Establishment of left–right asymmetry in vertebrate development: the node in mouse embryos

PubMed Central

Komatsu, Yoshihiro

2014-01-01

Establishment of vertebrate left–right asymmetry is a critical process for normal embryonic development. After the discovery of genes expressed asymmetrically along the left–right axis in chick embryos in the mid 1990s, the molecular mechanisms responsible for left–right patterning in vertebrate embryos have been studied extensively. In this review article, we discuss the mechanisms by which the initial symmetry along the left–right axis is broken in the mouse embryo. We focus on the role of primary cilia and molecular mechanisms of ciliogenesis at the node when symmetry is broken and left–right asymmetry is established. The node is considered a signaling center for early mouse embryonic development, and the results we review here have led to a better understanding of how the node functions and establishes left–right asymmetry. PMID:23771646

Establishment of left-right asymmetry in vertebrate development: the node in mouse embryos.

PubMed

Komatsu, Yoshihiro; Mishina, Yuji

2013-12-01

Establishment of vertebrate left-right asymmetry is a critical process for normal embryonic development. After the discovery of genes expressed asymmetrically along the left-right axis in chick embryos in the mid 1990s, the molecular mechanisms responsible for left-right patterning in vertebrate embryos have been studied extensively. In this review article, we discuss the mechanisms by which the initial symmetry along the left-right axis is broken in the mouse embryo. We focus on the role of primary cilia and molecular mechanisms of ciliogenesis at the node when symmetry is broken and left-right asymmetry is established. The node is considered a signaling center for early mouse embryonic development, and the results we review here have led to a better understanding of how the node functions and establishes left-right asymmetry.

Studying the effects of microgravity on lower vertebrate development and behavior

NASA Technical Reports Server (NTRS)

Wassersug, Richard J.; Pronych, Scott; Souza, Kenneth A.

1991-01-01

Lower vertebrates have been used in space research for at least 3 decades, and have a number of advantages such as the ability to be maintained safely in space conditions, high development rates, easy observability, and small size. Several major investigations with lower vertebrates are in the flight queue in various countries, and some of this research with amphibians that has Canadian Space Agency sponsorship is reviewed. In connection with NASA's frog embryology experiment, Canadian scientists will conduct postflight experiments on live tadpoles brought back from space to determine whether larvae that develop from these embryos are behaviorally normal. Swimming kinematics in particular will be examined, since a distinctive looping behavior of Xenopus tadpoles under microgravity has been noted. A collaborative study with the Institute of Biomedical Problems in Moscow is designed to elucidate the relationship between buoyancy regulation and lung development in tadpoles, and is scheduled to fly on a Biocosmos satellite in 1992.

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.

Regulative development of Xenopus laevis in microgravity

NASA Technical Reports Server (NTRS)

Black, S.; Larkin, K.; Jacqmotte, N.; Wassersug, R.; Pronych, S.; Souza, K.

1996-01-01

To test whether gravity is required for normal amphibian development, Xenopus leavis females were induced to ovulate aboard the orbiting Space Shuttle. Eggs were fertilized in vitro, and although early embryonic stages showed some abnormalities, the embryos were able to regulate and produce nearly normal larvae. These results demonstrate for the first time that a vertebrate can ovulate in the virtual absence of gravity, and that the eggs can develop to a free-living stage.

Normal development of the female reproductive system

EPA Science Inventory

The embryonic development of the female reproductive system involves a progression of events that is conserved across vertebrate species. The early gonad progresses from a form that is undifferentiated in both genotypic males and females. Rudimentary male (Wolffian) and female (M...

Multi-detector thoracic CT findings in cerebro-costo-mandibular syndrome: rib gaps and failure of costo-vertebral separation.

PubMed

Watson, Tom Anthony; Arthurs, Owen John; Muthialu, Nagarajan; Calder, Alistair Duncan

2014-02-01

Cerebro-costo-mandibular syndrome (CCMS) describes a triad of mandibular hypoplasia, brain dysfunction and posterior rib defects ("rib gaps"). We present the CT imaging for a 2-year-old girl with CCMS that highlights the rib gap defects and shows absent transverse processes with abnormal fusion of the ribs directly to the vertebral bodies. We argue that this is likely to relate to abnormal lateral sclerotome development in embryology, with the failure of normal costo-vertebral junctions compounding impaired thoracic function. The case also highlights the use of CT for specific indications in skeletal dysplasia.

The measurement of the normal thorax using the Haller index methodology at multiple vertebral levels.

PubMed

Archer, James E; Gardner, Adrian; Berryman, Fiona; Pynsent, Paul

2016-10-01

The Haller index is a ratio of thoracic width and height, measured from an axial CT image and used to describe the internal dimensions of the thoracic cage. Although the Haller index for a normal thorax has been established (Haller et al. 1987; Daunt et al. 2004), this is only at one undefined vertebral level in the thorax. What is not clear is how the Haller index describes the thorax at every vertebral level in the absence of sternal deformity, or how this is affected by age. This paper documents the shape of the thorax using the Haller index calculated from the thoracic width and height at all vertebral levels of the thorax between 8 and 18 years of age. The Haller Index changes with vertebral level, with the largest ratio seen in the most cranial levels of the thorax. Increasing age alters the shape of the thorax, with the most cranial vertebral levels having a greater Haller index over the mid thorax, which does not change. A slight increase is seen in the more caudal vertebral levels. These data highlight that a 'one size fits all' rule for chest width and depth ratio at all ages and all thoracic levels is not appropriate. The normal range for width to height ratio should be based on a patient's age and vertebral level. © 2016 Anatomical Society.

[A case of medulla oblongata compression by tortuous vertebral arteries presenting with spastic quadriplegia].

PubMed

Kamada, Takashi; Tateishi, Takahisa; Yamashita, Tamayo; Nagata, Shinji; Ohyagi, Yasumasa; Kira, Jun-Ichi

2013-01-01

We report a 58-year-old man showing spastic paraparesis due to medulla oblongata compression by tortuous vertebral arteries. He noticed weakness of both legs and gait disturbance at the age of 58 years and his symptoms progressively worsened during the following several months. General physical findings were normal. Blood pressure was normal and there were no signs of arteriosclerosis. Neurological examination on admission revealed lower-limb-dominant spasticity in all four extremities, lower-limb weakness, hyperreflexia in all extremities with positive Wartenberg's, Babinski's and Chaddock's signs, mild hypesthesia and hypopallesthesia in both lower limbs, and spastic gait. Cranial nerves were all normal. Serum was negative for antibodies against human T-cell lymphotropic virus-1 antibody. Nerve conduction and needle electromyographic studies of all four limbs revealed normal findings. Cervical, thoracic and lumbo-sacral magnetic resonance imaging (MRI) findings were all normal. Brain MRI and magnetic resonance angiography demonstrated bilateral tortuous vertebral arteries compressing the medulla oblongata. Neurovascular decompression of the right vertebral artery was performed because compression of the right side was more severe than that of the left side. Post-operative MRI revealed outward translocation of the right vertebral artery and relieved compression of the medulla oblongata on the right side. The patient's symptoms and neurological findings improved gradually after the operation. Bilateral pyramidal tract signs without cranial nerve dysfunction due to compression of the medulla oblongata by tortuous vertebral arteries are extremely rare and clinically indistinguishable from hereditary spastic paraplegia (HSP). Although we did not perform a genetic test for HSP, we consider that the spastic paraparesis and mild lower-limb hypesthesia were caused by compression of the medulla oblongata by bilateral tortuous vertebral arteries based on the post-operative improvement in symptoms. Given the favorable effects of surgery, tortuous vertebral arteries should be considered in the differential diagnosis of patients presenting with progressive spastic paraparesis.

Treatment of spinal fractures with paraplegia.

PubMed

Riska, E B; Myllynen, P

1981-01-01

Of 206 patients with vertebral fractures in the thoraco-lumbar spine with spinal cord injuries, an antero-lateral decompression with stabilization of the injured segment of the vertebral column was undertaken in 56 cases. In all these cases there was a compression of the spinal cord from the front. 8 patients made a complete recovery, 31 a good recovery, and 6 were improved. In 8 patients no improvement was noted. 2 patients developed pressure sores later and 1 patient died one year after the operation of uraemia. 22 patients out of 55 got a normal function of the bladder and 25 patients out of 54 a normal function of the anal sphincter. 16 patients out of 17 made a complete or good recovery after removal of a displaced rotated vertebral bony fragment from the spinal canal, and 7 patients out of 9 with wedge shaped fractures. In our clinic today, in cases of vertebral fractures with neural involvement, reduction and internal fixation with Harrington rods and fusion of the injured segment is undertaken as soon as possible, also during the night. If narrowing of the neural canal and compression of the spinal cord are verified, a decompression operation with interbody fusion is undertaken during the next days.

Dissociation of somatic growth from segmentation drives gigantism in snakes.

PubMed

Head, Jason J; David Polly, P

2007-06-22

Body size is significantly correlated with number of vertebrae (pleomerism) in multiple vertebrate lineages, indicating that change in number of body segments produced during somitogenesis is an important factor in evolutionary change in body size, but the role of segmentation in the evolution of extreme sizes, including gigantism, has not been examined. We explored the relationship between body size and vertebral count in basal snakes that exhibit gigantism. Boids, pythonids and the typhlopid genera, Typhlops and Rhinotyphlops, possess a positive relationship between body size and vertebral count, confirming the importance of pleomerism; however, giant taxa possessed fewer than expected vertebrae, indicating that a separate process underlies the evolution of gigantism in snakes. The lack of correlation between body size and vertebral number in giant taxa demonstrates dissociation of segment production in early development from somatic growth during maturation, indicating that gigantism is achieved by modifying development at a different stage from that normally selected for changes in body size.

Abnormal branching and regression of the notochord and its relationship to foregut abnormalities.

PubMed

Vleesch Dubois, V N; Quan Qi, B; Beasley, S W; Williams, A

2002-04-01

An abnormally positioned notochord has been reported in embryos that develop foregut abnormalities, vertebral defects and other abnormalities of the VATER association. This study examines the patterns of regression of the abnormal notochord in the rat model of the VATER association and investigates the relationship between developmental abnormalities of the notochord and those of the vertebra and foregut. Timed-pregnant Sprague-Dawley rats were given daily intraperitoneal injections of 1.75 mg/kg adriamycin on gestational days 6 - 9 inclusive. Rats were sacrificed between days 14 and 20 and their embryos harvested, histologically sectioned and stained and examined serially. The location and appearance of the degenerating notochord and its relationship to regional structural defects were analysed. All 26 embryos exposed to adriamycin developed foregut abnormalities and had an abnormal notochord. The notochord disappeared by a process of apoptotic degeneration that lagged behind that of the normal embryo: the notochord persisted in the abnormal embryo beyond day 17, whereas in the normal rat it had already disappeared. Similarly, formation of the nucleus pulposus was delayed. Vertebral abnormalities occurred when the notochord was ventrally-positioned. The notochord disappears during day 16 in the normal embryo whereas abnormal branches of the notochord persist until day 19 in the adriamycin-treated embryo. Degeneration of the notochord is dominated by apoptosis. An excessively ventrally-placed notochord is closely associated with abnormalities of the vertebral column, especially hemivertebrae.

Expression of Wnt signaling skeletal development genes in the cartilaginous fish, elephant shark (Callorhinchus milii).

PubMed

D'Souza, Damian G; Rana, Kesha; Milley, Kristi M; MacLean, Helen E; Zajac, Jeffrey D; Bell, Justin; Brenner, Sydney; Venkatesh, Byrappa; Richardson, Samantha J; Danks, Janine A

2013-11-01

Jawed vertebrates (Gnasthostomes) are broadly separated into cartilaginous fishes (Chondricthyes) and bony vertebrates (Osteichthyes). Cartilaginous fishes are divided into chimaeras (e.g. ratfish, rabbit fish and elephant shark) and elasmobranchs (e.g. sharks, rays and skates). Both cartilaginous fish and bony vertebrates are believed to have a common armoured bony ancestor (Class Placodermi), however cartilaginous fish are believed to have lost bone. This study has identified and investigated genes involved in skeletal development in vertebrates, in the cartilaginous fish, elephant shark (Callorhinchus milii). Ctnnb1 (β-catenin), Sfrp (secreted frizzled protein) and a single Sost or Sostdc1 gene (sclerostin or sclerostin domain-containing protein 1) were identified in the elephant shark genome and found to be expressed in a number of tissues, including cartilage. β-catenin was also localized in several elephant shark tissues. The expression of these genes, which belong to the Wnt/β-catenin pathway, is required for normal bone formation in mammals. These findings in the cartilaginous skeleton of elephant shark support the hypothesis that the common ancestor of cartilaginous fishes and bony vertebrates had the potential for making bone. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Radiographic liver size in Pekingese dogs versus other dog breeds.

PubMed

Choi, Jihye; Keh, Seoyeon; Kim, Hyunwook; Kim, Junyoung; Yoon, Junghee

2013-01-01

Differential diagnoses for canine liver disease are commonly based on radiographic estimates of liver size, however little has been published on breed variations. Aims of this study were to describe normal radiographic liver size in Pekingese dogs and to compare normal measurements for this breed with other dog breeds and Pekingese dogs with liver disease. Liver measurements were compared for clinically normal Pekingese (n = 61), normal non-Pekingese brachycephalic (n = 45), normal nonbrachycephalic (n = 71), and Pekingese breed dogs with liver disease (n = 22). For each dog, body weight, liver length, T11 vertebral length, thoracic depth, and thoracic width were measured on right lateral and ventrodorsal abdominal radiographs. Liver volume was calculated using a formula and ratios of liver length/T11 vertebral length and liver volume/body weight ratio were determined. Normal Pekingese dogs had a significantly smaller liver volume/body weight ratio (16.73 ± 5.67, P < 0.05) than normal non-Pekingese brachycephalic breed dogs (19.54 ± 5.03) and normal nonbrachycephalic breed dogs (18.72 ± 6.52). The liver length/T11 vertebral length ratio in normal Pekingese (4.64 ± 0.65) was significantly smaller than normal non-Pekingese brachycephalic breed dogs (5.16 ± 0.74) and normal nonbrachycephalic breed dogs (5.40 ± 0.74). Ratios of liver volume/body weight and liver length/T11 vertebral length in normal Pekingese were significantly different from Pekingese with liver diseases (P < 0.05). Findings supported our hypothesis that Pekingese dogs have a smaller normal radiographic liver size than other breeds. We recommend using 4.64× the length of the T11 vertebra as a radiographic criterion for normal liver length in Pekingese dogs. © 2012 Veterinary Radiology & Ultrasound.

Programmed cell death

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

NONE

The purpose of this conference to provide a multidisciplinary forum for exchange of state-of-the-art information on the role programmed cell death plays in normal development and homeostasis of many organisms. This volume contains abstracts of papers in the following areas: invertebrate development; immunology/neurology; bcl-2 family; biochemistry; programmed cell death in viruses; oncogenesis; vertebrate development; and diseases.

REACTIVITY PROFILE OF CONFORMATIONALLY-FLEXIBLE RETINOID RECEPTOR LIGANDS

EPA Science Inventory

Retinoids and associated derivatives represent a class of endogenousr hormones that bind to and activate different families of retinoic acid receptors (RARs, RXRs), and control many aspects of normal vertebrate development. Identification of potential RAR and RXRs ligands is of i...

Estimation of stature from radiologic anthropometry of the lumbar vertebral dimensions in Chinese.

PubMed

Zhang, Kui; Chang, Yun-feng; Fan, Fei; Deng, Zhen-hua

2015-11-01

The recent study was to assess the relationship between the radiologic anthropometry of the lumbar vertebral dimensions and stature in Chinese and to develop regression formulae to estimate stature from these dimensions. A total of 412 normal, healthy volunteers, comprising 206 males and 206 females, were recruited. The linear regression analysis were performed to assess the correlation between the stature and lengths of various segments of the lumbar vertebral column. Among the regression equations created for single variable, the predictive value was greatest for the reconstruction of stature from the lumbar segment in both sexes and subgroup analysis. When individual vertebral body was used, the heights of posterior vertebral body of L3 gave the most accurate results for male group, the heights of central vertebral body of L1 provided the most accurate results for female group and female group with age above 45 years, the heights of central vertebral body of L3 gave the most accurate results for the groups with age from 20-45 years for both sexes and the male group with age above 45 years. The heights of anterior vertebral body of L5 gave the less accurate results except for the heights of anterior vertebral body of L4 provided the less accurate result for the male group with age above 45 years. As expected, multiple regression equations were more successful than equations derived from a single variable. The research observations suggest lumbar vertebral dimensions to be useful in stature estimation among Chinese population. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Structural and functional characteristics of the thoracolumbar multifidus muscle in horses.

PubMed

García Liñeiro, J A; Graziotti, G H; Rodríguez Menéndez, J M; Ríos, C M; Affricano, N O; Victorica, C L

2017-03-01

The multifidus muscle fascicles of horses attach to vertebral spinous processes after crossing between one to six metameres. The fascicles within one or two metameres are difficult to distinguish in horses. A vertebral motion segment is anatomically formed by two adjacent vertebrae and the interposed soft tissue structures, and excessive mobility of a vertebral motion segment frequently causes osteoarthropathies in sport horses. The importance of the equine multifidus muscle as a vertebral motion segment stabilizer has been demonstrated; however, there is scant documentation of the structure and function of this muscle. By studying six sport horses postmortem, the normalized muscle fibre lengths of the the multifidus muscle attached to the thoracic (T)4, T9, T12, T17 and lumbar (L)3 vertebral motion segments were determined and the relative areas occupied by fibre types I, IIA and IIX were measured in the same muscles after immunohistochemical typying. The values for the normalized muscle fibre lengths and the relative areas were analysed as completely randomized blocks using an anova (P ≤ 0.05). The vertebral motion segments of the T4 vertebra include multifidus bundles extending between two and eight metameres; the vertebral motion segments of the T9, T12, T17 and L3 vertebrae contain fascicles extending between two and four metameres The muscle fibres with high normalized lengths that insert into the T4 (three and eight metameres) vertebral motion segment tend to have smaller physiological cross-sectional areas, indicating their diminished capacity to generate isometric force. In contrast, the significantly decreased normalized muscle fibre lengths and the increased physiological cross-sectional areas of the fascicles of three metameres with insertions on T9, T17, T12, L3 and the fascicles of four metameres with insertions on L3 increase their capacities to generate isometric muscle force and neutralize excessive movements of the vertebral segments with great mobility. There were no significant differences in the values of relative areas occupied by fibre types I, IIA and IIX. In considering the relative areas occupied by the fibre types in the multifidus muscle fascicles attached to each vertebral motion segment examined, the relative area occupied by the type I fibres was found to be significantly higher in the T4 vertebral motion segment than in the other segments. It can be concluded that the equine multifidus muscle in horses is an immunohistochemically homogeneous muscle with various architectural designs that have functional significance according to the vertebral motion segments considered. The results obtained in this study can serve as a basis for future research aimed at understanding the posture and dynamics of the equine spine. © 2016 Anatomical Society.

Sulphated glycosaminoglycans and proteoglycans in the developing vertebral column of juvenile Atlantic salmon (Salmo salar).

PubMed

Hannesson, Kirsten O; Ytteborg, Elisabeth; Takle, Harald; Enersen, Grethe; Bæverfjord, Grete; Pedersen, Mona E

2015-08-01

In the present study, the distribution of sulphated glycosaminoglycans (GAGs) in the developing vertebral column of Atlantic salmon (Salmo salar) at 700, 900, 1100 and 1400 d° was examined by light microscopy. The mineralization pattern was outlined by Alizarin red S and soft structures by Alcian blue. The temporal and spatial distribution patterns of different types of GAGs: chondroitin-4-sulphate/dermatan sulphate, chondroitin-6-sulphate, chondroitin-0-sulphate and keratan sulphate were addressed by immunohistochemistry using monoclonal antibodies against the different GAGs. The specific pattern obtained with the different antibodies suggests a unique role of the different GAG types in pattern formation and mineralization. In addition, the distribution of the different GAG types in normal and malformed vertebral columns from 15 g salmon was compared. A changed expression pattern of GAGs was found in the malformed vertebrae, indicating the involvement of these molecules during the pathogenesis. The molecular size of proteoglycans (PGs) in the vertebrae carrying GAGs was analysed with western blotting, and mRNA transcription of the PGs aggrecan, decorin, biglycan, fibromodulin and lumican by real-time qPCR. Our study reveals the importance of GAGs in development of vertebral column also in Atlantic salmon and indicates that a more comprehensive approach is necessary to completely understand the processes involved.

Magnetic resonance imaging features of Great Danes with and without clinical signs of cervical spondylomyelopathy

PubMed Central

Martin-Vaquero, Paula; da Costa, Ronaldo C.

2014-01-01

Objective To characterize and compare the MRI morphological features of the cervical vertebral column of Great Danes with and without clinical signs of cervical spondylomyelopathy (CSM). Design Prospective cohort study. Animals 30 Great Danes (15 clinically normal and 15 CSM-affected). Procedures All dogs underwent MRI of the cervical vertebral column (C2–3 through T1–2). Features evaluated included sites of subarachnoid space compression, spinal cord compression, or both; degree, cause, and direction of compression; MRI signal changes of the spinal cord; articular process (facet) joint characteristics; internal vertebral venous plexus visibility; and presence of extradural synovial cysts as well as presence and degree of intervertebral disk degeneration and foraminal stenosis. Results Clinically normal and CSM-affected dogs had 11 and 61 compressive sites, respectively, detected with MRI. All CSM-affected dogs had ≥ 1 site of spinal cord compression. No signal changes were observed in spinal cords of normal dogs, whereas 14 sites of hyperintensity were found in 9 CSM-affected dogs. Foraminal stenosis was present in 11 clinically normal and all CSM-affected dogs. The number of stenotic foraminal sites was significantly greater in the CSM-affected group, and severe stenosis appeared to be more common in this group than in the clinically normal group. Significant differences were identified between clinically normal and CSM-affected dogs with regard to amount of synovial fluid evident, regularity of articular surfaces, degree of articular process joint proliferation, and internal vertebral venous plexus visibility. Conclusions and Clinical Relevance Abnormalities were detected with MRI in several clinically normal Great Danes. Severe spinal cord compression, number of stenotic foraminal sites, and signal changes within the spinal cord distinguished CSM-affected from clinically normal Great Danes. PMID:25075822

Magnetic resonance imaging features of Great Danes with and without clinical signs of cervical spondylomyelopathy.

PubMed

Martin-Vaquero, Paula; da Costa, Ronaldo C

2014-08-15

To characterize and compare the MRI morphological features of the cervical vertebral column of Great Danes with and without clinical signs of cervical spondylomyelopathy (CSM). Prospective cohort study. 30 Great Danes (15 clinically normal and 15 CSM-affected). All dogs underwent MRI of the cervical vertebral column (C2-3 through T1-2). Features evaluated included sites of subarachnoid space compression, spinal cord compression, or both; degree, cause, and direction of compression; MRI signal changes of the spinal cord; articular process (facet) joint characteristics; internal vertebral venous plexus visibility; and presence of extradural synovial cysts as well as presence and degree of intervertebral disk degeneration and foraminal stenosis. Clinically normal and CSM-affected dogs had 11 and 61 compressive sites, respectively, detected with MRI. All CSM-affected dogs had ≥ 1 site of spinal cord compression. No signal changes were observed in spinal cords of normal dogs, whereas 14 sites of hyperintensity were found in 9 CSM-affected dogs. Foraminal stenosis was present in 11 clinically normal and all CSM-affected dogs. The number of stenotic foraminal sites was significantly greater in the CSM-affected group, and severe stenosis appeared to be more common in this group than in the clinically normal group. Significant differences were identified between clinically normal and CSM-affected dogs with regard to amount of synovial fluid evident, regularity of articular surfaces, degree of articular process joint proliferation, and internal vertebral venous plexus visibility. Abnormalities were detected with MRI in several clinically normal Great Danes. Severe spinal cord compression, number of stenotic foraminal sites, and signal changes within the spinal cord distinguished CSM-affected from clinically normal Great Danes.

[Cervical cord infarction associated with unilateral vertebral artery dissection due to golf swing].

PubMed

Tokumoto, Kazuki; Ueda, Nobuhiko

2014-01-01

A-68-year-old man experienced nuchal pain and bilateral shoulder weakness that occurred suddenly after he performed a golf swing. He was conscious. His cranial nerves were normal, but bilateral deltoid and biceps muscle strengths weakened. Magnetic resonance image (MRI) showed no brain stem infarctions or cervical epidural hematoma. We tentatively diagnosed him with concussion of the spinal cord because of mild recovery of his bilateral upper limb weakness after several hours; he was later discharged. The next day, he suddenly developed serious tetraplegia and was admitted to the emergency department. His breathing was controlled by a respirator as he had expectoration difficulty and respiratory muscle paralysis. A lesion in the cervical cord became apparent on MRI; the right vertebral artery was not detected on magnetic resonance angiography. Cervical MRI showed the intimal flap and a lack of flow void in the right vertebral artery. These findings revealed a right vertebral artery dissection. Cervical cord infarction due to unilateral vertebral artery dissection is rarer than posterior cerebral infarction due to the same pathogenesis; however, some such cases have been reported. We consider the present case to be caused by cervical cord infarction associated with unilateral vertebral artery dissection resulting from golf swing.

Cartilaginous development of the human craniovertebral junction as visualised by a new three-dimensional computer reconstruction technique.

PubMed

David, K M; McLachlan, J C; Aiton, J F; Whiten, S C; Smart, S D; Thorogood, P V; Crockard, H A

1998-02-01

Serial transverse histological sections of the human craniovertebral junction (CVJ) of 4 normal human embryos (aged 45 to 58 d) and of a fetus (77 d) were used to create 3-dimensional computer models of the CVJ. The main components modelled included the chondrified basioccipital, atlas and axis, notochord, the vertebrobasilar complex and the spinal cord. Chondrification of the component parts of CVJ had already begun at 45 d (Stage 18). The odontoid process appeared to develop from a short eminence of the axis forming a third occipital condyle with the caudal end of the basioccipital. The cartilaginous anterior arch of C1 appeared at 50-53 d (Stages 20-21). Neural arches of C1 and C2 showed gradual closure, but there was still a wide posterior spina bifida in the oldest reconstructed specimen (77 d fetus). The position of the notochord was constant throughout. The normal course of the vertebral arteries was already established and the chondrified vertebral foramina showed progressive closure. The findings confirm that the odontoid process is not derived solely from the centrum of C1 and that there is a 'natural basilar invagination' of C2 during normal embryonic development. On the basis of the observed shape and developmental pattern of structures of the cartilaginous human CVJ, we suggest that certain pathologies are likely to originate during the chondrification phase of development.

Disordered vertebral and rib morphology in pudgy mice. Structural relationships to human scoliosis.

PubMed

Shapiro, Frederic

2016-01-01

Normal and abnormal vertebral development have been studied over the past 200 years at increasing levels of resolution as techniques for biological investigation have improved. Disordered development of the axial skeleton from the early embryonic period on leads to structurally malformed vertebrae and intervertebral discs and ribs causing the severe deformities of scoliosis, kyphosis, and kyphoscoliosis. Developmental malformation of the axial skeleton therefore has led to considerable biological and clinical interest. This work will detail our studies on the structural deformities of the vertebral column and adjacent ribs in the pudgy mouse [1] caused by mutations in the delta-like 3 (Dll3) gene of the Notch family [2]. While gene abnormalities in the pudgy mouse have been outlined, there has been no in-depth assessment of the histopathology of the pudgy vertebral and rib abnormalities that this study will provide. In addition, although congenital scoliosis has been recognized as a clinical problem since the mid-nineteenth century (1800s) [3] and accurately defined by radiography since the early twentieth century (1900s) [4-6], there have been few detailed histopathologic studies of human cases. We will also relate our histopathologic findings in the pudgy mouse to the histopathology of human vertebral and rib malformations in clinical cases of congenital scoliosis, one of which we defined in detail previously [7].

Disruption of the Flnb gene in mice phenocopies the human disease spondylocarpotarsal synostosis syndrome.

PubMed

Farrington-Rock, Claire; Kirilova, Veneta; Dillard-Telm, Lisa; Borowsky, Alexander D; Chalk, Sara; Rock, Matthew J; Cohn, Daniel H; Krakow, Deborah

2008-03-01

Spondylocarpotarsal synostosis syndrome (SCT) is an autosomal recessive disease that is characterized by short stature, and fusions of the vertebrae and carpal and tarsal bones. SCT results from homozygosity or compound heterozygosity for nonsense mutations in FLNB. FLNB encodes filamin B, a multifunctional cytoplasmic protein that plays a critical role in skeletal development. Protein extracts derived from cells of SCT patients with nonsense mutations in FLNB did not contain filamin B, demonstrating that SCT results from absence of filamin B. To understand the role of filamin B in skeletal development, an Flnb-/- mouse model was generated. The Flnb-/- mice were phenotypically similar to individuals with SCT as they exhibited short stature and similar skeletal abnormalities. Newborn Flnb-/- mice had fusions between the neural arches of the vertebrae in the cervical and thoracic spine. At postnatal day 60, the vertebral fusions were more widespread and involved the vertebral bodies as well as the neural arches. In addition, fusions were seen in sternum and carpal bones. Analysis of the Flnb-/- mice phenotype showed that an absence of filamin B causes progressive vertebral fusions, which is contrary to the previous hypothesis that SCT results from failure of normal spinal segmentation. These findings suggest that spinal segmentation can occur normally in the absence of filamin B, but the protein is required for maintenance of intervertebral, carpal and sternal joints, and the joint fusion process commences antenatally.

Analysis of preexistent vertebral rotation in the normal infantile, juvenile, and adolescent spine.

PubMed

Janssen, Michiel M A; Kouwenhoven, Jan-Willem M; Schlösser, Tom P C; Viergever, Max A; Bartels, Lambertus W; Castelein, René M; Vincken, Koen L

2011-04-01

Vertebral rotation was systematically analyzed in the normal, nonscoliotic thoracic spine of children aged 0 to 16 years. Subgroups were created to match the infantile, juvenile, and adolescent age groups according to the criteria of the Scoliosis Research Society. To determine whether a distinct pattern of vertebral rotation in the transverse plane exists in the normal, nonscoliotic infantile, juvenile, and adolescent spine. We assume that, once the spine starts to deteriorate into a scoliotic deformity, it will follow a preexisting rotational pattern. Recently, we identified a rotational pattern in the normal nonscoliotic adult spine that corresponds to the most common curve types in adolescent idiopathic scoliosis. In infantile idiopathic scoliosis, curves are typically left sided and boys are affected more often than girls, whereas in adolescent idiopathic scoliosis, the thoracic curve is typically right sided and predominantly girls are affected. The present study is the first systematic analysis of vertebral rotation in the normal children's spine. Vertebral rotation in the transverse plane of T2-T12 was measured by using a semiautomatic method on 146 computed tomographic scans of children (0-16 years old) without clinical or radiologic evidence of spinal pathology. Scans were mainly made for reasons such as recurrent respiratory tract infections, malignancies, or immune disorders. Vertebral rotational patterns were analyzed in the infantile (0-3-year-old), juvenile (4-9-year-old), and adolescent (10-16-year-old) boys and girls. In the infantile spine, vertebrae T2-T6 were significantly rotated to the left (P < 0.001). In the juvenile spine, T4 was significantly rotated to the left. In the adolescent spine, T6-T12 were significantly rotated to the right (P ≤ 0.001). Rotation to the left was more pronounced in infantile boys than in the girls (P = 0.023). In juvenile and adolescent children, no statistical differences in rotation were found between the sexes. These data support the hypothesis that the direction of the spinal curve in idiopathic scoliosis is determined by the built-in rotational pattern that the spine exhibits at the time of onset. The well-known predominance of right-sided thoracic curves in adolescent idiopathic scoliosis and left-sided curves in infantile idiopathic scoliosis can be explained by the observed patterns of vertebral rotation that preexist at the corresponding age.

Enzymatic Metabolism of Vitamin A in Developing Vertebrate Embryos

PubMed Central

Metzler, Melissa A.; Sandell, Lisa L.

2016-01-01

Embryonic development is orchestrated by a small number of signaling pathways, one of which is the retinoic acid (RA) signaling pathway. Vitamin A is essential for vertebrate embryonic development because it is the molecular precursor of the essential signaling molecule RA. The level and distribution of RA signaling within a developing embryo must be tightly regulated; too much, or too little, or abnormal distribution, all disrupt embryonic development. Precise regulation of RA signaling during embryogenesis is achieved by proteins involved in vitamin A metabolism, retinoid transport, nuclear signaling, and RA catabolism. The reversible first step in conversion of the precursor vitamin A to the active retinoid RA is mediated by retinol dehydrogenase 10 (RDH10) and dehydrogenase/reductase (SDR family) member 3 (DHRS3), two related membrane-bound proteins that functionally activate each other to mediate the interconversion of retinol and retinal. Alcohol dehydrogenase (ADH) enzymes do not contribute to RA production under normal conditions during embryogenesis. Genes involved in vitamin A metabolism and RA catabolism are expressed in tissue-specific patterns and are subject to feedback regulation. Mutations in genes encoding these proteins disrupt morphogenesis of many systems in a developing embryo. Together these observations demonstrate the importance of vitamin A metabolism in regulating RA signaling during embryonic development in vertebrates. PMID:27983671

Dynamic Glycosylation Governs the Vertebrate COPII Protein Trafficking Pathway.

PubMed

Cox, Nathan J; Unlu, Gokhan; Bisnett, Brittany J; Meister, Thomas R; Condon, Brett M; Luo, Peter M; Smith, Timothy J; Hanna, Michael; Chhetri, Abhishek; Soderblom, Erik J; Audhya, Anjon; Knapik, Ela W; Boyce, Michael

2018-01-09

The COPII coat complex, which mediates secretory cargo trafficking from the endoplasmic reticulum, is a key control point for subcellular protein targeting. Because misdirected proteins cannot function, protein sorting by COPII is critical for establishing and maintaining normal cell and tissue homeostasis. Indeed, mutations in COPII genes cause a range of human pathologies, including cranio-lenticulo-sutural dysplasia (CLSD), which is characterized by collagen trafficking defects, craniofacial abnormalities, and skeletal dysmorphology. Detailed knowledge of the COPII pathway is required to understand its role in normal cell physiology and to devise new treatments for disorders in which it is disrupted. However, little is known about how vertebrates dynamically regulate COPII activity in response to developmental, metabolic, or pathological cues. Several COPII proteins are modified by O-linked β-N-acetylglucosamine (O-GlcNAc), a dynamic form of intracellular protein glycosylation, but the biochemical and functional effects of these modifications remain unclear. Here, we use a combination of chemical, biochemical, cellular, and genetic approaches to demonstrate that site-specific O-GlcNAcylation of COPII proteins mediates their protein-protein interactions and modulates cargo secretion. In particular, we show that individual O-GlcNAcylation sites of SEC23A, an essential COPII component, are required for its function in human cells and vertebrate development, because mutation of these sites impairs SEC23A-dependent in vivo collagen trafficking and skeletogenesis in a zebrafish model of CLSD. Our results indicate that O-GlcNAc is a conserved and critical regulatory modification in the vertebrate COPII-dependent trafficking pathway.

A Comparative Study of Vertebrate Corneal Structure: The Evolution of a Refractive Lens

PubMed Central

Winkler, Moritz; Shoa, Golroxan; Tran, Stephanie T.; Xie, Yilu; Thomasy, Sarah; Raghunathan, Vijay K.; Murphy, Christopher; Brown, Donald J.; Jester, James V.

2015-01-01

Purpose. Although corneal curvature plays an important role in determining the refractive power of the vertebrate eye, the mechanisms controlling corneal shape remain largely unknown. To address this question, we performed a comparative study of vertebrate corneal structure to identify potential evolutionarily based changes that correlate with the development of a corneal refractive lens. Methods. Nonlinear optical (NLO) imaging of second-harmonic–generated (SHG) signals was used to image collagen and three-dimensionally reconstruct the lamellar organization in corneas from different vertebrate clades. Results. Second-harmonic–generated images taken normal to the corneal surface showed that corneal collagen in all nonmammalian vertebrates was organized into sheets (fish and amphibians) or ribbons (reptiles and birds) extending from limbus to limbus that were oriented nearly orthogonal (ranging from 77.7°–88.2°) to their neighbors. The slight angular offset (2°–13°) created a rotational pattern that continued throughout the full thickness in fish and amphibians and to the very posterior layers in reptiles and birds. Interactions between lamellae were limited to “sutural” fibers in cartilaginous fish, and occasional lamellar branching in fish and amphibians. There was a marked increase in lamellar branching in higher vertebrates, such that birds ≫ reptiles > amphibians > fish. By contrast, mammalian corneas showed a nearly random collagen fiber organization with no orthogonal, chiral pattern. Conclusions. Our data indicate that nonmammalian vertebrate corneas share a common orthogonal collagen structural organization that shows increased lamellar branching in higher vertebrate species. Importantly, mammalian corneas showed a different structural organization, suggesting a divergent evolutionary background. PMID:26066606

A Comparative Study of Vertebrate Corneal Structure: The Evolution of a Refractive Lens.

PubMed

Winkler, Moritz; Shoa, Golroxan; Tran, Stephanie T; Xie, Yilu; Thomasy, Sarah; Raghunathan, Vijay K; Murphy, Christopher; Brown, Donald J; Jester, James V

2015-04-01

Although corneal curvature plays an important role in determining the refractive power of the vertebrate eye, the mechanisms controlling corneal shape remain largely unknown. To address this question, we performed a comparative study of vertebrate corneal structure to identify potential evolutionarily based changes that correlate with the development of a corneal refractive lens. Nonlinear optical (NLO) imaging of second-harmonic-generated (SHG) signals was used to image collagen and three-dimensionally reconstruct the lamellar organization in corneas from different vertebrate clades. Second-harmonic-generated images taken normal to the corneal surface showed that corneal collagen in all nonmammalian vertebrates was organized into sheets (fish and amphibians) or ribbons (reptiles and birds) extending from limbus to limbus that were oriented nearly orthogonal (ranging from 77.7°-88.2°) to their neighbors. The slight angular offset (2°-13°) created a rotational pattern that continued throughout the full thickness in fish and amphibians and to the very posterior layers in reptiles and birds. Interactions between lamellae were limited to "sutural" fibers in cartilaginous fish, and occasional lamellar branching in fish and amphibians. There was a marked increase in lamellar branching in higher vertebrates, such that birds ≫ reptiles > amphibians > fish. By contrast, mammalian corneas showed a nearly random collagen fiber organization with no orthogonal, chiral pattern. Our data indicate that nonmammalian vertebrate corneas share a common orthogonal collagen structural organization that shows increased lamellar branching in higher vertebrate species. Importantly, mammalian corneas showed a different structural organization, suggesting a divergent evolutionary background.

Postnatal progression of bone disease in the cervical spines of mucopolysaccharidosis I dogs

PubMed Central

Chiaro, Joseph A; Baron, Matthew D; del Alcazar, Chelsea; O’Donnell, Patricia; Shore, Eileen M; Elliott, Dawn M; Ponder, Katherine P; Haskins, Mark E; Smith, Lachlan J

2013-01-01

Introduction Mucopolysaccharidosis I (MPS I) is a lysosomal storage disorder characterized by deficient α-L-iduronidase activity leading to accumulation of poorly degraded dermatan and heparan sulfate glycosaminoglycans (GAGs). MPS I is associated with significant cervical spine disease, including vertebral dysplasia, odontoid hypoplasia, and accelerated disc degeneration, leading to spinal cord compression and kypho-scoliosis. The objective of this study was to establish the nature and rate of progression of cervical vertebral bone disease in MPS I using a canine model. Methods C2 vertebrae were obtained post-mortem from normal and MPS I dogs at 3, 6 and 12 months-of-age. Morphometric parameters and mineral density for the vertebral trabecular bone and odontoid process were determined using micro-computed tomography. Vertebrae were then processed for paraffin histology, and cartilage area in both the vertebral epiphyses and odontoid process were quantified. Results Vertebral bodies of MPS I dogs had lower trabecular bone volume/total volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N) and bone mineral density (BMD) than normals at all ages. For MPS I dogs, BV/TV, Tb.Th and BMD plateaued after 6 months-of-age. The odontoid process appeared morphologically abnormal for MPS I dogs at 6 and 12 months-of-age, although BV/TV and TMD were not significantly different from normals. MPS I dogs had significantly more cartilage in the vertebral epiphyses at both 3 and 6 months-of-age. At 12 months-of-age, epiphyseal growth plates in normal dogs were absent, but in MPS I dogs they persisted. Conclusions In this study we report reduced trabecular bone content and mineralization, and delayed cartilage to bone conversion in MPS I dogs from 3 months-of-age, which may increase vertebral fracture risk and contribute to progressive deformity. The abnormalities of the odontoid process we describe likely contribute to increased incidence of atlanto-axial subluxation observed clinically. Therapeutic strategies that enhance bone formation may decrease incidence of spine disease in MPS I patients. PMID:23563357

Quantitative skeletal evaluation based on cervical vertebral maturation: a longitudinal study of adolescents with normal occlusion.

PubMed

Chen, L; Liu, J; Xu, T; Long, X; Lin, J

2010-07-01

The study aims were to investigate the correlation between vertebral shape and hand-wrist maturation and to select characteristic parameters of C2-C5 (the second to fifth cervical vertebrae) for cervical vertebral maturation determination by mixed longitudinal data. 87 adolescents (32 males, 55 females) aged 8-18 years with normal occlusion were studied. Sequential lateral cephalograms and hand-wrist radiographs were taken annually for 6 consecutive years. Lateral cephalograms were divided into 11 maturation groups according to Fishman Skeletal Maturity Indicators (SMI). 62 morphological measurements of C2-C5 at 11 different developmental stages (SMI1-11) were measured and analysed. Locally weighted scatterplot smoothing, correlation coefficient analysis and variable cluster analysis were used for statistical analysis. Of the 62 cervical vertebral parameters, 44 were positively correlated with SMI, 6 were negatively correlated and 12 were not correlated. The correlation coefficients between cervical vertebral parameters and SMI were relatively high. Characteristic parameters for quantitative analysis of cervical vertebral maturation were selected. In summary, cervical vertebral maturation could be used reliably to evaluate the skeletal stage instead of the hand-wrist radiographic method. Selected characteristic parameters offered a simple and objective reference for the assessment of skeletal maturity and timing of orthognathic surgery. Copyright 2010 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Development of a finite element model of the ligamentous cervical vertebral column of a Great Dane.

PubMed

Bonelli, Marília de Albuquerque; Shah, Anoli; Goel, Vijay; Costa, Fabiano Séllos; da Costa, Ronaldo Casimiro

2018-06-01

Cervical spondylomyelopathy (CSM), also known as wobbler syndrome, affects mainly large and giant-breed dogs, causing compression of the cervical spinal cord and/or nerve roots. Structural and dynamic components seem to play a role in the development of CSM; however, pathogenesis is not yet fully understood. Finite element models have been used for years in human medicine to study the dynamic behavior of structures, but it has been mostly overlooked in veterinary studies. To our knowledge, no specific ligamentous spine models have been developed to investigate naturally occurring canine myelopathies and possible surgical treatments. The goal of this study was to develop a finite element model (FEM) of the C 2 -C 7 segment of the ligamentous cervical vertebral column of a neurologically normal Great Dane without imaging changes. The FEM of the intact C 2 -C 7 cervical vertebral column had a total of 188,906 elements (175,715 tetra elements and 12,740 hexa elements). The range of motion (in degrees) for the FEM subjected to a moment of 2Nm was approximately 27.94 in flexion, 25.86 in extension, 24.14 in left lateral bending, 25.27 in right lateral bending, 17.44 in left axial rotation, and 16.72 in right axial rotation. We constructed a ligamentous FEM of the C 2 -C 7 vertebral column of a Great Dane dog, which can serve as a platform to be modified and adapted for studies related to biomechanics of the cervical vertebral column and to further improve studies on osseous-associated cervical spondylomyelopathy. Copyright © 2018 Elsevier Ltd. All rights reserved.

Computer-aided diagnosis for osteoporosis using chest 3D CT images

NASA Astrophysics Data System (ADS)

Yoneda, K.; Matsuhiro, M.; Suzuki, H.; Kawata, Y.; Niki, N.; Nakano, Y.; Ohmatsu, H.; Kusumoto, M.; Tsuchida, T.; Eguchi, K.; Kaneko, M.

2016-03-01

The patients of osteoporosis comprised of about 13 million people in Japan and it is one of the problems the aging society has. In order to prevent the osteoporosis, it is necessary to do early detection and treatment. Multi-slice CT technology has been improving the three dimensional (3-D) image analysis with higher body axis resolution and shorter scan time. The 3-D image analysis using multi-slice CT images of thoracic vertebra can be used as a support to diagnose osteoporosis and at the same time can be used for lung cancer diagnosis which may lead to early detection. We develop automatic extraction and partitioning algorithm for spinal column by analyzing vertebral body structure, and the analysis algorithm of the vertebral body using shape analysis and a bone density measurement for the diagnosis of osteoporosis. Osteoporosis diagnosis support system obtained high extraction rate of the thoracic vertebral in both normal and low doses.

Meiosis completion and various sperm responses lead to unisexual and sexual reproduction modes in one clone of polyploid Carassius gibelio.

PubMed

Zhang, Jun; Sun, Min; Zhou, Li; Li, Zhi; Liu, Zhen; Li, Xi-Yin; Liu, Xiao-Li; Liu, Wei; Gui, Jian-Fang

2015-06-04

Unisexual polyploid vertebrates are commonly known to reproduce by gynogenesis, parthenogenesis, or hybridogenesis. One clone of polyploid Carassius gibelio has been revealed to possess multiple modes of unisexual gynogenesis and sexual reproduction, but the cytological and developmental mechanisms have remained unknown. In this study, normal meiosis completion was firstly confirmed by spindle co-localization of β-tubulin and Spindlin. Moreover, three types of various nuclear events and development behaviors were revealed by DAPI staining and BrdU-incorporated immunofluorescence detection during the first mitosis in the fertilized eggs by three kinds of different sperms. They include normal sexual reproduction in response to sperm from the same clone male, typical unisexual gynogenesis in response to sperm from the male of another species Cyprinus carpio, and an unusual hybrid-similar development mode in response to sperm from another different clone male. Based on these findings, we have discussed cytological and developmental mechanisms on multiple reproduction modes in the polyploid fish, and highlighted evolutionary significance of meiosis completion and evolutionary consequences of reproduction mode diversity in polyploid vertebrates.

Meiosis completion and various sperm responses lead to unisexual and sexual reproduction modes in one clone of polyploid Carassius gibelio

PubMed Central

Zhang, Jun; Sun, Min; Zhou, Li; Li, Zhi; Liu, Zhen; Li, Xi-Yin; Liu, Xiao-Li; Liu, Wei; Gui, Jian-Fang

2015-01-01

Unisexual polyploid vertebrates are commonly known to reproduce by gynogenesis, parthenogenesis, or hybridogenesis. One clone of polyploid Carassius gibelio has been revealed to possess multiple modes of unisexual gynogenesis and sexual reproduction, but the cytological and developmental mechanisms have remained unknown. In this study, normal meiosis completion was firstly confirmed by spindle co-localization of β-tubulin and Spindlin. Moreover, three types of various nuclear events and development behaviors were revealed by DAPI staining and BrdU-incorporated immunofluorescence detection during the first mitosis in the fertilized eggs by three kinds of different sperms. They include normal sexual reproduction in response to sperm from the same clone male, typical unisexual gynogenesis in response to sperm from the male of another species Cyprinus carpio, and an unusual hybrid-similar development mode in response to sperm from another different clone male. Based on these findings, we have discussed cytological and developmental mechanisms on multiple reproduction modes in the polyploid fish, and highlighted evolutionary significance of meiosis completion and evolutionary consequences of reproduction mode diversity in polyploid vertebrates. PMID:26042995

Autonomic control of circulation in fish: a comparative view.

PubMed

Sandblom, Erik; Axelsson, Michael

2011-11-16

The autonomic nervous system has a central role in the control and co-ordination of the cardiovascular system in all vertebrates. In fish, which represent the largest and most diverse vertebrate group, the autonomic control of the circulation displays a vast variation with a number of interesting deviations from the typical vertebrate pattern. This diversity ranges from virtually no known nervous control of the circulation in hagfish, to a fully developed dual control from both cholinergic and adrenergic nerves in teleost, much resembling the situation found in other vertebrate groups. This review summarizes current knowledge on the role of the autonomic nervous system in the control of the cardiovascular system in fish. We set out by providing an overview of the general trends and patterns in the major fish groups, and then a summary of how the autonomic nervous control is involved in normal daily activities such as barostatic control of blood pressure, as well as adjustments of the cardiovascular system during feeding and environmental hypoxia. Copyright © 2011 Elsevier B.V. All rights reserved.

Can simple rules control development of a pioneer vertebrate neuronal network generating behavior?

PubMed

Roberts, Alan; Conte, Deborah; Hull, Mike; Merrison-Hort, Robert; al Azad, Abul Kalam; Buhl, Edgar; Borisyuk, Roman; Soffe, Stephen R

2014-01-08

How do the pioneer networks in the axial core of the vertebrate nervous system first develop? Fundamental to understanding any full-scale neuronal network is knowledge of the constituent neurons, their properties, synaptic interconnections, and normal activity. Our novel strategy uses basic developmental rules to generate model networks that retain individual neuron and synapse resolution and are capable of reproducing correct, whole animal responses. We apply our developmental strategy to young Xenopus tadpoles, whose brainstem and spinal cord share a core vertebrate plan, but at a tractable complexity. Following detailed anatomical and physiological measurements to complete a descriptive library of each type of spinal neuron, we build models of their axon growth controlled by simple chemical gradients and physical barriers. By adding dendrites and allowing probabilistic formation of synaptic connections, we reconstruct network connectivity among up to 2000 neurons. When the resulting "network" is populated by model neurons and synapses, with properties based on physiology, it can respond to sensory stimulation by mimicking tadpole swimming behavior. This functioning model represents the most complete reconstruction of a vertebrate neuronal network that can reproduce the complex, rhythmic behavior of a whole animal. The findings validate our novel developmental strategy for generating realistic networks with individual neuron- and synapse-level resolution. We use it to demonstrate how early functional neuronal connectivity and behavior may in life result from simple developmental "rules," which lay out a scaffold for the vertebrate CNS without specific neuron-to-neuron recognition.

A necropsy and histomorphometric study of abnormalities in the course of the vertebral artery associated with ossified stylohyoid ligaments.

