine S; Plajzer-Frick, Ingrid; Lee, Elizabeth A; Kato, Momoe; Garvin, Tyler H; Akiyama, Jennifer A; Afzal, Veena; Lopez-Rios, Javier; Rubin, Edward M; Dickel, Diane E; Pennacchio, Len A; Visel, Axel

2016-10-20

The evolution of body shape is thought to be tightly coupled to changes in regulatory sequences, but specific molecular events associated with major morphological transitions in vertebrates have remained elusive. We identified snake-specific sequence changes within an otherwise highly conserved long-range limb enhancer of Sonic hedgehog (Shh). Transgenic mouse reporter assays revealed that the in vivo activity pattern of the enhancer is conserved across a wide range of vertebrates, including fish, but not in snakes. Genomic substitution of the mouse enhancer with its human or fish ortholog results in normal limb development. In contrast, replacement with snake orthologs caused severe limb reduction. Synthetic restoration of a single transcription factor binding site lost in the snake lineage reinstated full in vivo function to the snake enhancer. Our results demonstrate changes in a regulatory sequence associated with a major body plan transition and highlight the role of enhancers in morphological evolution. PAPERCLIP. Copyright © 2016 Elsevier Inc. All rights reserved.

Calpain 3 and CaMKIIβ signaling are required to induce HSP70 necessary for adaptive muscle growth after atrophy

PubMed Central

Kramerova, Irina; Torres, Jorge A; Eskin, Ascia; Nelson, Stanley F; Spencer, Melissa J

2018-01-01

Abstract Mutations in CAPN3 cause autosomal recessive limb girdle muscular dystrophy 2A. Calpain 3 (CAPN3) is a calcium dependent protease residing in the myofibrillar, cytosolic and triad fractions of skeletal muscle. At the triad, it colocalizes with calcium calmodulin kinase IIβ (CaMKIIβ). CAPN3 knock out mice (C3KO) show reduced triad integrity and blunted CaMKIIβ signaling, which correlates with impaired transcriptional activation of myofibrillar and oxidative metabolism genes in response to running exercise. These data suggest a role for CAPN3 and CaMKIIβ in gene regulation that takes place during adaptation to endurance exercise. To assess whether CAPN3- CaMKIIβ signaling influences skeletal muscle remodeling in other contexts, we subjected C3KO and wild type mice to hindlimb unloading and reloading and assessed CaMKIIβ signaling and gene expression by RNA-sequencing. After induced atrophy followed by 4 days of reloading, both CaMKIIβ activation and expression of inflammatory and cellular stress genes were increased. C3KO muscles failed to activate CaMKIIβ signaling, did not activate the same pattern of gene expression and demonstrated impaired growth at 4 days of reloading. Moreover, C3KO muscles failed to activate inducible HSP70, which was previously shown to be indispensible for the inflammatory response needed to promote muscle recovery. Likewise, C3KO showed diminished immune cell infiltration and decreased expression of pro-myogenic genes. These data support a role for CaMKIIβ signaling in induction of HSP70 and promotion of the inflammatory response during muscle growth and remodeling that occurs after atrophy, suggesting that CaMKIIβ regulates remodeling in multiple contexts: endurance exercise and growth after atrophy. PMID:29528394

Preliminary Study on Continuous Recognition of Elbow Flexion/Extension Using sEMG Signals for Bilateral Rehabilitation

PubMed Central

Song, Zhibin; Zhang, Songyuan

2016-01-01

Surface electromyography (sEMG) signals are closely related to the activation of human muscles and the motion of the human body, which can be used to estimate the dynamics of human limbs in the rehabilitation field. They also have the potential to be used in the application of bilateral rehabilitation, where hemiplegic patients can train their affected limbs following the motion of unaffected limbs via some rehabilitation devices. Traditional methods to process the sEMG focused on motion pattern recognition, namely, discrete patterns, which are not satisfactory for use in bilateral rehabilitation. In order to overcome this problem, in this paper, we built a relationship between sEMG signals and human motion in elbow flexion and extension on the sagittal plane. During the conducted experiments, four participants were required to perform elbow flexion and extension on the sagittal plane smoothly with only an inertia sensor in their hands, where forearm dynamics were not considered. In these circumstances, sEMG signals were weak compared to those with heavy loads or high acceleration. The contrastive experimental results show that continuous motion can also be obtained within an acceptable precision range. PMID:27775573

Preliminary Study on Continuous Recognition of Elbow Flexion/Extension Using sEMG Signals for Bilateral Rehabilitation.

PubMed

Song, Zhibin; Zhang, Songyuan

2016-10-19

Surface electromyography (sEMG) signals are closely related to the activation of human muscles and the motion of the human body, which can be used to estimate the dynamics of human limbs in the rehabilitation field. They also have the potential to be used in the application of bilateral rehabilitation, where hemiplegic patients can train their affected limbs following the motion of unaffected limbs via some rehabilitation devices. Traditional methods to process the sEMG focused on motion pattern recognition, namely, discrete patterns, which are not satisfactory for use in bilateral rehabilitation. In order to overcome this problem, in this paper, we built a relationship between sEMG signals and human motion in elbow flexion and extension on the sagittal plane. During the conducted experiments, four participants were required to perform elbow flexion and extension on the sagittal plane smoothly with only an inertia sensor in their hands, where forearm dynamics were not considered. In these circumstances, sEMG signals were weak compared to those with heavy loads or high acceleration. The contrastive experimental results show that continuous motion can also be obtained within an acceptable precision range.

Preclinical and clinical experience in vascular gene therapy: advantages over conservative/standard therapy.

PubMed

Nikol, S; Huehns, T Y

2001-04-01

No systemic pharmacological treatment has been shown to convincingly reduce the incidence of restenosis after angioplasty or increase the formation of collaterals in ischemic tissue in patients. The lack of success of many pharmaceutical agents in reducing restenosis rates or in inducing angiogenesis post-angioplasty and following stent implantation has encouraged the development of new technological treatment approaches. Gene therapy is a novel strategy with the potential to prevent some of the sequelae after arterial injury, particularly cell proliferation, and to induce growth of new vessels or remodeling of pre-existing vessel branches, which may help patients with critical ischemia. Gene therapy strategies have the advantage of minimizing systemic side effects and may have a long-term effect as the encoded protein is released. Most clinical trials investigating gene therapy for vascular disease have been uncontrolled phase I and IIa trials. Gene therapy into vessels with the genes for growth factors has been demonstrated to be feasible and efficient. Local drug delivery devices have been used in combination with gene therapy in several trials to maximize safety and efficiency. Data from experimental animal work indicates that gene therapy may modify intimal hyperplasia after arterial injury, but there are few clinical trials on restenosis in patients. Preliminary clinical results show only limited success in altering restenosis rates. In vitro and experimental in vivo investigations into gene therapy for angiogenesis demonstrate increased formation of collaterals and functional improvement of limb ischemia. There is some evidence of increased collateral formation and clinical improvement in patients with critical limb ischemia. Results of placebo-controlled and double-blind trials of gene therapy for vascular disease are awaited.

Similarities and Differences between Porcine Mandibular and Limb Bone Marrow Mesenchymal Stem Cells

PubMed Central

Lloyd, Brandon; Tee, Boon Ching; Headley, Colwyn; Emam, Hany; Mallery, Susan; Sun, Zongyang

2017-01-01

Objective Research has shown promise of using bone marrow mesenchymal stem cells (BMSCs) for craniofacial bone regeneration; yet little is known about the differences of BMSCs from limb and craniofacial bones. This study compared pig mandibular and tibia BMSCs for their in vitro proliferation, osteogenic differentiation properties and gene expression. Design Bone marrow was aspirated from the tibia and mandible of 3–4 month-old pigs (n=4), followed by BMSC isolation, culture-expansion and characterization by flow cytometry. Proliferation rates were assessed using population doubling times. Osteogenic differentiation was evaluated by alkaline phosphatase activity. Affymetrix porcine microarray was used to compare gene expressions of tibial and mandibular BMSCs, followed by real-time RT-PCR evaluation of certain genes. Results Our results showed that BMSCs from both locations expressed MSC markers but not hematopoietic markers. The proliferation and osteogenic differentiation potential of mandibular BMSCs were significantly stronger than those of tibial BMSCs. Microarray analysis identified 404 highly abundant genes, out of which 334 genes were matched between the two locations and annotated into the same functional groups including osteogenesis and angiogenesis, while 70 genes were mismatched and annotated into different functional groups. In addition, 48 genes were differentially expressed by at least 1.5-fold difference between the two locations, including higher expression of cranial neural crest-related gene BMP-4 in mandibular BMSCs, which was confirmed by real-time RT-PCR. Conclusions Altogether, these data indicate that despite strong similarities in gene expression between mandibular and tibial BMSCs, mandibular BMSCs express some genes differently than tibial BMSCs and have a phenotypic profile that may make them advantageous for craniofacial bone regeneration. PMID:28135571

STS-43 Earth observation of a colorful sunrise

NASA Image and Video Library

1991-08-11

STS-43 Earth observation taken aboard Atlantis, Orbiter Vehicle (OV) 104, captures the Earth's limb at sunrise with unusual cloud patterns silhouetted by the sunlight and rising into the terminator lines.

An exploration of adult body shape and limb proportions at Kellis 2, Dakhleh Oasis, Egypt.

PubMed

Bleuze, Michele M; Wheeler, Sandra M; Dupras, Tosha L; Williams, Lana J; El Molto, J

2014-03-01

Several studies have shown that the human body generally conforms to the ecogeographical expectations of Bergmann's and Allen's rules; however, recent evidence suggests that these expectations may not hold completely for some populations. Egypt is located at the crossroads of Sub-Saharan Africa, Southern Europe, and the Near East, and gene flow among groups in these regions may confound ecogeographical patterning. In this study, we test the fit of the adult physique of a large sample (N = 163) of females and males from the Kellis 2 cemetery (Dakhleh Oasis, Egypt) against ecogeographical predictions. Body shape (i.e., body mass relative to stature) was assessed by the femur head diameter to bicondylar femur length index (FHD/BFL), and brachial and crural indices were calculated to examine intralimb proportions. Body shape in the Kellis 2 sample is not significantly different from high-latitude groups and a Lower Nubian sample, and intralimb proportions are not significantly different from mid-latitude and other low-latitude groups. This study demonstrates the potential uniqueness of body shape and intralimb proportions in an ancient Egyptian sample, and further highlights the complex relationship between ecogeographic patterning and adaptation. Copyright © 2013 Wiley Periodicals, Inc.

A de novo interstitial 6q deletion in a boy with a split hand malformation.

PubMed

Duran-Gonzalez, Jorge; Gutierrez-Angulo, Melva; Garcia-Cruz, Diana; Ayala, Maria de la Luz; Padilla, Miguel; Davalos, Ingrid P

2007-01-01

We report on a de novo interstitial deletion of (6)(q15q22.2) in a 5-year-old boy with developmental delay, microcephaly, facial dysmorphism, cryptorchidism, congenital heart defect, and split-hand malformation. Previous reports and this patient suggest that 6q21 may contain a gene or genes related either directly or indirectly to limb development.

Effects of electromagnetic pulse on polydactyly of mouse fetuses.