PubMed Central

Johnson, C P; Scraggs, M; How, T; Burns, J

1995-01-01

AIMS--To establish whether abnormalities in the course of the vertebral artery occur and whether they are relevant to arterial injury associated with head and neck movements. METHODS--Twenty vertebral arteries were carefully dissected at necropsy and abnormalities in course were noted, along with any other bony or cartilaginous cervical anomalies. The effect of head and neck movement on these vessels was studied before a detailed histomorphometric examination was undertaken on sections of the excised arteries. RESULTS--Five vessels had an abnormal course. One vessel entered the transverse foramina of the fifth cervical vertebra rather than the sixth, but was otherwise normal. In two subjects both vertebral arteries were abnormal in the upper cervical portion with, in each case, a straight left vertebral artery and a right vertebral artery with a deficient loop, closely applied to the atlanto-axial joint. Both of these subjects also had completely ossified stylohyoid ligaments and the arteries visibly stretched with modest head and neck movements. Histology revealed variable degrees of smooth muscle disarray in the tunica media of two of the arteries with loop deficiencies. The circumference of one of the straight arteries was smaller than expected but in all other measured histomorphometric parameters these vessels appeared normal. CONCLUSIONS--Vertebral artery loops are deficient in a number of subjects. This finding is important given the recently described biomechanical susceptibility of the vertebral artery to longitudinal extension and may explain the smooth muscle changes, in that this may represent attempts at arterial wall remodelling. Subjects with such loop deficiencies may be more susceptible to a variety of head and neck insults and such abnormalities should be sought at necropsy in subjects who die as a result of fatal vertebral artery injury. Images PMID:7560170

Determination of vertebral range of motion using inertial measurement units in 27 Franches-Montagnes stallions and comparison between conditions and with a mixed population.

PubMed

Heim, C; Pfau, T; Gerber, V; Schweizer, C; Doherr, M; Schüpbach-Regula, G; Witte, S

2016-07-01

The diagnosis of equine back disorders is challenging. Objectively determining movement of the vertebral column may therefore be of value in a clinical setting. To establish whether surface-mounted inertial measurement units (IMUs) can be used to establish normal values for range of motion (ROM) of the vertebral column in a uniform population of horses trotting under different conditions. Vertebral ROM was established in Franches-Montagnes stallions and a general population of horses and the variability in measurements compared between the two groups. Repeatability and the influence of specific exercise condition (on ROM) were assessed. Finally, attempts were made to explain the findings of the study through the evaluation of factors that might influence ROM. Dorsoventral (DV) and mediolateral (ML) vertebral ROM was measured at a trot under different exercise conditions in 27 Franches-Montagnes stallions and six general population horses using IMUs distributed over the vertebral column. Variability in the ROM measurements was significantly higher for general population horses than for Franches-Montagnes stallions (both DV and ML ROM). Repeatability was strong to very strong for DV measurements and moderate for ML measurements. Trotting under saddle significantly reduced the ROM, with sitting trot resulting in a significantly lower ROM than rising trot. Age is unlikely to explain the low variability in vertebral ROM recorded in the Franches-Montagnes horses, while this may be associated with conformational factors. It was possible to establish a normal vertebral ROM for a group of Franches-Montagnes stallions. While within-breed variation was low in this population, further studies are necessary to determine variation in vertebral ROM for other breeds and to assess their utility for diagnosis of equine back disorders. © 2015 EVJ Ltd.

Mast cells are present in the choroid of the normal eye in most vertebrate classes.

PubMed

McMenamin, Paul Gerard; Polla, Emily

2013-07-01

Mast cells are bone marrow-derived tissue-homing leukocytes, which have traditionally been regarded as effector cells in allergic disorders, responses against parasites, and regulation of blood flow, but a broader perspective of their functional heterogeneity, such as immunomodulation, angiogenesis, tissue repair, and remodeling after injury, is now emerging. The persistence of mast cells in connective tissues throughout the evolution of vertebrates is evidence of strong selective pressure suggesting that these cells must have multiple beneficial and important roles in normal homeostasis. While mast cells are present within the uveal tract of eutherian mammals, there is little known about their presence in the choroid of other vertebrate classes. Eye tissues from a range of vertebrate species (fish, amphibian, reptiles, birds, marsupials, monotreme, and eutherian mammals) were investigated. Tissues were fixed in either 2% glutaraldehyde, 2% paraformaldehyde or a mixture of both and processed for resin embedding. Semi-thin sections of the retina and choroid were cut and stained with toluidine blue. Mast cells were identified in the choroid of all classes of vertebrates investigated except sharks. Their morphology, location, and staining characteristics were remarkably similar from teleost fish through to eutherian mammals and bore close morphological resemblance to mammalian connective tissue mast cells. The similar morphology and distribution of mast cells in the choroid of all vertebrate classes studied suggest a basic physiological function that has been retained since the evolution of the vertebrate eye. © 2013 American College of Veterinary Ophthalmologists.

Loss of col8a1a function during zebrafish embryogenesis results in congenital vertebral malformations.

PubMed

Gray, Ryan S; Wilm, Thomas P; Smith, Jeff; Bagnat, Michel; Dale, Rodney M; Topczewski, Jacek; Johnson, Stephen L; Solnica-Krezel, Lilianna

2014-02-01

Congenital vertebral malformations (CVM) occur in 1 in 1000 live births and in many cases can cause spinal deformities, such as scoliosis, and result in disability and distress of affected individuals. Many severe forms of the disease, such as spondylocostal dystostosis, are recessive monogenic traits affecting somitogenesis, however the etiologies of the majority of CVM cases remain undetermined. Here we demonstrate that morphological defects of the notochord in zebrafish can generate congenital-type spine defects. We characterize three recessive zebrafish leviathan/col8a1a mutant alleles ((m531, vu41, vu105)) that disrupt collagen type VIII alpha1a (col8a1a), and cause folding of the embryonic notochord and consequently adult vertebral column malformations. Furthermore, we provide evidence that a transient loss of col8a1a function or inhibition of Lysyl oxidases with drugs during embryogenesis was sufficient to generate vertebral fusions and scoliosis in the adult spine. Using periodic imaging of individual zebrafish, we correlate focal notochord defects of the embryo with vertebral malformations (VM) in the adult. Finally, we show that bends and kinks in the notochord can lead to aberrant apposition of osteoblasts normally confined to well-segmented areas of the developing vertebral bodies. Our results afford a novel mechanism for the formation of VM, independent of defects of somitogenesis, resulting from aberrant bone deposition at regions of misshapen notochord tissue. Copyright © 2013 Elsevier Inc. All rights reserved.

Loss of col8a1a Function during Zebrafish Embryogenesis Results in Congenital Vertebral Malformations

PubMed Central

Gray, Ryan S.; Wilm, Thomas; Smith, Jeff; Bagnat, Michel; Dale, Rodney M.; Topczewski, Jacek; Johnson, Stephen L.; Solnica-Krezel, Lilianna

2014-01-01

Congenital vertebral malformations (CVM) occur in 1 in 1,000 live births and in many cases can cause spinal deformities, such as scoliosis, and result in disability and distress of affected individuals. Many severe forms of the disease, such as spondylocostal dystostosis, are recessive monogenic traits affecting somitogenesis, however the etiologies of the majority of CVM cases remain undetermined. Here we demonstrate that morphological defects of the notochord in zebrafish can generate congenital-type spine defects. We characterize three recessive zebrafish leviathan/col8a1a mutant alleles (m531, vu41, vu105) that disrupt collagen type VIII alpha1a (col8a1a), and cause folding of the embryonic notochord and consequently adult vertebral column malformations. Furthermore, we provide evidence that a transient loss of col8a1a function or inhibition of Lysyl oxidases with drugs during embryogenesis was sufficient to generate vertebral fusions and scoliosis in the adult spine. Using periodic imaging of individual zebrafish, we correlate focal notochord defects of the embryo with vertebral malformations (VM) in the adult. Finally, we show that bends and kinks in the notochord can lead to aberrant apposition of osteoblasts normally confined to well-segmented areas of the developing vertebral bodies. Our results afford a novel mechanism for the formation of VM, independent of defects of somitogenesis, resulting from aberrant bone deposition at regions of misshapen notochord tissue. PMID:24333517

Node and midline defects are associated with left-right development in Delta1 mutant embryos.

PubMed

Przemeck, Gerhard K H; Heinzmann, Ulrich; Beckers, Johannes; Hrabé de Angelis, Martin

2003-01-01

Axes formation is a fundamental process of early embryonic development. In addition to the anteroposterior and dorsoventral axes, the determination of the left-right axis is crucial for the proper morphogenesis of internal organs and is evolutionarily conserved in vertebrates. Genes known to be required for the normal establishment and/or maintenance of left-right asymmetry in vertebrates include, for example, components of the TGF-beta family of intercellular signalling molecules and genes required for node and midline function. We report that Notch signalling, which previously had not been implicated in this morphogenetic process, is required for normal left-right determination in mice. We show, that the loss-of-function of the delta 1 (Dll1) gene causes a situs ambiguous phenotype, including randomisation of the direction of heart looping and embryonic turning. The most probable cause for this left-right defect in Dll1 mutant embryos is a failure in the development of proper midline structures. These originate from the node, which is disrupted and deformed in Dll1 mutant embryos. Based on expression analysis in wild-type and mutant embryos, we suggest a model, in which Notch signalling is required for the proper differentiation of node cells and node morphology.

Analyzing notochord segmentation and intervertebral disc formation using the twhh:gfp transgenic zebrafish model.

PubMed

Haga, Yutaka; Dominique, Vincent J; Du, Shao Jun

2009-10-01

To characterize the process of vertebral segmentation and disc formation in living animals, we analyzed tiggy-winkle hedgehog (twhh):green fluorescent protein (gfp) and sonic hedgehog (shh):gfp transgenic zebrafish models that display notochord-specific GFP expression. We found that they showed distinct patterns of expression in the intervertebral discs of late stage fish larvae and adult zebrafish. A segmented pattern of GFP expression was detected in the intervertebral disc of twhh:gfp transgenic fish. In contrast, little GFP expression was found in the intervertebral disc of shh:gfp transgenic fish. Treating twhh:gfp transgenic zebrafish larvae with exogenous retinoic acid (RA), a teratogenic factor on normal development, resulted in disruption of notochord segmentation and formation of oversized vertebrae. Histological analysis revealed that the oversized vertebrae are likely due to vertebral fusion. These studies demonstrate that the twhh:gfp transgenic zebrafish is a useful model for studying vertebral segmentation and disc formation, and moreover, that RA signaling may play a role in this process.

rbm47, a novel RNA binding protein, regulates zebrafish head development.

PubMed

Guan, Rui; El-Rass, Suzan; Spillane, David; Lam, Simon; Wang, Yuodong; Wu, Jing; Chen, Zhuchu; Wang, Anan; Jia, Zhengping; Keating, Armand; Hu, Jim; Wen, Xiao-Yan

2013-12-01

Vertebrate trunk induction requires inhibition of bone morphogenetic protein (BMP) signaling, whereas vertebrate head induction requires concerted inhibition of both Wnt and BMP signaling. RNA binding proteins play diverse roles in embryonic development and their roles in vertebrate head development remain to be elucidated. We first characterized the human RBM47 as an RNA binding protein that specifically binds RNA but not single-stranded DNA. Next, we knocked down rbm47 gene function in zebrafish using morpholinos targeting the start codon and exon-1/intron-1 splice junction. Down-regulation of rbm47 resulted in headless and small head phenotypes, which can be rescued by a wnt8a blocking morpholino. To further reveal the mechanism of rbm47's role in head development, microarrays were performed to screen genes differentially expressed in normal and knockdown embryos. epcam and a2ml were identified as the most significantly up- and down-regulated genes, respectively. The microarrays also confirmed up-regulation of several genes involved in head development, including gsk3a, otx2, and chordin, which are important regulators of Wnt signaling. Altogether, our findings reveal that Rbm47 is a novel RNA-binding protein critical for head formation and embryonic patterning during zebrafish embryogenesis which may act through a Wnt8a signaling pathway. Copyright © 2013 Wiley Periodicals, Inc.

Sonic hedgehog in the notochord is sufficient for patterning of the intervertebral discs

PubMed Central

Choi, Kyung-Suk; Lee, Chanmi; Harfe, Brian D.

2012-01-01

The intervertebral discs, located between adjacent vertebrae, are required for stability of the spine and distributing mechanical load throughout the vertebral column. All cell types located in thes middle regions of the discs, called nuclei pulposi, are derived from the embryonic notochord. Recently, it was shown that the hedgehog signaling pathway plays an essential role during formation of nuclei pulposi. However, during the time that nuclei pulposi are forming, Shh is expressed in both the notochord and the nearby floor plate. To determine the source of SHH protein sufficient for formation of nuclei pulposi we removed Shh from either the floor plate or the notochord using tamoxifen-inducible Cre alleles. Removal of Shh from the floor plate resulted in phenotypically normal intervertebral discs, indicating that Shh expression in this tissue is not required for disc patterning. In addition, embryos that lacked Shh in the floor plate had normal vertebral columns, demonstrating that Shh expression in the notochord is sufficient for pattering the entire vertebral column. Removal of Shh from the notochord resulted in the absence of Shh in the floor plate, loss of intervertebral discs and vertebral structures. These data indicate that Shh expression in the notochord is sufficient for patterning of the intervertebral discs and the vertebral column. PMID:22841806

Sonic hedgehog in the notochord is sufficient for patterning of the intervertebral discs.

PubMed

Choi, Kyung-Suk; Lee, Chanmi; Harfe, Brian D

2012-01-01

The intervertebral discs, located between adjacent vertebrae, are required for stability of the spine and distributing mechanical load throughout the vertebral column. All cell types located in the middle regions of the discs, called nuclei pulposi, are derived from the embryonic notochord. Recently, it was shown that the hedgehog signaling pathway plays an essential role during formation of nuclei pulposi. However, during the time that nuclei pulposi are forming, Shh is expressed in both the notochord and the nearby floor plate. To determine the source of SHH protein sufficient for formation of nuclei pulposi we removed Shh from either the floor plate or the notochord using tamoxifen-inducible Cre alleles. Removal of Shh from the floor plate resulted in phenotypically normal intervertebral discs, indicating that Shh expression in this tissue is not required for disc patterning. In addition, embryos that lacked Shh in the floor plate had normal vertebral columns, demonstrating that Shh expression in the notochord is sufficient for pattering the entire vertebral column. Removal of Shh from the notochord resulted in the absence of Shh in the floor plate, loss of intervertebral discs and vertebral structures. These data indicate that Shh expression in the notochord is sufficient for patterning of the intervertebral discs and the vertebral column. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

ANALYSIS ON THE VARIATION OF MEDIAL ROTATION VALUES ACCORDING TO THE POSITION OF THE HUMERAL DIAPHYSIS.

PubMed

Miyazaki, Alberto Naoki; Fregoneze, Marcelo; Santos, Pedro Doneux; da Silva, Luciana Andrade; do Val Sella, Guilherme; Cohen, Carina; Busin Giora, Taís Stedile; Checchia, Sergio Luiz; Raia, Fabio; Pekelman, Hélio; Cymrot, Raquel

2012-01-01

To analyze the validity of measurements of medial rotation (MR) of the shoulder, using vertebral levels, according to the variation in the position of the humeral diaphysis, and to test the bi-goniometer as a new measuring instrument. 140 shoulders (70 patients) were prospectively evaluated in cases presenting unilateral shoulder MR limitation. The vertebral level was evaluated by means of a visual scale and was correlated with the angle obtained according to the position of the humeral diaphysis, using the bi-goniometer developed with the Department of Mechanical Engineering of Mackenzie University. The maximum vertebral level reached through MR on the unaffected side ranged from T3 to T12, and on the affected side, from T6 to the trochanter. Repositioning of the affected limb in MR according to the angular values on the normal side showed that 57.13% of the patients reached lower levels, between the sacrum, gluteus and trochanter. From analysis on the maximum vertebral level attained and the variation between the affected angle x (frontal plane: abduction and MR of the shoulder) and the unaffected angle x in MR, we observed that the greater the angle of the diaphyseal axis was, the lower the variation in the vertebral level attained was. From evaluating the linear correlation between the variables of difference in maximum vertebral level reached and variation in the affected angle y (extension and abduction of the shoulder) and the unaffected angle y in MR, we observed that there was no well-established linear relationship between these variables. Measurement of MR using vertebral levels does not correspond to the real values, since it varies according to the positioning of the humeral diaphysis.

ANALYSIS ON THE VARIATION OF MEDIAL ROTATION VALUES ACCORDING TO THE POSITION OF THE HUMERAL DIAPHYSIS

PubMed Central

Miyazaki, Alberto Naoki; Fregoneze, Marcelo; Santos, Pedro Doneux; da Silva, Luciana Andrade; do Val Sella, Guilherme; Cohen, Carina; Busin Giora, Taís Stedile; Checchia, Sergio Luiz; Raia, Fabio; Pekelman, Hélio; Cymrot, Raquel

2015-01-01

Objective: To analyze the validity of measurements of medial rotation (MR) of the shoulder, using vertebral levels, according to the variation in the position of the humeral diaphysis, and to test the bi-goniometer as a new measuring instrument. Methods: 140 shoulders (70 patients) were prospectively evaluated in cases presenting unilateral shoulder MR limitation. The vertebral level was evaluated by means of a visual scale and was correlated with the angle obtained according to the position of the humeral diaphysis, using the bi-goniometer developed with the Department of Mechanical Engineering of Mackenzie University. Results: The maximum vertebral level reached through MR on the unaffected side ranged from T3 to T12, and on the affected side, from T6 to the trochanter. Repositioning of the affected limb in MR according to the angular values on the normal side showed that 57.13% of the patients reached lower levels, between the sacrum, gluteus and trochanter. From analysis on the maximum vertebral level attained and the variation between the affected angle x (frontal plane: abduction and MR of the shoulder) and the unaffected angle x in MR, we observed that the greater the angle of the diaphyseal axis was, the lower the variation in the vertebral level attained was. From evaluating the linear correlation between the variables of difference in maximum vertebral level reached and variation in the affected angle y (extension and abduction of the shoulder) and the unaffected angle y in MR, we observed that there was no well-established linear relationship between these variables. Conclusion: Measurement of MR using vertebral levels does not correspond to the real values, since it varies according to the positioning of the humeral diaphysis. PMID:27047845

Characterization of dSnoN and its relationship to Decapentaplegic signaling in Drosophila.

PubMed

Barrio, Rosa; López-Varea, Ana; Casado, Mar; de Celis, Jose F

2007-06-01

Vertebrate members of the ski/snoN family of proto-oncogenes antagonize TGFbeta and BMP signaling in a variety of experimental situations. This activity of Ski/SnoN proteins is related to their ability to interact with Smads, the proteins acting as key mediators of the transcriptional response to the TGFbeta superfamily members. However, despite extensive efforts to identify the physiological roles of the Ski/SnoN proteins, it is not yet clear whether they participate in regulating Activin and/or BMP signaling during normal development. It is therefore crucial to examine their roles in vivo mostly because of the large number of known Ski/SnoN-interacting proteins and the association between the up-regulation of these genes and cancer progression. Here we characterize the Drosophila homolog to vertebrate ski and snoN genes. The Drosophila dSnoN protein retains the ability of its vertebrate counterparts to antagonize BMP signaling in vivo and in cultured cells. dSnoN does not interfere with Mad phosphorylation but it interacts genetically with Mad, Medea and dSmad2. Mutations in either the Smad2-3 or Smad4 putative binding sites of dSnoN prevent the antagonism of dSnoN towards Dpp signaling, although homozygous flies for these mutations or for a genetic deficiency of the locus are viable and have wings of normal size and pattern.

43 CFR 11.62 - Injury determination phase-injury definition.

Code of Federal Regulations, 2014 CFR

2014-10-01

... normal brain ChE activity of the wildlife species. These enzymes are in the nervous system of vertebrate... are in the nervous systems of vertebrate organisms and the rate of ChE activity is associated with the... other organs, as well as soft tissues of the gastrointestinal tract and vascular system, when comparing...

43 CFR 11.62 - Injury determination phase-injury definition.

Code of Federal Regulations, 2010 CFR

2010-10-01

... normal brain ChE activity of the wildlife species. These enzymes are in the nervous system of vertebrate... are in the nervous systems of vertebrate organisms and the rate of ChE activity is associated with the... other organs, as well as soft tissues of the gastrointestinal tract and vascular system, when comparing...

43 CFR 11.62 - Injury determination phase-injury definition.

Code of Federal Regulations, 2013 CFR

2013-10-01

... normal brain ChE activity of the wildlife species. These enzymes are in the nervous system of vertebrate... are in the nervous systems of vertebrate organisms and the rate of ChE activity is associated with the... other organs, as well as soft tissues of the gastrointestinal tract and vascular system, when comparing...

43 CFR 11.62 - Injury determination phase-injury definition.

Code of Federal Regulations, 2011 CFR

2011-10-01

... normal brain ChE activity of the wildlife species. These enzymes are in the nervous system of vertebrate... are in the nervous systems of vertebrate organisms and the rate of ChE activity is associated with the... other organs, as well as soft tissues of the gastrointestinal tract and vascular system, when comparing...

Steroid Androgen Exposure during Development Has No Effect on Reproductive Physiology of Biomphalaria glabrata.

PubMed

Kaur, Satwant; Baynes, Alice; Lockyer, Anne E; Routledge, Edwin J; Jones, Catherine S; Noble, Leslie R; Jobling, Susan

2016-01-01

Gastropod mollusks have been proposed as alternative models for male reproductive toxicity testing, due to similarities in their reproductive anatomy compared to mammals, together with evidence that endocrine disrupting chemicals can cause effects in some mollusks analogous to those seen in mammals. To test this hypothesis, we used the freshwater pulmonate snail, Biomphalaria glabrata, for which various genetic tools and a draft genome have recently become available, to investigate the effects of two steroid androgens on the development of mollusk secondary sexual organs. Here we present the results of exposures to two potent androgens, the vertebrate steroid; 5α-dihydrotestosterone (DHT) and the pharmaceutical anabolic steroid; 17α-methyltestosterone (MT), under continuous flow-through conditions throughout embryonic development and up to sexual maturity. Secondary sexual gland morphology, histopathology and differential gene expression analysis were used to determine whether steroid androgens stimulated or inhibited organ development. No significant differences between tissues from control and exposed snails were identified, suggesting that these androgens elicited no biologically detectable response normally associated with exposure to androgens in vertebrate model systems. Identifying no effect of androgens in this mollusk is significant, not only in the context of the suitability of mollusks as alternative model organisms for testing vertebrate androgen receptor agonists but also, if applicable to other similar mollusks, in terms of the likely impacts of androgens and anti-androgenic pollutants present in the aquatic environment.

Steroid Androgen Exposure during Development Has No Effect on Reproductive Physiology of Biomphalaria glabrata

PubMed Central

Lockyer, Anne E.; Routledge, Edwin J.; Jones, Catherine S.; Noble, Leslie R.; Jobling, Susan

2016-01-01

Gastropod mollusks have been proposed as alternative models for male reproductive toxicity testing, due to similarities in their reproductive anatomy compared to mammals, together with evidence that endocrine disrupting chemicals can cause effects in some mollusks analogous to those seen in mammals. To test this hypothesis, we used the freshwater pulmonate snail, Biomphalaria glabrata, for which various genetic tools and a draft genome have recently become available, to investigate the effects of two steroid androgens on the development of mollusk secondary sexual organs. Here we present the results of exposures to two potent androgens, the vertebrate steroid; 5α-dihydrotestosterone (DHT) and the pharmaceutical anabolic steroid; 17α-methyltestosterone (MT), under continuous flow-through conditions throughout embryonic development and up to sexual maturity. Secondary sexual gland morphology, histopathology and differential gene expression analysis were used to determine whether steroid androgens stimulated or inhibited organ development. No significant differences between tissues from control and exposed snails were identified, suggesting that these androgens elicited no biologically detectable response normally associated with exposure to androgens in vertebrate model systems. Identifying no effect of androgens in this mollusk is significant, not only in the context of the suitability of mollusks as alternative model organisms for testing vertebrate androgen receptor agonists but also, if applicable to other similar mollusks, in terms of the likely impacts of androgens and anti-androgenic pollutants present in the aquatic environment. PMID:27448327

Biomechanical Evaluation of an Injectable and Biodegradable Copolymer P(PF-co-CL) in a Cadaveric Vertebral Body Defect Model

PubMed Central

Fang, Zhong; Giambini, Hugo; Zeng, Heng; Camp, Jon J.; Dadsetan, Mahrokh; Robb, Richard A.; An, Kai-Nan; Yaszemski, Michael J.

2014-01-01

A novel biodegradable copolymer, poly(propylene fumarate-co-caprolactone) [P(PF-co-CL)], has been developed in our laboratory as an injectable scaffold for bone defect repair. In the current study, we evaluated the ability of P(PF-co-CL) to reconstitute the load-bearing capacity of vertebral bodies with lytic lesions. Forty vertebral bodies from four fresh-frozen cadaveric thoracolumbar spines were used for this study. They were randomly divided into four groups: intact vertebral body (intact control), simulated defect without treatment (negative control), defect treated with P(PF-co-CL) (copolymer group), and defect treated with poly(methyl methacrylate) (PMMA group). Simulated metastatic lytic defects were made by removing a central core of the trabecular bone in each vertebral body with an approximate volume of 25% through an access hole in the side of the vertebrae. Defects were then filled by injecting either P(PF-co-CL) or PMMA in situ crosslinkable formulations. After the spines were imaged with quantitative computerized tomography, single vertebral body segments were harvested for mechanical testing. Specimens were compressed until failure or to 25% reduction in body height and ultimate strength and elastic modulus of each specimen were then calculated from the force–displacement data. The average failure strength of the copolymer group was 1.83 times stronger than the untreated negative group and it closely matched the intact vertebral bodies (intact control). The PMMA-treated vertebrae, however, had a failure strength 1.64 times larger compared with the intact control. The elastic modulus followed the same trend. This modulus mismatch between PMMA-treated vertebrae and the host vertebrae could potentially induce a fracture cascade and degenerative changes in adjacent intervertebral discs. In contrast, P(PF-co-CL) restored the mechanical properties of the treated segments similar to the normal, intact, vertebrae. Therefore, P(PF-co-CL) may be a suitable alternative to PMMA for vertebroplasty treatment of vertebral bodies with lytic defects. PMID:24256208

Relative shortening and functional tethering of spinal cord in adolescent scoliosis - Result of asynchronous neuro-osseous growth, summary of an electronic focus group debate of the IBSE.

PubMed

Chu, Winnie Cw; Lam, Wynnie Mw; Ng, Bobby Kw; Tze-Ping, Lam; Lee, Kwong-Man; Guo, Xia; Cheng, Jack Cy; Burwell, R Geoffrey; Dangerfield, Peter H; Jaspan, Tim

2008-06-27

There is no generally accepted scientific theory for the causes of adolescent idiopathic scoliosis (AIS). As part of its mission to widen understanding of scoliosis etiology, the International Federated Body on Scoliosis Etiology (IBSE) introduced the electronic focus group (EFG) as a means of increasing debate on knowledge of important topics. This has been designated as an on-line Delphi discussion. The Statement for this debate was written by Dr WCW Chu and colleagues who examine the spinal cord to vertebral growth interaction during adolescence in scoliosis. Using the multi-planar reconstruction technique of magnetic resonance imaging they investigated the relative length of spinal cord to vertebral column including ratios in 28 girls with AIS (mainly thoracic or double major curves) and 14 age-matched normal girls. Also evaluated were cerebellar tonsillar position, somatosensory evoked potentials (SSEPs), and clinical neurological examination. In severe AIS compared with normal controls, the vertebral column is significantly longer without detectable spinal cord lengthening. They speculate that anterior spinal column overgrowth relative to a normal length spinal cord exerts a stretching tethering force between the two ends, cranially and caudally leading to the initiation and progression of thoracic AIS. They support and develop the Roth-Porter concept of uncoupled neuro-osseous growth in the pathogenesis of AIS which now they prefer to term 'asynchronous neuro-osseous growth'. Morphological evidence about the curve apex suggests that the spinal cord is also affected, and a 'double pathology' is suggested. AIS is viewed as a disorder with a wide spectrum and a common neuroanatomical abnormality namely, a spinal cord of normal length but short relative to an abnormally lengthened anterior vertebral column. Neuroanatomical changes and/or abnormal neural function may be expressed only in severe cases. This asynchronous neuro-osseous growth concept is regarded as one component of a larger concept. The other component relates to the brain and cranium of AIS subjects because abnormalities have been found in brain (infratentorial and supratentorial) and skull (vault and base). The possible relevance of systemic melatonin-signaling pathway dysfunction, platelet calmodulin levels and putative vertebral vascular biology to the asynchronous neuro-osseous growth concept is discussed. A biomechanical model to test the spinal component of the concept is in hand. There is no published research on the biomechanical properties of the spinal cord for scoliosis specimens. Such research on normal spinal cords includes movements (kinematics), stress-strain responses to uniaxial loading, and anterior forces created by the stretched cord in forward flexion that may alter sagittal spinal shape during adolescent growth. The asynchronous neuro-osseous growth concept for the spine evokes controversy. Dr Chu and colleagues respond to five other concepts of pathogenesis for AIS and suggest that relative anterior spinal overgrowth and biomechanical growth modulation may also contribute to AIS pathogenesis.

Do unliganded thyroid hormone receptors have physiological functions?

PubMed

Chassande, O

2003-08-01

Thyroid hormone (TH) is required for the development of vertebrates and exerts numerous homeostatic functions in adults. TH acts through nuclear receptors which control the transcription of target genes. Unliganded and liganded thyroid hormone receptors (TRs) have been shown to exert opposite effects on the transcription of target genes in vitro. However, the occurance of an aporeceptor activity in vivo and its potential physiological significance has not been clearly addressed. Several data generated using experimental hypothyroidism and thyrotoxicosis in wild type and TR knockout mice support the notion that apoTRs have an intrinsic activity in several tIssues. ApoTRs, and in particular TRalpha1, are predominant during the early stages of vertebrate development and must be turned into holoTRs for post-natal development to proceed normally. However, the absence of striking alterations of embryonic and fetal development in mice devoid of TRs indicates that apoTRs do not play a fundamental role. During development, as well as in adults, apoTRs rather appears as a system which increases the range of transcriptional responses to moderate variations of T3.

CDC14A phosphatase is essential for hearing and male fertility in mouse and human.

PubMed

Imtiaz, Ayesha; Belyantseva, Inna A; Beirl, Alisha J; Fenollar-Ferrer, Cristina; Bashir, Rasheeda; Bukhari, Ihtisham; Bouzid, Amal; Shaukat, Uzma; Azaiez, Hela; Booth, Kevin T; Kahrizi, Kimia; Najmabadi, Hossein; Maqsood, Azra; Wilson, Elizabeth A; Fitzgerald, Tracy S; Tlili, Abdelaziz; Olszewski, Rafal; Lund, Merete; Chaudhry, Taimur; Rehman, Atteeq U; Starost, Matthew F; Waryah, Ali M; Hoa, Michael; Dong, Lijin; Morell, Robert J; Smith, Richard J H; Riazuddin, Sheikh; Masmoudi, Saber; Kindt, Katie S; Naz, Sadaf; Friedman, Thomas B

2018-03-01

The Cell Division-Cycle-14 gene encodes a dual-specificity phosphatase necessary in yeast for exit from mitosis. Numerous disparate roles of vertebrate Cell Division-Cycle-14 (CDC14A) have been proposed largely based on studies of cultured cancer cells in vitro. The in vivo functions of vertebrate CDC14A are largely unknown. We generated and analyzed mutations of zebrafish and mouse CDC14A, developed a computational structural model of human CDC14A protein and report four novel truncating and three missense alleles of CDC14A in human families segregating progressive, moderate-to-profound deafness. In five of these families segregating pathogenic variants of CDC14A, deaf males are infertile, while deaf females are fertile. Several recessive mutations of mouse Cdc14a, including a CRISPR/Cas9-edited phosphatase-dead p.C278S substitution, result in substantial perinatal lethality, but survivors recapitulate the human phenotype of deafness and male infertility. CDC14A protein localizes to inner ear hair cell kinocilia, basal bodies and sound-transducing stereocilia. Auditory hair cells of postnatal Cdc14a mutants develop normally, but subsequently degenerate causing deafness. Kinocilia of germ-line mutants of mouse and zebrafish have normal lengths, which does not recapitulate the published cdc14aa knockdown morphant phenotype of short kinocilia. In mutant male mice, degeneration of seminiferous tubules and spermiation defects result in low sperm count, and abnormal sperm motility and morphology. These findings for the first time define a new monogenic syndrome of deafness and male infertility revealing an absolute requirement in vivo of vertebrate CDC14A phosphatase activity for hearing and male fertility.

Effects of abnormal light-rearing conditions on retinal physiology in larvae zebrafish.

PubMed

Saszik, S; Bilotta, J

1999-11-01

Anatomic studies have found that zebrafish retinal neurons develop in a sequential fashion. In addition, exposure to abnormal light-rearing conditions produces deficits in visual behavior of larvae zebrafish, even though there appears to be little effect of the light-rearing conditions on the gross morphology of the retina. The purpose of this study was to assess the effects of abnormal light-rearing conditions on larvae zebrafish retinal physiology. Larvae zebrafish (Danio rerio) were exposed to constant light (LL), constant dark (DD), or normal cyclic light (LD) from fertilization to 6 days postfertilization (dpf). After 6 days, the animals were placed into normal cyclic light and tested at 6 to 8, 13 to 15, and 21 to 24 dpf. Electroretinogram (ERG) responses to visual stimuli, consisting of various wavelengths and irradiances, were recorded. Comparisons were made across the three age groups and the three light-rearing conditions. Deficits from the light-rearing conditions were seen immediately after exposure (6 8 dpf). The LL-condition subjects showed the greatest deficit in the UV and short-wavelength areas and the DD-condition subjects showed a slight deficit across the entire spectrum. At 13 to 15 dpf, the LL and DD groups showed an increase in sensitivity and by 21 to 24 dpf, the groups no longer differed from controls. Abnormal lighting environments can adversely influence the physiological development of the larvae zebrafish retina. The pattern of damage that was seen in zebrafish is similar to that found in other vertebrates, including higher vertebrates. However, unlike higher vertebrates, the zebrafish appears to be capable of regeneration. This suggests that the zebrafish would be a viable model for light environment effects and neural regeneration.

Age constraints on the dispersal of dinosaurs in the Late Triassic from magnetochronology of the Los Colorados Formation (Argentina).

PubMed

Kent, Dennis V; Santi Malnis, Paula; Colombi, Carina E; Alcober, Oscar A; Martínez, Ricardo N

2014-06-03

A measured magnetozone sequence defined by 24 sampling sites with normal polarity and 28 sites with reverse polarity characteristic magnetizations was established for the heretofore poorly age-constrained Los Colorados Formation and its dinosaur-bearing vertebrate fauna in the Ischigualasto-Villa Union continental rift basin of Argentina. The polarity pattern in this ∼600-m-thick red-bed section can be correlated to Chrons E7r to E15n of the Newark astrochronological polarity time scale. This represents a time interval from 227 to 213 Ma, indicating that the Los Colorados Formation is predominantly Norian in age, ending more than 11 My before the onset of the Jurassic. The magnetochronology confirms that the underlying Ischigualasto Formation and its vertebrate assemblages including some of the earliest known dinosaurs are of Carnian age. The oldest dated occurrences of vertebrate assemblages with dinosaurs in North America (Chinle Formation) are younger (Norian), and thus the rise of dinosaurs was diachronous across the Americas. Paleogeography of the Ischigualasto and Los Colorados Formations indicates prolonged residence in the austral temperate humid belt where a provincial vertebrate fauna with early dinosaurs may have incubated. Faunal dispersal across the Pangean supercontinent in the development of more cosmopolitan vertebrate assemblages later in the Norian may have been in response to reduced contrasts between climate zones and lowered barriers resulting from decreasing atmospheric pCO2 levels.

Age constraints on the dispersal of dinosaurs in the Late Triassic from magnetochronology of the Los Colorados Formation (Argentina)

PubMed Central

Kent, Dennis V.; Santi Malnis, Paula; Colombi, Carina E.; Alcober, Oscar A.; Martínez, Ricardo N.

2014-01-01

A measured magnetozone sequence defined by 24 sampling sites with normal polarity and 28 sites with reverse polarity characteristic magnetizations was established for the heretofore poorly age-constrained Los Colorados Formation and its dinosaur-bearing vertebrate fauna in the Ischigualasto–Villa Union continental rift basin of Argentina. The polarity pattern in this ∼600-m-thick red-bed section can be correlated to Chrons E7r to E15n of the Newark astrochronological polarity time scale. This represents a time interval from 227 to 213 Ma, indicating that the Los Colorados Formation is predominantly Norian in age, ending more than 11 My before the onset of the Jurassic. The magnetochronology confirms that the underlying Ischigualasto Formation and its vertebrate assemblages including some of the earliest known dinosaurs are of Carnian age. The oldest dated occurrences of vertebrate assemblages with dinosaurs in North America (Chinle Formation) are younger (Norian), and thus the rise of dinosaurs was diachronous across the Americas. Paleogeography of the Ischigualasto and Los Colorados Formations indicates prolonged residence in the austral temperate humid belt where a provincial vertebrate fauna with early dinosaurs may have incubated. Faunal dispersal across the Pangean supercontinent in the development of more cosmopolitan vertebrate assemblages later in the Norian may have been in response to reduced contrasts between climate zones and lowered barriers resulting from decreasing atmospheric pCO2 levels. PMID:24843149

Heads, Shoulders, Elbows, Knees, and Toes: Modular Gdf5 Enhancers Control Different Joints in the Vertebrate Skeleton

PubMed Central

Schoor, Michael; Mortlock, Doug P.; Reddi, A. Hari; Kingsley, David M.

2016-01-01

Synovial joints are crucial for support and locomotion in vertebrates, and are the frequent site of serious skeletal defects and degenerative diseases in humans. Growth and differentiation factor 5 (Gdf5) is one of the earliest markers of joint formation, is required for normal joint development in both mice and humans, and has been genetically linked to risk of common osteoarthritis in Eurasian populations. Here, we systematically survey the mouse Gdf5 gene for regulatory elements controlling expression in synovial joints. We identify separate regions of the locus that control expression in axial tissues, in proximal versus distal joints in the limbs, and in remarkably specific sub-sets of composite joints like the elbow. Predicted transcription factor binding sites within Gdf5 regulatory enhancers are required for expression in particular joints. The multiple enhancers that control Gdf5 expression in different joints are distributed over a hundred kilobases of DNA, including regions both upstream and downstream of Gdf5 coding exons. Functional rescue tests in mice confirm that the large flanking regions are required to restore normal joint formation and patterning. Orthologs of these enhancers are located throughout the large genomic region previously associated with common osteoarthritis risk in humans. The large array of modular enhancers for Gdf5 provide a new foundation for studying the spatial specificity of joint patterning in vertebrates, as well as new candidates for regulatory regions that may also influence osteoarthritis risk in human populations. PMID:27902701

The B. subtilis MgtE Magnesium Transporter Can Functionally Compensate TRPM7-Deficiency in Vertebrate B-Cells

PubMed Central

Sahni, Jaya; Song, Yumei; Scharenberg, Andrew M.

2012-01-01

Recent studies have shown that the vertebrate magnesium transporters Solute carrier family 41, members 1 and 2 (SLC41A1, SLC41A2) and Magnesium transporter subtype 1 (MagT1) can endow vertebrate B-cells lacking the ion-channel kinase Transient receptor potential cation channel, subfamily M, member 7 (TRPM7) with a capacity to grow and proliferate. SLC41A1 and SLC41A2 display distant homology to the prokaryotic family of Mg2+ transporters, MgtE, first characterized in Bacillus subtilis. These sequence similarities prompted us to investigate whether MgtE could potentially compensate for the lack of TRPM7 in the vertebrate TRPM7-deficient DT40 B-cell model system. Here, we report that overexpression of MgtE is able to rescue the growth of TRPM7-KO DT40 B-cells. However, contrary to a previous report that describes regulation of MgtE channel gating by Mg2+ in a bacterial spheroplast model system, whole cell patch clamp analysis revealed no detectable current development in TRPM7-deficient cells expressing MgtE. In addition, we observed that MgtE expression is strongly downregulated at high magnesium concentrations, similar to what has been described for its vertebrate homolog, SLC41A1. We also show that the N-terminal cytoplasmic domain of MgtE is required for normal MgtE channel function, functionally confirming the predicted importance of this domain in regulation of MgtE-mediated Mg2+ entry. Overall, our findings show that consistent with its proposed function, Mg2+ uptake mediated by MgtE is able to restore cell growth and proliferation of TRPM7-deficient cells and supports the concept of functional homology between MgtE and its vertebrate homologs. PMID:22970223

Symptomatic vertebral hemangioma in pregnancy treated antepartum. A case report with review of literature.

PubMed

Vijay, Kamath; Shetty, Ajoy P; Rajasekaran, S

2008-09-01

Pregnancy related compressive myelopathy secondary to vertebral hemangioma is a rare occurrence and its treatment antepartum is rare. We report a 22-year-old lady in her 26th-week of pregnancy who was treated in two stages--antepartum with a laminectomy and posterior stabilization. This resulted in complete recovery of the neurological deficits. She delivered a normal baby after 3 months, following which a corpectomy and fusion was performed. This two-staged approach appears safe and effective in treating symptomatic vertebral haemangiomas causing neurological deficits during pregnancy. A review of relevant literature has been done.

The hypothalamic-pituitary-thyroid (HPT) axis in fish and its role in fish development and reproduction.

PubMed

Blanton, Michael L; Specker, Jennifer L

2007-01-01

Bony fishes represent the largest vertebrate class and are a very diverse animal group. This chapter provides a thorough review of the available scientific literature on the thyroid system in these important vertebrate animals. The molecular components of the hypothalamic-pituitary-thyroid (HPT) axis in this group correspond closely to those of mammals. The thyroid tissue in the fishes is organized as diffuse follicles, with a few exceptions, rather than as an encapsulated gland as is found in most other vertebrate species. The features of this diffuse tissue in fishes are reviewed with an emphasis on feedback relationships within the HPT axis, the molecular biology of the thyroid system in fishes, and comparisons versus the thyroid systems of other vertebrate taxa. A review of the role of thyroid hormone in fish development and reproduction is included. Available information about the HPT axis in fishes is quite detailed for some species and rather limited or absent in others. This review focuses on species that have been intensively studied for their value as laboratory models in assays to investigate disruption in normal function of the thyroid system. In addition, in vitro and in vivo assay methods for screening chemicals for their potential to interfere with the thyroid system are reviewed. It is concluded that there are currently no in vitro or in vivo assays in fish species that are sufficiently developed to warrant recommendation for use to efficiently screen chemicals for thyroid disruption. Methods are available that can be used to measure thyroid hormones, although our ability to interpret the causes and implications of potential alterations in T4 or T3 levels in fishes is nonetheless limited without further research.

The Midblastula Transition Defines the Onset of Y RNA-Dependent DNA Replication in Xenopus laevis ▿

PubMed Central

Collart, Clara; Christov, Christo P.; Smith, James C.; Krude, Torsten

2011-01-01

Noncoding Y RNAs are essential for the initiation of chromosomal DNA replication in mammalian cell extracts, but their role in this process during early vertebrate development is unknown. Here, we use antisense morpholino nucleotides (MOs) to investigate Y RNA function in Xenopus laevis and zebrafish embryos. We show that embryos in which Y RNA function is inhibited by MOs develop normally until the midblastula transition (MBT) but then fail to replicate their DNA and die before gastrulation. Consistent with this observation, Y RNA function is not required for DNA replication in Xenopus egg extracts but is required for replication in a post-MBT cell line. Y RNAs do not bind chromatin in karyomeres before MBT, but they associate with interphase nuclei after MBT in an origin recognition complex (ORC)-dependent manner. Y RNA-specific MOs inhibit the association of Y RNAs with ORC, Cdt1, and HMGA1a proteins, suggesting that these molecular associations are essential for Y RNA function in DNA replication. The MBT is thus a transition point between Y RNA-independent and Y RNA-dependent control of vertebrate DNA replication. Our data suggest that in vertebrates Y RNAs function as a developmentally regulated layer of control over the evolutionarily conserved eukaryotic DNA replication machinery. PMID:21791613

In contrast to agonist monoclonal antibodies, both C-terminal truncated form and full length form of Pleiotrophin failed to activate vertebrate ALK (anaplastic lymphoma kinase)?

PubMed

Mathivet, Thomas; Mazot, Pierre; Vigny, Marc

2007-12-01

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase essentially and transiently expressed during development in specific regions of the central and peripheral nervous system. ALK expression persists at a lower level in the adult brain. Thus, it might play an important role in both the normal development and function of the nervous system. The nature of the cognate ligand of this receptor in vertebrates is still a matter of debate. Pleiotrophin and midkine have been proposed as ligands of ALK but several independent studies do not confirm this hypothesis. Interestingly, a recent study proposed that a C-terminal truncated form of Pleiotrophin (Pleiotrophin.15) and not the full length form (Pleiotrophin.18) promotes glioblastoma proliferation in an ALK-dependent fashion. These data were obviously a strong basis to conciliate the conflicting results so far reported in the literature. In the present study, we first purified to homogeneity the two forms of Pleiotrophin secreted by HEK 293 cells. In contrast to agonist monoclonal antibodies, both Pleiotrophin.15 and Pleiotrophin.18 failed to activate ALK in neuroblastoma and glioblastoma cells expressing this receptor. Thus, for our point of view, ALK is still an orphan receptor in vertebrates.

Building the backbone: the development and evolution of vertebral patterning.

PubMed

Fleming, Angeleen; Kishida, Marcia G; Kimmel, Charles B; Keynes, Roger J

2015-05-15

The segmented vertebral column comprises a repeat series of vertebrae, each consisting of two key components: the vertebral body (or centrum) and the vertebral arches. Despite being a defining feature of the vertebrates, much remains to be understood about vertebral development and evolution. Particular controversy surrounds whether vertebral component structures are homologous across vertebrates, how somite and vertebral patterning are connected, and the developmental origin of vertebral bone-mineralizing cells. Here, we assemble evidence from ichthyologists, palaeontologists and developmental biologists to consider these issues. Vertebral arch elements were present in early stem vertebrates, whereas centra arose later. We argue that centra are homologous among jawed vertebrates, and review evidence in teleosts that the notochord plays an instructive role in segmental patterning, alongside the somites, and contributes to mineralization. By clarifying the evolutionary relationship between centra and arches, and their varying modes of skeletal mineralization, we can better appreciate the detailed mechanisms that regulate and diversify vertebral patterning. © 2015. Published by The Company of Biologists Ltd.

Prevalence of vertebral fracture and densitometric osteoporosis in Spanish adult men: The Camargo Cohort Study.

PubMed

Olmos, José M; Hernández, José L; Martínez, Josefina; Pariente, Emilio; Castillo, Jesús; Prieto-Alhambra, Daniel; González-Macías, Jesús

2018-01-01

The aim of this study was to assess the prevalence of densitometric osteoporosis and vertebral fractures in Spanish men aged ≥50 years, and to study how the relationship between them may change depending on how osteoporosis is diagnosed. A community-based population of 1003 men aged ≥50 years was studied. Bone mineral density (BMD) was measured by DXA at the lumbar spine, femoral neck and total hip. Vertebral fractures were assessed by lateral thoracic and lumbar spine radiographs. The prevalence of osteoporosis was estimated with both the World Health Organization (WHO) (T-score of <-2.5 at the femoral neck, calculated using the young white female normal reference database) and the National Osteoporosis Foundation (NOF) criteria (T-score of <-2.5 at the femoral neck, total hip or lumbar spine, calculated using the young white male normal reference database). The prevalence of osteoporosis using the WHO criterion was 1.1% and using the NOF criterion was 13%, while that of vertebral fractures was 21.3%. The area under the curve (AUC) for the relationship between BMD and vertebral fracture prevalence was 0.64. The odds ratio for osteoporosis using the WHO definition was 2.57 (p = 0.13), and 1.78 (p = 0.007) using the NOF definition. Vertebral fracture prevalence rose with age. The prevalence of osteoporosis increased only moderately in men aged >70 years with the WHO criterion, and showed no change using the NOF definition. The prevalence of osteoporosis in Spanish men using the WHO definition is too small to have any meaningful clinical use. Although the figure is higher using the NOF definition, it would seem that population-based studies of BMD in men are of questionable value.

Vertebral reconstruction using the telescopic plate spacer-thoracolumbar (TPS-TL) device.

PubMed

Atalay, Basar; Riesenburger, Ron I; Schirmer, Clemens M; Bhadelia, Rafeeque A; Weller, Simcha J

2010-07-01

Retrospective study of surgical technique and outcome. The authors conducted a study to evaluate the ability of the TPS-TL (telescopic plate spacer-thoracolumbar) implant to correct kyphotic deformity and restore vertebral body height after vertebrectomy in the thoracolumbar spine. TPS-TL is a novel vertebral body replacement device that consists of an expandable cage with an integrated plate component for transvertebral screw fixation. This is a retrospective study of 20 patients who underwent anterior column reconstruction with TPS-TL after a 1 or 2 level thoracolumbar vertebrectomy. Preoperative and postoperative sagittal alignment and vertebral body heights were radiologically analyzed in all patients. The mean follow-up was 14 months. Preoperative and postoperative Cobb angles were measured to assess sagittal alignment. The average preoperative Cobb angle was 16.0 + or - 7 degrees. This was reduced to 9.8 + or - 10 degrees at the final follow-up (P<0.001). Percent of ideal vertebral body height was used to assess postoperative restoration of vertebral body height. This value was obtained by creating a ratio of the height of the effected vertebral levels to the height of the adjacent normal vertebral bodies. The mean percent of ideal vertebral body height improved from a preoperative value from 86.2 + or - 2% to 93.1 + or - 6% at the final follow-up (P<0.001). The TPS-TL implant is effective in restoring vertebral body height and correcting kyphotic deformity after thoracolumbar vertebrectomy.

UPTAKE OF STRONTIUM-85 IN NON-MALIGNANT VERTEBRAL LESIONS IN MAN

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

Bauer, G.C.H.; Scoccianti, P.

1961-01-01

By means of external scintillation counting, it was possible to demonstrate abnormally high spinal uptake of intravenously injected Sr/sup 85/ in various diseases of the vertebral column. A total dose of 50 mu c carrier-free Sr/sup 85/ was injected 7 to 14 days before recording spinal radioactivity with a collimated scintillation detector. An abnormal activity pattern was defined as a deviation from the normal pattern of twice the standard deviation of the normal mean value. Abnormal spinal patterns were detected in vertebral fractures, ankylosing spondylitis, tuberculous spondylitis, nonspecific discitis, and in a case with a lytic lesion of unknown origin.more » The value of 14 days was found more reliable than that at 7 days since by this time Sr/sup 85/ levels in soft tissues had fallen to low values. In 1 case, erroneous results were obtained from spinal counting due to a kidney stone which produced high activity in the spinal region. (H.H.D.)« less

Fyn/Yes and non-canonical Wnt signalling converge on RhoA in vertebrate gastrulation cell movements

PubMed Central

Jopling, Chris; den Hertog, Jeroen

2005-01-01

Convergent extension (CE) cell movements during gastrulation mediate extension of the anterior–posterior body axis of vertebrate embryos. Non-canonical Wnt5 and Wnt11 signalling is essential for normal CE movements in vertebrate gastrulation. Here, we show that morpholino (MO)-mediated double knock-down of the Fyn and Yes tyrosine kinases in zebrafish embryos impaired normal CE cell movements, resembling the silberblick and pipetail mutants, caused by mutations in wnt11 and wnt5, respectively. Co-injection of Fyn/Yes- and Wnt11- or Wnt5-MO was synergistic, but wnt11 or wnt5 RNA did not rescue the Fyn/Yes knockdown or vice versa. Remarkably, active RhoA rescued the Fyn/Yes knockdown as well as the Wnt11 knockdown, indicating that Fyn/Yes and Wnt11 signalling converged on RhoA. Our results show that Fyn and Yes act together with non-canonical Wnt signalling via RhoA in CE cell movements during gastrulation. PMID:15815683

Live dynamic analysis of mouse embryonic cardiogenesis with functional optical coherence tomography

NASA Astrophysics Data System (ADS)

Lopez, Andrew L.; Wang, Shang; Larina, Irina V.

2018-02-01

Hemodynamic load, contractile forces, and tissue elasticity are regulators of cardiac development and contribute to the mechanical homeostasis of the developing vertebrate heart. Congenital heart disease (CHD) is a prevalent condition in the United States that affects 8 in 1000 live births[1], and has been linked to disrupted cardiac biomechanics[2-4]. Therefore, it is important to understand how these forces integrate and regulate vertebrate cardiac development to inform clinical strategies to treat CHD early on by reintroducing proper mechanical load or modulating downstream factors that rely on mechanical signalling. Toward investigation of biomechanical regulation of mammalian cardiovascular dynamics and development, our methodology combines live mouse embryo culture protocols, state-of-the-art structural and functional Optical Coherence Tomography (OCT), second harmonic generation (SHG) microscopy, and computational analysis. Using these approaches, we assess functional aspects of the developing heart and characterize how they coincide with a determinant of tissue stiffness and main constituent of the extracellular matrix (ECM)—type I collagen. This work is bringing us closer to understanding how cardiac biomechanics change temporally and spatially during normal development, and how it regulates ECM to maintain mechanical homeostasis for proper function.

Can you hear me now? Understanding vertebrate middle ear development

PubMed Central

Chapman, Susan Caroline

2010-01-01

The middle ear is a composite organ formed from all three germ layers and the neural crest. It provides the link between the outside world and the inner ear, where sound is transduced and routed to the brain for processing. Extensive classical and modern studies have described the complex morphology and origin of the middle ear. Non-mammalian vertebrates have a single ossicle, the columella. Mammals have three functionally equivalent ossicles, designated the malleus, incus and stapes. In this review, I focus on the role of genes known to function in the middle ear. Genetic studies are beginning to unravel the induction and patterning of the multiple middle ear elements including the tympanum, skeletal elements, the air-filled cavity, and the insertion point into the inner ear oval window. Future studies that elucidate the integrated spatio-temporal signaling mechanisms required to pattern the middle ear organ system are needed. The longer-term translational benefits of understanding normal and abnormal ear development will have a direct impact on human health outcomes. PMID:21196256

Effects of Neonatal Enzyme Replacement Therapy and Simvastatin Treatment on Cervical Spine Disease in Mucopolysaccharidosis I Dogs

PubMed Central

Chiaro, Joseph A; O’Donnell, Patricia; Shore, Eileen M; Malhotra, Neil R; Ponder, Katherine P; Haskins, Mark E; Smith, Lachlan J

2014-01-01

Mucopolysaccharidosis I (MPS I) is a lysosomal storage disease characterized by deficient α-L-iduronidase activity, leading to the accumulation of poorly degraded glycosaminoglycans (GAGs). Children with MPS I exhibit high incidence of spine disease, including accelerated disc degeneration and vertebral dysplasia, which in turn lead to spinal cord compression and kypho-scoliosis. In this study we investigated the efficacy of neonatal enzyme replacement therapy (ERT), alone or in combination with oral simvastatin (ERT+SIM) for attenuating cervical spine disease progression in MPS I, using a canine model. Four groups were studied: normal controls; MPS I untreated; MPS I ERT treated; and MPS I ERT+SIM treated. Animals were euthanized at one year-of-age. Intervertebral disc condition and spinal cord compression were evaluated from MRIs and plain radiographs, vertebral bone condition and odontoid hypoplasia were evaluated using microcomputed tomography, and epiphyseal cartilage to bone conversion was evaluated histologically. Untreated MPS I animals exhibited more advanced disc degeneration and more severe spinal cord compression than normal animals. Both treatment groups resulted in partial preservation of disc condition and cord compression, with ERT+SIM not significantly better than ERT alone. Untreated MPS I animals had significantly lower vertebral trabecular bone volume and mineral density, while ERT treatment resulted in partial preservation of these properties. ERT+SIM treatment demonstrated similar, but not greater, efficacy. Both treatment groups partially normalized endochondral ossification in the vertebral epiphyses (as indicated by absence of persistent growth plate cartilage), and odontoid process size and morphology. These results indicate that ERT begun from a very early age attenuates the severity of cervical spine disease in MPS I, particularly for the vertebral bone and odontoid process, and that additional treatment with simvastatin does not provide a significant additional benefit over ERT alone. PMID:24898323

Reestablishment of radiographic kidney size in Miniature Schnauzer dogs

PubMed Central

SOHN, Jungmin; YUN, Sookyung; LEE, Jeosoon; CHANG, Dongwoo; CHOI, Mincheol; YOON, Junghee

2016-01-01

Kidney size may be altered in renal diseases, and the detection of kidney size alteration has diagnostic and prognostic values. We hypothesized that radiographic kidney size, the kidney length to the second lumbar vertebra (L2) length ratio, in normal Miniature Schnauzer dogs may be overestimated due to their shorter vertebral length. This study was conducted to evaluate radiographic and ultrasonographic kidney size and L2 length in clinically normal Miniature Schnauzers and other dog breeds to evaluate the effect of vertebral length on radiographic kidney size and to reestablish radiographic kidney size in normal Miniature Schnauzers. Abdominal radiographs and ultrasonograms from 49 Miniature Schnauzers and 54 other breeds without clinical evidence of renal disease and lumbar vertebral abnormality were retrospectively evaluated. Radiographic kidney size, in the Miniature Schnauzer (3.31 ± 0.26) was significantly larger than that in other breeds (2.94 ± 0.27). Relative L2 length, the L2 length to width ratio, in the Miniature Schnauzer (1.11 ± 0.06) was significantly shorter than that in other breeds (1.21 ± 0.09). However, ultrasonographic kidney sizes, kidney length to aorta diameter ratios, were within or very close to normal range both in the Miniature Schnauzer (6.75 ± 0.67) and other breeds (7.16 ± 1.01). Thus, Miniature Schnauzer dogs have breed-specific short vertebrae and consequently a larger radiographic kidney size, which was greater than standard reference in normal adult dogs. Care should be taken when evaluating radiographic kidney size in Miniature Schnauzers to prevent falsely diagnosed renomegaly. PMID:27594274

Skeletal maturation in obese patients.

PubMed

Giuca, Maria Rita; Pasini, Marco; Tecco, Simona; Marchetti, Enrico; Giannotti, Laura; Marzo, Giuseppe

2012-12-01

The objective of this study was to compare skeletal maturation in obese patients and in subjects of normal weight to evaluate the best timing for orthopedic and orthodontic treatment. The null hypothesis was that obese and normal-weight patients show similar degrees of skeletal maturation. The sample for this retrospective study consisted of 50 white patients (28 boys, 22 girls) whose x-rays (hand-wrist and lateral cephalometric radiographs) were already available. The test group included 25 obese patients (11 girls, 14 boys; average age, 9.8 ± 2.11 years), and the control group included 25 subjects of normal weight (11 girls, 14 boys; average age, 9.9 ± 2.5 years). Skeletal maturation was determined by using the carpal analysis method and the cervical vertebral maturation method. According to the carpal analysis, there was a significant difference between skeletal and chronologic ages between the test group (11.8 ± 11.4 months) and the control group (-2.9 ± 3.1 months). Furthermore, the obese subjects exhibited a significantly higher mean cervical vertebral maturation score (2.8 ± 0.7) than did the control subjects (2 ± 0.6) (P <0.05). Compared with the normal-weight subjects, the obese subjects showed a higher mean discrepancy between skeletal and chronologic ages according to the carpal analysis and had a significantly higher cervical vertebral maturation score. Thus, to account for the growth in obese patients with skeletal discrepancies, it might be necessary to perform examinations and dentofacial and orthopedic treatments earlier than in normal-weight subjects. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

The osteoporotic vertebral structure is well adapted to the loads of daily life, but not to infrequent "error" loads.

PubMed

Homminga, J; Van-Rietbergen, B; Lochmüller, E M; Weinans, H; Eckstein, F; Huiskes, R

2004-03-01

Osteoporotic vertebral fractures typically have a gradual onset, frequently remain clinically undetected, and do not seem to be related to traumatic events. The osteoporotic vertebrae may therefore be expected to display a less "optimal" bone architecture, leading to an uneven load distribution over the bone material. We evaluated the trabecular load distribution in an osteoporotic and a healthy vertebra under normal daily loading by combining three recent innovations: high resolution computed tomography (microCT) of entire bones, microfinite element analyses (microFEA), and parallel supercomputers. Much to our surprise, the number of highly loaded trabeculae was not higher in the osteoporotic vertebra than in the healthy one under normal daily loads (8% and 9%, respectively). The osteoporotic trabeculae were more oriented in the longitudinal direction, compensating for effects of bone loss and ensuring adequate stiffness for normal daily loading. The increased orientation did, however, make the osteoporotic structure less resistant against collateral "error" loads. In this case, the number of overloaded trabeculae in the osteoporotic vertebra was higher than in the healthy one (13% and 4%, respectively). These results strengthen the paradigm of a strong relationship between bone morphology and external loads applied during normal daily life. They also indicate that vertebral fractures result from actions like forward flexion or lifting, loads that may not be "daily" but are normally not traumatic either. If future clinical imaging techniques would enable such high-resolution images to be obtained in vivo, the combination of microCT and microFEA would produce a powerful tool to diagnose osteoporosis.

Reestablishment of radiographic kidney size in Miniature Schnauzer dogs.

PubMed

Sohn, Jungmin; Yun, Sookyung; Lee, Jeosoon; Chang, Dongwoo; Choi, Mincheol; Yoon, Junghee

2017-01-10

Kidney size may be altered in renal diseases, and the detection of kidney size alteration has diagnostic and prognostic values. We hypothesized that radiographic kidney size, the kidney length to the second lumbar vertebra (L2) length ratio, in normal Miniature Schnauzer dogs may be overestimated due to their shorter vertebral length. This study was conducted to evaluate radiographic and ultrasonographic kidney size and L2 length in clinically normal Miniature Schnauzers and other dog breeds to evaluate the effect of vertebral length on radiographic kidney size and to reestablish radiographic kidney size in normal Miniature Schnauzers. Abdominal radiographs and ultrasonograms from 49 Miniature Schnauzers and 54 other breeds without clinical evidence of renal disease and lumbar vertebral abnormality were retrospectively evaluated. Radiographic kidney size, in the Miniature Schnauzer (3.31 ± 0.26) was significantly larger than that in other breeds (2.94 ± 0.27). Relative L2 length, the L2 length to width ratio, in the Miniature Schnauzer (1.11 ± 0.06) was significantly shorter than that in other breeds (1.21 ± 0.09). However, ultrasonographic kidney sizes, kidney length to aorta diameter ratios, were within or very close to normal range both in the Miniature Schnauzer (6.75 ± 0.67) and other breeds (7.16 ± 1.01). Thus, Miniature Schnauzer dogs have breed-specific short vertebrae and consequently a larger radiographic kidney size, which was greater than standard reference in normal adult dogs. Care should be taken when evaluating radiographic kidney size in Miniature Schnauzers to prevent falsely diagnosed renomegaly.

Computerized tomographic determination of spinal bone mineral content

NASA Technical Reports Server (NTRS)

Cann, C. E.; Genant, H. K.

1980-01-01

The aims of the study were three-fold: to determine the magnitude of vertebral cancellous mineral loss in normal subjects during bedrest, to compare this loss with calcium balance and mineral loss in peripheral bones, and to use the vertebral measurements as an evaluative criterion for the C12MDP treatment and compare it with other methods. The methods used are described and the results from 14 subjects are presented.

Aspergillus vertebral osteomyelitis in immunocompetent patients.

PubMed

Sethi, Somika; Siraj, Fouzia; Kalra, Kl; Chopra, P

2012-03-01

Fungal infections are one of the important cause of morbidity and mortality in immunocompromised patients. Aspergillus vertebral osteomyelitis is extremely rare. We report two cases of aspergillus vertebral osteomyelitis in immunocompetent men in the absence of an underlying disorder. The clinical and radiological findings were suggestive of Pott's spine. The absolute CD4, CD8 counts and their ratio were normal. The HIV status was negative in both patients. Both patients underwent surgical decompression. The histopathology of tissue obtained were suggestive of aspergillus osteomyelitis. One patient had antifungal treatment for 3 months and was doing well at 1 year followup, whereas other patient did not turnup after 2 months.

Aspergillus vertebral osteomyelitis in immunocompetent patients

PubMed Central

Sethi, Somika; Siraj, Fouzia; Kalra, KL; Chopra, P

2012-01-01

Fungal infections are one of the important cause of morbidity and mortality in immunocompromised patients. Aspergillus vertebral osteomyelitis is extremely rare. We report two cases of aspergillus vertebral osteomyelitis in immunocompetent men in the absence of an underlying disorder. The clinical and radiological findings were suggestive of Pott's spine. The absolute CD4, CD8 counts and their ratio were normal. The HIV status was negative in both patients. Both patients underwent surgical decompression. The histopathology of tissue obtained were suggestive of aspergillus osteomyelitis. One patient had antifungal treatment for 3 months and was doing well at 1 year followup, whereas other patient did not turnup after 2 months. PMID:22448068

Symptomatic vertebral hemangioma in pregnancy treated antepartum. A case report with review of literature

PubMed Central

Vijay, Kamath; Shetty, Ajoy P.

2008-01-01

Pregnancy related compressive myelopathy secondary to vertebral hemangioma is a rare occurrence and its treatment antepartum is rare. We report a 22-year-old lady in her 26th-week of pregnancy who was treated in two stages––antepartum with a laminectomy and posterior stabilization. This resulted in complete recovery of the neurological deficits. She delivered a normal baby after 3 months, following which a corpectomy and fusion was performed. This two-staged approach appears safe and effective in treating symptomatic vertebral haemangiomas causing neurological deficits during pregnancy. A review of relevant literature has been done. PMID:18224354

An overview of vertebrate mineralization with emphasis on collagen-mineral interaction

NASA Technical Reports Server (NTRS)

Landis, W. J.

1999-01-01

The nucleation, growth, and development of mineral crystals through their interaction principally with collagen in normal bone and calcifying tendon have been elaborated by applying a number of different techniques for analysis of the inorganic and organic constituents of these tissues. The methods have included conventional and high voltage electron microscopy, electron diffraction, microscopic tomography and 3D image reconstruction, and atomic force microscopy. This summary presents results of these studies that have now characterized the size, shape, and aspects of the chemical nature of the crystals as well as their orientation, alignment, location, and distribution with respect to collagen. These data have provided the means for understanding more completely the formation and strength of the collagen-mineral composite present in most vertebrate calcifying tissues and, from that information, a basis for the adaptation of such tissues under mechanical constraints. In the context of the latter point, other data are given showing effects on collagen in bone cell cultures subjected to the unloading parameters of spaceflight. Implications of these results may be particularly relevant to explaining loss of bone by humans and other vertebrate animals during missions in space, during situations of extended fracture healing, long-term bedrest, physical immobilization, and related conditions. In a broader sense, the data speak to the response of bone and mineralized vertebrate tissues to changes in gravitational loading and applied mechanical forces in general.

A New Vertebral Body Replacement Strategy Using Expandable Polymeric Cages

PubMed Central

Liu, Xifeng; Paulsen, Alex; Giambini, Hugo; Guo, Ji; Miller, A. Lee; Lin, Po-Chun; Yaszemski, Michael J.

2017-01-01

We have developed a novel polymeric expandable cage that can be delivered via a posterior-only surgical approach for the treatment of noncontained vertebral defects. This approach is less invasive than an anterior-only or combined approach and much more cost-effective than currently used expandable metal cages. The polymeric expandable cage is composed of oligo poly(ethylene glycol) fumarate (OPF), a hydrogel that has been previously shown to have excellent nerve and bone tissue biocompatibility. OPF hydrogel cages can expand to twice their original diameter and length within a surgical time frame following hydration. Modulation of parameters such as polymeric network crosslink density or the introduction of charge to the network allowed for precise expansion kinetics. To meet specific requirements due to size variations in patient vertebral bodies, we fabricated a series of molds with varied diameters and explored the expansion kinetics of the OPF cages. Results showed a stable expansion ratio of approximately twofold to the original size within 20 min, regardless of the absolute value of the cage size. Following implantation of a dried OPF cage into a noncontained vertebral defect and its in situ expansion with normal saline, other augmentation biomaterials, such as poly(propylene fumarate) (PPF), can be injected to the lumen of the OPF cage and allowed to crosslink in situ. The OPF/PPF composite scaffold can provide the necessary rigidity and stability to the augmented spine. PMID:27835935

Update on the Notochord Including its Embryology, Molecular Development, and Pathology: A Primer for the Clinician

PubMed Central

Ramesh, Tushar; Nagula, Sai V; Saker, Erfanul; Shoja, Mohammadali; Loukas, Marios; Oskouian, Rod J; Tubbs, R. Shane

2017-01-01

The notochord is a rod-like embryological structure, which plays a vital role in the development of the vertebrate. Though embryological, remnants of this structure have been observed in the nucleus pulposus of the intervertebral discs of normal adults. Pathologically, these remnants can give rise to slow-growing and recurrent notochord-derived tumors called chordomas. Using standard search engines, the literature was reviewed regarding the anatomy, embryology, molecular development, and pathology of the human notochord. Clinicians who interpret imaging or treat patients with pathologies linked to the notochord should have a good working knowledge of its development and pathology. PMID:28480155

Establishment of estrogen receptor 1 (ESR1)-knockout medaka: ESR1 is dispensable for sexual development and reproduction in medaka, Oryzias latipes.

PubMed

Tohyama, Saki; Ogino, Yukiko; Lange, Anke; Myosho, Taijun; Kobayashi, Tohru; Hirano, Yu; Yamada, Gen; Sato, Tomomi; Tatarazako, Norihisa; Tyler, Charles R; Iguchi, Taisen; Miyagawa, Shinichi

2017-08-01

Estrogens play fundamental roles in regulating reproductive activities and they act through estrogen receptor (ESR) in all vertebrates. Most vertebrates have two ESR subtypes (ESR1 and ESR2), whereas teleost fish have at least three (Esr1, Esr2a and Esr2b). Intricate functionalization has been suggested among the Esr subtypes, but to date, distinct roles of Esr have been characterized in only a limited number of species. Study of loss-of-function in animal models is a powerful tool for application to understanding vertebrate reproductive biology. In the current study, we established esr1 knockout (KO) medaka using a TALEN approach and examined the effects of Esr1 ablation. Unexpectedly, esr1 KO medaka did not show any significant defects in their gonadal development or in their sexual characteristics. Neither male or female esr1 KO medaka exhibited any significant changes in sexual differentiation or reproductive activity compared with wild type controls. Interestingly, however, estrogen-induced vitellogenin gene expression, an estrogen-responsive biomarker in fish, was limited in the liver of esr1 KO males. Our findings, in contrast to mammals, indicate that Esr1 is dispensable for normal development and reproduction in medaka. We thus provide an evidence for estrogen receptor functionalization between mammals and fish. Our findings will also benefit interpretation of studies into the toxicological effects of estrogenic chemicals in fish. © 2017 Japanese Society of Developmental Biologists.

High-resolution computed tomography evaluation of the bronchial lumen to vertebral body diameter and pulmonary artery to vertebral body diameter ratios in anesthetized ventilated normal cats.

PubMed

Lee-Fowler, Tekla M; Cole, Robert C; Dillon, A Ray; Tillson, D Michael; Garbarino, Rachel; Barney, Sharron

2017-10-01

Objectives Bronchial lumen to pulmonary artery diameter (BA) ratio has been utilized to investigate pulmonary pathology on high-resolution CT images. Diseases affecting both the bronchi and pulmonary arteries render the BA ratio less useful. The purpose of the study was to establish bronchial lumen diameter to vertebral body diameter (BV) and pulmonary artery diameter to vertebral body diameter (AV) ratios in normal cats. Methods Using high-resolution CT images, 16 sets of measurements (sixth thoracic vertebral body [mid-body], each lobar bronchi and companion pulmonary artery diameter) were acquired from young adult female cats and 41 sets from pubertal female cats. Results Young adult and pubertal cat BV ratios were not statistically different from each other in any lung lobe. Significant differences between individual lung lobe BV ratios were noted on combined age group analysis. Caudal lung lobe AV ratios were significantly different between young adult and pubertal cats. All other lung lobe AV ratios were not significantly different. Caudal lung lobe AV ratios were significantly different from all other lung lobes but not from each other in both the young adult and pubertal cats. Conclusions and relevance BV ratio reference intervals determined for individual lung lobes could be applied to both young adult and pubertal cats. Separate AV ratios for individual lung lobes would be required for young adult and pubertal cats. These ratios should allow more accurate evaluation of cats with concurrent bronchial and pulmonary arterial disease.

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.

A novel mammal-specific three partite enhancer element regulates node and notochord-specific Noto expression.

PubMed

Alten, Leonie; Schuster-Gossler, Karin; Eichenlaub, Michael P; Wittbrodt, Beate; Wittbrodt, Joachim; Gossler, Achim

2012-01-01

The vertebrate organizer and notochord have conserved, essential functions for embryonic development and patterning. The restricted expression of developmental regulators in these tissues is directed by specific cis-regulatory modules (CRMs) whose sequence conservation varies considerably. Some CRMs have been conserved throughout vertebrates and likely represent ancestral regulatory networks, while others have diverged beyond recognition but still function over a wide evolutionary range. Here we identify and characterize a mammalian-specific CRM required for node and notochord specific (NNC) expression of NOTO, a transcription factor essential for node morphogenesis, nodal cilia movement and establishment of laterality in mouse. A 523 bp enhancer region (NOCE) upstream the Noto promoter was necessary and sufficient for NNC expression from the endogenous Noto locus. Three subregions in NOCE together mediated full activity in vivo. Binding sites for known transcription factors in NOCE were functional in vitro but dispensable for NOCE activity in vivo. A FOXA2 site in combination with a novel motif was necessary for NOCE activity in vivo. Strikingly, syntenic regions in non-mammalian vertebrates showed no recognizable sequence similarities. In contrast to its activity in mouse NOCE did not drive NNC expression in transgenic fish. NOCE represents a novel, mammal-specific CRM required for the highly restricted Noto expression in the node and nascent notochord and thus regulates normal node development and function.

Analysis of 14-3-3 Family Member Function in Xenopus Embryos by Microinjection of Antisense Morpholino Oligos

NASA Astrophysics Data System (ADS)

Lau, Jeffrey M. C.; Muslin, Anthony J.

The 14-3-3 intracellular phosphoserine/threonine-binding proteins are adapter molecules that regulate signal transduction, cell cycle, nutrient sensing, apoptotic, and cytoskeletal pathways. There are seven 14-3-3 family members, encoded by separate genes, in vertebrate organisms. To evaluate the role of individual 14-3-3 proteins in vertebrate embryonic development, we utilized an antisense morpholino oligo microinjection technique in Xenopus laevis embryos. By use of this method, we showed that embryos lacking specific 14-3-3 proteins displayed unique phenotypic abnormalities. Specifically, embryos lacking 14-3-3 τ exhibited gastrulation and axial patterning defects, but embryos lacking 14-3-3 γ exhibited eye defects without other abnormalities, and embryos lacking 14-3-3 ζ appeared completely normal. These and other results demonstrate the power and specificity of the morpholino antisense oligo microinjection technique.

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

Kvon, Evgeny Z.; Kamneva, Olga K.; Melo, Uirá S.

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. In this paper, 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 orthologsmore » 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.« less

Transcriptome analysis of the planarian eye identifies ovo as a specific regulator of eye regeneration

PubMed Central

Lapan, Sylvain W.; Reddien, Peter W.

2013-01-01

Summary Among the millions of invertebrate species with visual systems, the genetic basis of eye development and function is well understood only in Drosophila melanogaster. We describe an eye transcriptome for the planarian Schmidtea mediterranea. Planarian photoreceptors expressed orthologs of genes required for phototransduction and microvillus structure in Drosophila and vertebrates, and optic pigment cells expressed solute transporters and melanin synthesis enzymes similar to those active in the vertebrate retinal pigment epithelium. Orthologs of several planarian eye genes, such as bestrophin-1 and Usher syndrome genes, cause eye defects in mammals when perturbed and were not previously described to have roles in invertebrate eyes. Five previously undescribed planarian eye transcription factors were required for normal eye formation during head regeneration. In particular, a conserved, transcription factor-encoding ovo gene was expressed from the earliest stages of eye regeneration and was required for regeneration of all cell types of the eye. PMID:22884275

[Number of teeth and hormonal profile of postmenopausal women with osteoporosis, osteopenia and normal bone mineral density--a preliminary study].

PubMed

Stagraczyński, Maciej; Kulczyk, Tomasz; Leszczyński, Piotr; Męczekalski, Błażej

2015-10-01

Profound hypoestrogenism causes increased risk of osteoporosis and bone fracture in menopause. This period of women life is also characterized by decrease number of teeth and deterioration of oral cavity health. The aim of the study was to assess the number of teeth, hormonal profile (Follicle-stimualting hormone (FSH), estradiol (E2), testosterone (T) and dehydroepiandrosterone sulphate (DHEA-S) and the bone mineral density (BMD) of the lumbar part of the spine in postmenopausal women with osteoporosis, osteopenia and normal BMD. The next step of the study was to determine whether there was a correlation between vertebral mineral bone density, the hormonal profile and the number of teeth. A total number of 47 women was involved in the study. Based on the results of densitometry tests (DEXA) of vertebral column the subjects were divided into 3 groups: 10 with osteoporosis, 20 with osteopenia and 17 with normal BMD. All the subjects had undergone a hormonal assessment which included blood serum estimation for FSH, E2, DHEA-S and T levels. Also the total number of teeth present was recorded. Serum estradiol and testosterone levels in postmenopausal women were found to be positively correlated with the number of teeth present. A negative correlation was found between age and the number of maxillary teeth in postmenopausal women with osteopenia. There was no influence of serum FSH, estradiol, testosterone and DHEA-S levels on vertebral BMD loss in postmenopausal women. There was no correlation between teeth number and BMD of vertebral column. Serum levels of estradiol and testosterone in postmenopausal women positively correlate with teeth numbers. Age is the main risk factor for teeth loss in postmenopausal women. © 2015 MEDPRESS.

Left hemibody myoclonus due to anomalous right vertebral artery.

PubMed

Coelho, Miguel; Marti, Maria J; Valls-Solé, Josep; Pujol, Teresa; Tolosa, Eduardo

2005-01-01

A 43-year-old man presented with sporadic, sudden, brief, and involuntary jerks of his left limbs and trunk muscles. The electromyographic recordings showed short-lasting highly synchronized bursts, compatible with myoclonus limited to the left hemibody. Blink reflex, masseter silent period, cortical and spinal magnetic stimulation, somatosensory cortical evoked potentials, and electroencephalogram (EEG) were normal; the EEG back-averaging showed no spikes preceding the myoclonus. Magnetic resonance imaging and magnetic resonance angiography showed the presence of an anomalous nonectasic right vertebral artery compressing the right side of ventral medulla oblongata. We hypothesize that the aberrant right vertebral artery induced abnormal activation of descending motor tracts responsible for the myoclonus. (c) 2004 Movement Disorder Society.

Vertebrate Presynaptic Active Zone Assembly: a Role Accomplished by Diverse Molecular and Cellular Mechanisms.

PubMed

Torres, Viviana I; Inestrosa, Nibaldo C

2018-06-01

Among all the biological systems in vertebrates, the central nervous system (CNS) is the most complex, and its function depends on specialized contacts among neurons called synapses. The assembly and organization of synapses must be exquisitely regulated for a normal brain function and network activity. There has been a tremendous effort in recent decades to understand the molecular and cellular mechanisms participating in the formation of new synapses and their organization, maintenance, and regulation. At the vertebrate presynapses, proteins such as Piccolo, Bassoon, RIM, RIM-BPs, CAST/ELKS, liprin-α, and Munc13 are constant residents and participate in multiple and dynamic interactions with other regulatory proteins, which define network activity and normal brain function. Here, we review the function of these active zone (AZ) proteins and diverse factors involved in AZ assembly and maintenance, with an emphasis on axonal trafficking of precursor vesicles, protein homo- and hetero-oligomeric interactions as a mechanism of AZ trapping and stabilization, and the role of F-actin in presynaptic assembly and its modulation by Wnt signaling.

‘Monster… -omics’: on segmentation, re-segmentation, and vertebrae formation in amphibians and other vertebrates

PubMed Central

2013-01-01

Background The axial skeleton is one of the defining evolutionary landmarks of vertebrates. How this structure develops and how it has evolved in the different vertebrate lineages is, however, a matter of debate. Vertebrae and vertebral structures are derived from the embryonic somites, although the mechanisms of development are different between lineages. Discussion Using the anecdotal description of a teratological newt (Triturus dobrogicus) with an unusual malformation in its axial skeleton, we review, compare, and discuss the development of vertebral structures and, in particular, the development of centra from somitic cellular domains in different vertebrate groups. Vertebrae development through re-segmentation of the somitic sclerotomal cells is considered the general mechanism among vertebrates, which has been generalized from studies in amniotic model organisms. The prevalence of this mechanism among anamniotes is, however, controversial. We propose alternative developmental mechanisms for vertebrae formation that should be experimentally tested. Summary Research in model organisms, especially amniotes, is laying the foundations for a thorough understanding of the mechanisms of development of the axial skeleton in vertebrates, foundations that should expand the extent of future comparative studies. Although immersed in the ‘-omics’ era, we emphasize the need for an integrative and organismal approach in evolutionary developmental biology for a better understanding of the causal role of development in the evolution of morphological diversity in nature. PMID:23577917

The origin and diversification of the developmental mechanisms that pattern the vertebrate head skeleton.

PubMed

Square, Tyler; Jandzik, David; Romášek, Marek; Cerny, Robert; Medeiros, Daniel Meulemans

2017-07-15

The apparent evolvability of the vertebrate head skeleton has allowed a diverse array of shapes, sizes, and compositions of the head in order to better adapt species to their environments. This encompasses feeding, breathing, sensing, and communicating: the head skeleton somehow participated in the evolution of all these critical processes for the last 500 million years. Through evolution, present head diversity was made possible via developmental modifications to the first head skeletal genetic program. Understanding the development of the vertebrate common ancestor's head skeleton is thus an important step in identifying how different lineages have respectively achieved their many innovations in the head. To this end, cyclostomes (jawless vertebrates) are extremely useful, having diverged from jawed vertebrates approximately 400 million years ago, at the deepest node within living vertebrates. From this ancestral vantage point (that is, the node connecting cyclostomes and gnathostomes) we can best identify the earliest major differences in development between vertebrate classes, and start to address how these might translate onto morphology. In this review we survey what is currently known about the cell biology and gene expression during head development in modern vertebrates, allowing us to better characterize the developmental genetics driving head skeleton formation in the most recent common ancestor of all living vertebrates. By pairing this vertebrate composite with information from fossil chordates, we can also deduce how gene regulatory modules might have been arranged in the ancestral vertebrate head. Together, we can immediately begin to understand which aspects of head skeletal development are the most conserved, and which are divergent, informing us as to when the first differences appear during development, and thus which pathways or cell types might be involved in generating lineage specific shape and structure. Copyright © 2017 Elsevier Inc. All rights reserved.

Pathogenesis of lumbar spine disease in mucopolysaccharidosis VII

PubMed Central

Smith, Lachlan J; Baldo, Guilherme; Wu, Susan; Liu, Yuli; Whyte, Michael P; Giugliani, Roberto; Elliott, Dawn M; Haskins, Mark E; Ponder, Katherine P

2012-01-01

Mucopolysaccharidosis type VII (MPS VII) is characterized by deficient β-glucuronidase (GUSB) activity, which leads to accumulation of chondroitin, heparan and dermatan sulfate glycosaminoglycans (GAGs), and multisystemic disease. MPS VII patients can develop kypho-scoliotic deformity and spinal cord compression due to disease of intervertebral discs, vertebral bodies, and associated tissues. We have previously demonstrated in MPS VII dogs that intervertebral discs degenerate, vertebral bodies have irregular surfaces, and vertebral body epiphyses have reduced calcification, but the pathophysiological mechanisms underlying these changes are unclear. We hypothesized that some of these manifestations could be due to upregulation of destructive proteases, possibly via the binding of GAGs to Toll-like receptor 4 (TLR4), as has been proposed for other tissues in MPS models. In this study, the annulus fibrosus of the intervertebral disc of 6 month-old MPS VII dogs had cathepsin B and K activities that were 117- and 2-fold normal, respectively, which were associated with elevations in mRNA levels for cathepsins as well as TLR4. The epiphyses of MPS VII dogs had a marked elevation in mRNA for the cartilage-associated gene collagen II, consistent with a developmental delay in the conversion of the cartilage to bone in this region. A spine from a human patient with MPS VII exhibited similar increased cartilage in the vertebral bodies adjacent to the end plates, disorganization of the intervertebral discs, and irregular vertebral end plate morphology. These data suggest that the pathogenesis of destructive changes in the spine in MPS VII may involve upregulation of cathepsins. Inhibition of destructive proteases, such as cathepsins, might reduce spine disease in patients with MPS VII or related disorders. PMID:22513347

Expression of growth differentiation factor 6 in the human developing fetal spine retreats from vertebral ossifying regions and is restricted to cartilaginous tissues.

PubMed

Wei, Aiqun; Shen, Bojiang; Williams, Lisa A; Bhargav, Divya; Gulati, Twishi; Fang, Zhimin; Pathmanandavel, Sarennya; Diwan, Ashish D

2016-02-01

During embryogenesis vertebral segmentation is initiated by sclerotomal cell migration and condensation around the notochord, forming anlagen of vertebral bodies and intervertebral discs. The factors that govern the segmentation are not clear. Previous research demonstrated that mutations in growth differentiation factor 6 resulted in congenital vertebral fusion, suggesting this factor plays a role in development of vertebral column. In this study, we detected expression and localization of growth differentiation factor 6 in human fetal spinal column, especially in the period of early ossification of vertebrae and the developing intervertebral discs. The extracellular matrix proteins were also examined. Results showed that high levels of growth differentiation factor 6 were expressed in the nucleus pulposus of intervertebral discs and the hypertrophic chondrocytes adjacent to the ossification centre in vertebral bodies, where strong expression of proteoglycan and collagens was also detected. As fetal age increased, the expression of growth differentiation factor 6 was decreased correspondingly with the progress of ossification in vertebral bodies and restricted to cartilaginous regions. This expression pattern and the genetic link to vertebral fusion suggest that growth differentiation factor 6 may play an important role in suppression of ossification to ensure proper vertebral segmentation during spinal development. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Optimal design of vertebrate and insect sarcomeres.

PubMed

Otten, E

1987-01-01

This paper offers a model for the normalized length-tension relation of a muscle fiber based upon sarcomere design. Comparison with measurements published by Gordon et al. ('66) shows an accurate fit as long as the inhomogeneity of sarcomere length in a single muscle fiber is taken into account. Sequential change of filament length and the length of the cross-bridge-free zone leads the model to suggest that most vertebrate sarcomeres tested match the condition of optimal construction for the output of mechanical energy over a full sarcomere contraction movement. Joint optimization of all three morphometric parameters suggests that a slightly better (0.3%) design is theoretically possible. However, this theoretical sarcomere, optimally designed for the conversion of energy, has a low normalized contraction velocity; it provides a poorer match to the combined functional demands of high energy output and high contraction velocity than the real sarcomeres of vertebrates. The sarcomeres in fish myotomes appear to be built suboptimally for isometric contraction, but built optimally for that shortening velocity generating maximum power. During swimming, these muscles do indeed contract concentrically only. The sarcomeres of insect asynchronous flight muscles contract only slightly. They are not built optimally for maximum output of energy across the full range of contraction encountered in vertebrate sarcomeres, but are built almost optimally for the contraction range that they do in fact employ.

Score Distributions of the Balance Outcome Measure for Elder Rehabilitation (BOOMER) in Community-Dwelling Older Adults With Vertebral Fracture.

PubMed

Brown, Zachary M; Gibbs, Jenna C; Adachi, Jonathan D; Ashe, Maureen C; Hill, Keith D; Kendler, David L; Khan, Aliya; Papaioannou, Alexandra; Prasad, Sadhana; Wark, John D; Giangregorio, Lora M

2017-11-28

We sought to evaluate the Balance Outcome Measure for Elder Rehabilitation (BOOMER) in community-dwelling women 65 years and older with vertebral fracture and to describe score distributions and potential ceiling and floor effects. This was a secondary data analysis of baseline data from the Build Better Bones with Exercise randomized controlled trial using the BOOMER. A total of 141 women with osteoporosis and radiographically confirmed vertebral fracture were included. Concurrent validity and internal consistency were assessed in comparison to the Short Physical Performance Battery (SPPB). Normality and ceiling/floor effects of total BOOMER scores and component test items were also assessed. Exploratory analyses of assistive aid use and falls history were performed. Tests for concurrent validity demonstrated moderate correlation between total BOOMER and SPPB scores. The BOOMER component tests showed modest internal consistency. Substantial ceiling effect and nonnormal score distributions were present among overall sample and those not using assistive aids for total BOOMER scores, although scores were normally distributed for those using assistive aids. The static standing with eyes closed test demonstrated the greatest ceiling effects of the component tests, with 92% of participants achieving a maximal score. While the BOOMER compares well with the SPPB in community-dwelling women with vertebral fractures, researchers or clinicians considering using the BOOMER in similar or higher-functioning populations should be aware of the potential for ceiling effects.

Proton density fat fraction (PDFF) MRI for differentiation of benign and malignant vertebral lesions.

PubMed

Schmeel, Frederic Carsten; Luetkens, Julian Alexander; Wagenhäuser, Peter Johannes; Meier-Schroers, Michael; Kuetting, Daniel Lloyd; Feißt, Andreas; Gieseke, Jürgen; Schmeel, Leonard Christopher; Träber, Frank; Schild, Hans Heinz; Kukuk, Guido Matthias

2018-06-01

To investigate whether proton density fat fraction (PDFF) measurements using a six-echo modified Dixon sequence can help to differentiate between benign and malignant vertebral bone marrow lesions. Sixty-six patients were prospectively enrolled in our study. In addition to conventional MRI at 3.0-Tesla including at least sagittal T2-weighted/spectral attenuated inversion recovery and T1-weighted sequences, all patients underwent a sagittal six-echo modified Dixon sequence of the spine. The mean PDFF was calculated using regions of interest and compared between vertebral lesions. A cut-off value of 6.40% in PDFF was determined by receiver operating characteristic curves and used to differentiate between malignant (< 6.40%) and benign (≥ 6.40%) vertebral lesions. There were 77 benign and 44 malignant lesions. The PDFF of malignant lesions was statistically significant lower in comparison with benign lesions (p < 0.001) and normal vertebral bone marrow (p < 0.001). The areas under the curves (AUC) were 0.97 for differentiating benign from malignant lesions (p < 0.001) and 0.95 for differentiating acute vertebral fractures from malignant lesions (p < 0.001). This yielded a diagnostic accuracy of 96% in the differentiation of both benign lesions and acute vertebral fractures from malignancy. PDFF derived from six-echo modified Dixon allows for differentiation between benign and malignant vertebral lesions with a high diagnostic accuracy. • Establishing a diagnosis of indeterminate vertebral lesions is a common clinical problem • Benign bone marrow processes may mimic the signal alterations observed in malignancy • PDFF differentiates between benign and malignant lesions with a high diagnostic accuracy • PDFF of non-neoplastic vertebral lesions is significantly higher than that of malignancy • PDFF from six-echo modified Dixon may help avoid potentially harmful bone biopsy.

Evolution of endothelin receptors in vertebrates.

PubMed

Braasch, Ingo; Schartl, Manfred

2014-12-01

Endothelin receptors are G protein coupled receptors (GPCRs) of the β-group of rhodopsin receptors that bind to endothelin ligands, which are 21 amino acid long peptides derived from longer prepro-endothelin precursors. The most basal Ednr-like GPCR is found outside vertebrates in the cephalochordate amphioxus, but endothelin ligands are only present among vertebrates, including the lineages of jawless vertebrates (lampreys and hagfishes), cartilaginous vertebrates (sharks, rays, and chimaeras), and bony vertebrates (ray-finned fishes and lobe-finned vertebrates including tetrapods). A bona fide endothelin system is thus a vertebrate-specific innovation with important roles for regulating the cardiovascular system, renal and pulmonary processes, as well as for the development of the vertebrate-specific neural crest cell population and its derivatives. Expectedly, dysregulation of endothelin receptors and the endothelin system leads to a multitude of human diseases. Despite the importance of different types of endothelin receptors for vertebrate development and physiology, current knowledge on endothelin ligand-receptor interactions, on the expression of endothelin receptors and their ligands, and on the functional roles of the endothelin system for embryonic development and in adult vertebrates is very much biased towards amniote vertebrates. Recent analyses from a variety of vertebrate lineages, however, have shown that the endothelin system in lineages such as teleost fish and lampreys is more diverse and is divergent from the mammalian endothelin system. This diversity is mainly based on differential evolution of numerous endothelin system components among vertebrate lineages generated by two rounds of whole genome duplication (three in teleosts) during vertebrate evolution. Here we review current understanding of the evolutionary history of the endothelin receptor family in vertebrates supplemented with surveys on the endothelin receptor gene complement of newly available genome assemblies from phylogenetically informative taxa. Our assessment further highlights the diversity of the vertebrate endothelin system and calls for detailed functional and pharmacological analyses of the endothelin system beyond tetrapods. Copyright © 2014 Elsevier Inc. All rights reserved.

The posterior skeletal thorax: rib-vertebral angle and axial vertebral rotation asymmetries in adolescent idiopathic scoliosis.

PubMed

Burwell, R G; Aujla, R K; Freeman, B J C; Dangerfield, P H; Cole, A A; Kirby, A S; Polak, F J; Pratt, R K; Moulton, A

2008-01-01

The deformity of the ribcage in thoracic adolescent idiopathic scoliosis (AIS) is viewed by most as being secondary to the spinal deformity, though a few consider it primary or involved in curve aggravation. Those who consider it primary ascribe pathogenetic significance to rib-vertebra angle asymmetry. In thoracic AIS, supra-apical rib-vertebra angle differences (RVADs) are reported to be associated with the severity of the Cobb angle. In this paper we attempt to evaluate rib and spinal pathomechanisms in thoracic and thnoracolumbar AIS using spinal radiographs and real-time ultrasound. On the radiographs by costo-vertebral angle asymmetries (rib-vertebral angle differences RVADs, and rib-spinal angle differences RSADs), apical vertebral rotation (AV) and apical vertebral translation (AVT) were measured; and by ultrasound, spine-rib rotation differences (SRRDs) were estimated. RVADs are largest at two and three vertebral levels above the apex where they correlate significantly and positively with Cobb angle and AVT but not AVR. In right thoracic AIS, the cause(s) of the RVA asymmetries is unknown: it may result from trunk muscle imbalance, or from ribs adjusting passively within the constraint of the fourth column of the spine to increasing spinal curvature from whatever cause. Several possible mechanisms may drive axial vertebral rotation including, biplanar spinal asymmetry, relative anterior spinal overgrowth, dorsal shear forces in the presence of normal vertebral axial rotation, asymmetry of rib linear growth, trunk muscle imbalance causing rib-vertebra angle asymmetry weakening the spinal rotation-defending system of bipedal gait, and CNS mechanisms.

Preliminary Study of the Effects of Prolonged Acceleration on Spinal Dynamics of Baboons. 1. Acceleration. 2. Biomechanical Analysis

DTIC Science & Technology

1981-06-01

two systems to reduce distraction between the animals, The assigned (numbered) ECG leads were connected via long cables to the proper amplifier...midsection of the intervertebral disks, the articular capsules were sectioned, and the vertebral budies were cut away at the baa. of the pediclei using...on Normal and Avulsed Developing Avian Radii," .4viai- Space Environ, Med., 47?- 8214825. Negulesco, J. A. and T. Kossler, 1978, "Response of Articular

Pleurodeles waltl, amphibian, Urodele, is a suitable biological model for embryological and physiological space experiments on a vertebrate

NASA Astrophysics Data System (ADS)

Gualandris-Parisot, L.; Husson, D.; Foulquier, F.; Kan, P.; Davet, J.; Aimar, C.; Dournon, C.; Duprat, A. M.

2001-01-01

Pleurodeles waltl (amphibian, Urodele) is an appropriate biological model for space experiments on a vertebrate. One reason for interest in this animal concerns the study of the effects of absence of gravity on embryonic development. First, after mating (on Earth) the females retain live, functional sperm in their cloacum for up to 5 months, allowing normal in vivo fertilisation after hormonal stimulation. Second, their development is slow, which allows analyses of all the key stages of ontogenesis from the oocyte to swimming tailbud embryos or larvae. We have performed detailed studies and analyses of the effects of weightlessness on amphibian Pleurodeles embryos, fertilised and allowed to develop until the swimming larvae stage. These experiments were performed in space during three missions on the MIR-station: FERTILE I, FERTILE II and NEUROGENESIS respectively in 1996, 1998 and 1999. We show that in microgravity abnormalities appeared at specific stages of development compared to 1g-centrifuge control embryos and 1g-ground control embryos. In this report we describe abnormalities occurring in the central nervous system. These modifications occur during the neurulation process (delay in the closure of the neural tube and failure of closure of this tube in the cephalic area) and at the early tailbud stage (microcephaly observed in 40% of the microgravity-embryos). However, if acephalic and microcephalic embryos are not taken into account, these abnormalities did not disturb further morphological, biochemical and functional development and the embryos were able to regulate and a majority of normal hatching and swimming larvae were obtained in weightlessness with a developmental time-course equivalent to that of 1g-centrifuge control embryos (on the MIR station) and 1g-ground control embryos.

Morphometric analysis of the developing pediatric cervical spine.

PubMed

Johnson, Kyle T; Al-Holou, Wajd N; Anderson, Richard C E; Wilson, Thomas J; Karnati, Tejas; Ibrahim, Mohannad; Garton, Hugh J L; Maher, Cormac O

2016-09-01

OBJECTIVE Our understanding of pediatric cervical spine development remains incomplete. The purpose of this analysis was to quantitatively define cervical spine growth in a population of children with normal CT scans. METHODS A total of 1458 children older than 1 year and younger than 18 years of age who had undergone a cervical spine CT scan at the authors' institution were identified. Subjects were separated by sex and age (in years) into 34 groups. Following this assignment, subjects within each group were randomly selected for inclusion until a target of 15 subjects in each group had been measured. Linear measurements were performed on the midsagittal image of the cervical spine. Twenty-three unique measurements were obtained for each subject. RESULTS Data showed that normal vertical growth of the pediatric cervical spine continues up to 18 years of age in boys and 14 years of age in girls. Approximately 75% of the vertical growth occurs throughout the subaxial spine and 25% occurs across the craniovertebral region. The C-2 body is the largest single-segment contributor to vertical growth, but the subaxial vertebral bodies and disc spaces also contribute. Overall vertical growth of the cervical spine throughout childhood is dependent on individual vertebral body growth as well as vertical growth of the disc spaces. The majority of spinal canal diameter growth occurs by 4 years of age. CONCLUSIONS The authors' morphometric analyses establish parameters for normal pediatric cervical spine growth up to 18 years of age. These data should be considered when evaluating children for potential surgical intervention and provide a basis of comparison for studies investigating the effects of cervical spine instrumentation and fusion on subsequent growth.

Anthropometric measurements and vertebral deformities. European Vertebral Osteoporosis Study (EVOS) Group.

PubMed

Johnell, O; O'Neill, T; Felsenberg, D; Kanis, J; Cooper, C; Silman, A J

1997-08-15

To investigate the association between anthropometric indices and morphometrically determined vertebral deformity, the authors carried out a cross-sectional study using data from the European Vertebral Osteoporosis Study (EVOS), a population-based study of vertebral osteoporosis in 36 European centers from 19 countries. A total of 16,047 EVOS subjects were included in this analysis, of whom 1,973 subjects (915 males, 1,058 females) (12.3%) aged 50 years or over had one or more vertebral deformities ("cases"). The cases were compared with the 14,074 subjects (6,539 males, 7,535 females) with morphometrically normal spines ("controls"). Data were collected on self-reported height at age 25 years and minimum weight after age 25 years, as well as on current measured height and weight. Body mass index (BMI) and height and weight change were calculated from these data. The relations between these variables and vertebral deformity were examined separately by sex with logistic regression adjusting for age, smoking, and physical activity. In females, there was a significant trend of decreasing risk with increasing quintile of current weight, current BMI, and weight gain since age 25 years. In males, subjects in the lightest quintile for these measures were at increased risk but there was no evidence of a trend. An ecologic analysis by country revealed a negative correlation between mean BMI and the prevalence of deformity in females but not in males. The authors conclude that low body weight is associated with presence of vertebral deformity.

Thyroid hormones and their effects: a new perspective.

PubMed

Hulbert, A J

2000-11-01

The thyroid hormones are very hydrophobic and those that exhibit biological activity are 3',5',3,5-L-tetraiodothyronine (T4), 3',5,3-L-triiodothyronine (T3), 3',5',3-L-triiodothyronine (rT3) and 3,5',-L-diiothyronine (3,5-T2). At physiological pH, dissociation of the phenolic -OH group of these iodothyronines is an important determinant of their physical chemistry that impacts on their biological effects. When non-ionized these iodothyronines are strongly amphipathic. It is proposed that iodothyronines are normal constituents of biological membranes in vertebrates. In plasma of adult vertebrates, unbound T4 and T3 are regulated in the picomolar range whilst protein-bound T4 and T3 are maintained in the nanomolar range. The function of thyroid-hormone-binding plasma proteins is to ensure an even distrubtion throughout the body. Various iodothyronines are produced by three types of membrane-bound cellular deiodinase enzyme systems in vertebrates. The distribution of deiodinases varies between tissues and each has a distinct developmental profile. Thyroid hormones. (1) the nuclear receptor mode is especially important in the thyroid hormone axis that controls plasma and cellular levels of these hormones. (2) These hormones are strongly associated with membranes in tissues and normally rigidify these membranes. (3) They also affect the acyl composition of membrane bilayers and it is suggested that this is due to the cells responding to thyroid-hormone-induced membrane rigidificataion. Both their immediate effects on the physical state of membranes and the consequent changes in membrane composition result in several other thyroid hormone effects. Effects on metabolism may be due primarily to membrane acyl changes. There are other actions of thyroid hormones involving membrane receptors and influences on cellular interactions with the extracellulara matrix. The effects of thyroid hormones are reviewed and appear to b combinations of these various modes of action. During development, vertebrates show a surge in T4 and other thyroid hormones, as well as distinctive profiles in the appearance of the deiodinase enzymes and nuclear receptors. Evidence from the use of analogues supports multiple modes of action. Re-examination of data from th early 1960s supports a membrane action. Findings from receptor 'knockout' mice supports an important role for receptors in the development of the thyroid axis. These iodothyronines may be better thought of as 'vitamone'-like molecules than traditional hormonal messengers.