PubMed

Yang, Ming-Juan; Liu, Jun-Ye; Wang, Ya-Feng; Lang, Hai-Yang; Miao, Xia; Zhang, Li-Yan; Zeng, Li-Hua; Guo, Guo-Zhen

2013-07-01

There is an increasing public concern regarding potential health impacts from electromagnetic radiation exposure. Embryonic development is sensitive to the external environment, and limb development is vital for life quality. To determine the effects of electromagnetic pulse (EMP) on polydactyly of mouse fetuses, pregnant mice were sham-exposed or exposed to EMP (400 kV/m with 400 pulses) from Days 7 to 10 of pregnancy (Day 0 = day of detection of vaginal plug). As a positive control, mice were treated with 5-bromodeoxyuridine on Days 9 and 10. On Days 11 or 18, the fetuses were isolated. Compared with the sham-exposed group, the group exposed to EMP had increased rates of polydactyly fetuses (5.1% vs. 0.6%, P < 0.05) and abnormal gene expression (22.2% vs. 2.8%, P < 0.05). Ectopic expression of Fgf4 was detected in the apical ectodermal ridge, whereas overexpression and ectopic expression of Shh were detected in the zone of polarizing activity of limbs in the EMP-exposed group and in the positive control group. However, expression of Gli3 decreased in mesenchyme cells in those two groups. The percentages of programmed cell death of limbs in EMP-exposed and positive control group were decreased (3.57% and 2.94%, respectively, P < 0.05, compared with 7.76% in sham-exposed group). In conclusion, polydactyly induced by EMP was accompanied by abnormal expression of the above-mentioned genes and decreased percentage of programmed cell death during limb development. Copyright © 2013 Elsevier Inc. All rights reserved.

mRNA Quantification of NIPBL Isoforms A and B in Adult and Fetal Human Tissues, and a Potentially Pathological Variant Affecting Only Isoform A in Two Patients with Cornelia de Lange Syndrome

PubMed Central

Puisac, Beatriz; Teresa-Rodrigo, María-Esperanza; Hernández-Marcos, María; Baquero-Montoya, Carolina; Gil-Rodríguez, María-Concepción; Visnes, Torkild; Bot, Christopher; Gómez-Puertas, Paulino; Kaiser, Frank J.; Ramos, Feliciano J.; Ström, Lena; Pié, Juan

2017-01-01

Cornelia de Lange syndrome (CdLS) is a congenital developmental disorder characterized by craniofacial dysmorphia, growth retardation, limb malformations, and intellectual disability. Approximately 60% of patients with CdLS carry a recognizable pathological variant in the NIPBL gene, of which two isoforms, A and B, have been identified, and which only differ in the C-terminal segment. In this work, we describe the distribution pattern of the isoforms A and B mRNAs in tissues of adult and fetal origin, by qPCR (quantitative polymerase chain reaction). Our results show a higher gene expression of the isoform A, even though both seem to have the same tissue distribution. Interestingly, the expression in fetal tissues is higher than that of adults, especially in brain and skeletal muscle. Curiously, the study of fibroblasts of two siblings with a mild CdLS phenotype and a pathological variant specific of the isoform A of NIPBL (c.8387A > G; P.Tyr2796Cys), showed a similar reduction in both isoforms, and a normal sensitivity to DNA damage. Overall, these results suggest that the position of the pathological variant at the 3´ end of the NIPBL gene affecting only isoform A, is likely to be the cause of the atypical mild phenotype of the two brothers. PMID:28241484

Genetics Home Reference: CAV3-related distal myopathy

MedlinePlus

... can cause other caveolinopathies including limb-girdle muscular dystrophy , rippling muscle disease , isolated hyperCKemia , and a heart disorder called ... links) GeneReview: Caveolinopathies MedlinePlus Encyclopedia: Electromyography MedlinePlus Encyclopedia: Muscle ... Care Surgery and Rehabilitation Related ...

Innovative gait robot for the repetitive practice of floor walking and stair climbing up and down in stroke patients

PubMed Central

2010-01-01

Background Stair climbing up and down is an essential part of everyday's mobility. To enable wheelchair-dependent patients the repetitive practice of this task, a novel gait robot, G-EO-Systems (EO, Lat: I walk), based on the end-effector principle, has been designed. The trajectories of the foot plates are freely programmable enabling not only the practice of simulated floor walking but also stair climbing up and down. The article intended to compare lower limb muscle activation patterns of hemiparetic subjects during real floor walking and stairs climbing up, and during the corresponding simulated conditions on the machine, and secondly to demonstrate gait improvement on single case after training on the machine. Methods The muscle activation pattern of seven lower limb muscles of six hemiparetic patients during free and simulated walking on the floor and stair climbing was measured via dynamic electromyography. A non-ambulatory, sub-acute stroke patient additionally trained on the G-EO-Systems every workday for five weeks. Results The muscle activation patterns were comparable during the real and simulated conditions, both on the floor and during stair climbing up. Minor differences, concerning the real and simulated floor walking conditions, were a delayed (prolonged) onset (duration) of the thigh muscle activation on the machine across all subjects. Concerning stair climbing conditions, the shank muscle activation was more phasic and timely correct in selected patients on the device. The severely affected subject regained walking and stair climbing ability. Conclusions The G-EO-Systems is an interesting new option in gait rehabilitation after stroke. The lower limb muscle activation patterns were comparable, a training thus feasible, and the positive case report warrants further clinical studies. PMID:20584307

Innovative gait robot for the repetitive practice of floor walking and stair climbing up and down in stroke patients.

PubMed

Hesse, Stefan; Waldner, Andreas; Tomelleri, Christopher

2010-06-28

Stair climbing up and down is an essential part of everyday's mobility. To enable wheelchair-dependent patients the repetitive practice of this task, a novel gait robot, G-EO-Systems (EO, Lat: I walk), based on the end-effector principle, has been designed. The trajectories of the foot plates are freely programmable enabling not only the practice of simulated floor walking but also stair climbing up and down. The article intended to compare lower limb muscle activation patterns of hemiparetic subjects during real floor walking and stairs climbing up, and during the corresponding simulated conditions on the machine, and secondly to demonstrate gait improvement on single case after training on the machine. The muscle activation pattern of seven lower limb muscles of six hemiparetic patients during free and simulated walking on the floor and stair climbing was measured via dynamic electromyography. A non-ambulatory, sub-acute stroke patient additionally trained on the G-EO-Systems every workday for five weeks. The muscle activation patterns were comparable during the real and simulated conditions, both on the floor and during stair climbing up. Minor differences, concerning the real and simulated floor walking conditions, were a delayed (prolonged) onset (duration) of the thigh muscle activation on the machine across all subjects. Concerning stair climbing conditions, the shank muscle activation was more phasic and timely correct in selected patients on the device. The severely affected subject regained walking and stair climbing ability. The G-EO-Systems is an interesting new option in gait rehabilitation after stroke. The lower limb muscle activation patterns were comparable, a training thus feasible, and the positive case report warrants further clinical studies.

Heterogeneity of muscle recruitment pattern during pedaling in professional road cyclists: a magnetic resonance imaging and electromyography study.

PubMed

Hug, François; Bendahan, David; Le Fur, Yann; Cozzone, Patrick J; Grélot, Laurent

2004-07-01

Although a number of studies have been devoted to the analysis of the activity pattern of the muscles involved in pedaling in sedentary subjects and/or amateur cyclists, data on professional cyclists are scarce and the issue of inter-individual differences has never been addressed in detail. In the present series of experiments, we performed a non-invasive investigation using functional magnetic resonance imaging and surface electromyography to determine the pattern of activity of lower limb muscles during two different exhausting pedaling exercises in eight French professional cyclists. Each subject performed an incremental exercise during which electromyographic activity of eight lower limb muscles and respiratory variables were recorded. After a 3-h recovery period, transverse relaxation times (T2) were measured before and just after a standardized constant-load maximal exercise in order to quantify exercise-related T2 changes. The global EMG activity illustrated by the root mean square clearly showed a large inter-individual difference during the incremental exercise regardless of the investigated muscle (variation coefficient up to 81%). In addition, for most of the muscles investigated, the constant-load exercise induced T2 increases, which varied noticeably among the subjects. This high level of variation in the recruitment of lower limb muscles in professional cyclists during both incremental and constant-load exercises is surprising given the homogeneity related to maximal oxygen consumption and training volume. The high degree of expertise of these professional cyclists was not linked to the production of a common pattern of pedaling and our results provide an additional evidence that the nervous system has multiple ways of accomplishing a given motor task, as has been suggested previously by neural control theorists and experimentalists.

Dismounted Blast Injuries in Patients Treated at a Role 3 Military Hospital in Afghanistan: Patterns of Injury and Mortality.

PubMed

Oh, John S; Tubb, Creighton C; Poepping, Thomas P; Ryan, Paul; Clasper, Jonathan C; Katschke, Adrian R; Tuman, Caroline; Murray, Michael J

2016-09-01

The purposes of this study are to define the pattern of injuries sustained by dismounted troops exposed to improvised explosive devices blasts treated at a Role 3 combat support hospital and to assess injury patterns and mortality associated with the mechanism. Our hypothesis was that mortality is associated with pelvic fracture, massive transfusion, high Injury Severity Score (ISS), multiple limb amputations, and transfer from a Role 2 facility. Retrospective study of 457 patients. Analysis performed on trauma registry data and systematic review of radiographs. 99.9% were men with a median age of 23 years and median ISS 10. 141 patients (30.9%) required massive blood transfusion. Limb amputations were frequently observed injuries, 109 of 172 amputees (63.4%) had a double amputation. 34 subjects (7.4%) had pelvic fractures; majority of pelvic fractures (88%) were unstable (Tile B or C). Risk factors associated with the overall mortality rate of 1.8% were an ISS greater than 15 (odds ratio: 11.5; 95% confidence interval: 1.38, 533; p = 0.009), need for massive transfusion (p < 0.0001), and the presence of a pelvic fracture (odds ratio: 7.63; 95% confidence interval: 1.13, 41.3; p = 0.018). Dismounted improvised explosive devices blast injuries result in devastating multiple limb amputations and unstable pelvic fractures, which are associated with mortality after initial trauma resuscitation at a Role 3 hospital. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Cell tracing reveals a dorsoventral lineage restriction plane in the mouse limb bud mesenchyme.

PubMed

Arques, Carlos G; Doohan, Roisin; Sharpe, James; Torres, Miguel

2007-10-01

Regionalization of embryonic fields into independent units of growth and patterning is a widespread strategy during metazoan development. Compartments represent a particular instance of this regionalization, in which unit coherence is maintained by cell lineage restriction between adjacent regions. Lineage compartments have been described during insect and vertebrate development. Two common characteristics of the compartments described so far are their occurrence in epithelial structures and the presence of signaling regions at compartment borders. Whereas Drosophila compartmental organization represents a background subdivision of embryonic fields that is not necessarily related to anatomical structures, vertebrate compartment borders described thus far coincide with, or anticipate, anatomical or cell-type discontinuities. Here, we describe a general method for clonal analysis in the mouse and use it to determine the topology of clone distribution along the three limb axes. We identify a lineage restriction boundary at the limb mesenchyme dorsoventral border that is unrelated to any anatomical discontinuity, and whose lineage restriction border is not obviously associated with any signaling center. This restriction is the first example in vertebrates of a mechanism of primordium subdivision unrelated to anatomical boundaries. Furthermore, this is the first lineage compartment described within a mesenchymal structure in any organism, suggesting that lineage restrictions are fundamental not only for epithelial structures, but also for mesenchymal field patterning. No lineage compartmentalization was found along the proximodistal or anteroposterior axes, indicating that patterning along these axes does not involve restriction of cell dispersion at specific axial positions.