The effect of screw tunnels on the biomechanical stability of vertebral body after pedicle screws removal: a finite element analysis.

PubMed

Liu, Jia-Ming; Zhang, Yu; Zhou, Yang; Chen, Xuan-Yin; Huang, Shan-Hu; Hua, Zi-Kai; Liu, Zhi-Li

2017-06-01

Posterior reduction and pedicle screw fixation is a widely used procedure for thoracic and lumbar vertebrae fractures. Usually, the pedicle screws would be removed after the fracture healing and screw tunnels would be left. The aim of this study is to evaluate the effect of screw tunnels on the biomechanical stability of the lumbar vertebral body after pedicle screws removal by finite element analysis (FEA). First, the CT values of the screw tunnels wall in the fractured vertebral bodies were measured in patients whose pedicle screws were removed, and they were then compared with the values of vertebral cortical bone. Second, an adult patient was included and the CT images of the lumbar spine were harvested. Three dimensional finite element models of the L1 vertebra with unilateral or bilateral screw tunnels were created based on the CT images. Different compressive loads were vertically acted on the models. The maximum loads which the models sustained and the distribution of the force in the different parts of the models were recorded and compared with each other. The CT values of the tunnels wall and vertebral cortical bone were 387.126±62.342 and 399.204±53.612, which were not statistically different (P=0.149). The models of three dimensional tetrahedral mesh finite element of normal lumbar 1 vertebra were established with good geometric similarity and realistic appearance. After given the compressive loads, the cortical bone was the first one to reach its ultimate stress. The maximum loads which the bilateral screw tunnels model, unilateral screw tunnel model, and normal vertebral model can sustain were 3.97 Mpa, 3.83 Mpa, and 3.78 Mpa, respectively. For the diameter of the screw tunnels, the model with a diameter of 6.5 mm could sustain the largest load. In addition, the stress distributing on the outside of the cortical bone gradually decreased as the thickness of the tunnel wall increased. Based on the FEA, pedicle screw tunnels would not decrease the biomechanical stability and strength of the vertebral body. A large diameter of screw tunnel and thick tunnel wall were helpful for the biomechanical stability of the vertebral body.

Comparison of Morphological Characteristics of the Subaxial Cervical Spine between Athetoid Cerebral Palsy and Normal Control.

PubMed

Kim, Jun Young; Kwon, Jae Yeol; Kim, Moon Seok; Lee, Jeong Jae; Kim, Il Sup; Hong, Jae Taek

2018-03-01

To compare the morphometry of subaxial cervical spine between cerebral palsy (CP) and normal control. We retrospectively analyzed 72 patients with CP, as well as 72 patients from normal population. The two groups were matched for age, sex, and body mass index. Pedicle, lateral mass (LM), and vertebral foramen were evaluated using computed tomography (CT) imaging. Pedicle diameter, LM height, thickness, width and vertebral foramen asymmetry (VFA) were measured and compared between the two groups. Cervical dynamic motion, disc and facet joint degeneration were investigated. Additionally, we compared the morphology of LM between convex side and concave side with cervical scoliotic CP patients. LM height was smaller in CP group. LM thickness and width were larger in CP group at mid-cervical level. In 40 CP patients with cervical scoliosis, there were no height and width differences between convex and concave side. Pedicle outer diameter was not statistically different between two groups. Pedicle inner diameter was significantly smaller in CP group. Pedicle sclerosis was more frequent in CP patients. VFA was larger in CP group at C3, C4, and C5. Disc/facet degeneration grade was higher in the CP group. Cervical motion of CP group was smaller than those of the control group. LM morphology of CP patients was different from normal population. Sclerotic pedicles and vertebral foramen asymmetry were more commonly identified in CP patients. CP patients were more likely to demonstrate progressive disc/facet degeneration. This data may provide useful information on cervical posterior instrumentation in CP patients.

Relationship Between BMD and Prevalent Vertebral Fractures in Indian Women Older Than 50 Yr.

PubMed

Gupta, Yashdeep; Marwaha, Raman K; Kukreja, Subhash; Bhadra, Kuntal; Narang, Archana; Mani, Kalaivani; Mithal, Ambrish; Tandon, Nikhil

2016-01-01

The purpose of the study was to study the relationship of morphometric vertebral fractures with bone mineral density (BMD) in Indian women older than 50 yr. Four hundred fifteen healthy Indian women older than 50 yr (mean age: 62.8 yr) underwent lateral X-rays of the lumbar and thoracic spine. Genant's semiquantitative method was used to diagnose and classify morphometric vertebral fractures. BMD was measured by DXA at lumbar spine and total hip. Recruited subjects underwent anthropometric, biochemical, and hormonal evaluation. Vertebral fractures were present in 17.1% (95% confidence interval: 13.5, 20.8) subjects. Prevalence of osteoporosis based on BMD was 35.7%. By adding those with prevalent fractures, the number of women requiring therapy for osteoporosis would increase to 46.5%. The BMD measured at femur neck, total hip, and lumbar spine (L1eL4) was not found to be lower in women with vertebral fractures as compared with those without fractures. BMD was not found to be lower in women with vertebral fractures as compared with those without fractures. Significant number of additional subjects with BMD in the normal or osteopenic range become eligible for osteoporosis treatment when presence of vertebral fracture is used as an independent indication for such treatment. Copyright © 2016 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Drosophila hematopoiesis under normal conditions and in response to immune stress.

PubMed

Letourneau, Manon; Lapraz, Francois; Sharma, Anurag; Vanzo, Nathalie; Waltzer, Lucas; Crozatier, Michèle

2016-11-01

The emergence of hematopoietic progenitors and their differentiation into various highly specialized blood cell types constitute a finely tuned process. Unveiling the genetic cascades that control blood cell progenitor fate and understanding how they are modulated in response to environmental changes are two major challenges in the field of hematopoiesis. In the last 20 years, many studies have established important functional analogies between blood cell development in vertebrates and in the fruit fly, Drosophila melanogaster. Thereby, Drosophila has emerged as a powerful genetic model for studying mechanisms that control hematopoiesis during normal development or in pathological situations. Moreover, recent advances in Drosophila have highlighted how intricate cell communication networks and microenvironmental cues regulate blood cell homeostasis. They have also revealed the striking plasticity of Drosophila mature blood cells and the presence of different sites of hematopoiesis in the larva. This review provides an overview of Drosophila hematopoiesis during development and summarizes our current knowledge on the molecular processes controlling larval hematopoiesis, both under normal conditions and in response to an immune challenge, such as wasp parasitism. © 2016 Federation of European Biochemical Societies.

Thoracolumbar vertebral osteochondroma in a young dog.

PubMed

Santen, D R; Payne, J T; Pace, L W; Kroll, R A; Johnson, G C

1991-10-15

Osteosarcoma was diagnosed in a 7-month-old female German Shepherd Dog with hind limb paresis. Radiography revealed a circumscribed calcified mass in the dorsal vertebral lamina at T13-L1 resulting in extradural compression of the spinal cord. Surgical excision of the mass resulted in gradual return to normal neurologic function. Four weeks after surgery, the dog became severely atactic after rolling onto its back. A chip fracture of T13 was identified, and the dog was euthanatized at the owners' request.

Polymorphisms in VDR gene in Tunisian postmenopausal women are associated with osteopenia phenotype.

PubMed

Sassi, R; Sahli, H; Souissi, C; Sellami, S; Ben Ammar El Gaaied, A

2015-01-01

Osteopenia is characterized by intermediate values of bone mineral density (BMD) as compared to normal and osteoporotic subjects. BMD, a surrogate phenotype for osteoporosis, is influenced in part by genetic factors. Among the genes associated with BMD, the vitamin D receptor (VDR) was the first gene studied as a potential candidate associated with BMD in adult and postmenopausal bone loss. However, results are controversial. To determine whether VDR polymorphisms ApaI and TaqI are associated with BMD, osteopenia, osteoporosis and low-impact fracture risk in North Africans, these genotypes were analyzed in 566 postmenopausal Tunisian women. In postmenopausal Tunisian women, the GT ApaI genotype seems to be protective against osteoporosis development (p = 0.02; odds ratio = 0.54). Moreover, the presence of the combined GT/TT genotype of ApaI and TaqI polymorphisms is more frequent in normal BMD women than in osteoporotic women (p = 0.00; odds ratio = 0.41). Interestingly, the GG ApaI genotype is associated with osteopenia development (p = 0.02; odds ratio = 1.86) and also the TT TaqI polymorphism (p = 0.02; odds ratio = 1.53). The GG ApaI genotype is associated with a three times risk of vertebral fracture. The ApaI polymorphism showed an association with osteopenia and low-impact vertebral fracture incidence but not with osteoporosis. The TaqI polymorphism is associated specifically with the osteopenia phenotype. The presence of the two polymorphisms increases the risk to develop osteopenia in postmenopausal Tunisian women. Osteopenia seems to be genetically determined. However, osteoporosis is the result of interaction between genetic and environmental factors.

Molecular signaling in intervertebral disk development.

PubMed

DiPaola, Christian P; Farmer, James C; Manova, Katia; Niswander, Lee A

2005-09-01

The purpose of this investigation is to identify and study the expression pattern of pertinent molecular factors involved in the differentiation of the intervertebral disk (IVD). It is likely that hedgehog genes and the BMP inhibitors are key factors involved in spinal joint formation. Radioactive in situ hybridization with mRNA probes for pax-1, SHH, IHH and Noggin gene was performed on mouse embryo and adult tissue. Immunohistochemistry was performed to localize hedgehog receptor, "patched" (ptc). From 14.5 dpc until birth pax-1 mRNA was expressed in the developing anulus fibrosus (AF). During the same developmental period Noggin mRNA is highly expressed throughout the spine, in the developing AF, while ptc protein and SHH mRNA were expressed in the developing nucleus pulposus (NP). IHH mRNA was expressed by condensing chondrocytes of the vertebral bodies and later becomes confined to the vertebral endplate. We show for the first time that pax-1 is expressed in the adult intervertebral disk. Ptc expression in the NP is an indicator of hedgehog protein signaling in the developing IVD. The expression pattern of the BMP inhibitor Noggin appears to be important for the normal formation of the IVD and may prove to play a role in its segmental pattern formation.

[Osteological development of the vertebral column and caudal complex of Lujanus guttatus (Perciformes: Lutjanidae) larvae under rearing conditions].

PubMed

Rodríguez-Ibarra, Luz Estela; Abdo-de la Parra, María Isabel; Aguilar-Zárate, Gabriela; Valasco-Blanco, Gabriela; Ibarra-Castro, Leonardo

2015-03-01

The spotted rose snapper (Lutjanus guttatus) is an important commercial species in Mexico with good culture potential. The osteological study at early stages in this species is an important tool to confirm normal bone structure and for the detection of malformations that may occur during early development. This study was carried out in order to evaluate and describe the normal osteological development of the vertebral column and caudal complex of this species grown under controlled conditions. For this, a total of 540 larvae of L. guttatus, between 2.1 and 17.5 mm of total length (TL), were cultured during 36 days; culture conditions were 28 degrees C, 5.74 mg/L oxygen and 32.2 ups salinity with standard feeding rates. To detect growth changes, a sample of 15 organisms was daily taken from day one until day 36 of post-hatch (DPH). Samples were processed following standard techniques of clearing, and cartilage (alcian blue) and bone staining (alizarin red). Results showed that the vertebral column is composed of ten vertebrae in the abdominal region, and 14 vertebrae including the urostyle in the caudal region. The development of the axial skeleton starts with the neural arches and haemal arches at 3.8 mm TL. Caudal elements such as the hypurals and parahypural began to develop at 4.1 mm TL. Pre-flexion and flexion of the notochord and the formation of all hypurals were observed between 5.3 and 5.8 mm TL. Ossification of the vertebrae in the abdominal region and in some neural arches initiated at 9.5mm TL. In the caudal region, all the neural and haemal arches ossified at 10.2 mm TL. All the abdominal vertebrae and their respective neural arches and parapophyses ossified at 11.2 mm TL, while the elements of the caudal complex that ossified were the hypurals, parahypurals and modified haemal spines. All caudal fm rays, 12 neural spines and 3 haemal arches were ossified by 15.5 mm. The complete ossification process of this specie under laboratory culture conditions was observed when larvae reached 17.3 mm TL on 36 DPH. Detailed analysis of the osteological structures will allow a reference description to evaluate and detect malformations that may occur during the larval culture of the spotted rose snapper.

Vertebral formula and congenital abnormalities of the vertebral column in rabbits.

PubMed

Proks, P; Stehlik, L; Nyvltova, I; Necas, A; Vignoli, M; Jekl, V

2018-06-01

The aim of this retrospective study of 330 rabbits (164 males, 166 females) was to determine different vertebral formulas and prevalence of congenital vertebral anomalies in rabbits from radiographs of the cervical (C), thoracic (Th), lumbar (L) and sacral (S) segments of the vertebral column. The number of vertebrae in each segment of vertebral column, position of anticlinal vertebra and localisation and type of congenital abnormalities were recorded. In 280/330 rabbits (84.8%) with normal vertebral morphology, seven vertebral formulas were identified: C7/Th12/L7/S4 (252/330, 76.4%), C7/Th12/L6/S4 (11/330, 3.3%), C7/Th13/L7/S4 (8/330, 2.4%), C7/Th12/L7/S5 (4/330, 1.2%), C7/Th12/L8/S4 (3/330, 0.9%), C7/Th12/L7/S6 (1/330, 0.3%) and C7/Th11/L7/S4 (1/330, 0.3%). The anticlinal vertebra was identified as Th10 in 56.4% of rabbits and Th11 in 42.4% of rabbits. Congenital spinal abnormalities were identified in 50/330 (15.2%) rabbits, predominantly as a single pathology (n=44). Transitional vertebrae represented the most common abnormalities (n=41 rabbits) in the thoracolumbar (n=35) and lumbosacral segments (n=6). Five variants of thoracolumbar transitional vertebrae were identified. Cervical butterfly vertebrae were detected in three rabbits. One rabbit exhibited three congenital vertebral anomalies: cervical block vertebra, thoracic hemivertebra and thoracolumbar transitional vertebra. Five rabbits exhibited congenital vertebral abnormalities with concurrent malalignment, specifically cervical kyphosis/short vertebra (n=1), thoracic lordoscoliosis/thoracolumbar transitional vertebrae (n=1), thoracic kyphoscoliosis/wedge vertebrae (n=2) and thoracolumbar lordoscoliosis/thoracolumbar transitional vertebrae/lumbosacral transitional vertebrae (n=1). These findings suggest that vertebral columns in rabbits display a wide range of morphologies, with occasional congenital malformations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Nodal signalling in Xenopus: the role of Xnr5 in left/right asymmetry and heart development.

PubMed

Tadjuidje, Emmanuel; Kofron, Matthew; Mir, Adnan; Wylie, Christopher; Heasman, Janet; Cha, Sang-Wook

2016-08-01

Nodal class TGF-β signalling molecules play essential roles in establishing the vertebrate body plan. In all vertebrates, nodal family members have specific waves of expression required for tissue specification and axis formation. In Xenopus laevis, six nodal genes are expressed before gastrulation, raising the question of whether they have specific roles or act redundantly with each other. Here, we examine the role of Xnr5. We find it acts at the late blastula stage as a mesoderm inducer and repressor of ectodermal gene expression, a role it shares with Vg1. However, unlike Vg1, Xnr5 depletion reduces the expression of the nodal family member xnr1 at the gastrula stage. It is also required for left/right laterality by controlling the expression of the laterality genes xnr1, antivin (lefty) and pitx2 at the tailbud stage. In Xnr5-depleted embryos, the heart field is established normally, but symmetrical reduction in Xnr5 levels causes a severely stunted midline heart, first evidenced by a reduction in cardiac troponin mRNA levels, while left-sided reduction leads to randomization of the left/right axis. This work identifies Xnr5 as the earliest step in the signalling pathway establishing normal heart laterality in Xenopus. © 2016 The Authors.

Safety of Onyx Transarterial Embolization of Skull Base Dural Arteriovenous Fistulas from Meningeal Branches of the External Carotids also Fed by Meningeal Branches of Internal Carotid or Vertebral Arteries.

PubMed

Abud, Thiago G; Houdart, Emmanuel; Saint-Maurice, Jean-Pierre; Abud, Daniel G; Baccin, Carlos E; Nguyen, Andrew D; Abdala, Nitamar

2017-08-11

To analyze the angiographic and clinical results of transarterial embolization with Onyx (Medtronic-Covidien, Irvine, CA) in dural arteriovenous fistulas (DAVFs) partially fed by arteries arising from the carotid siphon or the vertebral arteries. We isolated 40 DAVFs supplied by either the tentorial artery of the internal carotid artery (ICA) or the posterior meningeal artery of the vertebral artery. These DAVFs were embolized with Onyx through the middle meningeal artery or the occipital artery. We reviewed the occurrence of reflux into the arteries of carotid or vertebral origin. In all the cases, reflux occurred into the first millimeters of the DAVF arterial feeders arising from carotid or vertebral arteries but slowly enough to be controlled by interruption of Onyx injection. Reflux was always minimal and Onyx never reached the ostium of the arteries. No cerebral ischemic complications occurred in our series. The behavior of Onyx is clearly different from that of cyanoacrylate glue, resulting in superior control during injection. Reflux into arteries arising from the ICA or vertebral artery during DAVF treatment always carries a risk of unintentional non-target embolization of normal cerebral vasculature but Onyx appears to be safe in this situation.

[Vertebral fractures in children with Type I Osteogenesis imperfecta].

PubMed

Sepúlveda, Andrea M; Terrazas, Claudia V; Sáez, Josefina; Reyes, María L

2017-06-01

Osteogenesis imperfecta (OI) is an hereditary disease affecting conective tissue, mainly associated to growth retardation and pathological fractures. OI type I (OI type I), is the mildest, most often, and homogeneous in its fenotype. Vertebral fractures are the most significant complications, associated to skeletical and cardiopulmonary morbidity. To characterize clinically a cohort of children with OI type I. A cohort of OI type I children younger than 20 year old was evaluated. Demographic, clinical, biochemical and radiological data were registered. Sixty seven patients were included, 55% male, 69% resident in the Metropolitan Region. The mean age of diagnose was 2.9 years, 70% presented vertebral fractures on follow-up, mostly thoracic, and 50% before the age of 5 years. Fifty percentage presented vertebral fractures at diagnose, which was about the age of 5 years. Bone metabolic parameters were in the normal range, without significant change at the moment of vertebral fractures. Calcium intake was found to be below American Academy of Pediatrics recommendations at the time of the first fracture. In this study OI type I has an early diagnose, and vertebral fractures show a high incidence, mostly in toddlers. Calcium intake was found to be below reccomended values, and should be closely supervised in these patients.

Knockdown of prothrombin in zebrafish.

PubMed

Day, Kenneth; Krishnegowda, Naveen; Jagadeeswaran, Pudur

2004-01-01

Thrombin is a serine protease generated from its zymogen, prothrombin, and plays a central role in the coagulation cascade. It is also important for mammalian development. The zebrafish has now been established as an excellent genetic model for studies on mammalian hemostasis and development. In this report, we used prothrombin-specific antisense morpholinos to knock down the levels of prothrombin to characterize the effects of prothrombin deficiency in the zebrafish embryo. Prothrombin morpholino-injected zebrafish embryos yielded an early phenotype exhibiting severe abnormalities that later showed occasional bleeding. In a second late phenotype, the embryos had no observable morphological abnormalities in early stages, but showed occasional bleeding at later stages. These phenotypes resembled characteristics shown by prothrombin knockout mice. Laser-induced vascular injury on some of the normal appearing phenotypic larvae showed a prolonged time to occlusion, and recombinant zebrafish prothrombin injected into these larvae restored a normal time to occlusion thus showing the specificity of the morpholino effect. The system developed here should be useful for investigation of the role of thrombin in vertebrate development.

Substantial vertebral body osteophytes protect against severe vertebral fractures in compression

PubMed Central

Aubin, Carl-Éric; Chaumoître, Kathia; Mac-Thiong, Jean-Marc; Ménard, Anne-Laure; Petit, Yvan; Garo, Anaïs; Arnoux, Pierre-Jean

2017-01-01

Recent findings suggest that vertebral osteophytes increase the resistance of the spine to compression. However, the role of vertebral osteophytes on the biomechanical response of the spine under fast dynamic compression, up to failure, is unclear. Seventeen human spine specimens composed of three vertebrae (from T5-T7 to T11-L1) and their surrounding soft tissues were harvested from nine cadavers, aged 77 to 92 years. Specimens were imaged using quantitative computer tomography (QCT) for medical observation, classification of the intervertebral disc degeneration (Thomson grade) and measurement of the vertebral trabecular density (VTD), height and cross-sectional area. Specimens were divided into two groups (with (n = 9) or without (n = 8) substantial vertebral body osteophytes) and compressed axially at a dynamic displacement rate of 1 m/s, up to failure. Normalized force-displacement curves, videos and QCT images allowed characterizing failure parameters (force, displacement and energy at failure) and fracture patterns. Results were analyzed using chi-squared tests for sampling distributions and linear regression for correlations between VTD and failure parameters. Specimens with substantial vertebral body osteophytes present higher stiffness (2.7 times on average) and force at failure (1.8 times on average) than other segments. The presence of osteophytes significantly influences the location, pattern and type of fracture. VTD was a good predictor of the dynamic force and energy at failure for specimens without substantial osteophytes. This study also showed that vertebral body osteophytes provide a protective mechanism to the underlying vertebra against severe compression fractures. PMID:29065144

Effect of once-yearly zoledronic acid five milligrams on fracture risk and change in femoral neck bone mineral density.

PubMed

Eastell, Richard; Black, Dennis M; Boonen, Steven; Adami, Silvano; Felsenberg, Dieter; Lippuner, Kurt; Cummings, Steven R; Delmas, Pierre D; Palermo, Lisa; Mesenbrink, Peter; Cauley, Jane A

2009-09-01

In the Health Outcomes and Reduced Incidence with Zoledronic Acid Once Yearly - Pivotal Fracture Trial (HORIZON-PFT), zoledronic acid (ZOL) 5 mg significantly reduced fracture risk. The aim of the study was to identify factors associated with greater efficacy during ZOL 5 mg treatment. We conducted a subgroup analysis (preplanned and post hoc) of a multicenter, double-blind, placebo-controlled, 36-month trial in 7765 women with postmenopausal osteoporosis. A single infusion of ZOL 5 mg or placebo was administered at baseline, 12, and 24 months. Primary endpoints were new vertebral fracture and hip fracture. Secondary endpoints were nonvertebral fracture and change in femoral neck bone mineral density (BMD). Baseline risk factor subgroups were age, BMD T-score and vertebral fracture status, total hip BMD, race, weight, geographical region, smoking, height loss, history of falls, physical activity, prior bisphosphonates, creatinine clearance, body mass index, and concomitant osteoporosis medications. Greater ZOL induced effects on vertebral fracture risk were seen with younger age (treatment-by-subgroup interaction, P = 0.05), normal creatinine clearance (P = 0.04), and body mass index >or= 25 kg/m(2) (P = 0.02). There were no significant treatment-factor interactions for hip or nonvertebral fracture or for change in BMD. ZOL appeared more effective in preventing vertebral fracture in younger women, overweight/obese women, and women with normal renal function. ZOL had similar effects irrespective of fracture risk factors or femoral neck BMD.

Ontogeny of the vertebral column of Eleutherodactylus johnstonei (Anura: Eleutherodactylidae) reveals heterochronies relative to metamorphic frogs.

PubMed

Meza-Joya, Fabio Leonardo; Ramos-Pallares, Eliana Patricia; Ramírez-Pinilla, Martha Patricia

2013-07-01

Over the last century, the morphogenesis of the vertebral column has been considered as a highly conserved process among anurans. This statement is based on the study of few metamorphic taxa, ignoring the role of developmental mechanisms underlying the evolution of specialized life-histories. Direct development in anurans has been regarded as evolutionarily derived and involves developmental recapitulation and repatterning at different levels in all amphibian taxa studied so far. Herein, we analyze the vertebral column morphogenesis of the direct-developing frog Eleutherodactylus johnstonei, describing the sequence of chondrification and ossification, based on cleared and double-stained specimens from early stage embryos to adults. In general, our results show that the morphogenesis of the vertebral column in E. johnstonei recapitulates the ancestral tadpole-like pattern of development. However, the analysis of the sequence of events using heterochrony plots shows important heterocronies relative to metamorphic species, such as a delay in the chondrification of the vertebral centra and in osteogenesis. These ontogenetic peculiarities may represent derived traits in direct-developing frogs and are possibly correlated with its unusual life history. In addition, several features of the vertebral column of E. johnstonei are highly variable from its typical morphology. We report some malformations and small deviations, which do not seem to affect the survival of individuals. These anomalies have also been found in other frogs, and include many vertebral defects, such as vertebral fusion, and vertebral preclusion and/or induction. Copyright © 2013 Wiley Periodicals, Inc.

Vertebral osteomyelitis and epidural abscess caused by gas gangrene presenting with complete paraplegia: a case report.

PubMed

Akagawa, Manabu; Kobayashi, Takashi; Miyakoshi, Naohisa; Abe, Eiji; Abe, Toshiki; Kikuchi, Kazuma; Shimada, Yoichi

2015-04-11

Gas gangrene is most often caused by Clostridium perfringens infection. Gas gangrene is a medical emergency that develops suddenly. The mortality rate is higher with trunk involvement than with involvement of the extremities, which carries a better prognosis. With respect to vertebral involvement, there are few reports in the literature. The purpose of this paper is to report a very rare case of vertebral osteomyelitis caused by gas gangrene. A 78-year-old Japanese woman with diabetes mellitus was admitted to our hospital with the chief complaints of back pain, dysuria, and complete paralysis of both legs. A computed tomography scan showed soft tissue swelling anterolaterally at intervertebral disc level T11/12 and a gas-containing epidural abscess that compressed her spinal cord. Cultures later grew Clostridium perfringens and Escherichia coli. Hemilaminectomy was done from T10 to T12, and an epidural abscess was removed. She went on to have fusion surgery 6 weeks after the initial operation and subsequently experienced complete pain relief. She was discharged 2 months later, at which time she was able to walk with a cane. Examination 18 months after surgery showed normal gait without a cane. Discitis caused by gas gangrene infection was successfully treated by immediate debridement and subsequent fusion surgery.

Vertebrate intersectin1 is repurposed to facilitate cortical midline connectivity and higher order cognition.

PubMed

Sengar, Ameet S; Ellegood, Jacob; Yiu, Adelaide P; Wang, Hua; Wang, Wei; Juneja, Subhash C; Lerch, Jason P; Josselyn, Sheena A; Henkelman, R Mark; Salter, Michael W; Egan, Sean E

2013-02-27

Invertebrate studies have highlighted a role for EH and SH3 domain Intersectin (Itsn) proteins in synaptic vesicle recycling and morphology. Mammals have two Itsn genes (Itsn1 and Itsn2), both of which can undergo alternative splicing to include DBL/PH and C2 domains not present in invertebrate Itsn proteins. To probe for specific and redundant functions of vertebrate Itsn genes, we generated Itsn1, Itsn2, and double mutant mice. While invertebrate mutants showed severe synaptic abnormalities, basal synaptic transmission and plasticity were unaffected at Schaffer CA1 synapses in mutant mice. Surprisingly, intercortical tracts-corpus callosum, ventral hippocampal, and anterior commissures-failed to cross the midline in mice lacking Itsn1, but not Itsn2. In contrast, tracts extending within hemispheres and those that decussate to more caudal brain segments appeared normal. Itsn1 mutant mice showed severe deficits in Morris water maze and contextual fear memory tasks, whereas mice lacking Itsn2 showed normal learning and memory. Thus, coincident with the acquisition of additional signaling domains, vertebrate Itsn1 has been functionally repurposed to also facilitate interhemispheric connectivity essential for high order cognitive functions.

Heat shock during early somitogenesis induces caudal vertebral column defects in Atlantic salmon (Salmo salar).

PubMed

Wargelius, Anna; Fjelldal, Per Gunnar; Hansen, Tom

2005-07-01

In several terrestrial vertebrates, heat shock (HS) during somitogenesis causes vertebral deformities. To determine if vertebral deformities can occur due to sudden temperature changes during early development in fish, Atlantic salmon embryos were HS treated during somitogenesis. Ten months later these individuals displayed a high prevalence of caudal vertebral column condensations (27-34%). The defects were located caudally of the abdominal cavity, displaying an even distribution in this region independent of time of HS. To determine if HS disturbed vertebral development during somitogenesis, two genes coding for markers of skeletal development were identified, namely, the secreted protein Shh (Sashh) and the transcription factor Twist (Satwist). These proteins are involved in the proliferation and specification of presumptive skeletal cells (sclerotome) in vertebrates. The spatial expression pattern of sashh and satwist in salmon indicated a functional conservation of these proteins. Furthermore, HS embryos displayed expressional disturbance in both sashh and satwist, indicating an effect of HS on sclerotomal cell patterning. However, the HS-protecting ability in embryos seems to be individually regulated because reduction in gene expression was not detected at all stages; in addition, HS did not induce somitic disturbance and vertebral deformity in all embryos.

The lamprey: a jawless vertebrate model system for examining origin of the neural crest and other vertebrate traits.

PubMed

Green, Stephen A; Bronner, Marianne E

2014-01-01

Lampreys are a group of jawless fishes that serve as an important point of comparison for studies of vertebrate evolution. Lampreys and hagfishes are agnathan fishes, the cyclostomes, which sit at a crucial phylogenetic position as the only living sister group of the jawed vertebrates. Comparisons between cyclostomes and jawed vertebrates can help identify shared derived (i.e. synapomorphic) traits that might have been inherited from ancestral early vertebrates, if unlikely to have arisen convergently by chance. One example of a uniquely vertebrate trait is the neural crest, an embryonic tissue that produces many cell types crucial to vertebrate features, such as the craniofacial skeleton, pigmentation of the skin, and much of the peripheral nervous system (Gans and Northcutt, 1983). Invertebrate chordates arguably lack unambiguous neural crest homologs, yet have cells with some similarities, making comparisons with lampreys and jawed vertebrates essential for inferring characteristics of development in early vertebrates, and how they may have evolved from nonvertebrate chordates. Here we review recent research on cyclostome neural crest development, including research on lamprey gene regulatory networks and differentiated neural crest fates. Copyright © 2014 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

Vestigial-like 3 is a novel Ets1 interacting partner and regulates trigeminal nerve formation and cranial neural crest migration

PubMed Central

Simon, Emilie; Thézé, Nadine; Fédou, Sandrine; Thiébaud, Pierre

2017-01-01

ABSTRACT Drosophila Vestigial is the founding member of a protein family containing a highly conserved domain, called Tondu, which mediates their interaction with members of the TEAD family of transcription factors (Scalloped in Drosophila). In Drosophila, the Vestigial/Scalloped complex controls wing development by regulating the expression of target genes through binding to MCAT sequences. In vertebrates, there are four Vestigial-like genes, the functions of which are still not well understood. Here, we describe the regulation and function of vestigial-like 3 (vgll3) during Xenopus early development. A combination of signals, including FGF8, Wnt8a, Hoxa2, Hoxb2 and retinoic acid, limits vgll3 expression to hindbrain rhombomere 2. We show that vgll3 regulates trigeminal placode and nerve formation and is required for normal neural crest development by affecting their migration and adhesion properties. At the molecular level, vgll3 is a potent activator of pax3, zic1, Wnt and FGF, which are important for brain patterning and neural crest cell formation. Vgll3 interacts in the embryo with Tead proteins but unexpectedly with Ets1, with which it is able to stimulate a MCAT driven luciferase reporter gene. Our findings highlight a critical function for vgll3 in vertebrate early development. PMID:28870996

Human amniotic fluid contaminants alter thyroid hormone signalling and early brain development in Xenopus embryos

NASA Astrophysics Data System (ADS)

Fini, Jean-Baptiste; Mughal, Bilal B.; Le Mével, Sébastien; Leemans, Michelle; Lettmann, Mélodie; Spirhanzlova, Petra; Affaticati, Pierre; Jenett, Arnim; Demeneix, Barbara A.

2017-03-01

Thyroid hormones are essential for normal brain development in vertebrates. In humans, abnormal maternal thyroid hormone levels during early pregnancy are associated with decreased offspring IQ and modified brain structure. As numerous environmental chemicals disrupt thyroid hormone signalling, we questioned whether exposure to ubiquitous chemicals affects thyroid hormone responses during early neurogenesis. We established a mixture of 15 common chemicals at concentrations reported in human amniotic fluid. An in vivo larval reporter (GFP) assay served to determine integrated thyroid hormone transcriptional responses. Dose-dependent effects of short-term (72 h) exposure to single chemicals and the mixture were found. qPCR on dissected brains showed significant changes in thyroid hormone-related genes including receptors, deiodinases and neural differentiation markers. Further, exposure to mixture also modified neural proliferation as well as neuron and oligodendrocyte size. Finally, exposed tadpoles showed behavioural responses with dose-dependent reductions in mobility. In conclusion, exposure to a mixture of ubiquitous chemicals at concentrations found in human amniotic fluid affect thyroid hormone-dependent transcription, gene expression, brain development and behaviour in early embryogenesis. As thyroid hormone signalling is strongly conserved across vertebrates the results suggest that ubiquitous chemical mixtures could be exerting adverse effects on foetal human brain development.

Does gravity influence the early stages of the development of the nervous system in an amphibian?

PubMed

Duprat, A M; Husson, D; Gualandris-Parisot, L

1998-11-01

As a result of previous studies using hypergravity (centrifuge) or virtual microgravity (clinostat), it was proposed that gravity was involved in embryonic development, i.e., in the establishment of the embryonic polarities and the body plan pattern which subsequently direct morphogenesis and organogenesis of the central nervous system and of sensory organs. Recent experiments were performed in space using sounding rockets and orbiting space-modules to ascertain whether gravity is indeed required for embryogenesis in Invertebrates and Vertebrates. Eggs fertilised in vivo or in vitro in microgravity showed some abnormalities during embryonic development but were able to regulate and produce nearly normal larvae. Copyright 1998 Elsevier Science B.V.

Quantification of localized vertebral deformities using a sparse wavelet-based shape model.

PubMed

Zewail, R; Elsafi, A; Durdle, N

2008-01-01

Medical experts often examine hundreds of spine x-ray images to determine existence of various pathologies. Common pathologies of interest are anterior osteophites, disc space narrowing, and wedging. By careful inspection of the outline shapes of the vertebral bodies, experts are able to identify and assess vertebral abnormalities with respect to the pathology under investigation. In this paper, we present a novel method for quantification of vertebral deformation using a sparse shape model. Using wavelets and Independent component analysis (ICA), we construct a sparse shape model that benefits from the approximation power of wavelets and the capability of ICA to capture higher order statistics in wavelet space. The new model is able to capture localized pathology-related shape deformations, hence it allows for quantification of vertebral shape variations. We investigate the capability of the model to predict localized pathology related deformations. Next, using support-vector machines, we demonstrate the diagnostic capabilities of the method through the discrimination of anterior osteophites in lumbar vertebrae. Experiments were conducted using a set of 150 contours from digital x-ray images of lumbar spine. Each vertebra is labeled as normal or abnormal. Results reported in this work focus on anterior osteophites as the pathology of interest.

Diagnosis and Management of Vertebral Compression Fractures.

PubMed

McCarthy, Jason; Davis, Amy

2016-07-01

Vertebral compression fractures (VCFs) are the most common complication of osteoporosis, affecting more than 700,000 Americans annually. Fracture risk increases with age, with four in 10 white women older than 50 years experiencing a hip, spine, or vertebral fracture in their lifetime. VCFs can lead to chronic pain, disfigurement, height loss, impaired activities of daily living, increased risk of pressure sores, pneumonia, and psychological distress. Patients with an acute VCF may report abrupt onset of back pain with position changes, coughing, sneezing, or lifting. Physical examination findings are often normal, but can demonstrate kyphosis and midline spine tenderness. More than two-thirds of patients are asymptomatic and diagnosed incidentally on plain radiography. Acute VCFs may be treated with analgesics such as acetaminophen, nonsteroidal anti-inflammatory drugs, narcotics, and calcitonin. Physicians must be mindful of medication adverse effects in older patients. Other conservative therapeutic options include limited bed rest, bracing, physical therapy, nerve root blocks, and epidural injections. Percutaneous vertebral augmentation, including vertebroplasty and kyphoplasty, is controversial, but can be considered in patients with inadequate pain relief with nonsurgical care or when persistent pain substantially affects quality of life. Family physicians can help prevent vertebral fractures through management of risk factors and the treatment of osteoporosis.

Contribution of vertebral deformities to chronic back pain and disability. The Study of Osteoporotic Fractures Research Group

NASA Technical Reports Server (NTRS)

Ettinger, B.; Black, D. M.; Nevitt, M. C.; Rundle, A. C.; Cauley, J. A.; Cummings, S. R.; Genant, H. K.

1992-01-01

Among 2992 white women aged 65-70 years recruited from population-based listings, we measured radiographic vertebral dimensions of T5-L4 and calculated ratios of heights: anterior/posterior, mid/posterior, and posterior/posterior of either adjacent vertebra. The degree of deformity for each vertebra was analyzed in terms of the number of standard deviations (SD) that ratio differed from the mean ratio calculated for the same vertebral level in this population. We correlated the severity of each woman's worst vertebral deformity with back pain, back disability in six activities of daily living, and height loss since age 25. Only 39.4% of the cohort had no vertebral deformity; 10.2% had a deformity greater than or equal to 4 SD. Vertebral deformities less than 4 SD below the mean were not associated with increased back pain, disability, or loss of height. In contrast, women whose deformity was greater than or equal to 4 SD had a 1.9 (95% CI, 1.5-2.4) times higher risk of moderate to severe back pain and a 2.6 (95% CI, 1.7-3.9) times higher risk of disability involving the back; they were also 2.5 (95% CI, 2.0-3.2) times more likely to have lost greater than or equal to 4 cm in height. All three types of vertebral deformity (wedge, end plate, and crush) were equally associated with these outcomes. Multiple deformities less than 4 SD did not increase the likelihood of these three outcomes, but multiple deformities greater than or equal to 4 SD tended to be associated with increased back pain, disability, and height loss. This large cross-sectional study suggests that vertebral deformities cause substantial pain, disability, or loss of height only if vertebral height ratios fall 4 SD below the normal mean. Much back pain could not be attributed to vertebral deformities, suggesting other causes.

Cervical vertebral fusion (Klippel-Feil) syndrome with consanguineous parents.

PubMed

Juberg, R C; Gershanik, J J

1976-06-01

We describe a female infant with the cervical vertebral fusion (Klippel-Feil) syndrome whom we recognized at birth because of her short neck, restriction of cervical movement, and low posterior hairline. X-ray examination showed anomalies of C1, and between C2-3 and C3-4; thus, we classified her as type II, with variable cervical fusion. At 24 months she was small and manifested hearing deficiency. The mother and father were consanguineous with five common ancestors four generations ago, which resulted in a coefficient of inbreeding equivalent to a second cousin relationship. The parents and grandparents were phenotypically normal, and the parents were radiologically normal. This form of the syndrome has previously been said to be autosomal dominant. Our conclusion of determination by a single autosomal recessive gene is evidence of genetic heterogeneity.

[Establishment and validation of normal human L1-L5 lumbar three-dimensional finite element model].

PubMed

Zhu, Zhenqi; Liu, Chenjun; Wang, Jiefu; Wang, Kaifeng; Huang, Zhixin; Wang, Weida; Liu, Haiying

2014-10-14

To create and validate a L1-L5 lumbar three-dimensional finite element model. The L1-L5 lumbar spines of a male healthy volunteer were scanned with computed tomography (CT). And a L1-L5 lumbar three-dimensional finite element model was created with the aid of software packages of Mimics, Geomagic and Ansys. Then border conditions were set, unit type was determined, finite element mesh was divided and a model was established for loading and calculating. Average model stiffness under the conditions of flexion, extension, lateral bending and axial rotation was calculated and compared with the outcomes of former articles for validation. A normal human L1-L5 lumbar three-dimensional finite element model was established to include 459 340 elements and 661 938 nodes. After constraining the inferior endplate of L5 vertebral body, 500 kg × m × s⁻² compressive loading was imposed averagely on the superior endplate of L1 vertebral body. Then 10 kg × m² × s⁻² moment simulating flexion, extension, lateral bending and axial rotation were imposed on the superior endplate of L1 vertebral body. Eventually the average stiffness of all directions was calculated and it was similar to the outcomes of former articles. The L1-L5 lumbar three-dimensional finite element model is validated so that it may used with biomechanical simulation and analysis of normal or surgical models.

Mechanisms of developmental neurite pruning.

PubMed

Schuldiner, Oren; Yaron, Avraham

2015-01-01

The precise wiring of the nervous system is a combined outcome of progressive and regressive events during development. Axon guidance and synapse formation intertwined with cell death and neurite pruning sculpt the mature circuitry. It is now well recognized that pruning of dendrites and axons as means to refine neuronal networks, is a wide spread phenomena required for the normal development of vertebrate and invertebrate nervous systems. Here we will review the arising principles of cellular and molecular mechanisms of neurite pruning. We will discuss these principles in light of studies in multiple neuronal systems, and speculate on potential explanations for the emergence of neurite pruning as a mechanism to sculpt the nervous system.

Fetal and post-natal lung defects reveal a novel and required role for Fgf8 in lung development

PubMed Central

Yu, Shibin; Poe, Bryan; Schwarz, Margaret; Elliot, Sarah; Albertine, Kurt H.; Fenton, Stephen; Garg, Vidu; Moon, Anne M.

2016-01-01

The fibroblast growth factor, FGF8, has been shown to be essential for vertebrate cardiovascular, craniofacial, brain and limb development. Here we report that Fgf8 function is required for normal progression through the late fetal stages of lung development that culminate in alveolar formation. Budding, lobation and branching morphogenesis are unaffected in early stage Fgf8 hypomorphic and conditional mutant lungs. Excess proliferation during fetal development disrupts distal airspace formation, mesenchymal and vascular remodeling, and Type I epithelial cell differentiation resulting in postnatal respiratory failure and death. Our findings reveal a previously unknown, critical role for Fgf8 function in fetal lung development and suggest that this factor may also contribute to postnatal alveologenesis. Given the high number of premature infants with alveolar dysgenesis and lung dysplasia, and the accumulating evidence that short-term benefits of available therapies may be outweighed by long term detrimental effects on postnatal alveologenesis, the therapeutic implications of identifying a factor or pathway that can be targeted to stimulate normal alveolar development are profound. PMID:20727874

An amphioxus winged helix/forkhead gene, AmphiFoxD: insights into vertebrate neural crest evolution

NASA Technical Reports Server (NTRS)

Yu, Jr-Kai; Holland, Nicholas D.; Holland, Linda Z.

2002-01-01

During amphioxus development, the neural plate is bordered by cells expressing many genes with homologs involved in vertebrate neural crest induction. However, these amphioxus cells evidently lack additional genetic programs for the cell delaminations, migrations, and differentiations characterizing definitive vertebrate neural crest. We characterize an amphioxus winged helix/forkhead gene (AmphiFoxD) closely related to vertebrate FoxD genes. Phylogenetic analysis indicates that the AmphiFoxD is basal to vertebrate FoxD1, FoxD2, FoxD3, FoxD4, and FoxD5. One of these vertebrate genes (FoxD3) consistently marks neural crest during development. Early in amphioxus development, AmphiFoxD is expressed medially in the anterior neural plate as well as in axial (notochordal) and paraxial mesoderm; later, the gene is expressed in the somites, notochord, cerebral vesicle (diencephalon), and hindgut endoderm. However, there is never any expression in cells bordering the neural plate. We speculate that an AmphiFoxD homolog in the common ancestor of amphioxus and vertebrates was involved in histogenic processes in the mesoderm (evagination and delamination of the somites and notochord); then, in the early vertebrates, descendant paralogs of this gene began functioning in the presumptive neural crest bordering the neural plate to help make possible the delaminations and cell migrations that characterize definitive vertebrate neural crest. Copyright 2002 Wiley-Liss, Inc.

Comparison of four morphometric definitions and a semiquantitative consensus reading for assessing prevalent vertebral fractures.

PubMed

Grados, F; Roux, C; de Vernejoul, M C; Utard, G; Sebert, J L; Fardellone, P

2001-01-01

The assessment of vertebral fracture in patients with osteoporosis by conventional radiography has been improved over the past 10 years using either the semiquantitative (SQ) method devised by Genant et al. or quantitative morphometry. However, there is still no internationally agreed definition for vertebral fracture and there have been few comparative studies between these different approaches. Our study assessed the reproducibility of the SQ method and of four commonly used morphometric algorithms (Melton's, Eastell's, Minne's and McCloskey's methods) for assessing prevalent vertebral fractures, and examined the agreement of each morphometric algorithm with a SQ consensus reading performed by three experts. With this consensus reading in place of a gold standard, we determined relative measures of sensitivity, specificity and optimal cutoff threshold for each morphometric algorithm. The study was conducted in 39 postmenopausal women who had at least one osteoporotic vertebral fracture. Normal values were derived from 84 healthy postmenopausal women with apparently normal vertebral bodies. Our results indicate that the concordance of SQ method was excellent (intraobserver agreement on serial radiographs = 96.4%, kappa = 0.91; agreement between individual readings and the consensus reading = 98%, kappa = 0.95). Three morphometric approaches demonstrated good intra- and interobserver concordance (Melton: intraobserver agreement on serial radiographs = 92.7%, kappa = 0.82, interobserver agreement = 91.1%, kappa = 0.79; Eastell: intraobserver agreement on serial radiographs = 87.6%, kappa = 0.66, interobserver agreement = 88.6%, kappa = 0.68; McCloskey: intraobserver agreement on serial radiographs = 91.5%, kappa = 0.72, interobserver agreement = 93.9%, kappa = 0.78). Except for McCloskey's method, the optimal cutoff thresholds defined in our study by highest kappa score or Youden index in comparison with the SQ consensus reading were near the cutoff thresholds that were arbitrarily fixed. The four morphometric algorithms provided a good agreement with the results of the SQ consensus reading, but the more complex algorithm did not provide better results and even if we adjusted the cutoff threshold, no morphometric algorithm agreed perfectly with the SQ consensus reading. We conclude that morphometric approaches currently used should not be employed alone to detect prevalent vertebral fractures in studies on osteoporosis, but should rather be used in combination with a visual assessment. The SQ approach that allows differential diagnosis of vertebral deformities and has demonstrated a better reproducibility can be employed alone when it is performed by experienced and well-trained readers.

Both cell-autonomous mechanisms and hormones contribute to sexual development in vertebrates and insects.

PubMed

Bear, Ashley; Monteiro, Antónia

2013-08-01

The differentiation of male and female characteristics in vertebrates and insects has long been thought to proceed via different mechanisms. Traditionally, vertebrate sexual development was thought to occur in two phases: a primary and a secondary phase, the primary phase involving the differentiation of the gonads, and the secondary phase involving the differentiation of other sexual traits via the influence of sex hormones secreted by the gonads. In contrast, insect sexual development was thought to depend exclusively on cell-autonomous expression of sex-specific genes. Recently, however, new evidence indicates that both vertebrates and insects rely on sex hormones as well as cell-autonomous mechanisms to develop sexual traits. Collectively, these new data challenge the traditional vertebrate definitions of primary and secondary sexual development, call for a redefinition of these terms, and indicate the need for research aimed at explaining the relative dependence on cell-autonomous versus hormonally guided sexual development in animals. © 2013 The Authors. BioEssays published by WILEY Periodicals, Inc.

Vertebral coplanar alignment: a standardized technique for three dimensional correction in scoliosis surgery: technical description and preliminary results in Lenke type 1 curves.

PubMed

Vallespir, Gabriel Pizà; Flores, Jesús Burgos; Trigueros, Ignacio Sanpera; Sierra, Eduardo Hevia; Fernández, Pedro Doménech; Olaverri, Juan Carlos Rodríguez; Alonso, Manuel García; Galea, Rafael Ramos; Francisco, Antonio Pérez; Rodríguez de Paz, Beatriz; Carbonell, Pedro Gutiérrez; Thomas, Javier Vicente; López, José Luís González; Paulino, José Ignacio Maruenda; Pitarque, Carlos Barrios; García, Oscar Riquelme

2008-06-15

Prospective multicentric study. To present the preliminary results of an innovative method for standardized correction of scoliosis, vertebral coplanar alignment (VCA), based on a novel concept: the relocation of vertebral axis in a single plane. Normal standing spine has no rotation in coronal or transverse planes, therefore X and Z axis of vertebrae are in the same plane: they are coplanar. VCA intends to relocate these axis in one plane, correcting rotation and translation, while X axis are returned to its normal posterior divergence in sagittal plane in thoracic spine. Twenty-five consecutive adolescent idiopathic scoliosis patients (Lenke type 1) underwent posterior surgery with segmental pedicle screw fixation. Slotted tubes were attached to convex side screws. Two longitudinal rods were inserted through the end of tubes. Then, they were separated along the slots, driving the tubes into one plane, making the axis of the vertebrae coplanar and thus correcting transverse rotation and coronal translation. To obtain kyphosis, distal ends of the tubes were spread in thoracic spine. Correction was maintained by locking a definitive rod in the concave side, then tubes were retrieved and the convex side rod, inserted and tightened. Correction was assessed on preoperative and postoperative full-spine standing radiograph. Vertebral rotation was measured on computed tomography-scan and magnetic resonance imaging. Preoperative average thoracic curves of 61 degrees were corrected to 16 degrees (73%). Preoperative average thoracolumbar curves of 39 degrees were corrected to 12 degrees (70%). Preoperative average thoracic apical rotation of 24 degrees was corrected to 11 degrees (56%). Preoperative average thoracic kyphosis of 18 degrees remained unchanged after surgery; however, no patients had kyphosis <10 degrees after surgery. Rib hump improved from 30 to 11 mm (65%). There were no perioperative complications. VCA provided excellent correction of coronal and transverse planes with normalization of thoracic kyphosis in Lenke type 1 adolescent idiopathic scoliosis surgery.

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.

Investigating Bacterial-Animal Symbioses with Light Sheet Microscopy

PubMed Central

Taormina, Michael J.; Jemielita, Matthew; Stephens, W. Zac; Burns, Adam R.; Troll, Joshua V.; Parthasarathy, Raghuveer; Guillemin, Karen

2014-01-01

SUMMARY Microbial colonization of the digestive tract is a crucial event in vertebrate development, required for maturation of host immunity and establishment of normal digestive physiology. Advances in genomic, proteomic, and metabolomic technologies are providing a more detailed picture of the constituents of the intestinal habitat, but these approaches lack the spatial and temporal resolution needed to characterize the assembly and dynamics of microbial communities in this complex environment. We report the use of light sheet microscopy to provide high resolution imaging of bacterial colonization of the zebrafish intestine. The methodology allows us to characterize bacterial population dynamics across the entire organ and the behaviors of individual bacterial and host cells throughout the colonization process. The large four-dimensional datasets generated by these imaging approaches require new strategies for image analysis. When integrated with other “omics” datasets, information about the spatial and temporal dynamics of microbial cells within the vertebrate intestine will provide new mechanistic insights into how microbial communities assemble and function within hosts. PMID:22983029

Transcriptome analysis of the planarian eye identifies ovo as a specific regulator of eye regeneration.

PubMed

Lapan, Sylvain W; Reddien, Peter W

2012-08-30

Among the millions of invertebrate species with visual systems, the genetic basis of eye development and function is well understood only in Drosophila melanogaster. We describe an eye transcriptome for the planarian Schmidtea mediterranea. Planarian photoreceptors expressed orthologs of genes required for phototransduction and microvillus structure in Drosophila and vertebrates, and optic pigment cells expressed solute transporters and melanin synthesis enzymes similar to those active in the vertebrate retinal pigment epithelium. Orthologs of several planarian eye genes, such as bestrophin-1 and Usher syndrome genes, cause eye defects in mammals when perturbed and were not previously described to have roles in invertebrate eyes. Five previously undescribed planarian eye transcription factors were required for normal eye formation during head regeneration. In particular, a conserved, transcription-factor-encoding ovo gene was expressed from the earliest stages of eye regeneration and was required for regeneration of all cell types of the eye. Copyright © 2012 The Authors. Published by Elsevier Inc. All rights reserved.

Characterizing the distribution of steroid sulfatase during embryonic development: when and where might metabolites of maternal steroids be reactivated?

PubMed

Paitz, Ryan T; Duffield, Kristin R; Bowden, Rachel M

2017-12-15

All vertebrate embryos are exposed to maternally derived steroids during development. In placental vertebrates, metabolism of maternal steroids by the placenta modulates embryonic exposure, but how exposure is regulated in oviparous vertebrates is less clear. Recent work in oviparous vertebrates has demonstrated that steroids are not static molecules, as they can be converted to more polar steroid sulfates by sulfotransferase enzymes. Importantly, these steroid sulfates can be converted back to the parent compound by the enzyme steroid sulfatase (STS). We investigated when and where STS was present during embryonic development in the red-eared slider turtle, Trachemys scripta We report that STS is present during all stages of development and in all tissues we examined. We conclude that STS activity may be particularly important for regulating maternal steroid exposure in oviparous vertebrates. © 2017. Published by The Company of Biologists Ltd.

Guiding Development Based Approach Practicum Vertebrates Taxonomy Scientific Study Program for Students of Biology Education

NASA Astrophysics Data System (ADS)

Arieska, M.; Syamsurizal, S.; Sumarmin, R.

2018-04-01

Students having difficulty in identifying and describing the vertebrate animals as well as less skilled in science process as practical. Increased expertise in scientific skills, one of which is through practical activities using practical guidance based on scientific approach. This study aims to produce practical guidance vertebrate taxonomy for biology education students PGRI STKIP West Sumatra valid. This study uses a model of Plomp development consisting of three phases: the initial investigation, floating or prototype stage, and the stage of assessment. Data collection instruments used in this study is a validation sheet guiding practicum. Data were analyzed descriptively based on data obtained from the field. The result of the development of practical guidance vertebrate taxonomic validity value of 3.22 is obtained with very valid category. Research and development has produced a practical guide based vertebrate taxonomic scientific approach very valid.

Kyphoplasty for vertebral augmentation in the elderly with osteoporotic vertebral compression fractures: scenarios and review of recent studies.

PubMed

Bednar, Timothy; Heyde, Christoph E; Bednar, Grace; Nguyen, David; Volpi, Elena; Przkora, Rene

2013-11-01

Vertebral compression fractures caused by osteoporosis are among the most common fractures in the elderly. The treatment focuses on pain control, maintenance of independence, and management of the osteoporosis. Elderly patients often encounter adverse effects to pain medications, do not tolerate bed rest, and are not ideal candidates for invasive spinal reconstructive surgery. Percutaneous vertebral augmentation (vertebroplasty or kyphoplasty) has become popular as a less-invasive alternative. However, studies have questioned the effectiveness of these procedures. The authors conducted a MEDLINE search using relevant search terms including osteoporosis, osteoporotic vertebral compression fracture, elderly, kyphoplasty and vertebroplasty. Two elderly patients presented with a fracture of their third and first lumbar vertebral body, respectively. One patient progressed well with conservative treatment, whereas the other patient was hospitalized secondary to pain after conservative measures failed to offer improvement. The hospitalized patient subsequently opted for a kyphoplasty and was able to resume his normal daily activities after the procedure. Selecting patients on an individual case-by-case basis can optimize the effectiveness and outcomes of a vertebral augmentation. This process includes the documentation of an osteoporotic vertebral compression fracture with the aide of imaging studies, including the acuity of the fracture as well as the correlation with the physical examination findings. Patients who are functional and improving under a conservative regimen are not candidates for kyphoplasty. However, if the conservative management is not successful after 4 to 6 weeks and the patient is at risk to become bedridden, an augmentation should be considered. A kyphoplasty procedure may be preferred over vertebroplasty, given the lower risk profile and better outcomes regarding spinal alignment. Published by Elsevier HS Journals, Inc.

Infra-renal angles, entry into inferior vena cava and vertebral levels of renal veins.

PubMed

Satyapal, K S

1999-10-01

Current norms for renal vasculature hold true in only half the population. Standard textbooks perpetuate old misconceptions regarding renal venous anatomy. This study is aimed to determine left and right infra-renal angles (L-IRA, R-IRA); entry level of renal veins into the inferior vena cava (IVC), and height of IVC under renal vein influence; and their vertebral level. One hundred morphologically normal en-bloc renal specimens randomly selected from post-mortem examinations were dissected and resin casted. IRA were also measured from venograms of 32 adult and 11 foetal cadavers, as were vertebral entry levels. IRA measurements (degrees) were as follows: left, 55 degrees +/- 16 degrees (20 degrees -102 degrees ); right, 60 degrees +/- 17 degrees (10 degrees -93 degrees ). Left vein entered IVC higher than right 54%, lower 36%, and opposite each other 10%. Vertical distance between lower borders of veins was 1.0 +/- 0.9 cm. Vertical distance of IVC under renal vein influence was 2.3 +/- 1.0 cm. Vertebral level of veins in adults lies between TI2-L2. In foetuses, IRA was as follows: left, 65 degrees +/- 12 degrees (45 degrees -90 degrees ); right, 58 degrees +/- 7 degrees (40 degrees -70 degrees ); vertebral level between T12 and L3. Similar IRA values from literature noted on right, 51 degrees (26 degrees -100 degrees ); differences on left, 77 degrees (43 degrees -94 degrees ), clearly differing from Williams et al. (Gray's Anatomy, 37(th) ed, 1989) statement that renal veins "open into the inferior vena cava almost at right angles." Large variations of IRA are not surprising since kidneys are considered normally "floating viscera," varying position with posture and respiratory movement as well as in live vs. cadaveric subjects. The entry level into the IVC also differs from Williams et al. This study uniquely quantitated actual height difference between lower borders of left and right veins. The data presented appears to be the first documentation of vertebral level of entry of renal veins into IVC in foetuses. These findings are clinically important for the angiographer, catheter design, and planning porto-renal shunt procedures. Copyright 1999 Wiley-Liss, Inc.

Molecular regionalization of the developing amphioxus neural tube challenges major partitions of the vertebrate brain.

PubMed

Albuixech-Crespo, Beatriz; López-Blanch, Laura; Burguera, Demian; Maeso, Ignacio; Sánchez-Arrones, Luisa; Moreno-Bravo, Juan Antonio; Somorjai, Ildiko; Pascual-Anaya, Juan; Puelles, Eduardo; Bovolenta, Paola; Garcia-Fernàndez, Jordi; Puelles, Luis; Irimia, Manuel; Ferran, José Luis

2017-04-01

All vertebrate brains develop following a common Bauplan defined by anteroposterior (AP) and dorsoventral (DV) subdivisions, characterized by largely conserved differential expression of gene markers. However, it is still unclear how this Bauplan originated during evolution. We studied the relative expression of 48 genes with key roles in vertebrate neural patterning in a representative amphioxus embryonic stage. Unlike nonchordates, amphioxus develops its central nervous system (CNS) from a neural plate that is homologous to that of vertebrates, allowing direct topological comparisons. The resulting genoarchitectonic model revealed that the amphioxus incipient neural tube is unexpectedly complex, consisting of several AP and DV molecular partitions. Strikingly, comparison with vertebrates indicates that the vertebrate thalamus, pretectum, and midbrain domains jointly correspond to a single amphioxus region, which we termed Di-Mesencephalic primordium (DiMes). This suggests that these domains have a common developmental and evolutionary origin, as supported by functional experiments manipulating secondary organizers in zebrafish and mice.

Molecular regionalization of the developing amphioxus neural tube challenges major partitions of the vertebrate brain

PubMed Central

Albuixech-Crespo, Beatriz; Maeso, Ignacio; Sánchez-Arrones, Luisa; Moreno-Bravo, Juan Antonio; Somorjai, Ildiko; Pascual-Anaya, Juan; Puelles, Eduardo; Bovolenta, Paola; Garcia-Fernàndez, Jordi; Puelles, Luis; Ferran, José Luis

2017-01-01

All vertebrate brains develop following a common Bauplan defined by anteroposterior (AP) and dorsoventral (DV) subdivisions, characterized by largely conserved differential expression of gene markers. However, it is still unclear how this Bauplan originated during evolution. We studied the relative expression of 48 genes with key roles in vertebrate neural patterning in a representative amphioxus embryonic stage. Unlike nonchordates, amphioxus develops its central nervous system (CNS) from a neural plate that is homologous to that of vertebrates, allowing direct topological comparisons. The resulting genoarchitectonic model revealed that the amphioxus incipient neural tube is unexpectedly complex, consisting of several AP and DV molecular partitions. Strikingly, comparison with vertebrates indicates that the vertebrate thalamus, pretectum, and midbrain domains jointly correspond to a single amphioxus region, which we termed Di-Mesencephalic primordium (DiMes). This suggests that these domains have a common developmental and evolutionary origin, as supported by functional experiments manipulating secondary organizers in zebrafish and mice. PMID:28422959

Scoliosis associated with airflow obstruction due to endothoracic vertebral hump.

PubMed

Ito, Kenyu; Kawakami, Noriaki; Miyasaka, Kazuyoshi; Tsuji, Taichi; Ohara, Tetsuya; Nohara, Ayato

2012-12-01

A retrospective clinical study of scoliosis-associated airflow obstruction due to endothoracic vertebral hump. The purpose of this study was to evaluate and present anatomical features of patients with scoliosis who showed airflow obstruction caused by endothoracic vertebral hump. It is well known that severe scoliosis causes airflow restriction due to thoracic cage deformity. There have been few reports of clinical data and anatomical features on scoliosis associated with airflow obstruction due to endothoracic vertebral hump. The subjects were 6 patients. The diagnoses were idiopathic scoliosis in 3 patients, symptomatic scoliosis in 2 patients, and thoracogenic scoliosis in 1 patient. The radiological outcome, comorbidities, pre- and postoperative respiratory function, and surgical complication were analyzed. Four patients had preoperative atelectasis on the convex side of the lower lobe and improved after the operations. All patients showed main thoracic curves and their apex was located at T7-T9. All patients had lordoscoliosis except 1, who demonstrated kyphosing scoliosis. The correction rate was 78% (62.8%-83.5%). Preoperative thoracic lordosis within the range of -5° to -47° was postoperatively corrected to a substantially normal kyphosis within the range of 9° to 24°. The average vital capacity, percent VC improved from 0.72 L (0.33-1.17 L) to 1.21 L (0.82-1.71 L) and 45.5% (37.3%- 50.8%) to 63.7% (41.0%-88.6%) relatively. Spine Penetration Index improved from 23% (18%-35%) to 16% (13%-19%). Endothoracic hump ratio improved from 1.34 (0.98-1.93) to 1.12 (0.86-1.28). Each patient with symptomatic scoliosis and thoracogenic scoliosis required relatively long periods of respiration management. Patients having lordoscoliosis with an apex located between T7 and T9 may develop airflow obstruction due to an endothoracic vertebral hump. Correction of lordoscoliosis through anterior and posterior approaches successfully improved endothoracic hump ratio and atelectasis in all patients.

Effect of Once-Yearly Zoledronic Acid Five Milligrams on Fracture Risk and Change in Femoral Neck Bone Mineral Density

PubMed Central

Eastell, Richard; Black, Dennis M.; Boonen, Steven; Adami, Silvano; Felsenberg, Dieter; Lippuner, Kurt; Cummings, Steven R.; Delmas, Pierre D.; Palermo, Lisa; Mesenbrink, Peter; Cauley, Jane A.

2016-01-01

Context In the Health Outcomes and Reduced Incidence with Zoledronic Acid Once Yearly – Pivotal Fracture Trial (HORIZON-PFT), zoledronic acid (ZOL) 5 mg significantly reduced fracture risk. Objective The aim of the study was to identify factors associated with greater efficacy during ZOL 5 mg treatment. Design, Setting, and Patients We conducted a subgroup analysis (preplanned and post hoc) of a multicenter, double-blind, placebo-controlled, 36-month trial in 7765 women with postmenopausal osteoporosis. Intervention A single infusion of ZOL 5 mg or placebo was administered at baseline, 12, and 24 months. Main Outcome Measures Primary endpoints were new vertebral fracture and hip fracture. Secondary endpoints were nonvertebral fracture and change in femoral neck bone mineral density (BMD). Baseline risk factor subgroups were age, BMD T-score and vertebral fracture status, total hip BMD, race, weight, geographical region, smoking, height loss, history of falls, physical activity, prior bisphosphonates, creatinine clearance, body mass index, and concomitant osteoporosis medications. Results Greater ZOL induced effects on vertebral fracture risk were seen with younger age (treatment-by-subgroup interaction, P =0.05), normal creatinine clearance (P =0.04), and body mass index ≥ 25 kg/m2 (P = 0.02). There were no significant treatment–factor interactions for hip or nonvertebral fracture or for change in BMD. Conclusions ZOL appeared more effective in preventing vertebral fracture in younger women, overweight/obese women, and women with normal renal function. ZOL had similar effects irrespective of fracture risk factors or femoral neck BMD. PMID:19567517

Interrogating the relevance of mitochondrial apoptosis for vertebrate development and postnatal tissue homeostasis

PubMed Central

Kaufmann, Thomas; Villunger, Andreas

2016-01-01

“Programmed cell death or ‘apoptosis’ is critical for organogenesis during embryonic development and tissue homeostasis in the adult. Its deregulation can contribute to a broad range of human pathologies, including neurodegeneration, cancer, or autoimmunity…” These or similar phrases have become generic opening statements in many reviews and textbooks describing the physiological relevance of apoptotic cell death. However, while the role in disease has been documented beyond doubt, facilitating innovative drug discovery, we wonder whether the former is really true. What goes wrong in vertebrate development or in adult tissue when the main route to apoptotic cell death, controlled by the BCL2 family, is impaired? Such scenarios have been mimicked by deletion of one or more prodeath genes within the BCL2 family, and gene targeting studies in mice exploring the consequences have been manifold. Many of these studies were geared toward understanding the role of BCL2 family proteins and mitochondrial apoptosis in disease, whereas fewer focused in detail on their role during normal development or tissue homeostasis, perhaps also due to an irritating lack of phenotype. Looking at these studies, the relevance of classical programmed cell death by apoptosis for development appears rather limited. Together, these many studies suggest either highly selective and context-dependent contributions of mitochondrial apoptosis or significant redundancy with alternative cell death mechanisms, as summarized and discussed here. PMID:27798841

The generation of vertebral segmental patterning in the chick embryo

PubMed Central

Senthinathan, Biruntha; Sousa, Cátia; Tannahill, David; Keynes, Roger

2012-01-01

We have carried out a series of experimental manipulations in the chick embryo to assess whether the notochord, neural tube and spinal nerves influence segmental patterning of the vertebral column. Using Pax1 expression in the somite-derived sclerotomes as a marker for segmentation of the developing intervertebral disc, our results exclude such an influence. In contrast to certain teleost species, where the notochord has been shown to generate segmentation of the vertebral bodies (chordacentra), these experiments indicate that segmental patterning of the avian vertebral column arises autonomously in the somite mesoderm. We suggest that in amniotes, the subdivision of each sclerotome into non-miscible anterior and posterior halves plays a critical role in establishing vertebral segmentation, and in maintaining left/right alignment of the developing vertebral elements at the body midline. PMID:22458512

Aspergillus vertebral osteomyelitis in a child with a primary monocyte killing defect: response to GM-CSF therapy.

PubMed

Abu Jawdeh, L; Haidar, R; Bitar, F; Mroueh, S; Akel, S; Nuwayri-Salti, N; Dbaibo, G S

2000-07-01

We report the first case of vertebral aspergillosis in a child with a primary defect in monocyte killing, an extremely rare immunodeficiency The diagnosis of defective monocyte killing was made by an in vitro assay that showed normal killing of Staphylococcus aureus by the patient's neutrophils but impaired killing by his monocytes. Importantly, the extensive granulomatous infection that involved the vertebral column, posterior mediastinum, pleura, and lung was not responsive to aggressive treatment with a combination of liposomal amphotericin B. intralesional amphotericin B. itraconazole, and granulocyte transfusions. Dramatic clinical and radiological improvement was only seen after the addition of granulocyte macrophage-colony stimulating factor (GM-CSF) to his treatment regimen. The use of GM-CSF in the treatment of invasive aspergillosis in immunocompromised patients requires further evaluation.

Facultative parthenogenesis in vertebrates: reproductive error or chance?

PubMed

Lampert, K P

2008-01-01

Parthenogenesis, the development of an embryo from a female gamete without any contribution of a male gamete, is very rare in vertebrates. Parthenogenetically reproducing species have, so far, only been found in the Squamate reptiles (lizards and snakes). Facultative parthenogenesis, switching between sexual and clonal reproduction, although quite common in invertebrates, e.g. Daphnia and aphids, seems to be even rarer in vertebrates. However, isolated cases of parthenogenetic development have been reported in all vertebrate groups. Facultative parthenogenesis in vertebrates has only been found in captive animals but might simply have been overlooked in natural populations. Even though its evolutionary impact is hard to determine and very likely varies depending on the ploidy restoration mechanisms and sex-determining mechanisms involved, facultative parthenogenesis is already discussed in conservation biology and medical research. To raise interest for facultative parthenogenesis especially in evolutionary biology, I summarize the current knowledge about facultative parthenogenesis in the different vertebrate groups, introduce mechanisms of diploid oocyte formation and discuss the genetic consequences and potential evolutionary impact of facultative parthenogenesis in vertebrates.

Analysis of Maternal Risk Factors Associated With Congenital Vertebral Malformations

PubMed Central

Hesemann, Jennifer; Lauer, Emily; Ziska, Stephen; Noonan, Kenneth; Nemeth, Blaise; Scott-Schwoerer, Jessica; McCarty, Catherine; Rasmussen, Kristen; Goldberg, Jacob M.; Sund, Sarah; Eickhoff, Jens; Raggio, Cathleen L.; Giampietro, Philip F.

2014-01-01

Study Design A retrospective chart review of cases with congenital vertebral malformations (CVM) and controls with normal spine morphology. Objective To determine the relative contribution of maternal environmental factors (MEF) during pregnancy including maternal insulin dependent diabetes mellitus, valproic acid, alcohol, smoking, hyperthermia, twin gestation, assisted reproductive technology, in-vitro fertilization and maternal clomiphene usage to CVM development. Summary of Background Data Congenital vertebral malformations (CVM) represent defects in formation and segmentation of somites occurring with an estimated incidence of between 0.13–0.50 per 1000 live births. CVM may be associated with congenital scoliosis, Klippel-Feil syndrome, hemifacial microsomia and VACTERL syndromes, and represent significant morbidity due to pain and cosmetic disfigurement. Methods A multicenter retrospective chart review of 229 cases with CVM and 267 controls with normal spine morphology between the ages of 1–50 years was performed in order to obtain the odds ratio (OR) of MEF related to CVM among cases vs. controls. CVM due to an underlying syndrome associated with a known gene mutation or chromosome etiology were excluded. An imputation based analysis was performed in which subjects with no documentation of MEF history were treated as no maternal exposure.” Univariate and multivariate analysis was conducted to calculate the OR. Results Of the 229 total cases, 104 cases had single or multiple CVM without additional congenital malformations (CM) (Group 1) and 125 cases had single or multiple CVM and additional CM (Group 2). Nineteen percent of total cases had an identified MEF. The OR (95% CI, P-value) for MEF history for Group 1 was 6.0 (2.4–15.1, P<0.001) in the univariate analysis. The OR for MEF history in Group 2 was 9.1 (95%CI, P-value) (3.8–21.6, P<0.001) in the univariate analysis. The results were confirmed in the multivariate analysis, after adjusting for age, gender, and institution. Discussion These results support a hypothesis for an association between the above MEF during pregnancy and CVM and have implications for development of prevention strategies. Further prospective studies are needed to quantify association between CVM and specific MEF. PMID:23446706

Evolution of the NET (NocA, Nlz, Elbow, TLP-1) protein family in metazoans: insights from expression data and phylogenetic analysis

PubMed Central

Pereira, Filipe; Duarte-Pereira, Sara; Silva, Raquel M.; da Costa, Luís Teixeira; Pereira-Castro, Isabel

2016-01-01

The NET (for NocA, Nlz, Elbow, TLP-1) protein family is a group of conserved zinc finger proteins linked to embryonic development and recently associated with breast cancer. The members of this family act as transcriptional repressors interacting with both class I histone deacetylases and Groucho/TLE co-repressors. In Drosophila, the NET family members Elbow and NocA are vital for the development of tracheae, eyes, wings and legs, whereas in vertebrates ZNF703 and ZNF503 are important for the development of the nervous system, eyes and limbs. Despite the relevance of this protein family in embryogenesis and cancer, many aspects of its origin and evolution remain unknown. Here, we show that NET family members are present and expressed in multiple metazoan lineages, from cnidarians to vertebrates. We identified several protein domains conserved in all metazoan species or in specific taxonomic groups. Our phylogenetic analysis suggests that the NET family emerged in the last common ancestor of cnidarians and bilaterians and that several rounds of independent events of gene duplication occurred throughout evolution. Overall, we provide novel data on the expression and evolutionary history of the NET family that can be relevant to understanding its biological role in both normal conditions and disease. PMID:27929068

Alternative approaches for vertebrate ecotoxicity tests in the 21st century: A review of developments over the last 2 decades and current status

EPA Science Inventory

The need for alternative approaches to the use of vertebrate animals for hazard assessing chemicals and pollutants has become of increasing importance. It is now the first consideration when initiating a vertebrate ecotoxicity test, to ensure that unnecessary use of vertebrate or...

Roles for FGF in lamprey pharyngeal pouch formation and skeletogenesis highlight ancestral functions in the vertebrate head.

PubMed

Jandzik, David; Hawkins, M Brent; Cattell, Maria V; Cerny, Robert; Square, Tyler A; Medeiros, Daniel M

2014-02-01

A defining feature of vertebrates (craniates) is a pronounced head supported and protected by a cellularized endoskeleton. In jawed vertebrates (gnathostomes), the head skeleton is made of rigid three-dimensional elements connected by joints. By contrast, the head skeleton of modern jawless vertebrates (agnathans) consists of thin rods of flexible cellular cartilage, a condition thought to reflect the ancestral vertebrate state. To better understand the origin and evolution of the gnathostome head skeleton, we have been analyzing head skeleton development in the agnathan, lamprey. The fibroblast growth factors FGF3 and FGF8 have various roles during head development in jawed vertebrates, including pharyngeal pouch morphogenesis, patterning of the oral skeleton and chondrogenesis. We isolated lamprey homologs of FGF3, FGF8 and FGF receptors and asked whether these functions are ancestral features of vertebrate development or gnathostome novelties. Using gene expression and pharmacological agents, we found that proper formation of the lamprey head skeleton requires two phases of FGF signaling: an early phase during which FGFs drive pharyngeal pouch formation, and a later phase when they directly regulate skeletal differentiation and patterning. In the context of gene expression and functional studies in gnathostomes, our results suggest that these roles for FGFs arose in the first vertebrates and that the evolution of the jaw and gnathostome cellular cartilage was driven by changes developmentally downstream from pharyngeal FGF signaling.

Embryonic development of the axial column in the little skate, Leucoraja erinacea.

PubMed

Criswell, Katharine E; Coates, Michael I; Gillis, J Andrew

2017-03-01

The morphological patterns and molecular mechanisms of vertebral column development are well understood in bony fishes (osteichthyans). However, vertebral column morphology in elasmobranch chondrichthyans (e.g., sharks and skates) differs from that of osteichthyans, and its development has not been extensively studied. Here, we characterize vertebral development in an elasmobranch fish, the little skate, Leucoraja erinacea, using microCT, paraffin histology, and whole-mount skeletal preparations. Vertebral development begins with the condensation of mesenchyme, first around the notochord, and subsequently around the neural tube and caudal artery and vein. Mesenchyme surrounding the notochord differentiates into a continuous sheath of spindle-shaped cells, which forms the precursor to the mineralized areolar calcification of the centrum. Mesenchyme around the neural tube and caudal artery/vein becomes united by a population of mesenchymal cells that condenses lateral to the sheath of spindle-shaped cells, with this mesenchymal complex eventually differentiating into the hyaline cartilage of the future neural arches, hemal arches, and outer centrum. The initially continuous layers of areolar tissue and outer hyaline cartilage eventually subdivide into discrete centra and arches, with the notochord constricted in the center of each vertebra by a late-forming "inner layer" of hyaline cartilage, and by a ring of areolar calcification located medial to the outer vertebral cartilage. The vertebrae of elasmobranchs are distinct among vertebrates, both in terms of their composition (i.e., with centra consisting of up to three tissues layers-an inner cartilage layer, a calcified areolar ring, and an outer layer of hyaline cartilage), and their mode of development (i.e., the subdivision of arch and outer centrum cartilage from an initially continuous layer of hyaline cartilage). Given the evident variation in patterns of vertebral construction, broad taxon sampling, and comparative developmental analyses are required to understand the diversity of mechanisms at work in the developing axial skeleton of vertebrates. J. Morphol. 278:300-320, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

The role of crumbs genes in the vertebrate cornea.

PubMed

Beyer, Jill; Zhao, Xinping C; Yee, Richard; Khaliq, Shagufta; McMahon, Timothy T; Ying, Hongyu; Yue, Beatrice Y J T; Malicki, Jarema J

2010-09-01

To evaluate the role of crumbs genes and related epithelial polarity loci in the vertebrate cornea. The authors used histologic analysis and electron microscopy to evaluate the corneas of zebrafish mutant for a crumbs locus oko meduzy (ome) and in mutants of four other loci, nagie oko (nok), heart and soul (has), mosaic eyes (moe), and ncad (formerly glass onion), that function in the same or related genetic pathways. In parallel, they performed an evaluation of corneas in human carriers of a crumbs gene, CRB1, and mutations using topography and biomicroscopy. The expression of the CRB1 gene in the normal human cornea was examined by polymerase chain reaction (PCR) and immunohistochemical staining. The corneas of zebrafish mutants display severe abnormalities of the epithelial and stromal layers. The epithelial cells do not properly adhere to each other, and fluid-filled spaces form between them. In addition, the layering of the corneal stroma is poorly formed or absent. The corneas of human carriers of CRB1 mutations display shape deviations compared with what has been observed in normal individuals. A PCR product of the correct size was obtained from normal human corneal samples. Sequence analyses confirmed its identity to be the human CRB1 gene. Immunohistochemical staining using anti-CRB1 yielded positive brown deposits in the human cornea. crumbs genes play a role in the differentiation of the vertebrate cornea. Corneal defects associated with crumbs gene mutations are very severe in the zebrafish model and, in comparison, appear clinically less pronounced in the human eye.

Closure of the vertebral canal in human embryos and fetuses.

PubMed

Mekonen, Hayelom K; Hikspoors, Jill P J M; Mommen, Greet; Kruepunga, Nutmethee; Köhler, S Eleonore; Lamers, Wouter H

2017-08-01

The vertebral column is the paradigm of the metameric architecture of the vertebrate body. Because the number of somites is a convenient parameter to stage early human embryos, we explored whether the closure of the vertebral canal could be used similarly for staging embryos between 7 and 10 weeks of development. Human embryos (5-10 weeks of development) were visualized using Amira 3D ® reconstruction and Cinema 4D ® remodelling software. Vertebral bodies were identifiable as loose mesenchymal structures between the dense mesenchymal intervertebral discs up to 6 weeks and then differentiated into cartilaginous structures in the 7th week. In this week, the dense mesenchymal neural processes also differentiated into cartilaginous structures. Transverse processes became identifiable at 6 weeks. The growth rate of all vertebral bodies was exponential and similar between 6 and 10 weeks, whereas the intervertebral discs hardly increased in size between 6 and 8 weeks and then followed vertebral growth between 8 and 10 weeks. The neural processes extended dorsolaterally (6th week), dorsally (7th week) and finally dorsomedially (8th and 9th weeks) to fuse at the midthoracic level at 9 weeks. From there, fusion extended cranially and caudally in the 10th week. Closure of the foramen magnum required the development of the supraoccipital bone as a craniomedial extension of the exoccipitals (neural processes of occipital vertebra 4), whereas a growth burst of sacral vertebra 1 delayed closure until 15 weeks. Both the cranial- and caudal-most vertebral bodies fused to form the basioccipital (occipital vertebrae 1-4) and sacrum (sacral vertebrae 1-5). In the sacrum, fusion of its so-called alar processes preceded that of the bodies by at least 6 weeks. In conclusion, the highly ordered and substantial changes in shape of the vertebral bodies leading to the formation of the vertebral canal make the development of the spine an excellent, continuous staging system for the (human) embryo between 6 and 10 weeks of development. © 2017 Anatomical Society.

The generation of vertebral segmental patterning in the chick embryo.

PubMed

Senthinathan, Biruntha; Sousa, Cátia; Tannahill, David; Keynes, Roger

2012-06-01

We have carried out a series of experimental manipulations in the chick embryo to assess whether the notochord, neural tube and spinal nerves influence segmental patterning of the vertebral column. Using Pax1 expression in the somite-derived sclerotomes as a marker for segmentation of the developing intervertebral disc, our results exclude such an influence. In contrast to certain teleost species, where the notochord has been shown to generate segmentation of the vertebral bodies (chordacentra), these experiments indicate that segmental patterning of the avian vertebral column arises autonomously in the somite mesoderm. We suggest that in amniotes, the subdivision of each sclerotome into non-miscible anterior and posterior halves plays a critical role in establishing vertebral segmentation, and in maintaining left/right alignment of the developing vertebral elements at the body midline. © 2012 The Authors. Journal of Anatomy © 2012 Anatomical Society.

Mechanisms of developmental neurite pruning

PubMed Central

Schuldiner, Oren; Yaron, Avraham

2016-01-01

The precise wiring of the nervous system is a combined outcome of progressive and regressive events during development. Axon guidance and synapse formation intertwined with cell death and neurite pruning sculpt the mature circuitry. It is now well recognized that pruning of dendrites and axons as means to refine neuronal networks, is a wide spread phenomena required for the normal development of vertebrate and invertebrate nervous systems. Here we will review the arising principles of cellular and molecular mechanisms of neurite pruning. We will discuss these principles in light of studies in multiple neuronal systems, and speculate on potential explanations for the emergence of neurite pruning as a mechanism to sculpt the nervous system. PMID:25213356

A unified anatomy ontology of the vertebrate skeletal system.

PubMed

Dahdul, Wasila M; Balhoff, James P; Blackburn, David C; Diehl, Alexander D; Haendel, Melissa A; Hall, Brian K; Lapp, Hilmar; Lundberg, John G; Mungall, Christopher J; Ringwald, Martin; Segerdell, Erik; Van Slyke, Ceri E; Vickaryous, Matthew K; Westerfield, Monte; Mabee, Paula M

2012-01-01

The skeleton is of fundamental importance in research in comparative vertebrate morphology, paleontology, biomechanics, developmental biology, and systematics. Motivated by research questions that require computational access to and comparative reasoning across the diverse skeletal phenotypes of vertebrates, we developed a module of anatomical concepts for the skeletal system, the Vertebrate Skeletal Anatomy Ontology (VSAO), to accommodate and unify the existing skeletal terminologies for the species-specific (mouse, the frog Xenopus, zebrafish) and multispecies (teleost, amphibian) vertebrate anatomy ontologies. Previous differences between these terminologies prevented even simple queries across databases pertaining to vertebrate morphology. This module of upper-level and specific skeletal terms currently includes 223 defined terms and 179 synonyms that integrate skeletal cells, tissues, biological processes, organs (skeletal elements such as bones and cartilages), and subdivisions of the skeletal system. The VSAO is designed to integrate with other ontologies, including the Common Anatomy Reference Ontology (CARO), Gene Ontology (GO), Uberon, and Cell Ontology (CL), and it is freely available to the community to be updated with additional terms required for research. Its structure accommodates anatomical variation among vertebrate species in development, structure, and composition. Annotation of diverse vertebrate phenotypes with this ontology will enable novel inquiries across the full spectrum of phenotypic diversity.

Vertebral fracture after aircraft ejection during Operation Desert Storm.

PubMed

Osborne, R G; Cook, A A

1997-04-01

During Operation Desert Storm, 21 United States and 2 Italian military personnel were held in Iraq as prisoners of war. Of these, 18 had ejected from fixed-wing, ejection seat-equipped, combat aircraft prior to their capture. Of the 18, 6 (33%) had sustained vertebral fractures; 4 of these were compression fractures. This fracture rate is comparable to that of previously studied groups. Fractures were noted to be at several different vertebral sites and after ejecting from a variety of aircraft. Apart from contusions and abrasions, vertebral fractures were the most common injuries discovered in this repatriated population. None of the vertebral fractures produced recognizable neurological disability. The development of vertebral fractures was neither associated with the use of any particular ejection system or aircraft nor did the development of vertebral fractures appear dependent on the age, height or length of service of the affected personnel. Ejected aircrew with low altitude mission profiles seemed more predisposed to vertebral fracture than those at high altitudes, but with a small sample population, this relationship was not statistically significant (p > 0.25). Reliable data were unavailable on aircrew positioning and preparation time for ejection.

A Unified Anatomy Ontology of the Vertebrate Skeletal System

PubMed Central

Dahdul, Wasila M.; Balhoff, James P.; Blackburn, David C.; Diehl, Alexander D.; Haendel, Melissa A.; Hall, Brian K.; Lapp, Hilmar; Lundberg, John G.; Mungall, Christopher J.; Ringwald, Martin; Segerdell, Erik; Van Slyke, Ceri E.; Vickaryous, Matthew K.; Westerfield, Monte; Mabee, Paula M.

2012-01-01

The skeleton is of fundamental importance in research in comparative vertebrate morphology, paleontology, biomechanics, developmental biology, and systematics. Motivated by research questions that require computational access to and comparative reasoning across the diverse skeletal phenotypes of vertebrates, we developed a module of anatomical concepts for the skeletal system, the Vertebrate Skeletal Anatomy Ontology (VSAO), to accommodate and unify the existing skeletal terminologies for the species-specific (mouse, the frog Xenopus, zebrafish) and multispecies (teleost, amphibian) vertebrate anatomy ontologies. Previous differences between these terminologies prevented even simple queries across databases pertaining to vertebrate morphology. This module of upper-level and specific skeletal terms currently includes 223 defined terms and 179 synonyms that integrate skeletal cells, tissues, biological processes, organs (skeletal elements such as bones and cartilages), and subdivisions of the skeletal system. The VSAO is designed to integrate with other ontologies, including the Common Anatomy Reference Ontology (CARO), Gene Ontology (GO), Uberon, and Cell Ontology (CL), and it is freely available to the community to be updated with additional terms required for research. Its structure accommodates anatomical variation among vertebrate species in development, structure, and composition. Annotation of diverse vertebrate phenotypes with this ontology will enable novel inquiries across the full spectrum of phenotypic diversity. PMID:23251424

Current Aeromedical Issues in Rotary Wing Operations.

DTIC Science & Technology

1999-08-01

normal lumbar lordosis (19). The spine losses the normal curve, the vertebral bodies tend to be closer together in front, and an increase in...a dorsally curved lumbar spine to the lumbar lordosis of his erect posture (Fig 1). From that transition comes his propensity to low back pain...flexibility of the lumbar spine relies upon the elasticity of the intervertebral discs. Fig 1. Change in lumbar lordosis with erect posture The

Vestigial-like 3 is a novel Ets1 interacting partner and regulates trigeminal nerve formation and cranial neural crest migration.

PubMed

Simon, Emilie; Thézé, Nadine; Fédou, Sandrine; Thiébaud, Pierre; Faucheux, Corinne

2017-10-15

Drosophila Vestigial is the founding member of a protein family containing a highly conserved domain, called Tondu, which mediates their interaction with members of the TEAD family of transcription factors (Scalloped in Drosophila ). In Drosophila , the Vestigial/Scalloped complex controls wing development by regulating the expression of target genes through binding to MCAT sequences. In vertebrates, there are four Vestigial-like genes, the functions of which are still not well understood. Here, we describe the regulation and function of vestigial-like 3 (vgll3) during Xenopus early development. A combination of signals, including FGF8, Wnt8a, Hoxa2, Hoxb2 and retinoic acid, limits vgll3 expression to hindbrain rhombomere 2. We show that vgll3 regulates trigeminal placode and nerve formation and is required for normal neural crest development by affecting their migration and adhesion properties. At the molecular level, vgll3 is a potent activator of pax3 , zic1 , Wnt and FGF , which are important for brain patterning and neural crest cell formation. Vgll3 interacts in the embryo with Tead proteins but unexpectedly with Ets1, with which it is able to stimulate a MCAT driven luciferase reporter gene. Our findings highlight a critical function for vgll3 in vertebrate early development. © 2017. Published by The Company of Biologists Ltd.

nr0b1 (DAX1) mutation in zebrafish causes female-to-male sex reversal through abnormal gonadal proliferation and differentiation.

PubMed

Chen, Sijie; Zhang, Hefei; Wang, Fenghua; Zhang, Wei; Peng, Gang

2016-09-15

Sex determinations are diverse in vertebrates. Although many sex-determining genes and pathways are conserved, the mechanistic roles of these genes and pathways in the genetic sex determination are not well understood. DAX1 (encoded by the NR0B1 gene) is a vertebrate specific orphan nuclear receptor that regulates gonadal development and sexual determination. In human, duplication of the NR0B1 gene leads to male-to-female sex reversal. In mice, Nr0b1 shows both pro-testis and anti-testis functions. We generated inheritable nr0b1 mutation in the zebrafish and found the nr0b1 mutation caused homozygous mutants to develop as fertile males due to female-to-male sex reversal. The nr0b1 mutation did not increase Caspase-3 labeling nor tp53 expression in the developing gonads. Introduction of a tp53 mutation into the nr0b1 mutant did not rescue the sex-reversal phenotype. Further examination revealed reduction in cell proliferation and abnormal somatic cell differentiation in the nr0b1 mutant gonads at the undifferentiated and bi-potential ovary stages. Together, our results suggest nr0b1 regulates somatic cell differentiation and cell proliferation to ensure normal sex development in the zebrafish. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Percutaneous pedicle screw fixation through the pedicle of fractured vertebra in the treatment of type A thoracolumbar fractures using Sextant system: an analysis of 38 cases.

PubMed

Wang, Hong-wei; Li, Chang-qing; Zhou, Yue; Zhang, Zheng-feng; Wang, Jian; Chu, Tong-wei

2010-06-01

To prospectively evaluate the feasibility, safety and efficacy of the percutaneous pedicle screw fixation through the pedicle of fractured vertebra in the treatment of type A thoracolumbar fractures using Sextant system in the retrospective non-randomized case-control study. A total of 38 consecutive non-randomized patients with type A thoracolumbar fractures, which had been stabilized posteriorly from December 2006 to March 2009, were examined retrospectively more than 9 months after surgery. Twenty-one patients had been treated conventionally with open pedicle screw fixation (OPSF) and 17 patients received minimally invasive treatment with Sextant percutaneous pedicle screw fixation (SPPSF). As a method of evaluation, the incision size, the intraoperation and postoperative volume of blood loss, operation time, postoperative hospital stay, blood transfusion, the radiological assessment of the sagittal Cobb;s angle, vertebral body angle and vertebral body height were recorded and compared. All patients were followed up for 8-24 months (average 11.6 months). There were significant differences in the incision size, surgical blood loss, surgical draining loss, operation time, hospital stay after operation, blood transfusion, the proportion of antalgic supplement and postoperative incisional VAS between the two groups (P less than 0.05). Mean preoperative kyphotic deformity was 16.0 degree and improved by 9.3 degree after surgery in OPSF group, but 15.2 degree and 10.3 degree respectively in SPPSF group. Mean preoperative angle of the fractured vertebral body was 15.9 degree and improved by 7.9 degree after surgery in OPSF group, but 14.9 degree and 6.6 degree respectively in SPPSF group. Mean anterior vertebral body height (% of normal) was 67.3% before surgery and 95.8% after surgery, but 69.1% and 90.1% respectively in SPPSF group. Mean posterior vertebral body height (% of normal) was 93.3% before surgery and 99.5% after surgery, but 88.9% and 93.3% respectively in SPPSF group. Among the patients whose 9-month follow-up films were available, 3.0 degree of kyphosis correction was lost in OPSF group, but 3.2 degree in SPPSF group. And 1.0 degree of the angle of the fractured vertebral body correction was lost in OPSF group, but 1.5 degree in SPPSF group. Then 3.0% of the anterior vertebral body height correction was lost in OPSF group, but 2.2% in SPPSF group. And 3.0% of the posterior vertebral body height correction was lost in OPSF group, but 2.5% in SPPSF group. The sagittal Cobb's angle, vertebral body angle and anterior height of the fractured vertebra were all significantly different in each group before and after operation (P less than 0.05). There were no significant differences in the postoperative sagittal Cobb's angle, vertebral body angle and the improvement of the vertebral body height and the kyphotic deformity correction between OPSF and SPPSF groups (P larger than 0.05), but there was significant difference in the postoperative anterior height of the fractured vertebra between the two groups (P less than 0.05). The percutaneous pedicle screw fixation through the pedicle of fractured vertebra using Sextant system is a good minimally-invasive surgical therapeutic choice for patients with type A thoracolumbar fracture except for that the SPPSF has a little insufficiency in resuming the anterior height of the fractured vertebra compared with OPSF.

Phylostratigraphic profiles reveal a deep evolutionary history of the vertebrate head sensory systems

PubMed Central

2013-01-01

Background The vertebrate head is a highly derived trait with a heavy concentration of sophisticated sensory organs that allow complex behaviour in this lineage. The head sensory structures arise during vertebrate development from cranial placodes and the neural crest. It is generally thought that derivatives of these ectodermal embryonic tissues played a central role in the evolutionary transition at the onset of vertebrates. Despite the obvious importance of head sensory organs for vertebrate biology, their evolutionary history is still uncertain. Results To give a fresh perspective on the adaptive history of the vertebrate head sensory organs, we applied genomic phylostratigraphy to large-scale in situ expression data of the developing zebrafish Danio rerio. Contrary to traditional predictions, we found that dominant adaptive signals in the analyzed sensory structures largely precede the evolutionary advent of vertebrates. The leading adaptive signals at the bilaterian-chordate transition suggested that the visual system was the first sensory structure to evolve. The olfactory, vestibuloauditory, and lateral line sensory organs displayed a strong link with the urochordate-vertebrate ancestor. The only structures that qualified as genuine vertebrate innovations were the neural crest derivatives, trigeminal ganglion and adenohypophysis. We also found evidence that the cranial placodes evolved before the neural crest despite their proposed embryological relatedness. Conclusions Taken together, our findings reveal pre-vertebrate roots and a stepwise adaptive history of the vertebrate sensory systems. This study also underscores that large genomic and expression datasets are rich sources of macroevolutionary information that can be recovered by phylostratigraphic mining. PMID:23587066

Testing Pullout Strength of Pedicle Screw Using Synthetic Bone Models: Is a Bilayer Foam Model a Better Representation of Vertebra?

PubMed

Varghese, Vicky; Krishnan, Venkatesh; Saravana Kumar, Gurunathan

2018-06-01

A biomechanical study. A new biomechanical model of the vertebra has been developed that accounts for the inhomogeneity of bone and the contribution of the pedicle toward the holding strength of a pedicle screw. Pullout strength studies are typically carried out on rigid polyurethane foams that represent the homogeneous vertebral framework of the spine. However, the contribution of the pedicle region, which contributes to the inhomogeneity in this framework, has not been considered in previous investigations. Therefore, we propose a new biomechanical model that can account for the vertebral inhomogeneity, especially the contribution of the pedicles toward the pullout strength of the pedicle screw. A bilayer foam model was developed by joining two foams representing the pedicle and the vertebra. The results of the pullout strength tests performed on the foam models were compared with those from the tests performed on the cadaver lumbar vertebra. Significant differences ( p <0.05) were observed between the pullout strength of the pedicle screw in extremely osteoporotic (0.18±0.11 kN), osteoporotic (0.37±0.14 kN), and normal (0.97±0.4 kN) cadaver vertebra. In the monolayer model, significant differences ( p <0.05) were observed in pullout strength between extremely osteoporotic (0.3±0.02 kN), osteoporotic (0.65±0.12 kN), and normal (0.99±0.04 kN) bone model. However, the bilayer foam model exhibited no significant differences ( p >0.05) in the pullout strength of pedicle screws between osteoporotic (0.85±0.08 kN) and extremely osteoporotic bone models (0.94±0.08 kN), but there was a significant difference ( p <0.05) between osteoporotic (0.94±0.08 kN) and normal bone models (1.19±0.05 kN). There were no significant differences ( p >0.05) in pullout strength between cadaver and bilayer foam model in normal bones. The new synthetic bone model that reflects the contribution of the pedicles to the pullout strength of the pedicle screws could provide a more efficacious means of testing pedicle-screw pullout strength. The bilayer model can match the pullout strength value of normal lumbar vertebra bone whereas the monolayer foam model was able to match that of the extremely osteoporotic lumbar vertebra.

Alternative approaches to vertebrate ecotoxicity tests in the 21st century: A review of developments over the last 2 decades and current status

USGS Publications Warehouse

Lillicrap, Adam; Belanger, Scott; Burden, Natalie; Du Pasquier, David; Embry, Michelle; Halder, Marlies; Lampi, Mark; Lee, Lucy; Norberg-King, Teresa J.; Rattner, Barnett A.; Schirmer, Kristin; Thomas, Paul

2016-01-01

The need for alternative approaches to the use of vertebrate animals for hazard assessment of chemicals and pollutants has become of increasing importance. It is now the first consideration when initiating a vertebrate ecotoxicity test, to ensure that unnecessary use of vertebrate organisms is minimized wherever possible. For some regulatory purposes, the use of vertebrate organisms for environmental risk assessments has been banned; in other situations, the number of organisms tested has been dramatically reduced or the severity of the procedure refined. However, there is still a long way to go to achieve a complete replacement of vertebrate organisms to generate environmental hazard data. The development of animal alternatives is based not just on ethical considerations but also on reducing the cost of performing vertebrate ecotoxicity tests and in some cases on providing better information aimed at improving environmental risk assessments. The present Focus article provides an overview of the considerable advances that have been made toward alternative approaches for ecotoxicity assessments over the last few decades.

Vertebral pneumatocyst. A case report.

PubMed

Laufer, L; Schulman, H; Hertzanu, Y

1996-02-01

This study illustrates intraosseous pneumatocyst of the vertebral body, a benign lesion. To review the incidence and location of this benign lesion during a 1-year period. Intraosseous pneumatocyst is a rare benign condition, commonly seen in iliac bone or sacrum. The etiology of this entity is unclear. Other locations of these lesions are very rare, and only a few isolated cases are reported in the literature. In the last year (1994-1995), vertebral pneumatocyst was incidentally found in four patients who underwent computed tomography examination for presumptive discal lesion. Axial computed tomography with 2- and 4-mm slice thickness was performed. The typical computed tomography patterns of intraosseous pneumatocyst involving the cervical, dorsal, or lumbar spine were found. The bony structure and joints were normal. To the best of our knowledge, intraosseous pneumatocyst located in the spinal process has not been reported. Intraosseous pneumatocyst is a benign lesion. Biopsy and follow-up are unnecessary.

Identification and functional characterization of muscle satellite cells in Drosophila

PubMed Central

Reichert, Heinrich

2017-01-01

Work on genetic model systems such as Drosophila and mouse has shown that the fundamental mechanisms of myogenesis are remarkably similar in vertebrates and invertebrates. Strikingly, however, satellite cells, the adult muscle stem cells that are essential for the regeneration of damaged muscles in vertebrates, have not been reported in invertebrates. In this study, we show that lineal descendants of muscle stem cells are present in adult muscle of Drosophila as small, unfused cells observed at the surface and in close proximity to the mature muscle fibers. Normally quiescent, following muscle fiber injury, we show that these cells express Zfh1 and engage in Notch-Delta-dependent proliferative activity and generate lineal descendant populations, which fuse with the injured muscle fiber. In view of strikingly similar morphological and functional features, we consider these novel cells to be the Drosophila equivalent of vertebrate muscle satellite cells. PMID:29072161

Relevant Anatomic and Morphological Measurements of the Rat Spine: Considerations for Rodent Models of Human Spine Trauma.

PubMed

Jaumard, Nicolas V; Leung, Jennifer; Gokhale, Akhilesh J; Guarino, Benjamin B; Welch, William C; Winkelstein, Beth A

2015-10-15

Basic science study measuring anatomical features of the cervical and lumbar spine in rat with normalized comparison with the human. The goal of this study is to comprehensively compare the rat and human cervical and lumbar spines to investigate whether the rat is an appropriate model for spine biomechanics investigations. Animal models have been used for a long time to investigate the effects of trauma, degenerative changes, and mechanical loading on the structure and function of the spine. Comparative studies have reported some mechanical properties and/or anatomical dimensions of the spine to be similar between various species. However, those studies are largely limited to the lumbar spine, and a comprehensive comparison of the rat and human spines is lacking. Spines were harvested from male Holtzman rats (n = 5) and were scanned using micro- computed tomography and digitally rendered in 3 dimensions to quantify the spinal bony anatomy, including the lateral width and anteroposterior depth of the vertebra, vertebral body, and spinal canal, as well as the vertebral body and intervertebral disc heights. Normalized measurements of the vertebra, vertebral body, and spinal canal of the rat were computed and compared with corresponding measurements from the literature for the human in the cervical and lumbar spinal regions. The vertebral dimensions of the rat spine vary more between spinal levels than in humans. Rat vertebrae are more slender than human vertebrae, but the width-to-depth axial aspect ratios are very similar in both species in both the cervical and lumbar regions, especially for the spinal canal. The similar spinal morphology in the axial plane between rats and humans supports using the rat spine as an appropriate surrogate for modeling axial and shear loading of the human spine.