THE RESPONSE OF X-IRRADIATED LIMBS OF ADULT URODELES TO NORMAL TISSUE GRAFTS. I. EFFECTS OF AUTOGRAFTS OF SIXTY-DAY FOREARM REGENERATES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stinson, B.D.

1963-06-01

Results are reported of autoplastic transplantation of parts of nonirradiated, regenerated forelimb to the contralateral x-irradiated forelimb in adult Triturus viridescens. The right forelimbs were exposed to various doses of localized irradiation (1000 to 5000 r) followed by amputation of both left and right forelimbs through the mid forearm. Left limbs regenerated normally, but irradiated right limbs failed to exhibit any significant degree of regenerative activity over a 3-month period. Both forelimbs were reamputated through the distal humerus and observed for an additional two months. Left limbs produced normal regenerates, but irradiated right limbs gave no gross evidence of regenerationmore » at any of the radiation dose levels. Normal left regenerates were reamputated immediately distal to the elbow on the 60th day after the second amputation; the severed forearm was trimmed with scissors along anterior and posterior borders and denuded of skin over its proximal half, leaving an essentially complete forearm region as a normal autograft. This was implanted into the irradiated right upper arm stump, after ablation of the distal half of its humerus, with normal proximodistal polarity in all cases. The irradiated stump was reamputated through the distal portion of the implanted normal autograft two weeks after implantation, and was observed for four months. Periodic gross observations showed that over 90% of irradiated upper arms formed regenerates at a rate which paralleled that of nonirradiated controls. However, regenerates formed on irradiated upper arms exhibited a restriction of morphogenetic capacity, only 60% attaining 3- and 4-digit stages. Most of the morphologically more complex regenerates which developed on the irradiated upper arm stumps manifested left limb asymmetry despite their formation on right irradiated stumps, suggesting a relation between the asymmetry of the normal graft and that of the resulting regenerate. All regenerates which developed on irradiated upper arms showed marked deficiencies in the restoration of a complete proximodistal structural pattern appropriate to the level of amputation through the irradiated stump. However, the actual pattern produced was appropriate to the level of amputation through the implanted normal autograft. These findings support the hypothesis that normal grafts promote the formation of regenerates on irradiated limbs through the autonomous developmental activity of the transected graft. (BBB)« less

Transcriptomics provides mechanistic indicators of fluoride toxicology on endochondral ossification in the hind limb of Bufo gargarizans.

PubMed

Chao, Wu; Zhang, Yuhui; Chai, Lihong; Wang, Hongyuan

2018-06-10

Endochondral ossification, the process by which most of the bone is formed, is regulated by many specific groups of molecules and extracellular matrix components. Hind limb of Bufo gargarizans is a model to study endochondral ossification during metamorphosis. Chinese toad (Bufo gargarizans) were exposed to different fluoride concentrations (0, 1, 5, 10 and 20 mg L -1 ) from G3 to G42. The development of hind limb of B. gargarizans was observed using the double staining methodology. The transcriptome of hind limb of B. gargarizans was conducted using RNA-seq approach, and differentially expressed gene was also validated. In addition, the location of Sox9 and Ihh in the growth cartilage was determined using in situ hybridization. Our results showed that 5 mg L -1 stimulated bone mineralization, while 10 and 20 mg L -1 exposure could inhibit the tibio-fibula, tarsus and metacarpals ossification. Besides, 10 mg F/L treatment could down-regulate Ihh, Sox9, D2, D3, TRα, TRβ, Wnt10, FGF3 and BMP6 expression, while up-regulate ObRb and HHAT mRNA expression in the hind limb of B. gargarizans. Transcript level changes of Ihh, Sox9, D2, D3, TRα, TRβ, Wnt10, FGF3 and BMP6 were consistent with the results of RT-qPCR. In situ hybridization revealed that Ihh was expressed in prehypertrophic chondrocytes, while Sox9 was abundantly expressed in proliferous, prehypertrophic and hypertrophic chondrocytes. However, 10 mg F-/L did not cause any affect in the location of the Ihh and Sox9 mRNA. Therefore, high concentration of fluoride could affect the ossification-related genes mRNA expression and then inhibit the endochondral ossification. The present study thus will greatly contribute to our understanding of the effect of environmental contaminant on ossification in amphibian. Copyright © 2018 Elsevier B.V. All rights reserved.

Lower limb motor restlessness in Asperger's disorder, measured using actometry.

PubMed

Tuisku, Katinka; Tani, Pekka; Nieminen-von Wendt, Taina; von Wendt, Lennart; Holi, Matti Mikael; Porkka-Heiskanen, Tarja; Lauerma, Hannu; Lindberg, Nina; Appelberg, Björn; Wahlbeck, Kristian

2004-08-30

The movement disturbances and brain imaging findings in Asperger's disorder (AD) suggest a dopaminergic deficit in movement regulation. Movement disorders of different etiologies have been quantified and specified with actometry. We compared 10 AD patients with 10 healthy controls, measuring their rest-activities by actometry. The lower limb motor activity was significantly higher in the AD group. They also displayed a rhythmic, periodic movement pattern similar to akathisia. These findings suggest a hypothesis of idiopathic akathisia and a special sensitivity to adverse effects of neuroleptic drugs.

Inhibition of Shh signalling in the chick wing gives insights into digit patterning and evolution.

PubMed

Pickering, Joseph; Towers, Matthew

2016-10-01

In an influential model of pattern formation, a gradient of Sonic hedgehog (Shh) signalling in the chick wing bud specifies cells with three antero-posterior positional values, which give rise to three morphologically different digits by a self-organizing mechanism with Turing-like properties. However, as four of the five digits of the mouse limb are morphologically similar in terms of phalangeal pattern, it has been suggested that self-organization alone could be sufficient. Here, we show that inhibition of Shh signalling at a specific stage of chick wing development results in a pattern of four digits, three of which can have the same number of phalanges. These patterning changes are dependent on a posterior extension of the apical ectodermal ridge, and this also allows the additional digit to arise from the Shh-producing cells of the polarizing region - an ability lost in ancestral theropod dinosaurs. Our analyses reveal that, if the specification of antero-posterior positional values is curtailed, self-organization can then produce several digits with the same number of phalanges. We present a model that may give important insights into how the number of digits and phalanges has diverged during the evolution of avian and mammalian limbs. © 2016. Published by The Company of Biologists Ltd.

Intra-limb coordination in karate kicking: Effect of impacting or not impacting a target.

PubMed

Quinzi, Federico; Sbriccoli, Paola; Alderson, Jacqueline; Di Mario, Alberto; Camomilla, Valentina

2014-02-01

This study aimed to investigate the kicking limb coordinative patterns adopted by karate practitioners (karateka) when impacting (IRK), or not impacting (NIRK) a target during a roundhouse kick. Six karateka performed three repetitions of both kicks while kicking limb kinematics were recorded using a stereophotogrammetric system. Intra-limb coordination was quantified for hip and knee flexion-extension from toe-off to kick completion, using the Continuous relative phase (CRP). Across the same time interval, thigh and shank angular momentum about the vertical axis of the body was calculated. For all trials, across all participants, CRP curve peaks and maximum and minimum angular momentum were determined. A RM-ANOVA was performed to test for differences between kicking conditions. The CRP analysis highlighted, during the central portion of both kicks, a delayed flexion of the hip with respect to the knee. Conversely, during the terminal portion of the CRP curves, the NIRK is performed with a more in-phase action, caused by a higher hip angular displacement. The NIRK is characterized by a lower angular momentum which may enhance control of the striking limb. It would seem that the issue of no impact appears to be solved through the control of all segments of the kicking limb, in contrast to the primary control of the lower leg only observed during the IRK. Copyright © 2013 Elsevier B.V. All rights reserved.

Load redistribution in walking and trotting Beagles with induced forelimb lameness.

PubMed

Abdelhadi, Jalal; Wefstaedt, Patrick; Galindo-Zamora, Vladimir; Anders, Alexandra; Nolte, Ingo; Schilling, Nadja

2013-01-01

To evaluate the load redistribution mechanisms in walking and trotting dogs with induced forelimb lameness. 7 healthy adult Beagles. Dogs walked and trotted on an instrumented treadmill to determine control values for peak and mean vertical force as well as vertical impulse for all 4 limbs. A small sphere was attached to the ventral pad of the right forelimb paw to induce a reversible lameness, and recordings were repeated for both gaits. Additionally, footfall patterns were assessed to test for changes in temporal gait variables. During walking and trotting, peak and mean vertical force as well as vertical impulse were decreased in the ipsilateral forelimb, increased in the contralateral hind limb, and remained unchanged in the ipsilateral hind limb after lameness was induced. All 3 variables were increased in the contralateral forelimb during trotting, whereas only mean vertical force and vertical impulse were increased during walking. Stance phase duration increased in the contralateral forelimb and hind limb during walking but not during trotting. Analysis of the results suggested that compensatory load redistribution mechanisms in dogs depend on the gait. All 4 limbs should be evaluated in basic research and clinical studies to determine the effects of lameness on the entire body. Further studies are necessary to elucidate specific mechanisms for unloading of the affected limb and to determine the long-term effects of load changes in animals with chronic lameness.

A three-dimensional thermal and electromagnetic model of whole limb heating with a MAPA.

PubMed

Charny, C K; Levin, R L

1991-10-01

Previous studies by the authors have shown that if properly implemented, the Pennes assumptions can be applied to quantify bioheat transfer during extremity heating. Given its relative numerical simplicity and its ability to predict temperatures in thermoregulated tissue, the Pennes model of bioheat transfer was utilized in a three-dimensional thermal model of limb heating. While the arterial blood temperature was assumed to be radially uniform within a cross section of the limb, axial gradients in the arterial and venous blood temperatures were computed with this three-dimensional model. A realistically shaped, three-dimensional finite element model of a tumor-bearing human lower leg was constructed and was "attached" mathematically to the whole body thermal model of man described in previous studies by the authors. The central as well as local thermoregulatory feedback control mechanisms which determine blood perfusion to the various tissues and rate of evaporation by sweating were input into the limb model. In addition, the temperature of the arterial blood which feeds into the most proximal section of the lower leg was computed by the whole body thermal model. The variations in the shape of the tissues which comprise the limb were obtained from computerized tomography scans. Axial variations in the energy deposition patterns along the length of the limb exposed to a miniannular phased array (MAPA) applicator were also input into this model of limb heating. Results indicate that proper positioning of the limb relative to the MAPA is a significant factor in determining the effectiveness of the treatment. A patient-specific hyperthermia protocol can be designed using this coupled electromagnetic and thermal model.