Vertebrobasilar system computed tomographic angiography in central vertigo

PubMed Central

Paşaoğlu, Lale

2017-01-01

Abstract The incidence of vertigo in the population is 20% to 30% and one-fourth of the cases are related to central causes. The aim of this study was to evaluate computed tomography angiography (CTA) findings of the vertebrobasilar system in central vertigo without stroke. CTA and magnetic resonance images of patients with vertigo were retrospectively evaluated. One hundred twenty-nine patients suspected of having central vertigo according to history, physical examination, and otological and neurological tests without signs of infarction on diffusion-weighted magnetic resonance imaging were included in the study. The control group included 120 patients with similar vascular disease risk factors but without vertigo. Vertebral and basilar artery diameters, hypoplasias, exit-site variations of vertebral artery, vertebrobasilar tortuosity, and stenosis of ≥50% detected on CTA were recorded for all patients. Independent-samples t test was used in variables with normal distribution, and Mann–Whitney U test in non-normal distribution. The difference of categorical variable distribution according to groups was analyzed with χ2 and/or Fisher exact test. Vertebral artery hypoplasia and ≥50% stenosis were seen more often in the vertigo group (P = 0.000, <0.001). Overall 78 (60.5%) vertigo patients had ≥50% stenosis, 54 (69.2%) had stenosis at V1 segment, 9 (11.5%) at V2 segment, 2 (2.5%) at V3 segment, and 13 (16.6%) at V4 segment. Both vertigo and control groups had similar basilar artery hypoplasia and ≥50% stenosis rates (P = 0.800, >0.05). CTA may be helpful to clarify the association between abnormal CTA findings of vertebral arteries and central vertigo. This article reveals the opportunity to diagnose posterior circulation abnormalities causing central vertigo with a feasible method such as CTA. PMID:28328808

Vertebrobasilar system computed tomographic angiography in central vertigo.

PubMed

Paşaoğlu, Lale

2017-03-01

The incidence of vertigo in the population is 20% to 30% and one-fourth of the cases are related to central causes. The aim of this study was to evaluate computed tomography angiography (CTA) findings of the vertebrobasilar system in central vertigo without stroke.CTA and magnetic resonance images of patients with vertigo were retrospectively evaluated. One hundred twenty-nine patients suspected of having central vertigo according to history, physical examination, and otological and neurological tests without signs of infarction on diffusion-weighted magnetic resonance imaging were included in the study. The control group included 120 patients with similar vascular disease risk factors but without vertigo. Vertebral and basilar artery diameters, hypoplasias, exit-site variations of vertebral artery, vertebrobasilar tortuosity, and stenosis of ≥50% detected on CTA were recorded for all patients. Independent-samples t test was used in variables with normal distribution, and Mann-Whitney U test in non-normal distribution. The difference of categorical variable distribution according to groups was analyzed with χ and/or Fisher exact test.Vertebral artery hypoplasia and ≥50% stenosis were seen more often in the vertigo group (P = 0.000, <0.001). Overall 78 (60.5%) vertigo patients had ≥50% stenosis, 54 (69.2%) had stenosis at V1 segment, 9 (11.5%) at V2 segment, 2 (2.5%) at V3 segment, and 13 (16.6%) at V4 segment. Both vertigo and control groups had similar basilar artery hypoplasia and ≥50% stenosis rates (P = 0.800, >0.05).CTA may be helpful to clarify the association between abnormal CTA findings of vertebral arteries and central vertigo.This article reveals the opportunity to diagnose posterior circulation abnormalities causing central vertigo with a feasible method such as CTA.

Vertebral heights and ratios are not only race-specific, but also gender- and region-specific: establishment of reference values for mainland Chinese.

PubMed

Ning, Lei; Song, Li-Jiang; Fan, Shun-Wu; Zhao, Xing; Chen, Yi-Lei; Li, Zhao-Zhi; Hu, Zi-Ang

2017-10-11

This study established gender-specific reference values in mainland Chinese (MC) and is important for quantitative morphometry for diagnosis and epidemiological study of osteoporotic vertebral compressive fracture. Comparisons of reference values among different racial populations are then performed to demonstrate the MC-specific characteristic. Osteoporotic vertebral compressive fracture (OVCF) is a common complication of osteoporosis in the elder population. Clinical diagnosis and epidemiological study of OVCF often employ quantitative morphometry, which relies heavily on the comparison of patients' vertebral parameters to existing reference values derived from the normal population. Thus, reference values are crucial in clinical diagnosis. To our knowledge, this is the first study to establish reference values of the mainland Chinese (MC) for quantitative morphometry. Vertebral heights including anterior (Ha), middle (Hm), posterior (Hp) heights, and predicted posterior height (pp) from T4 to L5 were obtained; and ratios of Ha/Hp, Hm/Hp and Hp/pp. were calculated from 585 MC (both female and male) for establishing reference values and subsequent comparisons with other studies. Vertebral heights increased progressively from T4 to L3 but then decreased in L4 and L5. Both genders showed similar ratios of vertebral dimensions, but male vertebrae were statistically larger than those of female (P < 0.01). Vertebral size of MC population was smaller than that of US and UK population, but was surprisingly larger than that of Hong Kong Chinese, although these two are commonly considered as one race. Data from different racial populations showed similar dimensional ratios in all vertebrae. We established gender-specific reference values for MC. Our results also indicated the necessity of establishing reference values that are not only race- and gender-specific, but also population- or region-specific for accurate quantitative morphometric assessment of OVCF.

Evolution of vertebrate mechanosensory hair cells and inner ears: toward identifying stimuli that select mutation driven altered morphologies

PubMed Central

Fritzsch, Bernd; Straka, Hans

2014-01-01

Among the major distance senses of vertebrates, the ear is unique in its complex morphological changes during evolution. Conceivably, these changes enable the ear to adapt toward sensing various physically well-characterized stimuli. This review develops a scenario that integrates sensory cell with organ evolution. We propose that molecular and cellular evolution of the vertebrate hair cells occurred prior to the formation of the vertebrate ear. We previously proposed that the genes driving hair cell differentiation, were aggregated in the otic region through developmental re-patterning that generated a unique vertebrate embryonic structure, the otic placode. In agreement with the presence of graviceptive receptors in many vertebrate outgroups, it is likely that the vertebrate ear originally functioned as a simple gravity-sensing organ. Based on the rare occurrence of angular acceleration receptors in vertebrate outgroups, we further propose that the canal system evolved with a more sophisticated ear morphogenesis. This evolving morphogenesis obviously turned the initial otocyst into a complex set of canals and recesses, harboring multiple sensory epithelia each adapted to the acquisition of a specific aspect of a given physical stimulus. As support for this evolutionary progression, we provide several details of the molecular basis of ear development. PMID:24281353

Infarcts presenting with a combination of medial medullary and posterior inferior cerebellar artery syndromes.

PubMed

Lee, Hyung; Baik, Seung Kug

2004-09-15

Cerebellar and medial medullary infarctions are well-known vertebrobasilar stroke syndromes. However, their development in a patient with distal vertebral artery occlusion has not been previously reported. A 49-year-old man with longstanding hypertension suddenly developed vertigo, right-sided Horner syndrome, and left-sided weakness. An MRI of the brain showed acute infarcts in the right inferior cerebellum (posterior inferior cerebellar artery territory) and the right upper medial medulla (direct penetrating branches of vertebral artery). Magnetic resonance angiogram showed occlusion of the distal vertebral artery on the right side. Atherothrombotic occlusion of the distal vertebral artery may cause this unusual combination of vertebrobasilar stroke.

Hedgehog signaling is required for formation of the notochord sheath and patterning of nuclei pulposi within the intervertebral discs

PubMed Central

Choi, Kyung-Suk; Harfe, Brian D.

2011-01-01

The vertebrae notochord is a transient rod-like structure that produces secreted factors that are responsible for patterning surrounding tissues. During later mouse embryogenesis, the notochord gives rise to the middle part of the intervertebral disc, called the nucleus pulposus. Currently, very little is known about the molecular mechanisms responsible for forming the intervertebral discs. Here we demonstrate that hedgehog signaling is required for formation of the intervertebral discs. Removal of hedgehog signaling in the notochord and nearby floorplate resulted in the formation of an aberrant notochord sheath that normally surrounds this structure. In the absence of the notochord sheath, small nuclei pulposi were formed, with most notochord cells dispersed throughout the vertebral bodies during embryogenesis. Our data suggest that the formation of the notochord sheath requires hedgehog signaling and that the sheath is essential for maintaining the rod-like structure of the notochord during early embryonic development. As notochord cells form nuclei pulposi, we propose that the notochord sheath functions as a “wrapper” around the notochord to constrain these cells along the vertebral column. PMID:21606373

Hedgehog signaling is required for formation of the notochord sheath and patterning of nuclei pulposi within the intervertebral discs.

PubMed

Choi, Kyung-Suk; Harfe, Brian D

2011-06-07

The vertebrae notochord is a transient rod-like structure that produces secreted factors that are responsible for patterning surrounding tissues. During later mouse embryogenesis, the notochord gives rise to the middle part of the intervertebral disc, called the nucleus pulposus. Currently, very little is known about the molecular mechanisms responsible for forming the intervertebral discs. Here we demonstrate that hedgehog signaling is required for formation of the intervertebral discs. Removal of hedgehog signaling in the notochord and nearby floorplate resulted in the formation of an aberrant notochord sheath that normally surrounds this structure. In the absence of the notochord sheath, small nuclei pulposi were formed, with most notochord cells dispersed throughout the vertebral bodies during embryogenesis. Our data suggest that the formation of the notochord sheath requires hedgehog signaling and that the sheath is essential for maintaining the rod-like structure of the notochord during early embryonic development. As notochord cells form nuclei pulposi, we propose that the notochord sheath functions as a "wrapper" around the notochord to constrain these cells along the vertebral column.

The zebrafish bozozok locus encodes Dharma, a homeodomain protein essential for induction of gastrula organizer and dorsoanterior embryonic structures.

PubMed

Fekany, K; Yamanaka, Y; Leung, T; Sirotkin, H I; Topczewski, J; Gates, M A; Hibi, M; Renucci, A; Stemple, D; Radbill, A; Schier, A F; Driever, W; Hirano, T; Talbot, W S; Solnica-Krezel, L

1999-04-01

The dorsal gastrula organizer plays a fundamental role in establishment of the vertebrate axis. We demonstrate that the zebrafish bozozok (boz) locus is required at the blastula stages for formation of the embryonic shield, the equivalent of the gastrula organizer and expression of multiple organizer-specific genes. Furthermore, boz is essential for specification of dorsoanterior embryonic structures, including notochord, prechordal mesendoderm, floor plate and forebrain. We report that boz mutations disrupt the homeobox gene dharma. Overexpression of boz in the extraembryonic yolk syncytial layer of boz mutant embryos is sufficient for normal development of the overlying blastoderm, revealing an involvement of extraembryonic structures in anterior patterning in fish similarly to murine embryos. Epistatic analyses indicate that boz acts downstream of beta-catenin and upstream to TGF-beta signaling or in a parallel pathway. These studies provide genetic evidence for an essential function of a homeodomain protein in beta-catenin-mediated induction of the dorsal gastrula organizer and place boz at the top of a hierarchy of zygotic genes specifying the dorsal midline of a vertebrate embryo.

Grading apical vertebral rotation without a computed tomography scan: a clinically relevant system based on the radiographic appearance of bilateral pedicle screws.

PubMed

Upasani, Vidyadhar V; Chambers, Reid C; Dalal, Ali H; Shah, Suken A; Lehman, Ronald A; Newton, Peter O

2009-08-01

Bench-top and retrospective analysis to assess vertebral rotation based on the appearance of bilateral pedicle screws in patients with adolescent idiopathic scoliosis (AIS). To develop a clinically relevant radiographic grading system for evaluating postoperative thoracic apical vertebral rotation that would correlate with computed tomography (CT) measures of rotation. The 3-column vertebral body control provided by bilateral pedicle screws has enabled scoliosis surgeons to develop advanced techniques of direct vertebral derotation. Our ability to accurately quantify spinal deformity in the axial plane, however, continues to be limited. Trigonometry was used to define the relationship between the position of bilateral pedicle screws and vertebral rotation. This relationship was validated using digital photographs of a bench-top model. The mathematical relationships were then used to calculate vertebral rotation from standing postoperative, posteroanterior radiographs in AIS patients and correlated with postoperative CT measures of rotation. Fourteen digital photographs of the bench-top model were independently analyzed twice by 3 coauthors. The mathematically calculated degree of rotation was found to correlate significantly with the actual degree of rotation (r = 0.99; P < 0.001) and the intra- and interobserver reliability for these measurements were both excellent (kappa = 0.98 and kappa = 0.97, respectively). In the retrospective analysis of 17 AIS patients, the average absolute difference between the radiographic measurement of rotation and the CT measure was only 1.9 degrees +/- 2.0 degrees (r = 0.92; P < 0.001). Based on these correlations a simple radiographic grading system for postoperative apical vertebral rotation was developed. An accurate assessment of vertebral rotation can be performed radiographically, using screw lengths and screw tip-to-rod distances of bilateral segmental pedicle screws and a trigonometric calculation. These data support the use of a simple radiographic grading system to approximate apical vertebral rotation in AIS patients treated with bilateral apical pedicle screws.

Interrogating the relevance of mitochondrial apoptosis for vertebrate development and postnatal tissue homeostasis.

PubMed

Tuzlak, Selma; Kaufmann, Thomas; Villunger, Andreas

2016-10-01

"Programmed cell death or 'apoptosis' is critical for organogenesis during embryonic development and tissue homeostasis in the adult. Its deregulation can contribute to a broad range of human pathologies, including neurodegeneration, cancer, or autoimmunity…" These or similar phrases have become generic opening statements in many reviews and textbooks describing the physiological relevance of apoptotic cell death. However, while the role in disease has been documented beyond doubt, facilitating innovative drug discovery, we wonder whether the former is really true. What goes wrong in vertebrate development or in adult tissue when the main route to apoptotic cell death, controlled by the BCL2 family, is impaired? Such scenarios have been mimicked by deletion of one or more prodeath genes within the BCL2 family, and gene targeting studies in mice exploring the consequences have been manifold. Many of these studies were geared toward understanding the role of BCL2 family proteins and mitochondrial apoptosis in disease, whereas fewer focused in detail on their role during normal development or tissue homeostasis, perhaps also due to an irritating lack of phenotype. Looking at these studies, the relevance of classical programmed cell death by apoptosis for development appears rather limited. Together, these many studies suggest either highly selective and context-dependent contributions of mitochondrial apoptosis or significant redundancy with alternative cell death mechanisms, as summarized and discussed here. © 2016 Tuzlak et al.; Published by Cold Spring Harbor Laboratory Press.

Zebrafish as a Model System for Environmental Health Studies in the Grade 9–12 Classroom

PubMed Central

Hesselbach, Renee; Carvan, Michael John; Goldberg, Barbara; Berg, Craig A.; Petering, David H.

2014-01-01

Abstract Developing zebrafish embryos were used as a model system for high school students to conduct scientific investigations that reveal features of normal development and to test how different environmental toxicants impact the developmental process. The primary goal of the module was to engage students from a wide range of socio-economic backgrounds, with particular focus on underserved inner-city high schools, in inquiry-based learning and hands-on experimentation. In addition, the module served as a platform for both teachers and students to design additional inquiry-based experiments. In this module, students spawned adult zebrafish to generate developing embryos, exposed the embryos to various toxicants, then gathered, and analyzed data obtained from control and experimental embryos. The module provided a flexible, experimental framework for students to test the effects of numerous environmental toxicants, such as ethanol, caffeine, and nicotine, on the development of a model vertebrate organism. Students also observed the effects of dose on experimental outcomes. From observations of the effects of the chemical agents on vertebrate embryos, students drew conclusions on how these chemicals could impact human development and health. Results of pre-tests and post-tests completed by participating students indicate statistically significant changes in awareness of the impact of environmental agents on fish and human beings In addition, the program's evaluator concluded that participation in the module resulted in significant changes in the attitude of students and teachers toward science in general and environmental health in particular. PMID:24941301

Quantitative cervical vertebral maturation assessment in adolescents with normal occlusion: a mixed longitudinal study.

PubMed

Chen, Li-Li; Xu, Tian-Min; Jiang, Jiu-Hui; Zhang, Xing-Zhong; Lin, Jiu-Xiang

2008-12-01

The purpose of this study was to establish a quantitative cervical vertebral maturation (CVM) system for adolescents with normal occlusion. Mixed longitudinal data were used. The subjects included 87 children and adolescents from 8 to 18 years old with normal occlusion (32 boys, 55 girls) selected from 901 candidates. Sequential lateral cephalograms and hand-wrist films were taken once a year for 6 years. The lateral cephalograms of all subjects were divided into 11 maturation groups according to the Fishman skeletal maturity indicators. The morphologic characteristics of the second, third, and fourth cervical vertebrae at 11 developmental stages were measured and analyzed. Three characteristic parameters (H4/W4, AH3/PH3, @2) were selected to determine the classification of CVM. With 3 morphologic variables, the quantitative CVM system including 4 maturational stages was established. An equation that can accurately estimate the maturation of the cervical vertebrae was established: CVM stage=-4.13+3.57xH4/W4+4.07xAH3/PH3+0.03x@2. The quantitative CVM method is an efficient, objective, and relatively simple approach to assess the level of skeletal maturation during adolescence.

Osteoporosis presenting in pregnancy, puerperium, and lactation.

PubMed

Kovacs, Christopher S

2014-12-01

To describe our current state of knowledge about the pathophysiology, incidence, and treatment of osteoporosis that presents during pregnancy, puerperium, and lactation. When vertebral fractures occur in pregnant or lactating women, it is usually unknown whether the skeleton was normal before pregnancy. Maternal adaptations increase bone resorption modestly during pregnancy but markedly during lactation. The net bone loss may occasionally precipitate fractures, especially in women who have underlying low bone mass or skeletal fragility prior to pregnancy. Bone mass and strength are normally restored postweaning. Transient osteoporosis of the hip is a sporadic disorder localized to one or both femoral heads; it is not due to generalized skeletal resorption. Anecdotal reports have used bisphosphonates, strontium ranelate, teriparatide, or vertebroplasty/kyphoplasty to treat postpartum vertebral fractures, but it is unclear whether these therapies had any added benefit over the spontaneous skeletal recovery that normally occurs after weaning. These relatively rare fragility fractures result from multifactorial causes, including skeletal disorders that precede pregnancy, and structural and metabolic stresses that can compromise skeletal strength during pregnancy and lactation. Further study is needed to determine when pharmacological or surgical therapy is warranted instead of conservative or expectant management.

The evolutionary origin of the vertebrate body plan: the problem of head segmentation.

PubMed

Onai, Takayuki; Irie, Naoki; Kuratani, Shigeru

2014-01-01

The basic body plan of vertebrates, as typified by the complex head structure, evolved from the last common ancestor approximately 530 Mya. In this review, we present a brief overview of historical discussions to disentangle the various concepts and arguments regarding the evolutionary development of the vertebrate body plan. We then explain the historical transition of the arguments about the vertebrate body plan from merely epistemological comparative morphology to comparative embryology as a scientific treatment on this topic. Finally, we review the current progress of molecular evidence regarding the basic vertebrate body plan, focusing on the link between the basic vertebrate body plan and the evolutionarily conserved developmental stages (phylotypic stages).

High-Dose α-Tocopherol Supplementation Does Not Induce Bone Loss in Normal Rats

PubMed Central

Kasai, Shunji; Ito, Akemi; Shindo, Kaori; Toyoshi, Tohru; Bando, Masahiro

2015-01-01

Oxidative stress affects bone turnover. Preventative effects of antioxidants such as vitamin E on reduced bone mineral density and fractures associated with aging, osteoporosis, and smoking have been examined in animals and humans. The effects of vitamin E (α-tocopherol; αT) on bone health have yielded conflicting and inconclusive results from animal studies. In this study, to determine the bone effects of αT, we investigated the in vivo effects of αT on the bone mineral density, bone mass, bone microstructure, bone resorption, and osteogenesis through peripheral quantitative computed tomography (pQCT) measurements, micro-computed tomography (micro-CT) analyses, and bone histomorphometry of lumbar vertebrae and femurs in normal female Wistar rats fed diets containing αT in different quantities (0, 30, 120, or 600 mg/kg diet) for 8 weeks. To validate our hypotheses regarding bone changes, we examined ovariectomized rats as an osteoporosis model and control sham-operated rats in parallel. As expected, ovariectomized rats had reduced bone mineral density in lumbar vertebrae and the distal metaphyses of their femurs, reduced bone mass and deteriorated microstructure of cancellous bones in the vertebral body and distal femur metaphyses, and reduced bone mass due to resorption-dominant enhanced bone turnover in secondary cancellous bones in these sites. In comparison, αT administered to normal rats, even at the highest dose, did not induce reduced bone mineral density of lumbar vertebrae and femurs or a reduced bone mass or fragile microstructure of cancellous bones of the vertebral body and distal femur metaphyses. Instead, αT-fed rats showed a tendency for an osteogenesis-dominant bone mass increase in secondary cancellous bones in the vertebral body, in which active bone remodeling occurs. Thus, αT consumption may have beneficial effects on bone health. PMID:26147575

Facultative parthenogenesis in a critically endangered wild vertebrate.

PubMed

Fields, Andrew T; Feldheim, Kevin A; Poulakis, Gregg R; Chapman, Demian D

2015-06-01

Facultative parthenogenesis - the ability of sexually reproducing species to sometimes produce offspring asexually - is known from a wide range of ordinarily sexually reproducing vertebrates in captivity, including some birds, reptiles and sharks [1-3]. Despite this, free-living parthenogens have never been observed in any of these taxa in the wild, although two free-living snakes were recently discovered each gestating a single parthenogen - one copperhead (Agkistrodon contortrix) and one cottonmouth (Agkistrodon piscivorus) [1]. Vertebrate parthenogens are characterized as being of the homogametic sex (e.g., females in sharks, males in birds) and by having elevated homozygosity compared to their mother [1-3], which may reduce their viability [4]. Although it is unknown if either of the parthenogenetic snakes would have been carried to term or survived in the wild, facultative parthenogenesis might have adaptive significance [1]. If this is true, it is reasonable to hypothesize that parthenogenesis would be found most often at low population density, when females risk reproductive failure because finding mates is difficult [5]. Here, we document the first examples of viable parthenogens living in a normally sexually reproducing wild vertebrate, the smalltooth sawfish (Pristis pectinata). We also provide a simple approach to screen any microsatellite DNA database for parthenogens, which will enable hypothesis-driven research on the significance of vertebrate parthenogenesis in the wild. Copyright © 2015 Elsevier Ltd. All rights reserved.

Testing Skills in Vertebrates

ERIC Educational Resources Information Center

Funk, Mildred Sears; Tosto, Pat

2007-01-01

In this article, the authors present a project that gives students examples of basic skills that many vertebrate species develop as they grow and function in their ecosystem. These activities involve information gathering about surroundings, learning how to use objects, and tracking and searching skills. Different vertebrate species may acquire…

Early embryonic brain development in rats requires the trophic influence of cerebrospinal fluid.

PubMed

Martin, C; Alonso, M I; Santiago, C; Moro, J A; De la Mano, A; Carretero, R; Gato, A

2009-11-01

Cerebrospinal fluid has shown itself to be an essential brain component during development. This is particularly evident at the earliest stages of development where a lot of research, performed mainly in chick embryos, supports the evidence that cerebrospinal fluid is involved in different mechanisms controlling brain growth and morphogenesis, by exerting a trophic effect on neuroepithelial precursor cells (NPC) involved in controlling the behaviour of these cells. Despite it being known that cerebrospinal fluid in mammals is directly involved in corticogenesis at fetal stages, the influence of cerebrospinal fluid on the activity of NPC at the earliest stages of brain development has not been demonstrated. Here, using "in vitro" organotypic cultures of rat embryo brain neuroepithelium in order to expose NPC to or deprive them of cerebrospinal fluid, we show that the neuroepithelium needs the trophic influence of cerebrospinal fluid to undergo normal rates of cell survival, replication and neurogenesis, suggesting that NPC are not self-sufficient to induce their normal activity. This data shows that cerebrospinal fluid is an essential component in chick and rat early brain development, suggesting that its influence could be constant in higher vertebrates.

Alternative approaches to vertebrate ecotoxicity tests in the 21st century: A review of developments over the last 2 decades and current status.

PubMed

Lillicrap, Adam; Belanger, Scott; Burden, Natalie; Pasquier, David Du; Embry, Michelle R; Halder, Marlies; Lampi, Mark A; Lee, Lucy; Norberg-King, Teresa; Rattner, Barnett A; Schirmer, Kristin; Thomas, Paul

2016-11-01

The need for alternative approaches to the use of vertebrate animals for hazard assessment of chemicals and pollutants has become of increasing importance. It is now the first consideration when initiating a vertebrate ecotoxicity test, to ensure that unnecessary use of vertebrate organisms is minimized wherever possible. For some regulatory purposes, the use of vertebrate organisms for environmental risk assessments has been banned; in other situations, the number of organisms tested has been dramatically reduced or the severity of the procedure refined. However, there is still a long way to go to achieve a complete replacement of vertebrate organisms to generate environmental hazard data. The development of animal alternatives is based not just on ethical considerations but also on reducing the cost of performing vertebrate ecotoxicity tests and in some cases on providing better information aimed at improving environmental risk assessments. The present Focus article provides an overview of the considerable advances that have been made toward alternative approaches for ecotoxicity assessments over the last few decades. Environ Toxicol Chem 2016;35:2637-2646. © 2016 SETAC. © 2016 SETAC.

Metamerism in cephalochordates and the problem of the vertebrate head.

PubMed

Onai, Takayuki; Adachi, Noritaka; Kuratani, Shigeru

2017-01-01

The vertebrate head characteristically exhibits a complex pattern with sense organs, brain, paired eyes and jaw muscles, and the brain case is not found in other chordates. How the extant vertebrate head has evolved remains enigmatic. Historically, there have been two conflicting views on the origin of the vertebrate head, segmental and non-segmental views. According to the segmentalists, the vertebrate head is organized as a metameric structure composed of segments equivalent to those in the trunk; a metamere in the vertebrate head was assumed to consist of a somite, a branchial arch and a set of cranial nerves, considering that the head evolved from rostral segments of amphioxus-like ancestral vertebrates. Non-segmentalists, however, considered that the vertebrate head was not segmental. In that case, the ancestral state of the vertebrate head may be non-segmented, and rostral segments in amphioxus might have been secondarily gained, or extant vertebrates might have evolved through radical modifications of amphioxus-like ancestral vertebrate head. Comparative studies of mesodermal development in amphioxus and vertebrate gastrula embryos have revealed that mesodermal gene expressions become segregated into two domains anteroposteriorly to specify the head mesoderm and trunk mesoderm only in vertebrates; in this segregation, key genes such as delta and hairy, involved in segment formation, are expressed in the trunk mesoderm, but not in the head mesoderm, strongly suggesting that the head mesoderm of extant vertebrates is not segmented. Taken together, the above finding possibly adds a new insight into the origin of the vertebrate head; the vertebrate head mesoderm would have evolved through an anteroposterior polarization of the paraxial mesoderm if the ancestral vertebrate had been amphioxus-like.

Distinct signals from the microbiota promote different aspects of zebrafish gut differentiation.

PubMed

Bates, Jennifer M; Mittge, Erika; Kuhlman, Julie; Baden, Katrina N; Cheesman, Sarah E; Guillemin, Karen

2006-09-15

All animals exist in intimate associations with microorganisms that play important roles in the hosts' normal development and tissue physiology. In vertebrates, the most populous and complex community of microbes resides in the digestive tract. Here, we describe the establishment of the gut microbiota and its role in digestive tract differentiation in the zebrafish model vertebrate, Danio rerio. We find that in the absence of the microbiota, the gut epithelium is arrested in aspects of its differentiation, as revealed by the lack of brush border intestinal alkaline phosphatase activity, the maintenance of immature patterns of glycan expression and a paucity of goblet and enteroendocrine cells. In addition, germ-free intestines fail to take up protein macromolecules in the distal intestine and exhibit faster motility. Reintroduction of a complex microbiota at later stages of development or mono-association of germ-free larvae with individual constituents of the microbiota reverses all of these germ-free phenotypes. Exposure of germ-free zebrafish to heat-killed preparations of the microbiota or bacterial lipopolysaccharide is sufficient to restore alkaline phosphatase activity but not mature patterns of Gal alpha1,3Gal containing glycans, indicating that the host perceives and responds to its associated microbiota by at least two distinct pathways.

Learning about Vertebrate Limb Development

ERIC Educational Resources Information Center

Liang, Jennifer O.; Noll, Matthew; Olsen, Shayna

2014-01-01

We have developed an upper-level undergraduate laboratory exercise that enables students to replicate a key experiment in developmental biology. In this exercise, students have the opportunity to observe live chick embryos and stain the apical ectodermal ridge, a key tissue required for development of the vertebrate limb. Impressively, every…

Preventive effects of conservative treatment with short-term teriparatide on the progression of vertebral body collapse after osteoporotic vertebral compression fracture.

PubMed

Park, J-H; Kang, K-C; Shin, D-E; Koh, Y-G; Son, J-S; Kim, B-H

2014-02-01

The progression of fractured vertebral collapse is not rare after a conservative treatment of vertebral compression fracture (VCF). Teriparatide has been shown to directly stimulate bone formation and improve bone density, but there is a lack of evidence regarding its use in fracture management. Conservative treatment with short-term teriparatide is effective for decreasing the progression of fractured vertebral body collapse. Few studies have reported on the prevention of collapsed vertebral body progression after osteoporotic VCF. Teriparatide rapidly enhances bone formation and increases bone strength. This study evaluated preventive effects of short-term teriparatide on the progression of vertebral body collapse after osteoporotic VCF. Radiographs of 68 women with single-level osteoporotic VCF at thoracolumbar junction (T11-L2) were reviewed. Among them, 32 patients were treated conservatively with teriparatide (minimum 3 months) (group I), and 36 were treated with antiresorptive (group II). We measured kyphosis and wedge angle of the fractured vertebral body, and ratios of anterior, middle, and posterior heights of the collapsed body to posterior height of a normal upper vertebra were determined. The degree of collapse progression was compared between two groups. The progression of fractured vertebral body collapse was shown in both groups, but the degree of progression was significantly lower in group I than in group II. At the last follow-up, mean increments of kyphosis and wedge angle were significantly lower in group I (4.0° ± 4.2° and 3.6° ± 3.6°) than in group II (6.8° ± 4.1° and 5.8° ± 3.5°) (p = 0.032 and p = 0.037). Decrement percentages of anterior and middle border height were significantly lower in group I (9.6 ± 10.3 and 7.4 ± 7.5 %) than in group II (18.1 ± 9.7 and 13.8 ± 12.2 %) (p = 0.001 and p = 0.025), but not in posterior height (p = 0.086). In female patients with single-level osteoporotic VCF at the thoracolumbar junction, short-term teriparatide treatment did not prevent but did decrease the progression of fractured vertebral body collapse.

Transcriptome analysis of vertebral bone in the flounder, Paralichthys olivaceus (Teleostei, Pleuronectiformes), using Illumina sequencing.

PubMed

Ibaraki, Harumi; Wu, Xiaoming; Uji, Susumu; Yokoi, Hayato; Sakai, Yoshifumi; Suzuki, Tohru

2015-12-01

The processes underlying vertebral development in teleosts and tetrapods differ markedly in a variety of ways. At present, the molecular basis of teleost vertebral development and growth is poorly understood. Understanding vertebral development at the molecular level is important for aquaculture to prevent vertebral anomalies that can arise from a variety of factors, including excess vitamin A (all-trans retinol, VA) in the diet. To facilitate studies on teloest vertebral development, we performed transcriptome analysis of four month old flounder, Paralichthys olivaceus, vertebrae using next-generation sequencing. Expression profile obtained demonstrates that some members of the hh, bmp, fgf, wnt gene families, and their receptors, hox, pax, sox, dlx and tbx gene families and ntl, which are known to function in notochord and somite development in embryos, are expressed in the vertebrae. It was also showed that in addition to the retinoic acid receptor (Rar), the vertebrae express alcohol dehydrogenase 1 and retinal dehydrogenase 2 which convert VA to all-trans-retinoic acid (RA). The assembled contigs also included cytochrome p450 family members, which inactivate RA, as well as phosphatidylcholine-retinol O-acetyltransferase, which converts VA to all-trans-retinyl ester, a stock form of VA. These data suggest that in teleost vertebrae, expression of various signals and transcription factors which function in the notochord and somite development is maintained until adult stage, and RA metabolism and signaling are active to regulate transcription of RA-responsible genes, such as hedgehog and hox genes. This is the first transcriptome analysis of teleost fish vertebrae. Copyright © 2015 Elsevier B.V. All rights reserved.

The Loss of Vacuolar Protein Sorting 11 (vps11) Causes Retinal Pathogenesis in a Vertebrate Model of Syndromic Albinism

PubMed Central

Thomas, Jennifer L.; Vihtelic, Thomas S.; denDekker, Aaron D.; Willer, Gregory; Luo, Xixia; Murphy, Taylor R.; Gregg, Ronald G.; Hyde, David R.

2011-01-01

Purpose. To establish the zebrafish platinum mutant as a model for studying vision defects caused by syndromic albinism diseases such as Chediak-Higashi syndrome, Griscelli syndrome, and Hermansky-Pudlak syndrome (HPS). Methods. Bulked segregant analysis and candidate gene sequencing revealed that the zebrafish platinum mutation is a single-nucleotide insertion in the vps11 (vacuolar protein sorting 11) gene. Expression of vps11 was determined by RT-PCR and in situ hybridization. Mutants were analyzed for pigmentation defects and retinal disease by histology, immunohistochemistry, and transmission electron microscopy. Results. Phenocopy and rescue experiments determined that a loss of Vps11 results in the platinum phenotype. Expression of vps11 appeared ubiquitous during zebrafish development, with stronger expression in the developing retina and retinal pigmented epithelium (RPE). Zebrafish platinum mutants exhibited reduced pigmentation in the body and RPE; however, melanophore development, migration, and dispersion occurred normally. RPE, photoreceptors, and inner retinal neurons formed normally in zebrafish platinum mutants. However, a gradual loss of RPE, an absence of mature melanosomes, and the subsequent degradation of RPE/photoreceptor interdigitation was observed. Conclusions. These data show that Vps11 is not necessary for normal retinal development or initiation of melanin biosynthesis, but is essential for melanosome maturation and healthy maintenance of the RPE and photoreceptors. PMID:21330665

The evolution of Msx gene function: expression and regulation of a sea urchin Msx class homeobox gene.

PubMed

Dobias, S L; Ma, L; Wu, H; Bell, J R; Maxson, R

1997-01-01

Msx- class homeobox genes, characterized by a distinct and highly conserved homeodomain, have been identified in a wide variety of metazoans from vertebrates to coelenterates. Although there is evidence that they participate in inductive tissue interactions that underlie vertebrate organogenesis, including those that pattern the neural crest, there is little information about their function in simple deuterostomes. Both to learn more about the ancient function of Msx genes, and to shed light on the evolution of developmental mechanisms within the lineage that gave rise to vertebrates, we have isolated and characterized Msx genes from ascidians and echinoderms. Here we describe the sequence and expression of a sea urchin (Strongylocentrotus purpouratus) Msx gene whose homeodomain is very similar to that of vertebrate Msx2. This gene, designated SpMsx, is first expressed in blastula stage embryos, apparently in a non-localized manner. Subsequently, during the early phases of gastrulation, SpMsx transcripts are expressed intensely in the invaginating archenteron and secondary mesenchyme, and at reduced levels in the ectoderm. In the latter part of gastrulation, SpMsx transcripts are concentrated in the oral ectoderm and gut, and continue to be expressed at those sites through the remainder of embryonic development. That vertebrate Msx genes are regulated by inductive tissue interactions and growth factors suggested to us that the restriction of SpMsx gene expression to the oral ectoderm and derivatives of the vegetal plate might similarly be regulated by the series of signaling events that pattern these embryonic territories. As a first test of this hypothesis, we examined the influence of exogastrulation and cell-dissociation on SpMsx gene expression. In experimentally-induced exogastrulae, SpMsx transcripts were distributed normally in the oral ectoderm, evaginated gut, and secondary mesenchyme. However, when embryos were dissociated into their component cells, SpMsx transcripts failed to accumulate. These data show that the localization of SpMsx transcripts in gastrulae does not depend on interactions between germ layers, yet the activation and maintenance of SpMsx expression does require cell-cell or cell-matrix interactions.

Identification of Thyroid Hormones and Functional Characterization of Thyroid Hormone Receptor in the Pacific Oyster Crassostrea gigas Provide Insight into Evolution of the Thyroid Hormone System

PubMed Central

Huang, Wen; Xu, Fei; Qu, Tao; Zhang, Rui; Li, Li; Que, Huayong; Zhang, Guofan

2015-01-01

Thyroid hormones (THs) play important roles in development, metamorphosis, and metabolism in vertebrates. During the past century, TH functions were regarded as a synapomorphy of vertebrates. More recently, accumulating evidence has gradually convinced us that TH functions also occur in invertebrate chordates. To date, however, TH-related studies in non-chordate invertebrates have been limited. In this study, THs were qualitatively detected by two reliable methods (HPLC and LC/MS) in a well-studied molluscan species, the Pacific oyster Crassostrea gigas. Quantitative measurement of THs during the development of C. gigas showed high TH contents during embryogenesis and that oyster embryos may synthesize THs endogenously. As a first step in elucidating the TH signaling cascade, an ortholog of vertebrate TH receptor (TR), the most critical gene mediating TH effects, was cloned in C. gigas. The sequence of CgTR has conserved DNA-binding and ligand-binding domains that normally characterize these receptors. Experimental results demonstrated that CgTR can repress gene expression through binding to promoters of target genes and can interact with oyster retinoid X receptor. Moreover, CgTR mRNA expression was activated by T4 and the transcriptional activity of CgTR promoter was repressed by unliganded CgTR protein. An atypical thyroid hormone response element (CgDR5) was found in the promoter of CgTR, which was verified by electrophoretic mobility shift assay (EMSA). These results indicated that some of the CgTR function is conserved. However, the EMSA assay showed that DNA binding specificity of CgTR was different from that of the vertebrate TR and experiments with two dual-luciferase reporter systems indicated that l-thyroxine, 3,3′,5-triiodothyronine, and triiodothyroacetic acid failed to activate the transcriptional activity of CgTR. This is the first study to functionally characterize TR in mollusks. The presence of THs and the functions of CgTR in mollusks contribute to better understanding of the evolution of the TH system. PMID:26710071

Correlation between Hox code and vertebral morphology in archosaurs.

PubMed

Böhmer, Christine; Rauhut, Oliver W M; Wörheide, Gert

2015-07-07

The relationship between developmental genes and phenotypic variation is of central interest in evolutionary biology. An excellent example is the role of Hox genes in the anteroposterior regionalization of the vertebral column in vertebrates. Archosaurs (crocodiles, dinosaurs including birds) are highly variable both in vertebral morphology and number. Nevertheless, functionally equivalent Hox genes are active in the axial skeleton during embryonic development, indicating that the morphological variation across taxa is likely owing to modifications in the pattern of Hox gene expression. By using geometric morphometrics, we demonstrate a correlation between vertebral Hox code and quantifiable vertebral morphology in modern archosaurs, in which the boundaries between morphological subgroups of vertebrae can be linked to anterior Hox gene expression boundaries. Our findings reveal homologous units of cervical vertebrae in modern archosaurs, each with their specific Hox gene pattern, enabling us to trace these homologies in the extinct sauropodomorph dinosaurs, a group with highly variable vertebral counts. Based on the quantifiable vertebral morphology, this allows us to infer the underlying genetic mechanisms in vertebral evolution in fossils, which represents not only an important case study, but will lead to a better understanding of the origin of morphological disparity in recent archosaur vertebral columns.

Correlation between Hox code and vertebral morphology in archosaurs

PubMed Central

Böhmer, Christine; Rauhut, Oliver W. M.; Wörheide, Gert

2015-01-01

The relationship between developmental genes and phenotypic variation is of central interest in evolutionary biology. An excellent example is the role of Hox genes in the anteroposterior regionalization of the vertebral column in vertebrates. Archosaurs (crocodiles, dinosaurs including birds) are highly variable both in vertebral morphology and number. Nevertheless, functionally equivalent Hox genes are active in the axial skeleton during embryonic development, indicating that the morphological variation across taxa is likely owing to modifications in the pattern of Hox gene expression. By using geometric morphometrics, we demonstrate a correlation between vertebral Hox code and quantifiable vertebral morphology in modern archosaurs, in which the boundaries between morphological subgroups of vertebrae can be linked to anterior Hox gene expression boundaries. Our findings reveal homologous units of cervical vertebrae in modern archosaurs, each with their specific Hox gene pattern, enabling us to trace these homologies in the extinct sauropodomorph dinosaurs, a group with highly variable vertebral counts. Based on the quantifiable vertebral morphology, this allows us to infer the underlying genetic mechanisms in vertebral evolution in fossils, which represents not only an important case study, but will lead to a better understanding of the origin of morphological disparity in recent archosaur vertebral columns. PMID:26085583

Identification of Estrogen Target Genes during Zebrafish Embryonic Development through Transcriptomic Analysis

EPA Science Inventory

Estrogen signaling is important for vertebrate embryonic development. Here we have used zebrafish (Danio rerio) as a vertebrate model to analyze estrogen signaling during development. Zebrafish embryos were exposed to 1 μM 17β-estradiol (E2) or vehicle from 3 hours to 4 days post...

Alternative approaches for vertebrate ecotoxicity tests in the ...

EPA Pesticide Factsheets

The need for alternative approaches to the use of vertebrate animals for hazard assessing chemicals and pollutants has become of increasing importance. It is now the first consideration when initiating a vertebrate ecotoxicity test, to ensure that unnecessary use of vertebrate organisms is minimised wherever possible. For some regulatory purposes, the use of vertebrate organisms for environmental risk assessments (ERA) has even been banned, and in other situations the numbers of organisms tested has been dramatically reduced, or the severity of the procedure refined. However, there is still a long way to go to achieve replacement of vertebrate organisms to generate environmental hazard data. The development of animal alternatives is not just based on ethical considerations but also to reduce the cost of performing vertebrate ecotoxicity tests and in some cases to provide better information aimed at improving ERAs. The present focus paper provides an overview of the considerable advances that have been made towards alternative approaches for ecotoxicity assessments over the last few decades. The need for alternative approaches to the use of vertebrate animals for hazard assessing chemicals and pollutants has become of increasing importance. It is now the first consideration when initiating a vertebrate ecotoxicity test, to ensure that unnecessary use of vertebrate organisms is minimised wherever possible. For some regulatory purposes, the use of vertebrate organi

Kyphoplasty increases vertebral height, decreases both pain score and opiate requirements while improving functional status.

PubMed

Tolba, Reda; Bolash, Robert B; Shroll, Joshua; Costandi, Shrif; Dalton, Jarrod E; Sanghvi, Chirag; Mekhail, Nagy

2014-03-01

Vertebral compression fractures can result from advanced osteoporosis, or less commonly from metastatic or traumatic insults to the vertebral column, and result in disabling pain and decreased functional capacity. Various vertebral augmentation options including kyphoplasty aim at preventing the sequelae of pain and immobility that can develop as the result of the vertebral fractures. The mechanism for pain relief following kyphoplasty is not entirely understood, and the restoration of a portion of the lost vertebral height is a subject of debate. We retrospectively reviewed radiographic imaging, pain relief, analgesic intake and functional outcomes in 67 consecutive patients who underwent single- or multilevel kyphoplasty with the primary goal of quantifying the restoration of lost vertebral height. We observed a mean of 45% of the lost vertebral height restored postprocedurally. Secondarily, kyphoplasty was associated with significant decreases in pain scores, daily morphine consumption and improvement in patient-reported functional measures. © 2013 World Institute of Pain.

Transgenic FingRs for Live Mapping of Synaptic Dynamics in Genetically-Defined Neurons

PubMed Central

Son, Jong-Hyun; Keefe, Matthew D.; Stevenson, Tamara J.; Barrios, Joshua P.; Anjewierden, Scott; Newton, James B.; Douglass, Adam D.; Bonkowsky, Joshua L.

2016-01-01

Tools for genetically-determined visualization of synaptic circuits and interactions are necessary to build connectomics of the vertebrate brain and to screen synaptic properties in neurological disease models. Here we develop a transgenic FingR (fibronectin intrabodies generated by mRNA display) technology for monitoring synapses in live zebrafish. We demonstrate FingR labeling of defined excitatory and inhibitory synapses, and show FingR applicability for dissecting synapse dynamics in normal and disease states. Using our system we show that chronic hypoxia, associated with neurological defects in preterm birth, affects dopaminergic neuron synapse number depending on the developmental timing of hypoxia. PMID:26728131

ARRAY TECHNOLOGY AS A TOOL TO MONITOR ENDOCRINE DISRUPTION IN WILD FISH POPULATIONS

EPA Science Inventory

A variety of anthropogenic chemicals are capable of binding to the estrogen receptor of vertebrate species. Binding of these compounds can interfere with homeostasis by disrupting normal gene expression patterns. The purpose of this study was to investigate the feasibility of ap...

Pediatric occipitocervical fusion: long-term radiographic changes in curvature, growth, and alignment.

PubMed

Martinez-Del-Campo, Eduardo; Turner, Jay D; Soriano-Baron, Hector; Newcomb, Anna G U S; Kalb, Samuel; Theodore, Nicholas

2016-11-01

OBJECTIVE The authors assessed the rate of vertebral growth, curvature, and alignment for multilevel constructs in the cervical spine after occipitocervical fixation (OCF) in pediatric patients and compared these results with those in published reports of growth in normal children. METHODS The authors assessed cervical spine radiographs and CT images of 18 patients who underwent occipitocervical arthrodesis. Measurements were made using postoperative and follow-up images available for 16 patients to determine cervical alignment (cervical spine alignment [CSA], C1-7 sagittal vertical axis [SVA], and C2-7 SVA) and curvature (cervical spine curvature [CSC] and C2-7 lordosis angle). Seventeen patients had postoperative and follow-up images available with which to measure vertebral body height (VBH), vertebral body width (VBW), and vertical growth percentage (VG%-that is, percentage change from postoperative to follow-up). Results for cervical spine growth were compared with normal parameters of 456 patients previously reported on in 2 studies. RESULTS Ten patients were girls and 8 were boys; their mean age was 6.7 ± 3.2 years. Constructs spanned occiput (Oc)-C2 (n = 2), Oc-C3 (n = 7), and Oc-C4 (n = 9). The mean duration of follow-up was 44.4 months (range 24-101 months). Comparison of postoperative to follow-up measures showed that the mean CSA increased by 1.8 ± 2.9 mm (p < 0.01); the mean C2-7 SVA and C1-7 SVA increased by 2.3 mm and 2.7 mm, respectively (p = 0.3); the mean CSC changed by -8.7° (p < 0.01) and the mean C2-7 lordosis angle changed by 2.6° (p = 0.5); and the cumulative mean VG% of the instrumented levels (C2-4) provided 51.5% of the total cervical growth (C2-7). The annual vertical growth rate was 4.4 mm/year. The VBW growth from C2-4 ranged from 13.9% to 16.6% (p < 0.001). The VBW of C-2 in instrumented patients appeared to be of a smaller diameter than that of normal patients, especially among those aged 5 to < 10 years and 10-15 years, with an increased diameter at the immediately inferior vertebral bodies compensating for the decreased width. No cervical deformation, malalignment, or detrimental clinical status was evident in any patient. CONCLUSIONS The craniovertebral junction and the upper cervical spine continue to present normal growth, curvature, and alignment parameters in children with OCF constructs spanning a distance as long as Oc-C4.

Neuro- and sensoriphysiological Adaptations to Microgravity using Fish as Model System

NASA Astrophysics Data System (ADS)

Anken, R.

The phylogenetic development of all organisms took place under constant gravity conditions, against which they achieved specific countermeasures for compensation and adaptation. On this background, it is still an open question to which extent altered gravity such as hyper- or microgravity (centrifuge/spaceflight) affects the normal individual development, either on the systemic level of the whole organism or on the level of individual organs or even single cells. The present review provides information on this topic, focusing on the effects of altered gravity on developing fish as model systems even for higher vertebrates including humans, with special emphasis on the effect of altered gravity on behaviour and particularly on the developing brain and vestibular system. Overall, the results speak in favour of the following concept: Short-term altered gravity (˜ 1 day) can induce transient sensorimotor disorders (kinetoses) due to malfunctions of the inner ear, originating from asymmetric otoliths. The regain of normal postural control is likely due to a reweighing of sensory inputs. During long-term altered gravity (several days and more), complex adptations on the level of the central and peripheral vestibular system occur. This work was financially supported by the German Aerospace Center (DLR) e.V. (FKZ: 50 WB 9997).

Reduction of XNkx2-10 expression leads to anterior defects and malformation of the embryonic heart.

PubMed

Allen, Bryan G; Allen-Brady, Kristina; Weeks, Daniel L

2006-10-01

Normal vertebrate heart development depends upon the expression of homeodomain containing proteins related to the Drosophila gene, tinman. In Xenopus laevis, three such genes have been identified in regions that will eventually give rise to the heart, XNkx2-3, XNkx2-5 and XNkx2-10. Although the expression domains of all three overlap in early development, distinctive differences have been noted. By the time the heart tube forms, there is little XNkx2-10 mRNA detected by in situ analysis in the embryonic heart while both XNkx2-3 and XNkx2-5 are clearly present. In addition, unlike XNkx2-3 and XNkx2-5, injection of XNkx2-10 mRNA does not increase the size of the embryonic heart. We have reexamined the expression and potential role of XNkx2-10 in development via oligonucleotide-mediated reduction of XNkx2-10 protein expression. We find that a decrease in XNkx2-10 leads to a broad spectrum of developmental abnormalities including a reduction in heart size. We conclude that XNkx2-10, like XNkx2-3 and XNkx2-5, is necessary for normal Xenopus heart development.

Reduction of XNkx2-10 expression leads to anterior defects and malformation of the embryonic heart

PubMed Central

Allen, Bryan G.; Allen-Brady, Kristina; Weeks, Daniel L.