Reliability of lower limb alignment measures using an established landmark-based method with a customized computer software program

PubMed Central

Sled, Elizabeth A.; Sheehy, Lisa M.; Felson, David T.; Costigan, Patrick A.; Lam, Miu; Cooke, T. Derek V.

2010-01-01

The objective of the study was to evaluate the reliability of frontal plane lower limb alignment measures using a landmark-based method by (1) comparing inter- and intra-reader reliability between measurements of alignment obtained manually with those using a computer program, and (2) determining inter- and intra-reader reliability of computer-assisted alignment measures from full-limb radiographs. An established method for measuring alignment was used, involving selection of 10 femoral and tibial bone landmarks. 1) To compare manual and computer methods, we used digital images and matching paper copies of five alignment patterns simulating healthy and malaligned limbs drawn using AutoCAD. Seven readers were trained in each system. Paper copies were measured manually and repeat measurements were performed daily for 3 days, followed by a similar routine with the digital images using the computer. 2) To examine the reliability of computer-assisted measures from full-limb radiographs, 100 images (200 limbs) were selected as a random sample from 1,500 full-limb digital radiographs which were part of the Multicenter Osteoarthritis (MOST) Study. Three trained readers used the software program to measure alignment twice from the batch of 100 images, with two or more weeks between batch handling. Manual and computer measures of alignment showed excellent agreement (intraclass correlations [ICCs] 0.977 – 0.999 for computer analysis; 0.820 – 0.995 for manual measures). The computer program applied to full-limb radiographs produced alignment measurements with high inter- and intra-reader reliability (ICCs 0.839 – 0.998). In conclusion, alignment measures using a bone landmark-based approach and a computer program were highly reliable between multiple readers. PMID:19882339

Which limb is it? Responses to vibrotactile stimulation in early infancy.

PubMed

Somogyi, Eszter; Jacquey, Lisa; Heed, Tobias; Hoffmann, Matej; Lockman, Jeffrey J; Granjon, Lionel; Fagard, Jacqueline; O'Regan, J Kevin

2017-12-11

This study focuses on how the body schema develops during the first months of life, by investigating infants' motor responses to localized vibrotactile stimulation on their limbs. Vibrotactile stimulation was provided by small buzzers that were attached to the infants' four limbs one at a time. Four age groups were compared cross-sectionally (3-, 4-, 5-, and 6-month-olds). We show that before they actually reach for the buzzer, which, according to previous studies, occurs around 7-8 months of age, infants demonstrate emerging knowledge about their body's configuration by producing specific movement patterns associated with the stimulated body area. At 3 months, infants responded with an increase in general activity when the buzzer was placed on the body, independently of the vibrator's location. Differentiated topographical awareness of the body seemed to appear around 5 months, with specific responses resulting from stimulation of the hands emerging first, followed by the differentiation of movement patterns associated with the stimulation of the feet. Qualitative analyses revealed specific movement types reliably associated with each stimulated location by 6 months of age, possibly preparing infants' ability to actually reach for the vibrating target. We discuss this result in relation to newborns' ability to learn specific movement patterns through intersensory contingency. Statement of contribution what is already known on infants' sensorimotor knowledge about their own bodies 3-month-olds readily learn to produce specific limb movements to obtain a desired effect (movement of a mobile). infants detect temporal and spatial correspondences between events involving their own body and visual events. what the present study adds until 4-5 months of age, infants mostly produce general motor responses to localized touch. this is because in the present study, infants could not rely on immediate contingent feedback. we propose a cephalocaudal developmental trend of topographic differentiation of body areas. © 2017 The Authors British Journal of Developmental Psychology published by John Wiley & Sons Ltd on behalf of British Psychological Society.

SIGMAR1 mutation associated with autosomal recessive Silver-like syndrome

PubMed Central

Horga, Alejandro; Tomaselli, Pedro J.; Gonzalez, Michael A.; Laurà, Matilde; Muntoni, Francesco; Manzur, Adnan Y.; Hanna, Michael G.; Blake, Julian C.; Houlden, Henry; Züchner, Stephan

2016-01-01

Objective: To describe the genetic and clinical features of a simplex patient with distal hereditary motor neuropathy (dHMN) and lower limb spasticity (Silver-like syndrome) due to a mutation in the sigma nonopioid intracellular receptor–1 gene (SIGMAR1) and review the phenotypic spectrum of mutations in this gene. Methods: We used whole-exome sequencing to investigate the proband. The variants of interest were investigated for segregation in the family using Sanger sequencing. Subsequently, a larger cohort of 16 unrelated dHMN patients was specifically screened for SIGMAR1 mutations. Results: In the proband, we identified a homozygous missense variant (c.194T>A, p.Leu65Gln) in exon 2 of SIGMAR1 as the probable causative mutation. Pathogenicity is supported by evolutionary conservation, in silico analyses, and the strong phenotypic similarities with previously reported cases carrying coding sequence mutations in SIGMAR1. No other mutations were identified in 16 additional patients with dHMN. Conclusions: We suggest that coding sequence mutations in SIGMAR1 present clinically with a combination of dHMN and pyramidal tract signs, with or without spasticity, in the lower limbs. Preferential involvement of extensor muscles of the upper limbs may be a distinctive feature of the disease. These observations should be confirmed in future studies. PMID:27629094

SIGMAR1 mutation associated with autosomal recessive Silver-like syndrome.

PubMed

Horga, Alejandro; Tomaselli, Pedro J; Gonzalez, Michael A; Laurà, Matilde; Muntoni, Francesco; Manzur, Adnan Y; Hanna, Michael G; Blake, Julian C; Houlden, Henry; Züchner, Stephan; Reilly, Mary M

2016-10-11

To describe the genetic and clinical features of a simplex patient with distal hereditary motor neuropathy (dHMN) and lower limb spasticity (Silver-like syndrome) due to a mutation in the sigma nonopioid intracellular receptor-1 gene (SIGMAR1) and review the phenotypic spectrum of mutations in this gene. We used whole-exome sequencing to investigate the proband. The variants of interest were investigated for segregation in the family using Sanger sequencing. Subsequently, a larger cohort of 16 unrelated dHMN patients was specifically screened for SIGMAR1 mutations. In the proband, we identified a homozygous missense variant (c.194T>A, p.Leu65Gln) in exon 2 of SIGMAR1 as the probable causative mutation. Pathogenicity is supported by evolutionary conservation, in silico analyses, and the strong phenotypic similarities with previously reported cases carrying coding sequence mutations in SIGMAR1. No other mutations were identified in 16 additional patients with dHMN. We suggest that coding sequence mutations in SIGMAR1 present clinically with a combination of dHMN and pyramidal tract signs, with or without spasticity, in the lower limbs. Preferential involvement of extensor muscles of the upper limbs may be a distinctive feature of the disease. These observations should be confirmed in future studies. © 2016 American Academy of Neurology.

Expanding the mutation and clinical spectrum of Roberts syndrome.

PubMed

Afifi, Hanan H; Abdel-Salam, Ghada M H; Eid, Maha M; Tosson, Angie M S; Shousha, Wafaa Gh; Abdel Azeem, Amira A; Farag, Mona K; Mehrez, Mennat I; Gaber, Khaled R

2016-07-01

Roberts syndrome and SC phocomelia syndrome are rare autosomal recessive genetic disorders representing the extremes of the spectrum of severity of the same condition, caused by mutations in ESCO2 gene. We report three new patients with Roberts syndrome from three unrelated consanguineous Egyptian families. All patients presented with growth retardation, mesomelic shortening of the limbs more in the upper than in the lower limbs and microcephaly. Patients were subjected to clinical, cytogenetic and radiologic examinations. Cytogenetic analysis showed the characteristic premature separation of centromeres and puffing of heterochromatic regions. Further, sequencing of the ESCO2 gene identified a novel mutation c.244_245dupCT (p.T83Pfs*20) in one family besides two previously reported mutations c.760_761insA (p.T254Nfs*27) and c.764_765delTT (p.F255Cfs*25). All mutations were in homozygous state, in exon 3. The severity of the mesomelic shortening of the limbs and craniofacial anomalies showed variability among patients. Interestingly, patient 1 had abnormal skin hypopigmentation. Serial fetal ultrasound examinations and measurements of long bones diagnosed two affected fetuses in two of the studied families. A literature review and case comparison was performed. In conclusion, we report a novel ESCO2 mutation and expand the clinical spectrum of Roberts syndrome. © 2015 Japanese Teratology Society.

Linking clinical measurements and kinematic gait patterns of toe-walking using fuzzy decision trees.

PubMed

Armand, Stéphane; Watelain, Eric; Roux, Emmanuel; Mercier, Moïse; Lepoutre, François-Xavier

2007-03-01

Toe-walking is one of the most prevalent gait deviations and has been linked to many diseases. Three major ankle kinematic patterns have been identified in toe-walkers, but the relationships between the causes of toe-walking and these patterns remain unknown. This study aims to identify these relationships. Clearly, such knowledge would increase our understanding of this gait deviation, and could help clinicians plan treatment. The large quantity of data provided by gait analysis often makes interpretation a difficult task. Artificial intelligence techniques were used in this study to facilitate interpretation as well as to decrease subjective interpretation. Of the 716 limbs evaluated, 240 showed signs of toe-walking and met inclusion criteria. The ankle kinematic pattern of the evaluated limbs during gait was assigned to one of three toe-walking pattern groups to build the training data set. Toe-walker clinical measurements (range of movement, muscle spasticity and muscle strength) were coded in fuzzy modalities, and fuzzy decision trees were induced to create intelligible rules allowing toe-walkers to be assigned to one of the three groups. A stratified 10-fold cross validation situated the classification accuracy at 81%. Twelve rules depicting the causes of toe-walking were selected, discussed and characterized using kinematic, kinetic and EMG charts. This study proposes an original approach to linking the possible causes of toe-walking with gait patterns.

B4GALNT2 (GALGT2) Gene Therapy Reduces Skeletal Muscle Pathology in the FKRP P448L Mouse Model of Limb Girdle Muscular Dystrophy 2I.

PubMed

Thomas, Paul J; Xu, Rui; Martin, Paul T

2016-09-01

Overexpression of B4GALNT2 (previously GALGT2) inhibits the development of muscle pathology in mouse models of Duchenne muscular dystrophy, congenital muscular dystrophy 1A, and limb girdle muscular dystrophy 2D. In these models, muscle GALGT2 overexpression induces the glycosylation of α dystroglycan with the cytotoxic T cell glycan and increases the overexpression of dystrophin and laminin α2 surrogates known to inhibit disease. Here, we show that GALGT2 gene therapy significantly reduces muscle pathology in FKRP P448Lneo(-) mice, a model for limb girdle muscular dystrophy 2I. rAAVrh74.MCK.GALGT2-treated FKRP P448Lneo(-) muscles showed reduced levels of centrally nucleated myofibers, reduced variance, increased size of myofiber diameters, reduced myofiber immunoglobulin G uptake, and reduced muscle wasting at 3 and 6 months after treatment. GALGT2 overexpression in FKRP P448Lneo(-) muscles did not cause substantial glycosylation of α dystroglycan with the cytotoxic T cell glycan or increased expression of dystrophin and laminin α2 surrogates in mature skeletal myofibers, but it increased the number of embryonic myosin-positive regenerating myofibers. These data demonstrate that GALGT2 overexpression can reduce the extent of muscle pathology in FKRP mutant muscles, but that it may do so via a mechanism that differs from its ability to induce surrogate gene expression. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Finite element analysis of pedestrian lower limb fractures by direct force: the result of being run over or impact?