2007-01-01

Normal vertebrate heart development depends upon the expression of homeodomain containing proteins related to the Drosophila gene, tinman. In Xenopus laevis, three such genes have been identified in regions that will eventually give rise to the heart, XNkx2-3, XNkx2-5 and XNkx2-10. Although the expression domains of all three overlap in early development, distinctive differences have been noted. By the time the heart tube forms, there is little XNkx2-10 mRNA detected by in situ analysis in the embryonic heart while both XNkx2-3 and XNkx2-5 are clearly present. In addition, unlike XNkx2-3 and XNkx2-5, injection of XNkx2-10 mRNA does not increase the size of the embryonic heart. We have reexamined the expression and potential role of XNkx2-10 in development via oligonucleotide-mediated reduction of XNkx2-10 protein expression. We find that a decrease in XNkx2-10 leads to a broad spectrum of developmental abnormalities including a reduction in heart size. We conclude that XNkx2-10, like XNkx2-3 and XNkx2-5, is necessary for normal Xenopus heart development. PMID:16949797

Discriminatory ability of quantitative ultrasound parameters and bone mineral density in a population-based sample of postmenopausal women with vertebral fractures: results of the Basel Osteoporosis Study.

PubMed

Hartl, F; Tyndall, A; Kraenzlin, M; Bachmeier, C; Gückel, C; Senn, U; Hans, D; Theiler, R

2002-02-01

The discriminatory potential to classify subjects with or without vertebral fractures was tested cross-sectionally with different methods for the measurement of bone status in a population-based sample of postmenopausal women. Quantitative ultrasound (QUS) measurement at the calcaneus (Lunar Achilles, Hologic Sahara), the proximal phalanges (Igea Bone Profiler), and measurement of bone mineral density (BMD) with dual-energy X-ray absorptiometry (DXA; Lunar Expert) at several anatomic sites was performed in 500 postmenopausal women (aged 65-75 years) randomly selected from the population. In addition, 50 young female subjects (20-40 years old) had QUS measurements and served as controls to express QUS results as T-score values. Radiographs of the lumbar and thoracic spine were performed in the elderly women. Two independent radiologists reviewed the X-rays for the presence of vertebral fractures. Of 486 eligible study participants, no fracture was seen in 396 participants. Single vertebral fractures were observed in 71 subjects; 19 individuals presented multiple fractures. The overall prevalence of vertebral fractures was 18.5%. Participants without vertebral fractures were compared with subjects with vertebral fractures. Normal statistical distributions were found for all bone measurement results. Risk of vertebral fracture in subjects with no and multiple vertebral fracture was estimated using age adjusted odds ratios (ORs) for QUS and dual-energy X-ray absorptiometry (DXA) values. Each SD decrease in bone measurement increased the risk of multiple vertebral fracture by 3.0 (95% CI, 1.6-5.6) for the Achilles stiffness, by 3.8 (95% CI, 1.8-8.2) for the Sahara QUI, 2.1 (95% CI, 1.3-3.4) for the Bone Profiler amplitude-dependent speed of sound (AD-SOS), and 2.1 (95% CI, 1.2-3.9) and 2.4 (95% CI, 1.3-4.3) for DXA lumbar spine and for DXA total hip, respectively. Results of a discriminant analysis showed sensitivities between 84% and 58% and specificities between 72% and 58% for the respective DXA and QUS parameters. Optimum fracture thresholds for QUS measurements derived from this analysis were calculated also. Optimum T-score threshold values for QUS measurements tended to be higher than those for DXA measurements. However, the performance of QUS measurements is at least comparable with DXA measurements in identifying subjects with multiple vertebral fractures randomly selected from the population.

Histone methyltransferase Dot1L plays a role in postembryonic development in Xenopus tropicalis

PubMed Central

Wen, Luan; Fu, Liezhen; Guo, Xiaogang; Chen, Yonglong; Shi, Yun-Bo

2015-01-01

Histone methylations have been implicated to play important roles in diverse cellular processes. Of particular interest is the methylation of histone H3K79, which is catalyzed by an evolutionarily conserved methyltransferase, disruptor of telomeric silencing (Dot1)-like (Dot1L). To investigate the role of Dot1L during vertebrate development, we have generated a Dot1L-specific transcription activator-like effector nuclease (TALEN) nuclease to knockdown endogenous Dot1L in Xenopus tropicalis, a diploid species highly related to the well-known developmental model Xenopus laevis, a pseudotetraploid amphibian. We show that the TALEN was extremely efficient in mutating Dot1L when expressed in fertilized eggs, creating essentially Dot1L knockout embryos with little H3K79 methylation. Importantly, we observed that Dot1L knockdown had no apparent effect on embryogenesis because normally feeding tadpoles were formed, consistent with the lack of maternal Dot1L expression. On the other hand, Dot1L knockdown severely retarded the growth of the tadpoles and led to tadpole lethality prior to metamorphosis. These findings suggest that Dot1L and H3K79 methylation play an important role for tadpole growth and development prior to metamorphosis into a frog. Our findings further reveal interesting similarities and differences between Xenopus and mouse development and suggest the existence of 2 separate phases of vertebrate development with distinct requirements for epigenetic modifications.—Wen, L., Fu, L., Guo, X., Chen, Y., Shi, Y.-B. Histone methyltransferase Dot1L plays a role in postembryonic development in Xenopus tropicalis. PMID:25366346

Microbiome evolution along divergent branches of the vertebrate tree of life: what is known and unknown.

PubMed

Colston, Timothy J; Jackson, Colin R

2016-08-01

Vertebrates harbour microbes both internally and externally, and collectively, these microorganisms (the 'microbiome') contain genes that outnumber the host's genetic information 10-fold. The majority of the microorganisms associated with vertebrates are found within the gut, where they influence host physiology, immunity and development. The development of next-generation sequencing has led to a surge in effort to characterize the microbiomes of various vertebrate hosts, a necessary first step to determine the functional role these communities play in host evolution or ecology. This shift away from a culture-based microbiological approach, limited in taxonomic breadth, has resulted in the emergence of patterns suggesting a core vertebrate microbiome dominated by members of the bacterial phyla Bacteroidetes, Proteobacteria and Firmicutes. Still, there is a substantial variation in the methodology used to characterize the microbiome, from differences in sample type to issues of sampling captive or wild hosts, and the majority (>90%) of studies have characterized the microbiome of mammals, which represent just 8% of described vertebrate species. Here, we review the state of microbiome studies of nonmammalian vertebrates and provide a synthesis of emerging patterns in the microbiome of those organisms. We highlight the importance of collection methods, and the need for greater taxonomic sampling of natural rather than captive hosts, a shift in approach that is needed to draw ecologically and evolutionarily relevant inferences. Finally, we recommend future directions for vertebrate microbiome research, so that attempts can be made to determine the role that microbial communities play in vertebrate biology and evolution. © 2016 John Wiley & Sons Ltd.

Conserved form and function of the germinal epithelium through 500 million years of vertebrate evolution.

PubMed

Grier, Harry J; Uribe, Mari Carmen; Lo Nostro, Fabiana L; Mims, Steven D; Parenti, Lynne R

2016-08-01

The germinal epithelium, i.e., the site of germ cell production in males and females, has maintained a constant form and function throughout 500 million years of vertebrate evolution. The distinguishing characteristic of germinal epithelia among all vertebrates, males, and females, is the presence of germ cells among somatic epithelial cells. The somatic epithelial cells, Sertoli cells in males or follicle (granulosa) cells in females, encompass and isolate germ cells. Morphology of all vertebrate germinal epithelia conforms to the standard definition of an epithelium: epithelial cells are interconnected, border a body surface or lumen, are avascular and are supported by a basement membrane. Variation in morphology of gonads, which develop from the germinal epithelium, is correlated with the evolution of reproductive modes. In hagfishes, lampreys, and elasmobranchs, the germinal epithelia of males produce spermatocysts. A major rearrangement of testis morphology diagnoses osteichthyans: the spermatocysts are arranged in tubules or lobules. In protogynous (female to male) sex reversal in teleost fishes, female germinal epithelial cells (prefollicle cells) and oogonia transform into the first male somatic cells (Sertoli cells) and spermatogonia in the developing testis lobules. This common origin of cell types from the germinal epithelium in fishes with protogynous sex reversal supports the homology of Sertoli cells and follicle cells. Spermatogenesis in amphibians develops within spermatocysts in testis lobules. In amniotes vertebrates, the testis is composed of seminiferous tubules wherein spermatogenesis occurs radially. Emerging research indicates that some mammals do not have lifetime determinate fecundity. The fact emerged that germinal epithelia occur in the gonads of all vertebrates examined herein of both sexes and has the same form and function across all vertebrate taxa. Continued study of the form and function of the germinal epithelium in vertebrates will increasingly clarify our understanding of vertebrate reproduction. J. Morphol. 277:1014-1044, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

The CW domain, a structural module shared amongst vertebrates, vertebrate-infecting parasites and higher plants.

PubMed

Perry, Jason; Zhao, Yunde

2003-11-01

A previously undetected domain, named CW for its conserved cysteine and tryptophan residues, appears to be a four-cysteine zinc-finger motif found exclusively in vertebrates, vertebrate-infecting parasites and higher plants. Of the twelve distinct nuclear protein families that comprise the CW domain-containing superfamily, only the microrchida (MORC) family has begun to be characterized. However, several families contain other domains suggesting a relationship between the CW domain and either chromatin methylation status or early embryonic development.

Role of notochord cells and sclerotome-derived cells in vertebral column development in fugu, Takifugu rubripes: histological and gene expression analyses.

PubMed

Kaneko, Takamasa; Freeha, Khalid; Wu, Xiaoming; Mogi, Makoto; Uji, Susumu; Yokoi, Hayato; Suzuki, Tohru

2016-10-01

Despite the common structure of vertebrates, the development of the vertebral column differs widely between teleosts and tetrapods in several respects, including the ossification of the centrum and the function of the notochord. In contrast to tetrapods, vertebral development in teleosts is not fully understood, particularly for large fish with highly ossified bones. We therefore examined the histology and gene expression profile of vertebral development in fugu, Takifugu rubripes, a model organism for genomic research. Ossification of the fugu centrum is carried out by outer osteoblasts expressing col1a1, col2a1, and sparc, and the growing centra completely divide the notochord into double cone-shaped segments that function as intercentral joints. In this process, the notochord basal cells produce a thick notochord sheath exhibiting Alcian-blue-reactive cartilaginous properties and composing the intercentral ligament in cooperation with the external ligament connective tissue. Synthesis of the matrix by the basal cells was ascertained by an in vitro test. Expression of twist2 indicates that this connective tissue is descended from the embryonic sclerotome. Notochord basal cells express sox9, ihhb, shh, and col2a1a, suggesting that the signaling system involved in chondrocyte proliferation and matrix production also functions in notochord cells for notochord sheath formation. We further found that the notochord expression of both ntla and shh is maintained in the fugu vertebral column, whereas it is turned off after embryogenesis in zebrafish. Thus, our results demonstrate that, in contrast to zebrafish, a dynamic morphogenesis and molecular network continues to function in fugu until the establishment of the adult vertebral column.

Evolution of the regionalization and patterning of the vertebrate telencephalon: what can we learn from cyclostomes?

PubMed

Sugahara, Fumiaki; Murakami, Yasunori; Adachi, Noritaka; Kuratani, Shigeru

2013-08-01

The telencephalon, the most anterior part of the vertebrate central nervous system (CNS), is a highly diversified region of the vertebrate body. Its evolutionary origin remains elusive, especially with regard to the ancestral state of its architecture as well as the origin of telencephalon-specific neuron subtypes. Cyclostomes (lampreys and hagfish), the sister group of the gnathostomes (jawed vertebrates), serve as valuable models for studying the evolution of the vertebrate CNS. Here, we summarize recent studies on the development of the telencephalon in the lamprey. By comparing detailed developmental studies in mammals, we illustrate a possible ancestral developmental plan underlying the diversification of the vertebrate telencephalon and propose possible approaches for understanding the early evolution of the telencephalon. Copyright © 2013 Elsevier Ltd. All rights reserved.

Quantification of diagenesis in Cenozoic sharks: Elemental and mineralogical changes

NASA Astrophysics Data System (ADS)

Labs-Hochstein, Joann; MacFadden, Bruce J.

2006-10-01

Diagenesis of bone during fossilization is pervasive, however, the extent of this process varies with depositional environment. This study quantifies diagenesis of shark vertebral centra through analysis of a suite of physical and chemical characters including crystallinty index (CI), carbonate content, and elemental concentrations. Although shark skeletons are initially cartilaginous, the soft cartilage of the vertebral centra is replaced with carbonate hydroxyapatite during growth. Nine vertebral centra are analyzed from lamnoid (Lamnoidea) sharks ranging in age from the cretaceous to recent using Fourier transform infrared spectroscopy (FT-IR) and inductively coupled plasma mass spectrometry (ICPMS). The variables CI, carbonate content, rare earth element (REE) concentrations, Ca/P, Ba/Ca, Sr/Ba, (La/Yb) N, (La/Y) N, (La/Yb) N vs. (La/Sm) N, La/Yb, and Ce anomalies elucidate the diagenetic and depositional environments of the seven fossil vertebral centra. The two extant centra demonstrate the initial, unaltered end-member conditions for these variables. Two fossil vertebral centra ( Carcharodon megalodon and Isurus hastalis) demonstrate a strong terrestrial influence during diagenesis (distinctive flattening of shale-normalized REE patterns) that masked the seawater signal. Three centra ( Carcharodon auriculatus, Carcharodon angustidens, and Creotxyrhina mantelli) have indications of some terrestrial influx evident by some flattening of the REE patterns relative to seawater. The terrestrial influence in these five shark centra ( C. megalodon, I. hastalis, C. auriculatus, C. angustidens and C. mantelli) are interpreted to represent a primarily nearshore habitat for these species. In contrast, the two Otodus obliquus centra have REE patterns that represent the original seawater signal and have no indications of terrigenous input. These results indicate that fossil shark vertebral centra have the potential to understand diagenesis and reconstruct paleooceanographic environments.

High-resolution-cone beam tomography analysis of bone microarchitecture in patients with acromegaly and radiological vertebral fractures.

PubMed

Maffezzoni, Filippo; Maddalo, Michele; Frara, Stefano; Mezzone, Monica; Zorza, Ivan; Baruffaldi, Fabio; Doglietto, Francesco; Mazziotti, Gherardo; Maroldi, Roberto; Giustina, Andrea

2016-11-01

Vertebral fractures are an emerging complication of acromegaly but their prediction is still difficult occurring even in patients with normal bone mineral density. In this study we evaluated the ability of high-resolution cone-beam computed tomography to provide information on skeletal abnormalities associated with vertebral fractures in acromegaly. 40 patients (24 females, 16 males; median age 57 years, range 25-72) and 21 healthy volunteers (10 females, 11 males; median age 60 years, range: 25-68) were evaluated for trabecular (bone volume/trabecular volume ratio, mean trabecular separation, and mean trabecular thickness) and cortical (thickness and porosity) parameters at distal radius using a high-resolution cone-beam computed tomography system. All acromegaly patients were evaluated for morphometric vertebral fractures and for mineral bone density by dual-energy X-ray absorptiometry at lumbar spine, total hip, femoral neck, and distal radius. Acromegaly patients with vertebral fractures (15 cases) had significantly (p < 0.05) lower bone volume/trabecular volume ratio, greater mean trabecular separation, and higher cortical porosity vs. nonfractured patients, without statistically significant differences in mean trabecular thickness and cortical thickness. Fractured and nonfractured acromegaly patients did not have significant differences in bone density at either skeletal site. Patients with acromegaly showed lower bone volume/trabecular volume ratio (p = 0.003) and mean trabecular thickness (p < 0.001) and greater mean trabecular separation (p = 0.02) as compared to control subjects, without significant differences in cortical thickness and porosity. This study shows for the first time that abnormalities of bone microstructure are associated with radiological vertebral fractures in acromegaly. High-resolution cone-beam computed tomography at the distal radius may be useful to evaluate and predict the effects of acromegaly on bone microstructure.

Expression analysis of Egr-1 ortholog in metamorphic brain of honeybee (Apis mellifera L.): Possible evolutionary conservation of roles of Egr in eye development in vertebrates and insects.

PubMed

Ugajin, Atsushi; Watanabe, Takayuki; Uchiyama, Hironobu; Sasaki, Tetsuhiko; Yajima, Shunsuke; Ono, Masato

2016-09-16

Specific genes quickly transcribed after extracellular stimuli without de novo protein synthesis are known as immediate early genes (IEGs) and are thought to contribute to learning and memory processes in the mature nervous system of vertebrates. A recent study revealed that the homolog of Early growth response protein-1 (Egr-1), which is one of the best-characterized vertebrate IEGs, shared similar properties as a neural activity-dependent gene in the adult brain of insects. With regard to the roles of vertebrate Egr-1 in neural development, the contribution to the development and growth of visual systems has been reported. However, in insects, the expression dynamics of the Egr-1 homologous gene during neural development remains poorly understood. Our expression analysis demonstrated that AmEgr, a honeybee homolog of Egr-1, was transiently upregulated in the developing brain during the early to mid pupal stages. In situ hybridization and 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry revealed that AmEgr was mainly expressed in post-mitotic cells in optic lobes, the primary visual center of the insect brain. These findings suggest the evolutionarily conserved role of Egr homologs in the development of visual systems in vertebrates and insects. Copyright © 2016 Elsevier Inc. All rights reserved.

Parthenogenesis: birth of a new lineage or reproductive accident?

PubMed

van der Kooi, Casper J; Schwander, Tanja

2015-08-03

Parthenogenesis - the ability to produce offspring from unfertilized eggs - is widespread among invertebrates and now increasingly found in normally sexual vertebrates. Are these cases reproductive errors or could they be a first step in the emergence of new parthenogenetic lineages? Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

A Symptomatic Case of Thoracic Vertebral Hemangioma Causing Lower Limb Spastic Paresis.

PubMed

Alfawareh, Mohammad; Alotaibi, Tariq; Labeeb, Abdallah; Audat, Ziad

2016-10-31

BACKGROUND Despite being the most common tumor of the spine, vertebral hemangioma is rarely symptomatic in adults. In fact, only 0.9-1.2% of all vertebral hemangiomas may be symptomatic. When hemangiomas occur in the thoracic vertebrae, they are more likely to be symptomatic due to the narrow vertebral canal dimensions that mandate more aggressive management prior to the onset of severe neurological sequelae. CASE REPORT An 18-year-old male presented to the emergency room with a one-month history of mild to moderate mid-thoracic back pain, radiating to both lower limbs. It was associated with both lower limb weakness and decreased sensation. There was no history of bowel or bladder incontinence. Neurological examination revealed lower limb weakness with power 3/5, exaggerated deep tendon reflexes, bilateral sustained clonus, impaired sensation below the umbilicus, spasticity, and a positive Babinski sign. A CT scan showed a diffuse body lesion at the 8th thoracic vertebra with coarse trabeculations, corduroy appearance, or jail-bar sign. The patient underwent decompression and fixation. Biopsy of permanent samples showed proliferation of blood vessels with dilated spaces and no malignant cells, consistent with hemangioma. Postoperatively, spasticity improved, and the patient regained normal power. CONCLUSIONS Symptomatic vertebral hemangiomas are rare but should be considered as a differential diagnosis. They can present with severe neurological symptoms. When managed appropriately, patients regain full motor and sensory function. Decompression resulted in quick relief of symptoms, which was followed by an extensive rehabilitation program.

Lumbar vertebral pedicles: radiologic anatomy and pathology

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

Patel, N.P.; Kumar, R.; Kinkhabwala, M.

1988-01-01

With the advancement of high-resolution computed tomography (CT) scanning the spine has added new knowledge to the various conditions affecting the pedicles. We wish to review the entire spectrum of pedicular lesions: the embryology, normal anatomy, normal variants, pitfalls, congenital anomalies, and pathological conditions are discussed. Different imaging modalities involving CT, isotope bone scanning, and Magnetic Resonance Imaging (MRI) are used to complement plain films of the lumbar spine. This subject review is an excellent source for future reference to lumbar pedicular lesions. 27 references.

Using whole mount in situ hybridization to link molecular and organismal biology.

PubMed

Jacobs, Nicole L; Albertson, R Craig; Wiles, Jason R

2011-03-31

Whole mount in situ hybridization (WISH) is a common technique in molecular biology laboratories used to study gene expression through the localization of specific mRNA transcripts within whole mount specimen. This technique (adapted from Albertson and Yelick, 2005) was used in an upper level undergraduate Comparative Vertebrate Biology laboratory classroom at Syracuse University. The first two thirds of the Comparative Vertebrate Biology lab course gave students the opportunity to study the embryology and gross anatomy of several organisms representing various chordate taxa primarily via traditional dissections and the use of models. The final portion of the course involved an innovative approach to teaching anatomy through observation of vertebrate development employing molecular techniques in which WISH was performed on zebrafish embryos. A heterozygous fibroblast growth factor 8 a (fgf8a) mutant line, ace, was used. Due to Mendelian inheritance, ace intercrosses produced wild type, heterozygous, and homozygous ace/fgf8a mutants in a 1:2:1 ratio. RNA probes with known expression patterns in the midline and in developing anatomical structures such as the heart, somites, tailbud, myotome, and brain were used. WISH was performed using zebrafish at the 13 somite and prim-6 stages, with students performing the staining reaction in class. The study of zebrafish embryos at different stages of development gave students the ability to observe how these anatomical structures changed over ontogeny. In addition, some ace/fgf8a mutants displayed improper heart looping, and defects in somite and brain development. The students in this lab observed the normal development of various organ systems using both external anatomy as well as gene expression patterns. They also identified and described embryos displaying improper anatomical development and gene expression (i.e., putative mutants). For instructors at institutions that do not already own the necessary equipment or where funds for lab and curricular innovation are limited, the financial cost of the reagents and apparatus may be a factor to consider, as will the time and effort required on the part of the instructor regardless of the setting. Nevertheless, we contend that the use of WISH in this type of classroom laboratory setting can provide an important link between developmental genetics and anatomy. As technology advances and the ability to study organismal development at the molecular level becomes easier, cheaper, and increasingly popular, many evolutionary biologists, ecologists, and physiologists are turning to research strategies in the field of molecular biology. Using WISH in a Comparative Vertebrate Biology laboratory classroom is one example of how molecules and anatomy can converge within a single course. This gives upper level college students the opportunity to practice modern biological research techniques, leading to a more diversified education and the promotion of future interdisciplinary scientific research.

The role of the notochord in amniote vertebral column segmentation.

PubMed

Ward, Lizzy; Pang, Angel S W; Evans, Susan E; Stern, Claudio D

2018-07-01

The vertebral column is segmented, comprising an alternating series of vertebrae and intervertebral discs along the head-tail axis. The vertebrae and outer portion (annulus fibrosus) of the disc are derived from the sclerotome part of the somites, whereas the inner nucleus pulposus of the disc is derived from the notochord. Here we investigate the role of the notochord in vertebral patterning through a series of microsurgical experiments in chick embryos. Ablation of the notochord causes loss of segmentation of vertebral bodies and discs. However, the notochord cannot segment in the absence of the surrounding sclerotome. To test whether the notochord dictates sclerotome segmentation, we grafted an ectopic notochord. We find that the intrinsic segmentation of the sclerotome is dominant over any segmental information the notochord may possess, and no evidence that the chick notochord is intrinsically segmented. We propose that the segmental pattern of vertebral bodies and discs in chick is dictated by the sclerotome, which first signals to the notochord to ensure that the nucleus pulposus develops in register with the somite-derived annulus fibrosus. Later, the notochord is required for maintenance of sclerotome segmentation as the mature vertebral bodies and intervertebral discs form. These results highlight differences in vertebral development between amniotes and teleosts including zebrafish, where the notochord dictates the segmental pattern. The relative importance of the sclerotome and notochord in vertebral patterning has changed significantly during evolution. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Expression profiling during ocular development identifies 2 Nlz genes with a critical role in optic fissure closure.

PubMed

Brown, Jacob D; Dutta, Sunit; Bharti, Kapil; Bonner, Robert F; Munson, Peter J; Dawid, Igor B; Akhtar, Amana L; Onojafe, Ighovie F; Alur, Ramakrishna P; Gross, Jeffrey M; Hejtmancik, J Fielding; Jiao, Xiaodong; Chan, Wai-Yee; Brooks, Brian P

2009-02-03

The gene networks underlying closure of the optic fissure during vertebrate eye development are poorly understood. Here, we profile global gene expression during optic fissure closure using laser capture microdissected (LCM) tissue from the margins of the fissure. From these data, we identify a unique role for the C(2)H(2) zinc finger proteins Nlz1 and Nlz2 in normal fissure closure. Gene knockdown of nlz1 and/or nlz2 in zebrafish leads to a failure of the optic fissure to close, a phenotype which closely resembles that seen in human uveal coloboma. We also identify misregulation of pax2 in the developing eye of morphant fish, suggesting that Nlz1 and Nlz2 act upstream of the Pax2 pathway in directing proper closure of the optic fissure.

The dual-specificity protein phosphatase DUSP9/MKP-4 is essential for placental function but is not required for normal embryonic development.

PubMed

Christie, Graham R; Williams, David J; Macisaac, Fiona; Dickinson, Robin J; Rosewell, Ian; Keyse, Stephen M

2005-09-01

To elucidate the physiological role(s) of DUSP9 (dual-specificity phosphatase 9), also known as MKP-4 (mitogen-activated protein kinase [MAPK] phosphatase 4), the gene was deleted in mice. Crossing male chimeras with wild-type females resulted in heterozygous (DUSP9(+/-)) females. However, when these animals were crossed with wild-type (DUSP9(+/y)) males none of the progeny carried the targeted DUSP9 allele, indicating that both female heterozygous and male null (DUSP9(-/y)) animals die in utero. The DUSP9 gene is on the X chromosome, and this pattern of embryonic lethality is consistent with the selective inactivation of the paternal X chromosome in the extraembryonic tissues of the mouse, suggesting that DUSP9/MKP4 performs an essential function during placental development. Examination of embryos between 8 and 10.5 days postcoitum confirmed that lethality was due to a failure of labyrinth development, and this correlates exactly with the normal expression pattern of DUSP9/MKP-4 in the trophoblast giant cells and labyrinth of the placenta. Finally, when the placental defect was rescued, male null (DUSP9(-/y)) embryos developed to term, appeared normal, and were fertile. Our results indicate that DUSP9/MKP-4 is essential for placental organogenesis but is otherwise dispensable for mammalian embryonic development and highlights the critical role of dual-specificity MAPK phosphatases in the regulation of developmental outcomes in vertebrates.

Asymmetry of the Vertebral Body and Pedicles in the True Transverse Plane in Adolescent Idiopathic Scoliosis: A CT-Based Study.

PubMed

Brink, Rob C; Schlösser, Tom P C; Colo, Dino; Vincken, Koen L; van Stralen, Marijn; Hui, Steve C N; Chu, Winnie C W; Cheng, Jack C Y; Castelein, René M

2017-01-01

Cross-sectional. To quantify the asymmetry of the vertebral bodies and pedicles in the true transverse plane in adolescent idiopathic scoliosis (AIS) and to compare this with normal anatomy. There is an ongoing debate about the existence and magnitude of the vertebral body and pedicle asymmetry in AIS and whether this is an expression of a primary growth disturbance, or secondary to asymmetrical loading. Vertebral body asymmetry, defined as left-right overlap of the vertebral endplates (ie, 100%: perfect symmetry, 0%: complete asymmetry) was evaluated in the true transverse plane on CT scans of 77 AIS patients and 32 non-scoliotic controls. Additionally, the pedicle width, length, and angle and the length of the ideal screw trajectory were calculated. Scoliotic vertebrae were on average more asymmetric than controls (thoracic: AIS 96.0% vs. controls 96.4%; p = .005, lumbar: 95.8% vs. 97.2%; p < .001) and more pronounced around the thoracic apex (95.8%) than at the end vertebrae (96.3%; p = .031). In the thoracic apex; the concave pedicle was thinner (4.5 vs. 5.4 mm; p < .001) and longer (20.9 vs. 17.9 mm; p < .001), the length of the ideal screw trajectory was longer (43.0 vs. 37.3 mm; p < .001), and the transverse pedicle angle was greater (12.3° vs. 5.7°; p < .001) than the convex one. The axial rotation showed no clear correlation with the asymmetry. Even in non-scoliotic controls is a degree of vertebral body and pedicle asymmetry, but scoliotic vertebrae showed slightly more asymmetry, mostly around the thoracic apex. In contrast to the existing literature, there is no major asymmetry in the true transverse plane in AIS and no uniform relation between the axial rotation and vertebral asymmetry could be observed in these moderate to severe patients, suggesting that asymmetrical vertebral growth does not initiate rotation, but rather follows it as a secondary phenomenon. Level 4. Copyright © 2016 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

Identifying osteoporotic vertebral endplate and cortex fractures

PubMed Central

Santiago, Fernando Ruiz; Deng, Min; Nogueira-Barbosa, Marcello H.

2017-01-01

Osteoporosis is the most common metabolic bone disease, and vertebral fractures (VFs) are the most common osteoporotic fracture. A single atraumatic VF may lead to the diagnosis of osteoporosis. Prevalent VFs increase the risk of future vertebral and non-vertebral osteoporotic fracture independent of bone mineral density (BMD). The accurate and clear reporting of VF is essential to ensure patients with osteoporosis receive appropriate treatment. Radiologist has a vital role in the diagnosis of this disease. Several morphometrical and radiological methods for detecting osteoporotic VF have been proposed, but there is no consensus regarding the definition of osteoporotic VF. A vertebra may fracture yet not ever result in measurable changes in radiographic height or area. To overcome these difficulties, algorithm-based qualitative approach (ABQ) was developed with a focus on the identification of change in the vertebral endplate. Evidence of endplate fracture (rather than variation in vertebral shape) is the primary indicator of osteoporotic fracture according to ABQ criteria. Other changes that may mimic osteoporotic fractures should be systemically excluded. It is also possible that vertebral cortex fracture may not initially occur in endplate. Particularly, vertebral cortex fracture can occur in anterior vertebral cortex without gross vertebral deformity (VD), or fractures deform the anterior vertebral cortex without endplate disruption. This article aims to serve as a teaching material for physicians or researchers to identify vertebral endplate/cortex fracture (ECF). Emphasis is particularly dedicated to identifying ECF which may not be associated apparent vertebral body collapse. We believe a combined approach based on standardized radiologic evaluation by experts and morphometry measurement is the most appropriate approach to detect and classify VFs. PMID:29184768

Early Evolution of Conserved Regulatory Sequences Associated with Development in Vertebrates

PubMed Central

McEwen, Gayle K.; Goode, Debbie K.; Parker, Hugo J.; Woolfe, Adam; Callaway, Heather; Elgar, Greg

2009-01-01

Comparisons between diverse vertebrate genomes have uncovered thousands of highly conserved non-coding sequences, an increasing number of which have been shown to function as enhancers during early development. Despite their extreme conservation over 500 million years from humans to cartilaginous fish, these elements appear to be largely absent in invertebrates, and, to date, there has been little understanding of their mode of action or the evolutionary processes that have modelled them. We have now exploited emerging genomic sequence data for the sea lamprey, Petromyzon marinus, to explore the depth of conservation of this type of element in the earliest diverging extant vertebrate lineage, the jawless fish (agnathans). We searched for conserved non-coding elements (CNEs) at 13 human gene loci and identified lamprey elements associated with all but two of these gene regions. Although markedly shorter and less well conserved than within jawed vertebrates, identified lamprey CNEs are able to drive specific patterns of expression in zebrafish embryos, which are almost identical to those driven by the equivalent human elements. These CNEs are therefore a unique and defining characteristic of all vertebrates. Furthermore, alignment of lamprey and other vertebrate CNEs should permit the identification of persistent sequence signatures that are responsible for common patterns of expression and contribute to the elucidation of the regulatory language in CNEs. Identifying the core regulatory code for development, common to all vertebrates, provides a foundation upon which regulatory networks can be constructed and might also illuminate how large conserved regulatory sequence blocks evolve and become fixed in genomic DNA. PMID:20011110

Age, gender, and skeletal variation in bone marrow composition: a preliminary study at 3.0 Tesla.

PubMed

Liney, Gary P; Bernard, Clare P; Manton, David J; Turnbull, Lindsay W; Langton, Chris M

2007-09-01

To evaluate the efficacy of MR Spectroscopy (MRS) at 3.0 Tesla for the assessment of normal bone marrow composition and assess the variation in terms of age, gender, and skeletal site. A total of 16 normal subjects (aged between eight and 57 years) were investigated on a 3.0 Tesla GE Signa system. To investigate axial and peripheral skeleton differences, non-water-suppressed spectra were acquired from single voxels in the calcaneus and lumbar spine. In addition, spectra were acquired at multiple vertebral bodies to assess variation within the lumbar spine. Data was also correlated with bone mineral density (BMD) measured in six subjects using dual-energy X-ray absorptiometry (DXA). Fat content was an order of magnitude greater in the heel compared to the spine. An age-related increase was demonstrated in the spine with values greater in men compared to female subjects. Significant trends in vertebral bodies within the same subjects were also shown, with fat content increasing L5 > L1. Population coefficient of variation (CV) was greater for fat fraction (FF) compared to BMD. Significant normal variations of marrow composition have been demonstrated, which provide important data for the future interpretation of patient investigations. (c) 2007 Wiley-Liss, Inc.

Identification of vimentin- and elastin-like transcripts specifically expressed in developing notochord of Atlantic salmon (Salmo salar L.).

PubMed

Sagstad, Anita; Grotmol, Sindre; Kryvi, Harald; Krossøy, Christel; Totland, Geir K; Malde, Ketil; Wang, Shou; Hansen, Tom; Wargelius, Anna

2011-11-01

The notochord functions as the midline structural element of all vertebrate embryos, and allows movement and growth at early developmental stages. Moreover, during embryonic development, notochord cells produce secreted factors that provide positional and fate information to a broad variety of cells within adjacent tissues, for instance those of the vertebrae, central nervous system and somites. Due to the large size of the embryo, the salmon notochord is useful to study as a model for exploring notochord development. To investigate factors that might be involved in notochord development, a normalized cDNA library was constructed from a mix of notochords from ∼500 to ∼800 day°. From the 1968 Sanger-sequenced transcripts, 22 genes were identified to be predominantly expressed in the notochord compared to other organs of salmon. Twelve of these genes were found to show expressional regulation around mineralization of the notochord sheath; 11 genes were up-regulated and one gene was down-regulated. Two genes were found to be specifically expressed in the notochord; these genes showed similarity to vimentin (acc. no GT297094) and elastin (acc. no GT297478). In-situ results showed that the vimentin- like transcript was expressed in both chordocytes and chordoblasts, whereas the elastin- like transcript was uniquely expressed in the chordoblasts lining the notochordal sheath. In salmon aquaculture, vertebral deformities are a common problem, and some malformations have been linked to the notochord. The expression of identified transcripts provides further insight into processes taking place in the developing notochord, prior to and during the early mineralization period.

Novel Hedgehog pathway targets against basal cell carcinoma

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

Tang, Jean Y.; Department of Epidemiology and Biostatistics, University of California, San Francisco, CA; So, P.-L.

2007-11-01

The Hedgehog signaling pathway plays a key role in directing growth and patterning during embryonic development and is required in vertebrates for the normal development of many structures, including the neural tube, axial skeleton, skin, and hair. Aberrant activation of the Hedgehog (Hh) pathway in adult tissue is associated with the development of basal cell carcinoma (BCC), medulloblastoma, and a subset of pancreatic, gastrointestinal, and other cancers. This review will provide an overview of what is known about the mechanisms by which activation of Hedgehog signaling leads to the development of BCCs and will review two recent papers suggesting thatmore » agents that modulate sterol levels might influence the Hh pathway. Thus, sterols may be a new therapeutic target for the treatment of BCCs, and readily available agents such as statins (HMG-CoA reductase inhibitors) or vitamin D might be helpful in reducing BCC incidence.« less

The vertebrate Hox gene regulatory network for hindbrain segmentation: Evolution and diversification: Coupling of a Hox gene regulatory network to hindbrain segmentation is an ancient trait originating at the base of vertebrates.

PubMed

Parker, Hugo J; Bronner, Marianne E; Krumlauf, Robb

2016-06-01

Hindbrain development is orchestrated by a vertebrate gene regulatory network that generates segmental patterning along the anterior-posterior axis via Hox genes. Here, we review analyses of vertebrate and invertebrate chordate models that inform upon the evolutionary origin and diversification of this network. Evidence from the sea lamprey reveals that the hindbrain regulatory network generates rhombomeric compartments with segmental Hox expression and an underlying Hox code. We infer that this basal feature was present in ancestral vertebrates and, as an evolutionarily constrained developmental state, is fundamentally important for patterning of the vertebrate hindbrain across diverse lineages. Despite the common ground plan, vertebrates exhibit neuroanatomical diversity in lineage-specific patterns, with different vertebrates revealing variations of Hox expression in the hindbrain that could underlie this diversification. Invertebrate chordates lack hindbrain segmentation but exhibit some conserved aspects of this network, with retinoic acid signaling playing a role in establishing nested domains of Hox expression. © 2016 WILEY Periodicals, Inc.

Genomics, evolution and development of amphioxus and tunicates: The Goldilocks principle.

PubMed

Holland, Linda Z

2015-06-01

Morphological comparisons among extant animals have long been used to infer their long-extinct ancestors for which the fossil record is poor or non-existent. For evolution of the vertebrates, the comparison has typically involved amphioxus and vertebrates. Both groups are evolving relatively slowly, and their genomes share a high level of synteny. Both vertebrates and amphioxus have regulative development in which cell fates become fixed only gradually during embryogenesis. Thus, their development fits a modified hourglass model in which constraints are greatest at the phylotypic stage (i.e., the late neurula/early larva), but are somewhat greater on earlier development than on later development. In contrast, the third group of chordates, the tunicates, which are sister group to vertebrates, are evolving rapidly. Constraints on evolution of tunicate genomes are relaxed, and they have discarded key developmental genes and organized much of their coding sequences into operons, which are transcribed as a single mRNA that undergoes trans-splicing. This contrasts with vertebrates and amphioxus, whose genomes are not organized into operons. Concomitantly, tunicates have switched to determinant development with very early fixation of cell fates. Thus, tunicate development more closely fits a progressive divergence model (shaped more like a wine glass than an hourglass) in which the constraints on the zygote and very early development are greatest. This model can help explain why tunicate body plans are so very diverse. The relaxed constraints on development after early cleavage stages are correlated with relaxed constraints on genome evolution. The question remains: which came first? © 2014 Wiley Periodicals, Inc.

Twist functions in vertebral column formation in medaka, Oryzias latipes.

PubMed

Yasutake, Junichi; Inohaya, Keiji; Kudo, Akira

2004-07-01

Medaka twist, a basic helix-loop-helix (bHLH) transcription factor, is expressed in the sclerotome during embryogenesis. We previously established a line of twist-EGFP transgenic medaka, whose EGFP expression is regulated by the twist promoter; therefore, we could observe the behavior of sclerotomal cells in vivo. In the transgenic medaka embryos, EGFP-positive sclerotomal cells migrated dorsally around the notochord and the neural tube, where at a later stage the vertebral column would be formed. This finding strongly suggests that twist-expressing sclerotomal cells participate in vertebral column formation in medaka. To clarify the function of twist gene in the sclerotome, we performed knockdown analysis of twist by using two kinds of morpholino antisense oligonucleotides targeted against twist (MO1 and MO2). Both the MO1 and MO2 morphants exhibited absence of neural arches, which are bilaterally paired, dorsomedially oriented bones on the dorsal aspect of the centrum. In addition, MO2, which blocks translation of only endogenous twist mRNA in the twist-EGFP transgenic medaka, did not affect the migration pattern of EGFP-positive cells, revealing that the migration of sclerotome-derived cells were normal in the absence of twist gene function. These results demonstrate that medaka twist functions in vertebral column formation by regulating the sclerotomal cell differentiation.

Lumbar vertebral haemangioma causing pathological fracture, epidural haemorrhage, and cord compression: a case report and review of literature.

PubMed

Vinay, S; Khan, S K; Braybrooke, J R

2011-01-01

Vertebral haemangiomas are recognized to be one of the commonest benign tumours of the vertebral column, occurring mostly in the thoracic spine. The vast majority of these are asymptomatic. Infrequently, these can turn symptomatic and cause neurological deficit (cord compression) through any of four reported mechanisms: (1) epidural extension; (2) expansion of the involved vertebra(e) causing spinal canal stenosis; (3) spontaneous epidural haemorrhage; (4) pathological burst fracture. Thoracic haemangiomas have been reported to be more likely to produce cord compression than lumbar haemangiomas. A forty-nine year old male with acute onset spinal cord compression from a pathological fracture in a first lumbar vertebral haemangioma. An MRI delineated the haemangioma and extent of bleeding that caused the cord compression. These were confirmed during surgery and the haematoma was evacuated. The spine was instrumented from T12 to L2, and a cement vertebroplasty was performed intra-operatively. Written consent for publication was obtained from the patient. The junctional location of the first lumbar vertebra, and the structural weakness from normal bone being replaced by the haemangioma, probably caused it to fracture under axial loading. This pathological fracture caused bleeding from the vascularized bone, resulting in cord compression.

Lumbar vertebral haemangioma causing pathological fracture, epidural haemorrhage, and cord compression: a case report and review of literature

PubMed Central

Vinay, S; Khan, SK; Braybrooke, JR

2011-01-01

Context Vertebral haemangiomas are recognized to be one of the commonest benign tumours of the vertebral column, occurring mostly in the thoracic spine. The vast majority of these are asymptomatic. Infrequently, these can turn symptomatic and cause neurological deficit (cord compression) through any of four reported mechanisms: (1) epidural extension; (2) expansion of the involved vertebra(e) causing spinal canal stenosis; (3) spontaneous epidural haemorrhage; (4) pathological burst fracture. Thoracic haemangiomas have been reported to be more likely to produce cord compression than lumbar haemangiomas. Findings A forty-nine year old male with acute onset spinal cord compression from a pathological fracture in a first lumbar vertebral haemangioma. An MRI delineated the haemangioma and extent of bleeding that caused the cord compression. These were confirmed during surgery and the haematoma was evacuated. The spine was instrumented from T12 to L2, and a cement vertebroplasty was performed intra-operatively. Written consent for publication was obtained from the patient. Clinical Relevance The junctional location of the first lumbar vertebra, and the structural weakness from normal bone being replaced by the haemangioma, probably caused it to fracture under axial loading. This pathological fracture caused bleeding from the vascularized bone, resulting in cord compression. PMID:21756575

[Vertebroplasty: state of the art].

PubMed

Chiras, J; Barragán-Campos, H M; Cormier, E; Jean, B; Rose, M; LeJean, L

2007-09-01

Over the last 10 years, there has been much development in the management of metastatic and osteoporotic vertebral compression fractures using vertebroplasty. This percutaneous image-guided interventional radiology procedure allows stabilization of a vertebral body by injection of an acrylic cement and frequently results in significant symptomatic relief. During cement polymerisation, an exothermic reaction may destroy adjacent tumor cells. Advances have been made to reduce complications from extravasation of cement in veins or surrounding soft tissues. Safety relates to experience but also to technical parameters: optimal cement radio-density, adequate digital fluoroscopy unit (single or bi-plane digital angiography unit), development of cements other than PMMA to avoid the risk of adjacent vertebral compression fractures. The rate of symptomatic relief from vertebroplasty performed for its principal indications (vertebral hemangioma, metastases, osteoporotic fractures) reaches 90-95%. The rate of complications is about 2% for metastases and less than 0.5% for osteoporotic fractures. Vertebroplasty plays a major role in the management of specific bone weakening vertebral lesions causing, obviating the need for kyphoplasty.

In vivo genome-wide analysis of multiple tissues identifies gene regulatory networks, novel functions and downstream regulatory genes for Bapx1 and its co-regulation with Sox9 in the mammalian vertebral column.

PubMed

Chatterjee, Sumantra; Sivakamasundari, V; Yap, Sook Peng; Kraus, Petra; Kumar, Vibhor; Xing, Xing; Lim, Siew Lan; Sng, Joel; Prabhakar, Shyam; Lufkin, Thomas

2014-12-05

Vertebrate organogenesis is a highly complex process involving sequential cascades of transcription factor activation or repression. Interestingly a single developmental control gene can occasionally be essential for the morphogenesis and differentiation of tissues and organs arising from vastly disparate embryological lineages. Here we elucidated the role of the mammalian homeobox gene Bapx1 during the embryogenesis of five distinct organs at E12.5 - vertebral column, spleen, gut, forelimb and hindlimb - using expression profiling of sorted wildtype and mutant cells combined with genome wide binding site analysis. Furthermore we analyzed the development of the vertebral column at the molecular level by combining transcriptional profiling and genome wide binding data for Bapx1 with similarly generated data sets for Sox9 to assemble a detailed gene regulatory network revealing genes previously not reported to be controlled by either of these two transcription factors. The gene regulatory network appears to control cell fate decisions and morphogenesis in the vertebral column along with the prevention of premature chondrocyte differentiation thus providing a detailed molecular view of vertebral column development.

Fertilization and development of eggs of the South African clawed toad, Xenopus laevis, on sounding rockets in space

NASA Astrophysics Data System (ADS)

Ubbels, Geertje A.; Berendsen, Willem; Kerkvliet, Sonja; Narraway, Jenny

Egg rotation and centrifugation experiments strongly suggest a role for gravity in the determination of the spatial structure of amphibian embryos. Decisive experiments can only be made in Space. Eggs of Xenopus laevis, the South African clawed toad, were the first vertebrate eggs which were successfully fertilized on Sounding Rockets in Space. Unfixed, newly fertilized eggs survived reentry, and a reasonable number showed a seemingly normal gastrulation but died between gastrulation and neurulation. Only a few reached the larval stage, but these developed abnormally. In the future, we inted to test whether this abnormal morphogenesis is due to reentry perturbations, or due to a real microgravity effect, through perturbation of the reinitiation of meiosis and other processes, or started by later sperm penetration.

Fertilization and development of eggs of the South African clawed toad, Xenopus laevis, on sounding rockets in space.

PubMed

Ubbels, G A; Berendsen, W; Kerkvliet, S; Narraway, J

1992-01-01

Egg rotation and centrifugation experiments strongly suggest a role for gravity in the determination of the spatial structure of amphibian embryos. Decisive experiments can only be made in Space. Eggs of Xenopus laevis, the South African clawed toad, were the first vertebrate eggs which were successfully fertilized on Sounding Rockets in Space. Unfixed, newly fertilized eggs survived reentry, and a reasonable number showed a seemingly normal gastrulation but died between gastrulation and neurulation. Only a few reached the larval stage, but these developed abnormally. In the future, we intend to test whether this abnormal morphogenesis is due to reentry perturbations, or due to a real microgravity effect, through perturbation of the reinitiation of meiosis and other processes, or started by later sperm penetration.

Long-term in vivo study of vertebrate embryonic development using noninvasive harmonics optical microscopy

NASA Astrophysics Data System (ADS)

Chen, Szu-Yu; Hsieh, C.-S.; Chu, S.-W.; Lin, Cheng-Yung; Ko, C.-Y.; Chen, Y.-C.; Tsai, Huai-Jen; Hu, C.-H.; Sun, Chi-Kuang

2005-03-01

Harmonics optical microscopy (HOM) provides a truly "noninvasive" tool for in vivo and long-term study of vertebrate embryonic development. Based on the nonlinear natures, it provides sub-micrometer 3D spatial resolution and high 3D optical-sectioning power (~1μm axial resolution) without using invasive and toxic fluorophores. Since only virtual-level-transition is involved, HOM is known to leave no energy deposition and no photodamages. Combined with second harmonic generation, which is sensitive to specific structure such as nerve and muscle fibers, HOM can be used to do functional studies of early developmental dynamics of many vertebrate physiological systems. Recently, zebrafish has become a standard model for many biological and medical studies of vertebrates, due to the similarity between embryonic development of zebrafish and human being. Zebrafish embryos now have been used to study many vertebrate physiological systems. We have demonstrated an in vivo HOM study of developmental dynamics of several embryonic physiological systems in live zebrafish embryos, with focuses on the developments of brains, eyes, ears, and hearts. Based on a femtosecond Cr:forsterite laser, which provides the deepest penetration (~1.5mm) and least photodamage in the zebrafish embryo, complete developing processes of different physiological systems within a period of time longer than 20 hours can be non-invasively observed inside the same embryo.

Normal anatomy and histology of the adult zebrafish.

PubMed

Menke, Aswin L; Spitsbergen, Jan M; Wolterbeek, Andre P M; Woutersen, Ruud A

2011-08-01

The zebrafish has been shown to be an excellent vertebrate model for studying the roles of specific genes and signaling pathways. The sequencing of its genome and the relative ease with which gene modifications can be performed have led to the creation of numerous human disease models that can be used for testing the potential and the toxicity of new pharmaceutical compounds. Many pharmaceutical companies already use the zebrafish for prescreening purposes. So far, the focus has been on ecotoxicity and the effects on embryonic development, but there is a trend to expand the use of the zebrafish with acute, subchronic, and chronic toxicity studies that are currently still carried out with the more conventional test animals such as rodents. However, before we can fully realize the potential of the zebrafish as an animal model for understanding human development, disease, and toxicology, we must first greatly advance our knowledge of normal zebrafish physiology, anatomy, and histology. To further this knowledge, we describe, in the present article, location and histology of the major zebrafish organ systems with a brief description of their function.

[Comparison of classical 2D measurement of scoliosis and 3D measurement using vertebral vectors; advantages for prognosis and treatment evaluation].

PubMed

Illés, Tamás

2011-03-01

The EOS system is a new medical imaging device based on low-dose X-rays, gaseous detectors and dedicated software for 3D reconstruction. It was developed by Nobel prizewinner Georges Charpak. A new concept--the vertebral vector--is used to facilitate the interpretation of EOS data, especially in the horizontal plane. We studied 95 cases of idiopathic scoliosis before and after surgery by means of classical methods and using vertebral vectors, in order to compare the accuracy of the two approaches. The vertebral vector permits simultaneous analysis of the scoliotic curvature in the frontal, sagittal and horizontal planes, as precisely as classical methods. The use of the vertebral vector simplifies and facilitates the interpretation of the mass of information provided by EOS. After analyzing the horizontal data, the first goal of corrective intervention would be to reduce the lateral vertebral deviation. The reduction in vertebral rotation seems less important. This is a new element in the therapeutic management of spinal deformations.

Analysis of Vertebral Bone Strength, Fracture Pattern, and Fracture Location: A Validation Study Using a Computed Tomography-Based Nonlinear Finite Element Analysis

PubMed Central

Imai, Kazuhiro

2015-01-01

Finite element analysis (FEA) is an advanced computer technique of structural stress analysis developed in engineering mechanics. Because the compressive behavior of vertebral bone shows nonlinear behavior, a nonlinear FEA should be utilized to analyze the clinical vertebral fracture. In this article, a computed tomography-based nonlinear FEA (CT/FEA) to analyze the vertebral bone strength, fracture pattern, and fracture location is introduced. The accuracy of the CT/FEA was validated by performing experimental mechanical testing with human cadaveric specimens. Vertebral bone strength and the minimum principal strain at the vertebral surface were accurately analyzed using the CT/FEA. The experimental fracture pattern and fracture location were also accurately simulated. Optimization of the element size was performed by assessing the accuracy of the CT/FEA, and the optimum element size was assumed to be 2 mm. It is expected that the CT/FEA will be valuable in analyzing vertebral fracture risk and assessing therapeutic effects on osteoporosis. PMID:26029476

CRISPR/Cas9-mediated mutagenesis in the sea lamprey Petromyzon marinus: a powerful tool for understanding ancestral gene functions in vertebrates

PubMed Central

Square, Tyler; Romášek, Marek; Jandzik, David; Cattell, Maria V.; Klymkowsky, Michael; Medeiros, Daniel M.