PubMed

Li, Zhengdong; Zou, Donghua; Liu, Ningguo; Zhong, Liangwei; Shao, Yu; Wan, Lei; Huang, Ping; Chen, Yijiu

2013-06-10

The elucidation and prediction of the biomechanics of lower limb fractures could serve as a useful tool in forensic practices. Finite element (FE) analysis could potentially help in the understanding of the fracture mechanisms of lower limb fractures frequently caused by car-pedestrian accidents. Our aim was (1) to develop and validate a FE model of the human lower limb, (2) to assess the biomechanics of specific injuries concerning run-over and impact loading conditions, and (3) to reconstruct one real car-pedestrian collision case using the model created in this study. We developed a novel lower limb FE model and simulated three different loading scenarios. The geometry of the model was reconstructed using Mimics 13.0 based on computed tomography (CT) scans from an actual traffic accident. The material properties were based upon a synthesis of data found in published literature. The FE model validation and injury reconstruction were conducted using the LS-DYNA code. The FE model was validated by a comparison of the simulation results of three-point bending, overall lateral impact tests and published postmortem human surrogate (PMHS) results. Simulated loading scenarios of running-over the thigh with a wheel, the impact on the upper leg, and impact on the lower thigh were conducted with velocities of 10 m/s, 20 m/s, and 40 m/s, respectively. We compared the injuries resulting from one actual case with the simulated results in order to explore the possible fracture bio-mechanism. The peak fracture forces, maximum bending moments, and energy lost ratio exhibited no significant differences between the FE simulations and the literature data. Under simulated run-over conditions, the segmental fracture pattern was formed and the femur fracture patterns and mechanisms were consistent with the actual injury features of the case. Our study demonstrated that this simulation method could potentially be effective in identifying forensic cases and exploring of the injury mechanisms of lower limb fractures encountered due to inflicted lesions. This model can also help to distinguish between possible and impossible scenarios. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Anatomical Network Comparison of Human Upper and Lower, Newborn and Adult, and Normal and Abnormal Limbs, with Notes on Development, Pathology and Limb Serial Homology vs. Homoplasy

PubMed Central

Diogo, Rui; Esteve-Altava, Borja; Smith, Christopher; Boughner, Julia C.; Rasskin-Gutman, Diego

2015-01-01

How do the various anatomical parts (modules) of the animal body evolve into very different integrated forms (integration) yet still function properly without decreasing the individual’s survival? This long-standing question remains unanswered for multiple reasons, including lack of consensus about conceptual definitions and approaches, as well as a reasonable bias toward the study of hard tissues over soft tissues. A major difficulty concerns the non-trivial technical hurdles of addressing this problem, specifically the lack of quantitative tools to quantify and compare variation across multiple disparate anatomical parts and tissue types. In this paper we apply for the first time a powerful new quantitative tool, Anatomical Network Analysis (AnNA), to examine and compare in detail the musculoskeletal modularity and integration of normal and abnormal human upper and lower limbs. In contrast to other morphological methods, the strength of AnNA is that it allows efficient and direct empirical comparisons among body parts with even vastly different architectures (e.g. upper and lower limbs) and diverse or complex tissue composition (e.g. bones, cartilages and muscles), by quantifying the spatial organization of these parts—their topological patterns relative to each other—using tools borrowed from network theory. Our results reveal similarities between the skeletal networks of the normal newborn/adult upper limb vs. lower limb, with exception to the shoulder vs. pelvis. However, when muscles are included, the overall musculoskeletal network organization of the upper limb is strikingly different from that of the lower limb, particularly that of the more proximal structures of each limb. Importantly, the obtained data provide further evidence to be added to the vast amount of paleontological, gross anatomical, developmental, molecular and embryological data recently obtained that contradicts the long-standing dogma that the upper and lower limbs are serial homologues. In addition, the AnNA of the limbs of a trisomy 18 human fetus strongly supports Pere Alberch's ill-named "logic of monsters" hypothesis, and contradicts the commonly accepted idea that birth defects often lead to lower integration (i.e. more parcellation) of anatomical structures. PMID:26452269

Anatomical Network Comparison of Human Upper and Lower, Newborn and Adult, and Normal and Abnormal Limbs, with Notes on Development, Pathology and Limb Serial Homology vs. Homoplasy.

PubMed

Diogo, Rui; Esteve-Altava, Borja; Smith, Christopher; Boughner, Julia C; Rasskin-Gutman, Diego

2015-01-01

How do the various anatomical parts (modules) of the animal body evolve into very different integrated forms (integration) yet still function properly without decreasing the individual's survival? This long-standing question remains unanswered for multiple reasons, including lack of consensus about conceptual definitions and approaches, as well as a reasonable bias toward the study of hard tissues over soft tissues. A major difficulty concerns the non-trivial technical hurdles of addressing this problem, specifically the lack of quantitative tools to quantify and compare variation across multiple disparate anatomical parts and tissue types. In this paper we apply for the first time a powerful new quantitative tool, Anatomical Network Analysis (AnNA), to examine and compare in detail the musculoskeletal modularity and integration of normal and abnormal human upper and lower limbs. In contrast to other morphological methods, the strength of AnNA is that it allows efficient and direct empirical comparisons among body parts with even vastly different architectures (e.g. upper and lower limbs) and diverse or complex tissue composition (e.g. bones, cartilages and muscles), by quantifying the spatial organization of these parts-their topological patterns relative to each other-using tools borrowed from network theory. Our results reveal similarities between the skeletal networks of the normal newborn/adult upper limb vs. lower limb, with exception to the shoulder vs. pelvis. However, when muscles are included, the overall musculoskeletal network organization of the upper limb is strikingly different from that of the lower limb, particularly that of the more proximal structures of each limb. Importantly, the obtained data provide further evidence to be added to the vast amount of paleontological, gross anatomical, developmental, molecular and embryological data recently obtained that contradicts the long-standing dogma that the upper and lower limbs are serial homologues. In addition, the AnNA of the limbs of a trisomy 18 human fetus strongly supports Pere Alberch's ill-named "logic of monsters" hypothesis, and contradicts the commonly accepted idea that birth defects often lead to lower integration (i.e. more parcellation) of anatomical structures.

Loss and Re-emergence of Legs in Snakes by Modular Evolution of Sonic hedgehog and HOXD Enhancers.

PubMed

Leal, Francisca; Cohn, Martin J

2016-11-07

Limb reduction and loss are hallmarks of snake evolution. Although advanced snakes are completely limbless, basal and intermediate snakes retain pelvic girdles and small rudiments of the femur. Moreover, legs may have re-emerged in extinct snake lineages [1-5], suggesting that the mechanisms of limb development were not completely lost in snakes. Here we report that hindlimb development arrests in python embryos as a result of mutations that abolish essential transcription factor binding sites in the limb-specific enhancer of Sonic hedgehog (SHH). Consequently, SHH transcription is weak and transient in python hindlimb buds, leading to early termination of a genetic circuit that drives limb outgrowth. Our results suggest that degenerate evolution of the SHH limb enhancer played a role in reduction of hindlimbs during snake evolution. By contrast, HOXD digit enhancers are conserved in pythons, and HOXD gene expression in the hindlimb buds progresses to the distal phase, forming an autopodial (digit) domain. Python hindlimb buds then develop transitory pre-chondrogenic condensations of the tibia, fibula, and footplate, raising the possibility that re-emergence of hindlimbs during snake evolution did not require de novo re-evolution of lost structures but instead could have resulted from persistence of embryonic legs. VIDEO ABSTRACT. Copyright © 2016 Elsevier Ltd. All rights reserved.

Finding the neck-trunk boundary in snakes: anteroposterior dissociation of myological characteristics in snakes and its implications for their neck and trunk body regionalization.

PubMed

Tsuihiji, Takanobu; Kearney, Maureen; Rieppel, Olivier

2012-09-01

The neck and trunk regionalization of the presacral musculoskeletal system in snakes and other limb-reduced squamates was assessed based on observations on craniovertebral and body wall muscles. It was confirmed that myological features characterizing the neck in quadrupedal squamates (i.e., squamates with well-developed limbs) are retained in all examined snakes, contradicting the complete lack of the neck in snakes hypothesized in previous studies. However, the posterior-most origins of the craniovertebral muscles and the anterior-most bony attachments of the body wall muscles that are located at around the neck-trunk boundary in quadrupedal squamates were found to be dissociated anteroposteriorly in snakes. Together with results of a recent study that the anterior expression boundaries of Hox genes coinciding with the neck-trunk boundary in quadrupedal amniotes were dissociated anteroposteriorly in a colubrid snake, these observations support the hypothesis that structures usually associated with the neck-trunk boundary in quadrupedal squamates are displaced relative to one another in snakes. Whereas certain craniovertebral muscles are elongated in some snakes, results of optimization on an ophidian cladogram show that the most recent common ancestor of extant snakes would have had the longest craniovertebral muscle, M. rectus capitis anterior, that is elongated only by several segments compared with that of quadrupedal squamates. Therefore, even such a posteriorly displaced "cervical" characteristic plesiomorphically lies fairly anteriorly in the greatly elongated precloacal region of snakes, suggesting that the trunk, not the neck, would have contributed most to the elongation of the snake precloacal region. A similar dissociation of structures usually associated with the neck-trunk boundary in quadrupedal squamates is observed in limb-reduced squamates, suggesting that these forms and snakes may share a developmental mechanism producing modifications in the anterior-posterior patterning associated with body elongation. Copyright © 2012 Wiley Periodicals, Inc.

Flower Development and Perianth Identity Candidate Genes in the Basal Angiosperm Aristolochia fimbriata (Piperales: Aristolochiaceae)

PubMed Central

Pabón-Mora, Natalia; Suárez-Baron, Harold; Ambrose, Barbara A.; González, Favio

2015-01-01

Aristolochia fimbriata (Aristolochiaceae: Piperales) exhibits highly synorganized flowers with a single convoluted structure forming a petaloid perianth that surrounds the gynostemium, putatively formed by the congenital fusion between stamens and the upper portion of the carpels. Here we present the flower development and morphology of A. fimbriata, together with the expression of the key regulatory genes that participate in flower development, particularly those likely controlling perianth identity. A. fimbriata is a member of the magnoliids, and thus gene expression detected for all ABCE MADS-box genes in this taxon, can also help to elucidate patterns of gene expression prior the independent duplications of these genes in eudicots and monocots. Using both floral development and anatomy in combination with the isolation of MADS-box gene homologs, gene phylogenetic analyses and expression studies (both by reverse transcription PCR and in situ hybridization), we present hypotheses on floral organ identity genes involved in the formation of this bizarre flower. We found that most MADS-box genes were expressed in vegetative and reproductive tissues with the exception of AfimSEP2, AfimAGL6, and AfimSTK transcripts that are only found in flowers and capsules but are not detected in leaves. Two genes show ubiquitous expression; AfimFUL that is found in all floral organs at all developmental stages as well as in leaves and capsules, and AfimAG that has low expression in leaves and is found in all floral organs at all stages with a considerable reduction of expression in the limb of anthetic flowers. Our results indicate that expression of AfimFUL is indicative of pleiotropic roles and not of a perianth identity specific function. On the other hand, expression of B-class genes, AfimAP3 and AfimPI, suggests their conserved role in stamen identity and corroborates that the perianth is sepal and not petal-derived. Our data also postulates an AGL6 ortholog as a candidate gene for sepal identity in the Aristolochiaceae and provides testable hypothesis for a modified ABCE model in synorganized magnoliid flowers. PMID:26697047

Upper limb performance and the structuring of joint movement in teenagers with cerebral palsy: the reciprocal role of task demands and action capabilities.

PubMed

Figueiredo, Priscilla Rezende Pereira; Silva, Paula Lanna; Avelar, Bruna Silva; da Fonseca, Sérgio Teixeira; Bootsma, Reinoud J; Mancini, Marisa Cotta

2015-04-01

Individuals with unilateral cerebral palsy (CP) demonstrate reduced performance in upper limb tasks compared to typically developing (TD) peers. We examined whether task conditions modify differences between teenagers with and without CP during a reciprocal aiming task. Twenty teenagers (nine CP and 11 TD) moved a pointer between two targets as fast as possible without missing a target. Task conditions were manipulated by changing the targets' size, by modifying the inertial properties of the pointer and by varying the upper limb used to perform the task (preferred/non-affected and non-preferred/affected upper limbs). While compared to TD peers, CP teenagers exhibited lower performance (longer movement times). Such differences were attenuated when the task was performed with the preferred upper limb and when accuracy requirements were less stringent. CP teenagers were not differentially affected by the pointer inertia manipulation. Task conditions not only affected performance but also joint kinematics. CP teenagers revealed less movement at the elbow and more movement at the shoulder when performing the task with their less skilled upper limb. However, both CP and TD teenagers demonstrated a larger contribution of trunk movement when facing more challenging task conditions. The overall pattern of results indicated that the joint kinematics employed by individuals with unilateral CP constituted adaptive responses to task requirements. Thus, the explanation of the effects of unilateral CP on upper limb behavior needs to go beyond a context-indifferent manifestation of the brain injury to include the interaction between task demands and action capabilities.

The Center for Regenerative Biology and Medicine at Mount Desert Island Biological Laboratory

DTIC Science & Technology

2013-06-01

system through in vivo disruption of gene function. 15. SUBJECT TERMS limb regeneration Positional Memory Code Axolotl ...another selection factor to identify those genes that are similarly controlled in both Polypterus and axolotl samples. These comparisons revealed a...sequence IDs among Axolotl and Polypterus contigs that were up-regulated and down regulated greater than 2-fold between 0 and 7 dpa. (Left) The

Mutations in DDR2 Gene Cause SMED with Short Limbs and Abnormal Calcifications

PubMed Central

Bargal, Ruth; Cormier-Daire, Valerie; Ben-Neriah, Ziva; Le Merrer, Martine; Sosna, Jacob; Melki, Judith; Zangen, David H.; Smithson, Sarah F.; Borochowitz, Zvi; Belostotsky, Ruth; Raas-Rothschild, Annick

2009-01-01

Summary The spondylo-meta-epiphyseal dysplasia [SMED] short limb-hand type [SMED-SL] is a rare autosomal-recessive disease, first reported by Borochowitz et al. in 1993.1 Since then, 14 affected patients have been reported.2–5 We diagnosed 6 patients from 5 different consanguineous Arab Muslim families from the Jerusalem area with SMED-SL. Additionally, we studied two patients from Algerian and Pakistani ancestry and the parents of the first Jewish patients reported.1 Using a homozygosity mapping strategy, we located a candidate region on chromosome 1q23 spanning 2.4 Mb. The position of the Discoidin Domain Receptor 2 (DDR2) gene within the candidate region and the similarity of the ddr2 knockout mouse to the SMED patients' phenotype prompted us to study this gene6. We identified three missense mutations c.2254 C > T [R752C], c. 2177 T > G [I726R], c.2138C > T [T713I] and one splice site mutation [IVS17+1g > a] in the conserved sequence encoding the tyrosine kinase domain of the DDR2 gene. The results of this study will permit an accurate early prenatal diagnosis and carrier screening for families at risk. PMID:19110212

Hydrops fetalis and pulmonary lymphangiectasia due to FOXC2 mutation: an autosomal dominant hereditary lymphedema syndrome with variable expression.

PubMed

de Bruyn, Gwendolyn; Casaer, Alexandra; Devolder, Katrien; Van Acker, Geert; Logghe, Hilde; Devriendt, Koen; Cornette, Luc

2012-03-01

Non-immune hydrops fetalis may find its origin within genetically determined lymphedema syndromes, caused by mutations in FOXC2 and SOX-18. We describe a newborn girl, diagnosed with non-immune hydrops fetalis at a gestational age of 30 weeks. Family history revealed the presence of an autosomal dominant late-onset form of lymphedema of the lower limbs in her father, associated with an aberrant implantation of the eyelashes in some individuals. The newborn, hydropic girl suffered from severe pulmonary lymphangiectasia, resulting in terminal respiratory failure at the age of 3 months. Genetic analysis in both the father and the newborn girl demonstrated a heterozygous FOXC2 mutation, i.e., c.939C>A, p.Tyr313X. Her two older sisters are currently asymptomatic and the parents decided not to test them for the FOXC2 mutation. Patients with a mutation in the FOXC2 transcription factor usually show lower limb lymphedema with onset at or after puberty, together with distichiasis. However, the eye manifestations can be very mild and easily overlooked. The association between FOXC2 mutation and neonatal hydrops resulting in terminal respiratory failure is not reported so far. Therefore, in sporadic patients diagnosed with non-immune hydrops fetalis, lymphangiogenic genes should be systematically screened for mutations. In addition, all cases of fetal edema must prompt a thorough analysis of the familial pedigree, in order to detect familial patterns and to facilitate adequate antenatal counseling.

A matter of life or limb? A review of traumatic injury patterns and anesthesia techniques for disaster relief after major earthquakes.

PubMed

Missair, Andres; Pretto, Ernesto A; Visan, Alexandru; Lobo, Laila; Paula, Frank; Castillo-Pedraza, Catalina; Cooper, Lebron; Gebhard, Ralf E

2013-10-01

All modalities of anesthetic care, including conscious sedation, general, and regional anesthesia, have been used to manage earthquake survivors who require urgent surgical intervention during the acute phase of medical relief. Consequently, we felt that a review of epidemiologic data from major earthquakes in the context of urgent intraoperative management was warranted to optimize anesthesia disaster preparedness for future medical relief operations. The primary outcome measure of this study was to identify the predominant preoperative injury pattern (anatomic location and pathology) of survivors presenting for surgical care immediately after major earthquakes during the acute phase of medical relief (0-15 days after disaster). The injury pattern is of significant relevance because it closely relates to the anesthetic techniques available for patient management. We discuss our findings in the context of evidence-based strategies for anesthetic management during the acute phase of medical relief after major earthquakes and the associated obstacles of devastated medical infrastructure. To identify reports on acute medical care in the aftermath of natural disasters, a query was conducted using MEDLINE/PubMed, Embase, CINAHL, as well as an online search engine (Google Scholar). The search terms were "disaster" and "earthquake" in combination with "injury," "trauma," "surgery," "anesthesia," and "wounds." Our investigation focused only on studies of acute traumatic injury that specified surgical intervention among survivors in the acute phase of medical relief. A total of 31 articles reporting on 15 major earthquakes (between 1980 and 2010) and the treatment of more than 33,410 patients met our specific inclusion criteria. The mean incidence of traumatic limb injury per major earthquake was 68.0%. The global incidence of traumatic limb injury was 54.3% (18,144/33,410 patients). The pooled estimate of the proportion of limb injuries was calculated to be 67.95%, with a 95% confidence interval of 62.32% to 73.58%. Based on this analysis, early disaster surgical intervention will focus on surviving patients with limb injury. All anesthetic techniques have been safely used for medical relief. While regional anesthesia may be an intuitive choice based on these findings, in the context of collapsed medical infrastructure, provider experience may dictate the available anesthetic techniques for earthquake survivors requiring urgent surgery.

A comparison of hemisphere-specific training pattern in Inter-limb Learning Transfer (ILT) for stroke patients with hemiparesis.

PubMed

Yoo, In-gyu; Jung, Min-ye; Yoo, Eun-young; Park, Ji-hyuk; Kang, Dae-hyuk; Lee, Jin

2014-01-01

Stroke patients have major problems with impaired upper-extremity function. Unfortunately, many patients do not experience a full recovery from movement deficits in the upper extremities. The purpose of this study was to compare the effectiveness of inter-limb learning transfer (ILT) to the contralateral upper limb after both hemisphere-specific and -unspecific ipsilateral upper limb training for stroke patients with hemiparesis. Twenty-four stroke patients with hemiparesis participated. The hemisphere-specific training group performed reaching movements in a customized training setting in which non-dominant limb training participants began from a single starting location and proceeded to one of three target locations (1S3T condition); the dominant limb training participants started from one of three starting locations and proceeded to a single target location (3S1T condition). The hemisphere-unspecific training group performed these movements starting under reverse-start and target conditions. The non-dominant to dominant limb transfer, the hemisphere-specific training group performance time decreased significantly as compared with the pre-training session (p < 0.05). Also, the isolation contraction ratio was decreased significantly from that of the pre-training session in the biceps brachii muscles and increased significantly in the upper trapezius muscles (p < 0.05). And, dominant to non-dominant limb transfer in the hemisphere-specific training group significantly increased RMS amplitudes from the pre-training session in the biceps brachii and triceps muscles (p < 0.05). Also, the isolation contraction ratio was increased significantly from that of the pre-training session in the biceps brachii muscles and decreased significantly in the upper trapezius muscles (p < 0.05). However, the hemisphere-unspecific training group showed no significant differences in inter-limb learning transfer (ILT). The transfer of hemisphere-specific training from one arm to the other had a more positive influence on functional recovery than did hemisphere-unspecific training for patients with stroke and hemiparesis.

ASSOCIATION BETWEEN LONG-TERM QUADRICEPS WEAKNESS AND EARLY WALKING MUSCLE CO-CONTRACTION AFTER TOTAL KNEE ARTHROPLASTY

PubMed Central

Yoshida, Yuri; Mizner, Ryan L.; Snyder-Mackler, Lynn

2013-01-01

INTRODUCTION Quadriceps weakness is one of the primary post-operative impairments that persist long term for patients after total knee arthroplasty (TKA). We hypothesized that early gait muscle recruitment patterns of the quadriceps and hamstrings with diminished knee performance at 3 months after surgery would be related to long-term quadriceps strength at one year after TKA. METHODS Twenty-one subjects who underwent primary unilateral TKA and 14 age-matched healthy controls were analyzed. At three months after TKA, the maximum voluntary isometric contraction of quadriceps and a comprehensive gait analysis were performed. Quadriceps strength was assessed again at one year after surgery. RESULTS Quadriceps muscle recruitment of the operated limb was greater than the non-operated limb during the loading response of gait (p=0.03), but there were no significant differences in hamstring recruitment or co-contraction between limbs (p>0.05). There were significant differences in quadriceps muscle recruitment during gait between the non-operated limb of TKA group and healthy control group (p<0.05). The TKA group showed a significant inverse relationship between one year quadriceps strength and co-contraction (r = −0.543) and hamstring muscle recruitment (r = −0.480) during loading response at 3 months after TKA. CONCLUSIONS The results revealed a reverse relationship where stronger patients tended to demonstrate lower quadriceps recruitment at 3 months post-surgery that was not observed in the healthy peer group. The altered neuromuscular patterns of quadriceps and hamstrings during gait may influence chronic quadriceps strength in individuals after TKA. PMID:23352711

Mutation of Growth Arrest Specific 8 Reveals a Role in Motile Cilia Function and Human Disease

PubMed Central

Lewis, Wesley R.; Malarkey, Erik B.; Tritschler, Douglas; Bower, Raqual; Pasek, Raymond C.; Porath, Jonathan D.; Birket, Susan E.; Saunier, Sophie; Antignac, Corinne; Leigh, Margaret W.; Zariwala, Maimoona A.; Drummond, Iain A.; Parant, John M.; Hildebrandt, Friedhelm; Yoder, Bradley K.

2016-01-01

Ciliopathies are genetic disorders arising from dysfunction of microtubule-based cellular appendages called cilia. Different cilia types possess distinct stereotypic microtubule doublet arrangements with non-motile or ‘primary’ cilia having a 9+0 and motile cilia have a 9+2 array of microtubule doublets. Primary cilia are critical sensory and signaling centers needed for normal mammalian development. Defects in their structure/function result in a spectrum of clinical and developmental pathologies including abnormal neural tube and limb patterning. Altered patterning phenotypes in the limb and neural tube are due to perturbations in the hedgehog (Hh) signaling pathway. Motile cilia are important in fluid movement and defects in motility result in chronic respiratory infections, altered left-right asymmetry, and infertility. These features are the hallmarks of Primary Ciliary Dyskinesia (PCD, OMIM 244400). While mutations in several genes are associated with PCD in patients and animal models, the genetic lesion in many cases is unknown. We assessed the in vivo functions of Growth Arrest Specific 8 (GAS8). GAS8 shares strong sequence similarity with the Chlamydomonas Nexin-Dynein Regulatory Complex (NDRC) protein 4 (DRC4) where it is needed for proper flagella motility. In mammalian cells, the GAS8 protein localizes not only to the microtubule axoneme of motile cilia, but also to the base of non-motile cilia. Gas8 was recently implicated in the Hh signaling pathway as a regulator of Smoothened trafficking into the cilium. Here, we generate the first mouse with a Gas8 mutation and show that it causes severe PCD phenotypes; however, there were no overt Hh pathway phenotypes. In addition, we identified two human patients with missense variants in Gas8. Rescue experiments in Chlamydomonas revealed a subtle defect in swim velocity compared to controls. Further experiments using CRISPR/Cas9 homology driven repair (HDR) to generate one of these human missense variants in mice demonstrated that this allele is likely pathogenic. PMID:27472056

Mutation of Growth Arrest Specific 8 Reveals a Role in Motile Cilia Function and Human Disease.

PubMed

Lewis, Wesley R; Malarkey, Erik B; Tritschler, Douglas; Bower, Raqual; Pasek, Raymond C; Porath, Jonathan D; Birket, Susan E; Saunier, Sophie; Antignac, Corinne; Knowles, Michael R; Leigh, Margaret W; Zariwala, Maimoona A; Challa, Anil K; Kesterson, Robert A; Rowe, Steven M; Drummond, Iain A; Parant, John M; Hildebrandt, Friedhelm; Porter, Mary E; Yoder, Bradley K; Berbari, Nicolas F

2016-07-01

Ciliopathies are genetic disorders arising from dysfunction of microtubule-based cellular appendages called cilia. Different cilia types possess distinct stereotypic microtubule doublet arrangements with non-motile or 'primary' cilia having a 9+0 and motile cilia have a 9+2 array of microtubule doublets. Primary cilia are critical sensory and signaling centers needed for normal mammalian development. Defects in their structure/function result in a spectrum of clinical and developmental pathologies including abnormal neural tube and limb patterning. Altered patterning phenotypes in the limb and neural tube are due to perturbations in the hedgehog (Hh) signaling pathway. Motile cilia are important in fluid movement and defects in motility result in chronic respiratory infections, altered left-right asymmetry, and infertility. These features are the hallmarks of Primary Ciliary Dyskinesia (PCD, OMIM 244400). While mutations in several genes are associated with PCD in patients and animal models, the genetic lesion in many cases is unknown. We assessed the in vivo functions of Growth Arrest Specific 8 (GAS8). GAS8 shares strong sequence similarity with the Chlamydomonas Nexin-Dynein Regulatory Complex (NDRC) protein 4 (DRC4) where it is needed for proper flagella motility. In mammalian cells, the GAS8 protein localizes not only to the microtubule axoneme of motile cilia, but also to the base of non-motile cilia. Gas8 was recently implicated in the Hh signaling pathway as a regulator of Smoothened trafficking into the cilium. Here, we generate the first mouse with a Gas8 mutation and show that it causes severe PCD phenotypes; however, there were no overt Hh pathway phenotypes. In addition, we identified two human patients with missense variants in Gas8. Rescue experiments in Chlamydomonas revealed a subtle defect in swim velocity compared to controls. Further experiments using CRISPR/Cas9 homology driven repair (HDR) to generate one of these human missense variants in mice demonstrated that this allele is likely pathogenic.

Genetic analysis in a variant of limb girdle muscular dystrophy in an inbred aboriginal community

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greenberg, C.R.; Nylen, E.G.; Halliday, W.

1994-09-01

Limb girdle muscular dystrophy (LGMD) is a heterogeneous group of disorders with variable inheritance patterns, age-of-onset, rates of progression and patterns of muscle involvement. To date, 4 different chromosomal assignments have been described; LGMD1 to chromosome 5q, LGMD2 to chromosome 15q, SCARMD to chromosome 13q and a fourth locus on chromosome 2p. Because of this genetic heterogeneity, only large unambiguous multiplex families which are clearly linked to a particular locus can be utilized in a genetic analysis. We now report preliminary findings in a large highly inbred aboriginal kindred with 8 probands (5 females, 3 males) from 6 nuclear familiesmore » with a progressive LMD. All presented in their mid- to late teens with gait disturbances. At time of presentation all except one had both proximal as well as distal muscle involvement, facial muscle sparing, CK levels 25 to 100 times normal (3762-20,400 U/l), dystrophic muscle biopsies and normal dystrophin and dystrophin-associated glycoprotein expression. We have studied the segregation of highly informative microsatellite markers for FBN1, D15S132 and the gene for thrombospondin on chromosome 15q and D2S134, D2S136, D2S147, and D2S166 on chromosome 2. Linkage to chromosome 15q has been excluded and two-point lod scores are not significant as yet to either confirm or exclude linkage to chromosome 2p. However, visual inspection reveals that affected individuals are not consistently homozygous for the chromosome 2p markers as would be predicted in such an inbred population. Clinically, SCARMD is unlikely and if the locus on chromosomes 2p and 5q can also be excluded, a genome-wide search using evenly spaced microsatellites will be initiated. A second geographically distinct aboriginal kindred with a similar clinical phenotype has now also been identified.« less

Flexible kinesthetic distance perception: when do your arms tell you how far you have walked?

PubMed

Harrison, Steven J; Kuznetsov, Nikita; Breheim, Samuel

2013-01-01

Given the flexible organization of locomotion evidenced in the many ways the limbs can be coordinated, the authors explored the potentially correspondingly flexible organization of nonvisual (kinesthetic) distance perception. As kinesthetic distance perception is known to be affected by how the limbs are coordinated, the authors probed the potential perceptual contribution of the arms during locomotion by manipulating arm-leg coordination patterns in blind-walked distance-matching tasks. Whereas manipulation of arm-leg coordination for walking with free-swinging arms had no observable perceptual consequences, comparable manipulation for walking with hiking poles did affect distance matching. These results suggest that under conditions in which the arms act to propel the body (e.g., crawling or stair-climbing) a person's nonvisual sense of movement is conveyed in the coordinated actions of all four limbs.

Lower limb ischaemia in patients with diabetic foot ulcers and gangrene: recognition, anatomic patterns and revascularization strategies.

PubMed

Mills, Joseph L

2016-01-01

The confluence of several chronic conditions--in particular ageing, peripheral artery disease, diabetes, and chronic kidney disease--has created a global wave of lower limbs at risk for major amputation. While frequently asymptomatic or not lifestyle limiting, at least 1% of the population has peripheral artery disease of sufficient severity to be limb threatening. To avoid the critical error of failing to diagnose ischaemia, all patients with diabetic foot ulcers and gangrene should routinely undergo physiologic evaluation of foot perfusion. Ankle brachial index is useful when measurable, but may be falsely elevated or not obtainable in as many as 30% of patients with diabetic foot ulcers primarily because of medial calcinosis. Toe pressures and skin perfusion pressures are applicable to such patients. Copyright © 2016 John Wiley & Sons, Ltd.

Muscle Synergies Heavily Influence the Neural Control of Arm Endpoint Stiffness and Energy Consumption

PubMed Central

Inouye, Joshua M.; Valero-Cuevas, Francisco J.

2016-01-01

Much debate has arisen from research on muscle synergies with respect to both limb impedance control and energy consumption. Studies of limb impedance control in the context of reaching movements and postural tasks have produced divergent findings, and this study explores whether the use of synergies by the central nervous system (CNS) can resolve these findings and also provide insights on mechanisms of energy consumption. In this study, we phrase these debates at the conceptual level of interactions between neural degrees of freedom and tasks constraints. This allows us to examine the ability of experimentally-observed synergies—correlated muscle activations—to control both energy consumption and the stiffness component of limb endpoint impedance. In our nominal 6-muscle planar arm model, muscle synergies and the desired size, shape, and orientation of endpoint stiffness ellipses, are expressed as linear constraints that define the set of feasible muscle activation patterns. Quadratic programming allows us to predict whether and how energy consumption can be minimized throughout the workspace of the limb given those linear constraints. We show that the presence of synergies drastically decreases the ability of the CNS to vary the properties of the endpoint stiffness and can even preclude the ability to minimize energy. Furthermore, the capacity to minimize energy consumption—when available—can be greatly affected by arm posture. Our computational approach helps reconcile divergent findings and conclusions about task-specific regulation of endpoint stiffness and energy consumption in the context of synergies. But more generally, these results provide further evidence that the benefits and disadvantages of muscle synergies go hand-in-hand with the structure of feasible muscle activation patterns afforded by the mechanics of the limb and task constraints. These insights will help design experiments to elucidate the interplay between synergies and the mechanisms of learning, plasticity, versatility and pathology in neuromuscular systems. PMID:26867014

Characterizing sampling and quality screening biases in infrared and microwave limb sounding

NASA Astrophysics Data System (ADS)

Millán, Luis F.; Livesey, Nathaniel J.; Santee, Michelle L.; von Clarmann, Thomas

2018-03-01

This study investigates orbital sampling biases and evaluates the additional impact caused by data quality screening for the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) and the Aura Microwave Limb Sounder (MLS). MIPAS acts as a proxy for typical infrared limb emission sounders, while MLS acts as a proxy for microwave limb sounders. These biases were calculated for temperature and several trace gases by interpolating model fields to real sampling patterns and, additionally, screening those locations as directed by their corresponding quality criteria. Both instruments have dense uniform sampling patterns typical of limb emission sounders, producing almost identical sampling biases. However, there is a substantial difference between the number of locations discarded. MIPAS, as a mid-infrared instrument, is very sensitive to clouds, and measurements affected by them are thus rejected from the analysis. For example, in the tropics, the MIPAS yield is strongly affected by clouds, while MLS is mostly unaffected. The results show that upper-tropospheric sampling biases in zonally averaged data, for both instruments, can be up to 10 to 30 %, depending on the species, and up to 3 K for temperature. For MIPAS, the sampling reduction due to quality screening worsens the biases, leading to values as large as 30 to 100 % for the trace gases and expanding the 3 K bias region for temperature. This type of sampling bias is largely induced by the geophysical origins of the screening (e.g. clouds). Further, analysis of long-term time series reveals that these additional quality screening biases may affect the ability to accurately detect upper-tropospheric long-term changes using such data. In contrast, MLS data quality screening removes sufficiently few points that no additional bias is introduced, although its penetration is limited to the upper troposphere, while MIPAS may cover well into the mid-troposphere in cloud-free scenarios. We emphasize that the results of this study refer only to the representativeness of the respective data, not to their intrinsic quality.

Leg and trunk muscle coordination and postural sway during increasingly difficult standing balance tasks in young and older adults.

PubMed

Donath, Lars; Kurz, Eduard; Roth, Ralf; Zahner, Lukas; Faude, Oliver

2016-09-01

Ageing impairs body balance and increases older adults' fall risk. Balance training can improve intrinsic fall risk factors. However, age comparisons of muscle activity responses during balance tasks are lacking. This study investigated relative muscle activity, muscle coordination and postural sway during various recommended static balance training tasks. Muscle activity (%MVC), amplitude ratios (AR) and co-activity (CAI) were determined during standing tasks for 30s (1: double limb stance on a foam surface, eyes open; 2: double limb stance on firm ground, eyes closed; 3: double limb stance, feet in step position on a foam surface, eyes open; 4: double limb stance, feet in step position on firm ground, eyes closed; 5: single limb stance on firm ground, eyes open) in 20 healthy young adults (24±2 y) and 20 older adults (73±6 y). Surface electromyography (SEMG) was applied (SENIAM guidelines) to ankle (tibialis anterior, soleus, medial gastrocnemius, peroneus longus) and thigh (vastus lateralis, vastus medialis, biceps femoris, semitendinosus) muscles (non-dominant leg). Electrodes over trunk (multifidus and internal oblique) muscles were applied bilaterally. Two- to six-fold higher levels of relative muscle activity were found in older adults for ankle (0.0002

Split-arm swinging: the effect of arm swinging manipulation on interlimb coordination during walking.

PubMed

Bondi, Moshe; Zeilig, Gabi; Bloch, Ayala; Fasano, Alfonso; Plotnik, Meir

2017-08-01

Human locomotion is defined by bilateral coordination of gait (BCG) and shared features with the fore-hindlimb coordination of quadrupeds. The objective of the present study is to explore the influence of arm swinging (AS) on BCG. Sixteen young, healthy individuals (eight women; eight right motor-dominant, eight left-motor dominant) participated. Participants performed 10 walking trials (2 min). In each of the trials AS was unilaterally manipulated (e.g., arm restriction, weight on the wrist), bilaterally manipulated, or not manipulated. The order of trials was random. Walking trials were performed on a treadmill. Gait kinematics were recorded by a motion capture system. Using feedback-controlled belt speed allowed the participants to walk at a self-determined gait speed. Effects of the manipulations were assessed by AS amplitudes and the phase coordination index (PCI), which quantifies the left-right anti-phased stepping pattern. Most of the AS manipulations caused an increase in PCI values (i.e., reduced lower limb coordination). Unilateral AS manipulation had a reciprocal effect on the AS amplitude of the other arm such that, for example, over-swinging of the right arm led to a decrease in the AS amplitude of the left arm. Side of motor dominance was not found to have a significant impact on PCI and AS amplitude. The present findings suggest that lower limb BCG is markedly influenced by the rhythmic AS during walking. It may thus be important for gait rehabilitation programs targeting BCG to take AS into account. NEW & NOTEWORTHY Control mechanisms for four-limb coordination in human locomotion are not fully known. To study the influence of arm swinging (AS) on bilateral coordination of the lower limbs during walking, we introduced a split-AS paradigm in young, healthy adults. AS manipulations caused deterioration in the anti-phased stepping pattern and impacted the AS amplitudes for the contralateral arm, suggesting that lower limb coordination is markedly influenced by the rhythmic AS during walking. Copyright © 2017 the American Physiological Society.

Muscle Synergies Heavily Influence the Neural Control of Arm Endpoint Stiffness and Energy Consumption.

PubMed

Inouye, Joshua M; Valero-Cuevas, Francisco J

2016-02-01

Much debate has arisen from research on muscle synergies with respect to both limb impedance control and energy consumption. Studies of limb impedance control in the context of reaching movements and postural tasks have produced divergent findings, and this study explores whether the use of synergies by the central nervous system (CNS) can resolve these findings and also provide insights on mechanisms of energy consumption. In this study, we phrase these debates at the conceptual level of interactions between neural degrees of freedom and tasks constraints. This allows us to examine the ability of experimentally-observed synergies--correlated muscle activations--to control both energy consumption and the stiffness component of limb endpoint impedance. In our nominal 6-muscle planar arm model, muscle synergies and the desired size, shape, and orientation of endpoint stiffness ellipses, are expressed as linear constraints that define the set of feasible muscle activation patterns. Quadratic programming allows us to predict whether and how energy consumption can be minimized throughout the workspace of the limb given those linear constraints. We show that the presence of synergies drastically decreases the ability of the CNS to vary the properties of the endpoint stiffness and can even preclude the ability to minimize energy. Furthermore, the capacity to minimize energy consumption--when available--can be greatly affected by arm posture. Our computational approach helps reconcile divergent findings and conclusions about task-specific regulation of endpoint stiffness and energy consumption in the context of synergies. But more generally, these results provide further evidence that the benefits and disadvantages of muscle synergies go hand-in-hand with the structure of feasible muscle activation patterns afforded by the mechanics of the limb and task constraints. These insights will help design experiments to elucidate the interplay between synergies and the mechanisms of learning, plasticity, versatility and pathology in neuromuscular systems.

Misexpression experiment of Tbx5 in axolotl (Ambystoma mexicanum) hindlimb blastema.

PubMed

Shimokawa, Takashi; Kominami, Rieko; Yasutaka, Satoru; Shinohara, Harumichi

2013-01-01

Axolotls (Ambystoma mexicanum) have the ability to regenerate amputated limbs throughout their life span. In the present study, we attempted to elucidate how axolotls can specify limb type correctly during the regeneration process. We misexpressed Tbx5 in regenerating hindlimb blastema, and consequently a forelimb-like hindlimb regenerated from the hindlimb blastema. On the other hand, no change was observed in Tbx5-overexpressing forelimb blastema, and thus we considered that Tbx5 plays a key role in the specification of forelimb during the regeneration process of axolotl limbs. However, axolotls' fore- and hindlimbs have very similar structures except for the number of fingers, and it was very difficult to judge whether the forelimb-like regenerate was a true forelimb or merely a forelimb-like hindlimb. Therefore, in order to confirm our conclusion, we have to investigate other genes that are expressed differentially between fore- and hindlimbs in future experiments.

Foot speed, foot-strike and footwear: linking gait mechanics and running ground reaction forces.

PubMed

Clark, Kenneth P; Ryan, Laurence J; Weyand, Peter G

2014-06-15

Running performance, energy requirements and musculoskeletal stresses are directly related to the action-reaction forces between the limb and the ground. For human runners, the force-time patterns from individual footfalls can vary considerably across speed, foot-strike and footwear conditions. Here, we used four human footfalls with distinctly different vertical force-time waveform patterns to evaluate whether a basic mechanical model might explain all of them. Our model partitions the body's total mass (1.0 Mb) into two invariant mass fractions (lower limb=0.08, remaining body mass=0.92) and allows the instantaneous collisional velocities of the former to vary. The best fits achieved (R(2) range=0.95-0.98, mean=0.97 ± 0.01) indicate that the model is capable of accounting for nearly all of the variability observed in the four waveform types tested: barefoot jog, rear-foot strike run, fore-foot strike run and fore-foot strike sprint. We conclude that different running ground reaction force-time patterns may have the same mechanical basis. © 2014. Published by The Company of Biologists Ltd.

Intraspecific ecomorphological variation: linear and geometric morphometrics reveal habitat-related patterns within Podarcis bocagei wall lizards.

PubMed

Kaliontzopoulou, Antigoni; Carretero, M A; Llorente, G A

2010-06-01

Morphological variation in relation to habitat is known to occur in several lizard groups. Comparative studies have linked morphology and habitat use, showing that locomotion is the principal mediator of this evolutionary relationship. Here, we investigate intraspecific ecomorphological variation in Podarcis bocagei by examining three habitat types, representing a variety between saxicolous and ground-dwelling habits. Our results indicate variation in absolute and relative limb length, but patterns are only partially concordant to biomechanical predictions. Whereas the femur and hind foot are longer in ground-dwelling lizards, confirming previous observations, the tibia and hind limb are relatively shorter, contradicting expectations. Additionally, head shape varies substantially between habitats, in line with a hypothesis of mechanical restrictions related to microhabitat and refuge use. Finally, we detect male-specific variation between habitats in total body size and head size, providing evidence for interactions between natural and sexual selection. Although performance and behaviour studies are necessary to definitely confirm the functional and evolutionary significance of the observed patterns, our study indicates that ecomorphological adaptations can arise in a very short evolutionary time in this group of lizards.

Reaction-diffusion systems and external morphogen gradients: the two-dimensional case, with an application to skeletal pattern formation.

PubMed

Glimm, Tilmann; Zhang, Jianying; Shen, Yun-Qiu; Newman, Stuart A

2012-03-01

We investigate a reaction-diffusion system consisting of an activator and an inhibitor in a two-dimensional domain. There is a morphogen gradient in the domain. The production of the activator depends on the concentration of the morphogen. Mathematically, this leads to reaction-diffusion equations with explicitly space-dependent terms. It is well known that in the absence of an external morphogen, the system can produce either spots or stripes via the Turing bifurcation. We derive first-order expansions for the possible patterns in the presence of an external morphogen and show how both stripes and spots are affected. This work generalizes previous one-dimensional results to two dimensions. Specifically, we consider the quasi-one-dimensional case of a thin rectangular domain and the case of a square domain. We apply the results to a model of skeletal pattern formation in vertebrate limbs. In the framework of reaction-diffusion models, our results suggest a simple explanation for some recent experimental findings in the mouse limb which are much harder to explain in positional-information-type models.