2015-01-01

Lamprey is one of only two living jawless vertebrates, a group that includes the first vertebrates. Comparisons between lamprey and jawed vertebrates have yielded important insights into the origin and evolution of vertebrate physiology, morphology and development. Despite its key phylogenetic position, studies of lamprey have been limited by their complex life history, which makes traditional genetic approaches impossible. The CRISPR/Cas9 system is a bacterial defense mechanism that was recently adapted to achieve high-efficiency targeted mutagenesis in eukaryotes. Here we report CRISPR/Cas9-mediated disruption of the genes Tyrosinase and FGF8/17/18 in the sea lamprey Petromyzon marinus, and detail optimized parameters for producing mutant F0 embryos. Using phenotype and genotype analyses, we show that CRISPR/Cas9 is highly effective in the sea lamprey, with a majority of injected embryos developing into complete or partial mutants. The ability to create large numbers of mutant embryos without inbred lines opens exciting new possibilities for studying development in lamprey and other non-traditional model organisms with life histories that prohibit the generation of mutant lines. PMID:26511928

The influence of sex, age and BMI on the degeneration of the lumbar spine

PubMed Central

Zukowski, Lisa A; Falsetti, Anthony B; Tillman, Mark D

2012-01-01

Previous research on lumbar spine osteophyte formation has focused on patterned development and the relation of age and sex to degeneration within the vertebral bodies. The inclusion of osteophytes originating on the laminae and body mass index (BMI) may result in a more complete evaluation. This study investigates lumbar osteophyte development on the laminae and vertebral bodies to determine whether osteophyte development: (i) is related bilaterally, at different lumbar levels, and superior and inferior margins; (ii) on the laminae and vertebral bodies are reciprocally dependent responses; (iii) is correlated with sex, age and/or BMI. Seventy-six individuals (39 females, 37 males) were randomly selected from a modern skeletal collection (Bass Donated Collection). Osteophyte development was scored in eight regions on each vertebra at all five lumbar levels. A factor analysis considered all 40 scoring regions and Pearson's correlation analyses assessed the relatedness of age and BMI with the consequent factors. The factor analysis separated the variables into two similar factors for males and females defined as: (i) superior and inferior vertebral body scores and (ii) superior laminar scores at higher lumbar levels. The factor analysis also determined a third factor for females defined as: (iii) inferior laminar scores at lower lumbar levels. The severity of vertebral body osteophytes increased with age for both sexes. Additionally for females, as BMI increased, osteophyte severity increased for both the superior laminar margins higher in the column and the vertebral bodies. Dissimilarities between the factors in males and females and the correlation of BMI to osteophyte severity exclusively in females provide evidence for different biomechanical processes influencing osteophyte development. PMID:22050626

Development of space-fertilized eggs and formation of primordial germ cells in the embryos of medaka fish

NASA Astrophysics Data System (ADS)

Ijiri, K.

In the second International Microgravity Laboratory (IML-2) mission in 1994, four small Japanese killifish (Medaka, Oryzias latipes) made a space travel of 15 days aboard a space shuttle. These four adult Medaka fish successfully mated in space for the first time among vertebrate animals. Moreover, the eggs they laid developed normally, at least in their external appearance, hatching as fry (baby fish) in space. Fish mated and laid eggs every day during the first week. Near the end of the mission most of the eggs had a well-developed body with two pigmented eyes. In total, 43 eggs were laid (detected), out of which 8 fry hatched in space, as truly `space-originated' babies. A further 30 fry hatched within 3 days after landing. This is the normal hatching rate, compared with the ground-based data. Among the 8 space-originated fry, four were killed for histological sections, and germ cells at the gonadal region were counted for each fry. Their numbers were in the range of the germ cells of the normal control fry (ground-kept samples). Thus, as embryos developed normally in their external appearance, inside the embryos the formation of primordial germ cells took place normally in space, and their migration to the genital ridges was not hindered by microgravity. The two of the remaining space-originated fry have grown up and been creating their offspring in the laboratory. This proved that the primordial germ cells formed in space were also normal from a functional point of view. The four space-travelled adult fish re-started mating and laying eggs on the 7th day after landing and continued to do so every day afterward. Fertilization rate and hatchability of these eggs were as high as the eggs laid by the laboratory-kept fish. This fact implies that in gametogenesis of adult fish, there are no specific stages of germ cells extremely susceptible to microgravity.

Amphibian metamorphosis as a model for studying endocrine disruption on vertebrate development: effect of bisphenol A on thyroid hormone action.

PubMed

Heimeier, Rachel A; Shi, Yun-Bo

2010-09-01

Thyroid hormone (TH) is essential for proper development in vertebrates. TH deficiency during gestation and early postnatal development produces severe neurological, skeletal, metabolism and growth abnormalities. It is therefore important to consider environmental chemicals that may interfere with TH signaling. Exposure to environmental contaminants that disrupt TH action may underlie the increasing incidence of human developmental disorders worldwide. One contaminant of concern is the xenoestrogen bisphenol A (BPA), a chemical widely used to manufacture polycarbonate plastics and epoxy resins. The difficulty in studying uterus-enclosed mammalian embryos has hampered the analysis on the direct effects of BPA during vertebrate development. As TH action at the cellular level is highly conserved across vertebrate species, amphibian metamorphosis serves as an important TH-dependent in vivo vertebrate model for studying potential contributions of BPA toward human developmental disorders. Using Xenopus laevis as a model, we and others have demonstrated the inhibitory effects of BPA exposure on metamorphosis. Genome-wide gene expression analysis revealed that surprisingly, BPA primarily targets the TH-signaling pathway essential for metamorphosis in Xenopus laevis. Given the importance of the genomic effects of TH during metamorphosis and the conservation in its regulation in higher vertebrates, these observations suggest that the effect of BPA in human embryogenesis is through the inhibition of the TH pathway and warrants further investigation. Our findings further argue for the critical need to use in vivo animal models coupled with systematic molecular analysis to determine the developmental effects of endocrine disrupting compounds. Published by Elsevier Inc.

Vertebral Adaptations to Large Body Size in Theropod Dinosaurs.

PubMed

Wilson, John P; Woodruff, D Cary; Gardner, Jacob D; Flora, Holley M; Horner, John R; Organ, Chris L

2016-01-01

Rugose projections on the anterior and posterior aspects of vertebral neural spines appear throughout Amniota and result from the mineralization of the supraspinous and interspinous ligaments via metaplasia, the process of permanent tissue-type transformation. In mammals, this metaplasia is generally pathological or stress induced, but is a normal part of development in some clades of birds. Such structures, though phylogenetically sporadic, appear throughout the fossil record of non-avian theropod dinosaurs, yet their physiological and adaptive significance has remained unexamined. Here we show novel histologic and phylogenetic evidence that neural spine projections were a physiological response to biomechanical stress in large-bodied theropod species. Metaplastic projections also appear to vary between immature and mature individuals of the same species, with immature animals either lacking them or exhibiting smaller projections, supporting the hypothesis that these structures develop through ontogeny as a result of increasing bending stress subjected to the spinal column. Metaplastic mineralization of spinal ligaments would likely affect the flexibility of the spinal column, increasing passive support for body weight. A stiff spinal column would also provide biomechanical support for the primary hip flexors and, therefore, may have played a role in locomotor efficiency and mobility in large-bodied species. This new association of interspinal ligament metaplasia in Theropoda with large body size contributes additional insight to our understanding of the diverse biomechanical coping mechanisms developed throughout Dinosauria, and stresses the significance of phylogenetic methods when testing for biological trends, evolutionary or not.

A case-control study of quality of life and functional impairment in women with long-standing vertebral osteoporotic fracture.

PubMed

Hall, S E; Criddle, R A; Comito, T L; Prince, R L

1999-01-01

There have been several studies of the impact of vertebral osteoporotic fracture on the quality of life and functionality of individual subjects. To date, however, no direct comparisons with age-matched normal subjects without vertebral fracture have been made. The radiographs of 145 female clinic patients with vertebral fractures were reviewed by the study physicians. The controls were recruited from the electoral role and by media appeal. One hundred and sixty-seven women had radiographs taken to determine those without vertebral fracture. Fracture subjects and controls had to be ambulant and were excluded if they had significant radiologic evidence of degenerative disk or joint disease of the spine. One hundred cases and one hundred controls were matched by 5-year age groups. The number, position and severity of the vertebral fracture on the lateral radiographs of the cases was recorded. Quality of life was measured using the Short Form-36 (SF-36) (maximum score 100) and a utility score calculated from these results (maximum score 1). Two measurements of functionality were employed: the Modified Barthel Index (MBI) to assess the activities of daily living (maximum score 100) and the Timed 'Up & Go' (TUG) that measured the time taken for the subject to rise from sitting in a chair, walk 3 m along a line, return to the chair and sit down. The fracture subjects had 2.9 +/- 1.6 (mean +/- SD) vertebral fractures and the time since last fracture was 5.1 +/- 4.8 years. The SF-36 physical function component summary index results were: fracture subjects 36 +/- 11, controls 48 +/- 9 (p < 0.001). The SF-36 mental health component summary index results were: fracture subjects 50 +/- 11, controls 54 +/- 8 (p < 0.05). The utility scores were: fracture subjects 0.64 +/- 0.08, controls 0.72 +/- 0.07 (p < 0.001). The MBI results were: fracture subjects 97 +/- 5, controls 99 +/- 1 (p < 0.01). The TUG results were: fracture subjects 13.8 +/- 7.3 s, controls 10.1 +/- 4.1 s (p < 0.01). TUG and MBI scores correlated well with SF-36 scores; however, no domain of the SF-36 or functional measure correlated with either the number of vertebral fractures or the time since last vertebral fracture. Thus, clinically reported vertebral fractures impair both the quality of life and functionality of these subjects. The adverse impact of vertebral fracture on quality of life and functionality needs to be recognized by medical practitioners, subjects and the community, so that adequate health resources can be devoted to the prevention and treatment of this debilitating condition condition.

There is no highly conserved embryonic stage in the vertebrates: implications for current theories of evolution and development.

PubMed

Richardson, M K; Hanken, J; Gooneratne, M L; Pieau, C; Raynaud, A; Selwood, L; Wright, G M

1997-08-01

Embryos of different species of vertebrate share a common organisation and often look similar. Adult differences among species become more apparent through divergence at later stages. Some authors have suggested that members of most or all vertebrate clades pass through a virtually identical, conserved stage. This idea was promoted by Haeckel, and has recently been revived in the context of claims regarding the universality of developmental mechanisms. Thus embryonic resemblance at the tailbud stage has been linked with a conserved pattern of developmental gene expression - the zootype. Haeckel's drawings of the external morphology of various vertebrates remain the most comprehensive comparative data purporting to show a conserved stage. However, their accuracy has been questioned and only a narrow range of species was illustrated. In view of the current widespread interest in evolutionary developmental biology, and especially in the conservation of developmental mechanisms, re-examination of the extent of variation in vertebrate embryos is long overdue. We present here the first review of the external morphology of tailbud embryos, illustrated with original specimens from a wide range of vertebrate groups. We find that embryos at the tailbud stage - thought to correspond to a conserved stage - show variations in form due to allometry, heterochrony, and differences in body plan and somite number. These variations foreshadow important differences in adult body form. Contrary to recent claims that all vertebrate embryos pass through a stage when they are the same size, we find a greater than 10-fold variation in greatest length at the tailbud stage. Our survey seriously undermines the credibility of Haeckel's drawings, which depict not a conserved stage for vertebrates, but a stylised amniote embryo. In fact, the taxonomic level of greatest resemblance among vertebrate embryos is below the subphylum. The wide variation in morphology among vertebrate embryos is difficult to reconcile with the idea of a phyogenetically-conserved tailbud stage, and suggests that at least some developmental mechanisms are not highly constrained by the zootype. Our study also highlights the dangers of drawing general conclusions about vertebrate development from studies of gene expression in a small number of laboratory species.

Nanotechnology for treating osteoporotic vertebral fractures

PubMed Central

Gao, Chunxia; Wei, Donglei; Yang, Huilin; Chen, Tao; Yang, Lei

2015-01-01

Osteoporosis is a serious public health problem affecting hundreds of millions of aged people worldwide, with severe consequences including vertebral fractures that are associated with significant morbidity and mortality. To augment or treat osteoporotic vertebral fractures, a number of surgical approaches including minimally invasive vertebroplasty and kyphoplasty have been developed. However, these approaches face problems and difficulties with efficacy and long-term stability. Recent advances and progress in nanotechnology are opening up new opportunities to improve the surgical procedures for treating osteoporotic vertebral fractures. This article reviews the improvements enabled by new nanomaterials and focuses on new injectable biomaterials like bone cements and surgical instruments for treating vertebral fractures. This article also provides an introduction to osteoporotic vertebral fractures and current clinical treatments, along with the rationale and efficacy of utilizing nanomaterials to modify and improve biomaterials or instruments. In addition, perspectives on future trends with injectable bone cements and surgical instruments enhanced by nanotechnology are provided. PMID:26316746

Timing Embryo Segmentation: Dynamics and Regulatory Mechanisms of the Vertebrate Segmentation Clock

PubMed Central

Resende, Tatiana P.; Andrade, Raquel P.; Palmeirim, Isabel

2014-01-01

All vertebrate species present a segmented body, easily observed in the vertebrate column and its associated components, which provides a high degree of motility to the adult body and efficient protection of the internal organs. The sequential formation of the segmented precursors of the vertebral column during embryonic development, the somites, is governed by an oscillating genetic network, the somitogenesis molecular clock. Herein, we provide an overview of the molecular clock operating during somite formation and its underlying molecular regulatory mechanisms. Human congenital vertebral malformations have been associated with perturbations in these oscillatory mechanisms. Thus, a better comprehension of the molecular mechanisms regulating somite formation is required in order to fully understand the origin of human skeletal malformations. PMID:24895605

Development and validation of a subject-specific finite element model of the functional spinal unit to predict vertebral strength.

PubMed

Lee, Chu-Hee; Landham, Priyan R; Eastell, Richard; Adams, Michael A; Dolan, Patricia; Yang, Lang

2017-09-01

Finite element models of an isolated vertebral body cannot accurately predict compressive strength of the spinal column because, in life, compressive load is variably distributed across the vertebral body and neural arch. The purpose of this study was to develop and validate a patient-specific finite element model of a functional spinal unit, and then use the model to predict vertebral strength from medical images. A total of 16 cadaveric functional spinal units were scanned and then tested mechanically in bending and compression to generate a vertebral wedge fracture. Before testing, an image processing and finite element analysis framework (SpineVox-Pro), developed previously in MATLAB using ANSYS APDL, was used to generate a subject-specific finite element model with eight-node hexahedral elements. Transversely isotropic linear-elastic material properties were assigned to vertebrae, and simple homogeneous linear-elastic properties were assigned to the intervertebral disc. Forward bending loading conditions were applied to simulate manual handling. Results showed that vertebral strengths measured by experiment were positively correlated with strengths predicted by the functional spinal unit finite element model with von Mises or Drucker-Prager failure criteria ( R 2  = 0.80-0.87), with areal bone mineral density measured by dual-energy X-ray absorptiometry ( R 2  = 0.54) and with volumetric bone mineral density from quantitative computed tomography ( R 2  = 0.79). Large-displacement non-linear analyses on all specimens did not improve predictions. We conclude that subject-specific finite element models of a functional spinal unit have potential to estimate the vertebral strength better than bone mineral density alone.

Planar induction of anteroposterior pattern in the developing central nervous system of Xenopus laevis

NASA Technical Reports Server (NTRS)

Doniach, T.; Phillips, C. R.; Gerhart, J. C.

1992-01-01

It has long been thought that anteroposterior (A-P) pattern in the vertebrate central nervous system is induced in the embryo's dorsal ectoderm exclusively by signals passing vertically from underlying, patterned dorsal mesoderm. Explants from early gastrulae of the frog Xenopus laevis were prepared in which vertical contact between dorsal ectoderm and mesoderm was prevented but planar contact was maintained. In these, four position-specific neural markers (engrailed-2, Krox-20, XlHbox 1, and XlHbox 6) were expressed in the ectoderm in the same A-P order as in the embryo. Thus, planar signals alone, following a path available in the normal embryo, can induce A-P neural pattern.

Gene disruption reveals a dispensable role for plasmepsin VII in the Plasmodium berghei life cycle.

PubMed

Mastan, Babu S; Kumari, Anchala; Gupta, Dinesh; Mishra, Satish; Kumar, Kota Arun

2014-06-01

Plasmepsins (PM), aspartic proteases of Plasmodium, comprises a family of ten proteins that perform critical functions in Plasmodium life cycle. Except VII and VIII, functions of the remaining plasmepsin members have been well characterized. Here, we have generated a mutant parasite lacking PM VII in Plasmodium berghei using reverse genetics approach. Systematic comparison of growth kinetics and infection in both mosquito and vertebrate host revealed that PM VII depleted mutants exhibited no defects in development and progressed normally throughout the parasite life cycle. These studies suggest a dispensable role for PM VII in Plasmodium berghei life cycle. Copyright © 2014 Elsevier B.V. All rights reserved.

Lumbar Facet Tropism: A Comprehensive Review.

PubMed

Alonso, Fernando; Kirkpatrick, Christina M; Jeong, William; Fisahn, Christian; Usman, Sameera; Rustagi, Tarush; Loukas, Marios; Chapman, Jens R; Oskouian, Rod J; Tubbs, R Shane

2017-06-01

Scattered reports exist in the medical literature regarding facet tropism. However, this finding has had mixed conclusions regarding its origin and impact on the normal spine. We performed a literature review of the anatomy, embryology, biomechanics, and pathology related to lumbar facet tropism. Facet tropism is most commonly found at L4-L5 vertebral segments and there is some evidence that this condition may lead to facet degenerative spondylolisthesis, intervertebral disc disease, and other degenerative conditions. Long-term analyses of patients are necessary to elucidate relationships between associated findings and facet tropism. In addition, a universally agreed definition that is more precise should be developed for future investigative studies. Copyright © 2017 Elsevier Inc. All rights reserved.

Amphioxus and lamprey AP-2 genes: implications for neural crest evolution and migration patterns

NASA Technical Reports Server (NTRS)

Meulemans, Daniel; Bronner-Fraser, Marianne

2002-01-01

The neural crest is a uniquely vertebrate cell type present in the most basal vertebrates, but not in cephalochordates. We have studied differences in regulation of the neural crest marker AP-2 across two evolutionary transitions: invertebrate to vertebrate, and agnathan to gnathostome. Isolation and comparison of amphioxus, lamprey and axolotl AP-2 reveals its extensive expansion in the vertebrate dorsal neural tube and pharyngeal arches, implying co-option of AP-2 genes by neural crest cells early in vertebrate evolution. Expression in non-neural ectoderm is a conserved feature in amphioxus and vertebrates, suggesting an ancient role for AP-2 genes in this tissue. There is also common expression in subsets of ventrolateral neurons in the anterior neural tube, consistent with a primitive role in brain development. Comparison of AP-2 expression in axolotl and lamprey suggests an elaboration of cranial neural crest patterning in gnathostomes. However, migration of AP-2-expressing neural crest cells medial to the pharyngeal arch mesoderm appears to be a primitive feature retained in all vertebrates. Because AP-2 has essential roles in cranial neural crest differentiation and proliferation, the co-option of AP-2 by neural crest cells in the vertebrate lineage was a potentially crucial event in vertebrate evolution.

Evolution of vertebrate central nervous system is accompanied by novel expression changes of duplicate genes.

PubMed

Chen, Yuan; Ding, Yun; Zhang, Zuming; Wang, Wen; Chen, Jun-Yuan; Ueno, Naoto; Mao, Bingyu

2011-12-20

The evolution of the central nervous system (CNS) is one of the most striking changes during the transition from invertebrates to vertebrates. As a major source of genetic novelties, gene duplication might play an important role in the functional innovation of vertebrate CNS. In this study, we focused on a group of CNS-biased genes that duplicated during early vertebrate evolution. We investigated the tempo-spatial expression patterns of 33 duplicate gene families and their orthologs during the embryonic development of the vertebrate Xenopus laevis and the cephalochordate Brachiostoma belcheri. Almost all the identified duplicate genes are differentially expressed in the CNS in Xenopus embryos, and more than 50% and 30% duplicate genes are expressed in the telencephalon and mid-hindbrain boundary, respectively, which are mostly considered as two innovations in the vertebrate CNS. Interestingly, more than 50% of the amphioxus orthologs do not show apparent expression in the CNS in amphioxus embryos as detected by in situ hybridization, indicating that some of the vertebrate CNS-biased duplicate genes might arise from non-CNS genes in invertebrates. Our data accentuate the functional contribution of gene duplication in the CNS evolution of vertebrate and uncover an invertebrate non-CNS history for some vertebrate CNS-biased duplicate genes. Copyright © 2011. Published by Elsevier Ltd.

Concepts on the pathogenesis of adolescent idiopathic scoliosis. Bone growth and mass, vertebral column, spinal cord, brain, skull, extra-spinal left-right skeletal length asymmetries, disproportions and molecular pathogenesis.

PubMed

Burwell, R Geoffrey; Dangerfield, Peter H; Freeman, Brian J C

2008-01-01

There is no generally accepted scientific theory for the causes of adolescent idiopathic scoliosis (AIS). Encouraging advances thought to be related to AIS pathogenesis have recently been made in several fields including anthropometry of bone growth, bone mass, spinal growth modulation, extra-spinal left-right skeletal length asymmetries and disproportions, magnetic resonance imaging of vertebral column, spinal cord, brain, skull, and molecular pathogenesis. These advances are leading to the evaluation of new treatments including attempts at minimally invasive surgery on the spine and peri-apical ribs. Several concepts of AIS are outlined indicating their clinical applications but not their research potential. The concepts, by derivation morphological, molecular and mathematical, are addressed in 15 sections: 1) initiating and progressive factors; 2) relative anterior spinal overgrowth; 3) dorsal shear forces that create axial rotational instability; 4) rotational preconstraint; 5) uncoupled, or asynchronous, spinal neuro-osseous growth; 6) brain, nervous system and skull; 7) a novel neuro-osseous escalator concept based on a putative abnormality of two normal polarized processes namely, a) increasing skeletal dimensions, and b) the CNS body schema - both contained within a neuro-osseous timing of maturation (NOTOM) concept; 8) transverse plane pelvic rotation, skeletal asymmetries and developmental theory; 9) thoraco-spinal concept; 10) origin in contracture at the hips; 11) osteopenia; 12) melatonin deficiency; 13) systemic melatonin-signaling pathway dysfunction; 14) platelet calmodulin dysfunction; and 15) biomechanical spinal growth modulation. From these concepts, a collective model for AIS pathogenesis is formulated. The central concept of this model includes the body schema of the neural systems, widely-studied in adults, that control normal posture and coordinated movements with frames of reference in the posterior parietal cortex. The escalator concept has implications for the normal development of upright posture, and the evolution in humans of neural control, the trunk and unique bipedal gait.

Vertebral growth modulation by hemicircumferential electrocoagulation: an experimental study in pigs.

PubMed

Caballero, Alberto; Barrios, Carlos; Burgos, Jesús; Hevia, Eduardo; Correa, Carlos

2011-08-01

This experimental study in pigs was aimed at evaluating spinal growth disorders after partial arrest of the vertebral epiphyseal plates (EP) and neurocentral cartilages (NCC). Unilateral and multisegmental single or combined lesions of the physeal structures were performed by electrocoagulation throughout a video-assisted thoracoscopical approach. Thirty 4-week-old domestic pigs (mean weight 16 kg) were included in the experiments. The superior and inferior epiphyseal plates of T5 to T9 vertebra were damaged in ten animals by hemicircumferential electrocoagulation (group I). In other ten pigs (group II), right NCC at the same T5-T9 levels were damaged. Ten other animals underwent combined lesions of the ipsilateral hemiepiphyseal plates and NCC at the T5-T9 levels. A total of 26 animals could be evaluated after 12 weeks of follow-up using conventional X-rays, CT scans and histology. The pigs with hemicircumferential EP damage developed very slight concave non-structured scoliotic deformities without vertebral rotation.(mean 12° Cobb; range10-16°). Some of the damaged vertebra showed a marked wedgening with unilateral development alteration of the vertebral body, including the adjacent discs The animals with damage of the NCC developed mild scoliotic curves (mean 19° Cobb; range 16-24°) with convexity opposite to the damaged side and loss of physiological kyphosis. The injured segments showed an asymmetric growth with hypoplasia of the pedicle and costovertebral joints at the damaged side. The pigs undergoing combined EP and NCC lesions developed minimal non-structured curves, ranging from 10 to 12° Cobb. In these animals there was a lack of growth of a vertebral hemibody and disc hypoplasia at the damaged segments. Both damage of the NCC and the EP affect the height of the vertebral body. No spinal stenosis was found in any case. In most cases, the adjacent superior and inferior vertebral EP to damaged segments had a compensatory growth that maintained the straight spinal shape. In summary, unilateral direct lesion of the EP by hemicircumferential thoracoscopic electrocoagulation modifies vertebral growth, but is not able to induce true scoliostic curves in pigs. Only animals with damaged NCC developed mild scoliotic curves of lordotic type. This work rediscovers and emphasizes the decisive role of the neurocentral cartilage in the ethiopatogeny of idiopathic scoliosis.

Evaluation of normal abdominal aortic diameters in the Indian population using computed tomography.

PubMed

Jasper, A; Harshe, G; Keshava, S N; Kulkarni, G; Stephen, E; Agarwal, S

2014-01-01

The aim of this study was to establish normal diameters for the suprarenal and infrarenal abdominal aorta measured at T12 and L3 vertebral levels in the Indian population and to study the variation in aortic diameters with age, sex, height, weight, body mass index (BMI), and body surface area (BSA). One hundred and forty-two patients who underwent helical contrast-enhanced computed tomography (CT) scans of the abdomen for non-cardiovascular reasons were recruited.. The mean internal diameters of the suprarenal and infrarenal abdominal aorta (maximum anteroposterior and transverse diameter) were measured at T12 and L3 vertebral levels and tabulated according to various age groups for both men and women. Pearson correlation coefficient was used to evaluate the correlation between aortic diameters, height, weight, BSA, and BMI. The mean diameters of the suprarenal and infrarenal abdominal aorta measured at T12 and L3 vertebral levels, in men were 19.0 ± 2.3 and 13.8 ± 1.9 mm and in women 17.1 ± 2.3 and 12.0 ± 1.6 mm, respectively. The aortic diameter progressively increased in caliber with increasing age of the patients and was smaller in women than men. A significant positive correlation was found in men between the suprarenal and infrarenal aortic diameters and weight, BSA, and BMI. In women, this correlation was significant in the infrarenal aorta but not in the suprarenal aorta. We obtained a set of normal values for the abdominal aorta in the Indian population. The aortic diameters correlated with age, gender, and body size of the patients as seen with previously published data in the Western population. A brief comparison of data between Indian and Western population showed that the values obtained were less than published elsewhere and hence, this should be considered while formulating intervention protocols.

Paleomagnetism of the Cretaceous Galula Formation and implications for vertebrate evolution

NASA Astrophysics Data System (ADS)

Widlansky, Sarah J.; Clyde, William C.; O'Connor, Patrick M.; Roberts, Eric M.; Stevens, Nancy J.

2018-03-01

This study uses magnetostratigraphy to help constrain the age of the paleontologically important Galula Formation (Rukwa Rift Basin, southwestern Tanzania). The formation preserves a Cretaceous vertebrate fauna, including saurischian dinosaurs, a putative gondwanatherian mammal, and notosuchian crocodyliforms. With better dating, the Galula Formation and its fossils help fill a temporal gap in our understanding of vertebrate evolution in continental Africa, enabling better evaluation of competing paleobiogeographic hypotheses concerning faunal exchange throughout Gondwana during the Cretaceous. Paleomagnetic samples for this study were collected from the Namba (higher in section) and Mtuka (lower in section) members of the Galula Formation and underwent stepwise thermal demagnetization. All samples displayed a strong normal magnetic polarity overprint, and maximum unblocking temperatures at approximately 690 °C. Three short reversed intervals were identified in the Namba Member, whereas the Mtuka Member lacked any clear reversals. Given the relatively limited existing age constraints, one interpretation correlates the Namba Member to Chron C32. An alternative correlation assigns reversals in the Namba Member to recently proposed short reversals near the end of the Cretaceous Normal Superchron (Chron C34), a time that is traditionally interpreted as having stable normal polarity. The lack of reversals in the Mtuka Member supports deposition within Chron C34. These data suggest that the Namba Member is no older than Late Cretaceous (Cenomanian-Campanian), with the Mtuka Member less well constrained to the middle Cretaceous (Aptian-Cenomanian). The paleomagnetic results are supported by the application of fold and reversal tests for paleomagnetic stability, and paleomagnetic poles for the Namba (246.4°/77.9°, α95 5.9°) and Mtuka (217.1°/72.2°, α95 11.1°) members closely matching the apparent polar wander path for Africa during the Late Cretaceous. These results confidently indicate a Late Creteceous age assignment for the Namba Member of the Galula Formation, a unit that has yielded key crocodyliform (e.g., Pakasuchus; Rukwasuchus) and dinosaur (e.g., Rukwatitan; Shingopana) fossils from eastern Africa.

Facet orientation in the thoracolumbar spine: three-dimensional anatomic and biomechanical analysis.

PubMed

Masharawi, Youssef; Rothschild, Bruce; Dar, Gali; Peleg, Smadar; Robinson, Dror; Been, Ella; Hershkovitz, Israel

2004-08-15

Thoracolumbar facet orientations were measured and analyzed. To establish a comprehensive database for facet orientation in the thoracolumbar vertebrae and to determine the normal human condition. Most studies on facet orientation have based their conclusions on two-dimensional measurements, in small samples or isolated vertebrae. The amount of normal asymmetry in facet orientation is poorly addressed. Transverse and longitudinal facet angles were measured directly from 240 human vertebral columns (males/females, blacks/whites). The specimens' osteologic material is part of the Hamann-Todd Osteological Collection housed at the Cleveland Museum of Natural History (Cleveland, OH). A total of 4,080 vertebrae (T1-L5) from the vertebral columns of individuals 20 to 80 years of age were measured, using a Microscribe three-dimensional apparatus (Immersion Co., San Jose, CA). Data were recorded directly on computer software. Statistical analysis included paired t tests and analysis of variance. RESULTS.: Facet orientation is independent of gender, age, and ethnic group. Asymmetry in facet orientation is found in the thorax. All thoracolumbar facets are positioned in an oblique plane. In the transverse plane, all facets from T1 to T11 are positioned with an anterior inclination of approximately 25 degrees to 30 degrees from the frontal plane. The facets of T12-L2 are oriented closer to the midsagittal plane of the vertebral body (mean range, 25.89 degrees-33.87 degrees), while the facets of L3-L5 are oriented away from that plane (mean range, 40.40 degrees-56.30 degrees). Facet transverse orientation at the thoracolumbar junction is highly variable (approximately 80% with approximately 101 degrees and approximately 20% with 35 degrees). All facets are oriented more vertically from T1 (approximately 150 degrees) to L5 (approximately 170 degrees). The facet sagittal orientations of the lumbar zygoapophyseal joints are not equivalent. CONCLUSIONS.: Asymmetry in facet orientation is a normal characteristic in the thorax.

Can the pattern of vertebral marrow oedema differentiate intervertebral disc infection from degenerative changes?

PubMed

Shrot, S; Sayah, A; Berkowitz, F

2017-07-01

To evaluate whether various patterns of bone marrow oedema could be used to discriminate between infection and degenerative change. Seventy patients with imaging features suspicious for discitis and available clinical follow-up were blindly reviewed for vertebral marrow oedema on sagittal short-tau inversion recovery (STIR) images according to the following patterns: I, vertebra oedema is adjacent to the intervertebral space and sharply-marginated; II, vertebral oedema is adjacent to the intervertebral space but not sharply marginated from normal marrow or involves the entire vertebral body; and III, vertebral oedema is distant from the endplate with intervening hypointense marrow signal. Of 45 patients with a clinical diagnosis of discitis, pattern II was the most common oedema pattern (64%). Approximately 20% and 9% of discitis patients showed patterns I and III, respectively. In patients with degenerative changes, 44% patients showed pattern I, 32% showed pattern II, and 24% showed pattern III. Pattern II had a sensitivity, specificity, and positive predictive value of 0.64, 0.68, and 0.78 for diagnosing spine infection, respectively. Although bone marrow oedema in infective discitis most often extends from the disc space and has indistinct margins, the oedema may also have sharp margins or be remote from the involved intervertebral space. Bone marrow oedema patterns of infective discitis overlap with those of degenerative disease and are not sufficiently reliable to exclude infection in cases with magnetic resonance imaging findings suggestive of discitis. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Design and preliminary biomechanical analysis of artificial cervical joint complex.

PubMed

Jian, Yu; Lan-Tao, Liu; Zhao, Jian-ning; Jian-ning, Zhao

2013-06-01

To design an artificial cervical joint complex (ACJC) prosthesis for non-fusion reconstruction after cervical subtotal corpectomy, and to evaluate the biomechanical stability, preservation of segment movements and influence on adjacent inter-vertebral movements of this prosthesis. The prosthesis was composed of three parts: the upper/lower joint head and the middle artificial vertebrae made of Cobalt-Chromium-Molybdenum (Co-Cr-Mo) alloy and polyethylene with a ball-and-socket joint design resembling the multi-axial movement in normal inter-vertebral spaces. Biomechanical tests of intact spine (control), Orion locking plate system and ACJC prosthesis were performed on formalin-fixed cervical spine specimens from 21 healthy cadavers to compare stability, range of motion (ROM) of the surgical segment and ROM of adjacent inter-vertebral spaces. As for stability of the whole lower cervical spine, there was no significant difference of flexion, extension, lateral bending and torsion between intact spine group and ACJC prosthesis group. As for segment movements, difference in flexion, lateral bending or torsion between ACJC prosthesis group and control group was not statistically significant, while ACJC prosthesis group showed an increase in extension (P < 0.05) compared to that of the control group. In addition, ACJC prosthesis group demonstrated better flexion, extension and lateral bending compared to those of Orion plating system group (P < 0.05). Difference in adjacent inter-vertebral ROM of the ACJC prosthesis group was not statistically significant compared to that of the control group. After cervical subtotal corpectomy, reconstruction with ACJC prosthesis not only obtained instant stability, but also reserved segment motions effectively, without abnormal gain of mobility at adjacent inter-vertebral spaces.

Maternal thyroid hormones enhance hatching success but decrease nestling body mass in the rock pigeon (Columba livia).

PubMed

Hsu, Bin-Yan; Dijkstra, Cor; Darras, Veerle M; de Vries, Bonnie; Groothuis, Ton G G

2017-01-01

Thyroid hormones (THs) - triiodothyronine (T3) and thyroxine (T4) - are essential for embryonic development in vertebrates. All vertebrate embryos are exposed to THs from maternal origin. As maternal TH levels are known to be essential to embryonic development, the natural variation of maternal THs probably represents a pathway of maternal effects that can modify offspring phenotype. However, potential fitness consequences of variation of maternal TH exposure within the normal physiological range and without confounding effects of the mother have never been experimentally investigated. We experimentally manipulated the levels of yolk T3 and T4 within the physiological range in a species in which the embryo develops outside the mother's body, the Rock Pigeon (Columba livia) eggs. Making use of the natural difference of yolk testosterone between the two eggs of pigeon clutches, we were also able to investigate the potential interaction between THs and testosterone. Elevated yolk TH levels enhanced embryonic development and hatching success, and reduced body mass but not tarsus length between day 14 and fledging. The yolk hormones increased plasma T4 concentrations in females but reduced it in males, in line with the effect on metabolic rate at hatching. Plasma concentrations of T3 and testosterone were not significantly affected. The effects of treatment did not differ between eggs with high or low testosterone levels. Our data indicate that natural variation in maternal yolk TH levels affects offspring phenotype and embryonic survival, potentially influencing maternal and chick fitness. Copyright © 2016 Elsevier Inc. All rights reserved.

TALE transcription factors during early development of the vertebrate brain and eye.

PubMed

Schulte, Dorothea; Frank, Dale

2014-01-01

Our brain's cognitive performance arises from the coordinated activities of billions of nerve cells. Despite a high degree of morphological and functional differences, all neurons of the vertebrate central nervous system (CNS) arise from a common field of multipotent progenitors. Cell fate specification and differentiation are directed by multistep processes that include inductive/external cues, such as the extracellular matrix or growth factors, and cell-intrinsic determinants, such as transcription factors and epigenetic modulators of proteins and DNA. Here we review recent findings implicating TALE-homeodomain proteins in these processes. Although originally identified as HOX-cofactors, TALE proteins also contribute to many physiological processes that do not require HOX-activity. Particular focus is, therefore, given to HOX-dependent and -independent functions of TALE proteins during early vertebrate brain development. Additionally, we provide an overview about known upstream and downstream factors of TALE proteins in the developing vertebrate brain and discuss general concepts of how TALE proteins function to modulate neuronal cell fate specification. Copyright © 2013 Wiley Periodicals, Inc.

Effects of Weightlessness on Vestibular Development of Quail

NASA Technical Reports Server (NTRS)

Fritzsch, Bernd; Bruce, Laura L.

1997-01-01

The lack of gravity is known to alter vestibular responses in developing and adult vertebrates. One cause of these altered responses may be changes in the connections between the vestibular receptor and the brain. Therefore we propose to investigate the effects of gravity on the formations of connections between the gravity receptors of the ear and the brain in developing quail incubated in space beginning at an age before these connections are established (incubation day three) until near the time of hatching, when they are to some extent functional. This investigation will make use of a novel technique, the diffusion of a lipophilic dye, DiI, in fixed tissue. This technique can thus be used to analyze the connections in specimens fixed in orbit, thus eliminating changes due to the earth's gravity. The evaluation of the data will enable us to detect gross deviations from normal patterns as well as detailed quantitative deviations.

The SET1 Complex Selects Actively Transcribed Target Genes via Multivalent Interaction with CpG Island Chromatin.

PubMed

Brown, David A; Di Cerbo, Vincenzo; Feldmann, Angelika; Ahn, Jaewoo; Ito, Shinsuke; Blackledge, Neil P; Nakayama, Manabu; McClellan, Michael; Dimitrova, Emilia; Turberfield, Anne H; Long, Hannah K; King, Hamish W; Kriaucionis, Skirmantas; Schermelleh, Lothar; Kutateladze, Tatiana G; Koseki, Haruhiko; Klose, Robert J

2017-09-05

Chromatin modifications and the promoter-associated epigenome are important for the regulation of gene expression. However, the mechanisms by which chromatin-modifying complexes are targeted to the appropriate gene promoters in vertebrates and how they influence gene expression have remained poorly defined. Here, using a combination of live-cell imaging and functional genomics, we discover that the vertebrate SET1 complex is targeted to actively transcribed gene promoters through CFP1, which engages in a form of multivalent chromatin reading that involves recognition of non-methylated DNA and histone H3 lysine 4 trimethylation (H3K4me3). CFP1 defines SET1 complex occupancy on chromatin, and its multivalent interactions are required for the SET1 complex to place H3K4me3. In the absence of CFP1, gene expression is perturbed, suggesting that normal targeting and function of the SET1 complex are central to creating an appropriately functioning vertebrate promoter-associated epigenome. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Handed behavior in hagfish--an ancient vertebrate lineage--and a survey of lateralized behaviors in other invertebrate chordates and elongate vertebrates.

PubMed

Miyashita, Tetsuto; Palmer, A Richard

2014-04-01

Hagfish represent an ancient lineage of boneless and jawless vertebrates. Among several curious behaviors they exhibit, solitary individuals in one dominant genus of hagfish (Eptatretus spp.) regularly rest in a tightly coiled posture. We present the first systematic treatment of this distinctive behavior. Individual northeastern Pacific hagfish (E. stoutii) exhibited significant handedness (preferred orientation of coiling). However, right-coiling and left-coiling individuals were equally common in the population. Individual hagfish likely develop a preference for one direction by repeating the preceding coiling direction. We also revisit classical accounts of chordate natural history and compare the coiling behavior of Eptatretus with other handed or lateralized behaviors in non-vertebrate chordates, lampreys, and derived vertebrates with elongate bodies. Handed behaviors occur in many of these groups, but they likely evolved independently. In contrast to vertebrates, morphological asymmetries may bias lateralized larval behaviors toward one side in cephalochordates and tunicates. As a consequence, no known handed behavior can be inferred to have existed in the common ancestor of vertebrates.

Differential segmental growth of the vertebral column of the rat (Rattus norvegicus).

PubMed

Bergmann, Philip J; Melin, Amanda D; Russell, Anthony P

2006-01-01

Despite the pervasive occurrence of segmental morphologies in the animal kingdom, the study of segmental growth is almost entirely lacking, but may have significant implications for understanding the development of these organisms. We investigate the segmental and regional growth of the entire vertebral column of the rat (Rattus norvegicus) by fitting a Gompertz curve to length and age data for each vertebra and each vertebral region. Regional lengths are calculated by summing constituent vertebral lengths and intervertebral space lengths for cervical, thoracic, lumbar, sacral, and caudal regions. Gompertz curves allow for the estimation of parameters representing neonatal and adult vertebral and regional lengths, as well as initial growth rate and the rate of exponential growth decay. Findings demonstrate differences between neonatal and adult rats in terms of relative vertebral lengths, and differential growth rates between sequential vertebrae and vertebral regions. Specifically, relative differences in the length of vertebrae indicate increasing differences caudad. Vertebral length in neonates increases from the atlas to the middle of the thoracic series and decreases in length caudad, while adult vertebral lengths tend to increase caudad. There is also a general trend of increasing vertebral and regional initial growth and rate of growth decay caudad. Anteroposterior patterns of growth are sexually dimorphic, with males having longer vertebrae than females at any given age. Differences are more pronounced (a) increasingly caudad along the body axis, and (b) in adulthood than in neonates. Elucidated patterns of growth are influenced by a combination of developmental, functional, and genetic factors.

Chordate betagamma-crystallins and the evolutionary developmental biology of the vertebrate lens.

PubMed

Riyahi, Kumars; Shimeld, Sebastian M

2007-07-01

Several animal lineages, including the vertebrates, have evolved sophisticated eyes with lenses that refract light to generate an image. The nearest invertebrate relatives of the vertebrates, such as the ascidians (sea squirts) and amphioxus, have only basic light detecting organs, leading to the widely-held view that the vertebrate lens is an innovation that evolved in early vertebrates. From an embryological perspective the lens is different from the rest of the eye, in that the eye is primarily of neural origin while the lens derives from a non-neural ectodermal placode which invaginates into the developing eye. How such an organ could have evolved has attracted much speculation. Recently, however, molecular developmental studies of sea squirts have started to suggest a possible evolutionary origin for the lens. First, studies of the Pax, Six, Eya and other gene families have indicated that sea squirts have areas of non-neural ectoderm homologous to placodes, suggesting an origin for the embryological characteristics of the lens. Second, the evolution and regulation of the betagamma-crystallins has been studied. These form one of the key crystallin gene families responsible for the transparency of the lens, and regulatory conservation between the betagamma-crystallin gene in the sea squirt Ciona intestinalis and the vertebrate visual system has been experimentally demonstrated. These data, together with knowledge of the morphological, physiological and gene expression similarities between the C. intestinalis ocellus and vertebrate retina, have led us to propose a hypothesis for the evolution of the vertebrate lens and integrated vertebrate eye via the co-option and combination of ancient gene regulatory networks; one controlling morphogenetic aspects of lens development and one controlling the expression of a gene family responsible for the biophysical properties of the lens, with the components of the retina having evolved from an ancestral photoreceptive organ derived from the anterior central nervous system.

Rapid effects of the aromatase inhibitor fadrozole on steroid production and gene expression in the ovary of female fathead minnows (Pimephales promelas)

EPA Science Inventory

Cytochrome P450 aromatase catalyzes conversion of C19 androgens to C18 estrogens and is critical for normal reproduction in female vertebrates. Fadrozole is a well-studied aromatase inhibitor that has been shown to suppress estrogen production in the ovaries of fish. However, l...

Course of the inferior vena cava on lateral films exposed in different positions.

PubMed

Lien, H H; Bakke, S J

1981-01-01

The distance from the posterior border of the inferior vena cava to the anterior vertebral margin was measured in 100 presumably normal patients in the supine position. Seventeen of these were also examined in the right and left lateral positions and the changes in course of the vena cava compared with the supine position.

Amphiastral Mitotic Spindle Assembly in Vertebrate Cells Lacking Centrosomes

PubMed Central

Hornick, Jessica E.; Mader, Christopher C.; Tribble, Emily K.; Bagne, Cydney C.; Vaughan, Kevin T.; Shaw, Sidney L.; Hinchcliffe, Edward H.

2011-01-01

Summary The role of centrosomes/centrioles during mitotic spindle assembly in vertebrates remains controversial. In cell-free extracts and experimentally derived acentrosomal cells, randomly oriented microtubules (MTs) self-organize around mitotic chromosomes and assemble anastral spindles [1, 2, 3]. However, vertebrate somatic cells normally assemble a connected pair of polarized, astral MT arrays – termed an amphiaster (“a star on both sides” [4]) – that is formed by the splitting and separation of the microtubule-organizing center (MTOC) well before nuclear envelope breakdown (NEB) [5]. Whether amphiaster formation requires splitting of duplicated centrosomes is not known. We found that when centrosomes were removed from living vertebrate cells early in their cell cycle, an acentriolar MTOC re-assembled, and prior to NEB, a functional amphiastral spindle formed. Cytoplasmic dynein, dynactin, and pericentrin are all recruited to the interphase aMTOC, and the activity of kinesin-5 is needed for amphiaster formation. Mitosis proceeded on time and these karyoplasts divided in two. However, ~35% of aMTOCs failed to split/separate before NEB, and these entered mitosis with persistent monastral spindles. The chromatin-mediated RAN-GTP pathway could not restore bipolarity to monastral spindles, and these cells exited mitosis as single daughters. Our data reveal the novel finding that MTOC separation and amphiaster formation does not absolutely require the centrosome, but in its absence, the fidelity of bipolar spindle assembly is highly compromised. PMID:21439826

The fickle finger of fate

PubMed Central

de la Fuente, Luis; Helms, Jill A.

2005-01-01

In this issue of the JCI, Niedermaier and colleagues demonstrate that a chromosomal inversion in mice results in dysregulation of Sonic hedgehog (Shh), such that Shh is ectopically expressed in a skeletogenic domain typically occupied by Indian hedgehog (Ihh). This molecular reversal eliminates phalangeal joint spaces, and consequently, Short digits (Dsh) heterozygotes (Dsh/+) have brachydactyly (shortened digits). Ihh is normally downregulated in regions that will become the joint space, but in Dsh/+ mice, Shh bypasses this regulatory control and persists; accordingly, cells maintain their chondrogenic fate and the developed digits are shorter than normal. The significance of these data extends far beyond the field of skeletal biology: they hint at the very real possibility that the endogenous Shh regulatory region contains a repressor designed to segregate the activity of Shh from Ihh. The existence of such a repressor provides a window into the distant past, revealing that Shh and Ihh must once have shared responsibilities in establishing tissue boundaries and orchestrating vertebrate tissue morphogenesis. PMID:15841172

Notochord vacuoles are lysosome-related organelles that function in axis and spine morphogenesis.

PubMed

Ellis, Kathryn; Bagwell, Jennifer; Bagnat, Michel

2013-03-04

The notochord plays critical structural and signaling roles during vertebrate development. At the center of the vertebrate notochord is a large fluid-filled organelle, the notochord vacuole. Although these highly conserved intracellular structures have been described for decades, little is known about the molecular mechanisms involved in their biogenesis and maintenance. Here we show that zebrafish notochord vacuoles are specialized lysosome-related organelles whose formation and maintenance requires late endosomal trafficking regulated by the vacuole-specific Rab32a and H(+)-ATPase-dependent acidification. We establish that notochord vacuoles are required for body axis elongation during embryonic development and identify a novel role in spine morphogenesis. Thus, the vertebrate notochord plays important structural roles beyond early development.

Notochord vacuoles are lysosome-related organelles that function in axis and spine morphogenesis

PubMed Central

Ellis, Kathryn; Bagwell, Jennifer

2013-01-01

The notochord plays critical structural and signaling roles during vertebrate development. At the center of the vertebrate notochord is a large fluid-filled organelle, the notochord vacuole. Although these highly conserved intracellular structures have been described for decades, little is known about the molecular mechanisms involved in their biogenesis and maintenance. Here we show that zebrafish notochord vacuoles are specialized lysosome-related organelles whose formation and maintenance requires late endosomal trafficking regulated by the vacuole-specific Rab32a and H+-ATPase–dependent acidification. We establish that notochord vacuoles are required for body axis elongation during embryonic development and identify a novel role in spine morphogenesis. Thus, the vertebrate notochord plays important structural roles beyond early development. PMID:23460678

The role of flow in the morphodynamics of embryonic heart

NASA Astrophysics Data System (ADS)

Gharib, Morteza

2017-11-01

Nature has shown us that some hearts do not require valves to achieve unidirectional flow. In its earliest stages, the vertebrate heart consists of a primitive tube that drives blood through a simple vascular network nourishing tissues and other developing organ systems. We have shown that in the case of the embryonic zebrafish heart, an elastic wave resonance mechanism based on impedance mismatches at the boundaries of the heart tube is the likely mechanism responsible for the valveless pumping behavior. When functioning normally, mature heart valves prevent intracardiac retrograde blood flow; before valves develop there is considerable regurgitation, resulting in oscillatory flow between the atrium and ventricle. We show that reversing flows are particularly strong stimuli to endothelial cells and that heart valves form as a developmental response to oscillatory blood flow through the maturing heart.

Ciona intestinalis: chordate development made simple.

PubMed

Passamaneck, Yale J; Di Gregorio, Anna

2005-05-01

Thanks to their transparent and rapidly developing mosaic embryos, ascidians (or sea squirts) have been a model system for embryological studies for over a century. Recently, ascidians have entered the postgenomic era, with the sequencing of the Ciona intestinalis genome and the accumulation of molecular resources that rival those available for fruit flies and mice. One strength of ascidians as a model system is their close similarity to vertebrates. Literature reporting molecular homologies between vertebrate and ascidian tissues has flourished over the past 15 years, since the first ascidian genes were cloned. However, it should not be forgotten that ascidians diverged from the lineage leading to vertebrates over 500 million years ago. Here, we review the main similarities and differences so far identified, at the molecular level, between ascidian and vertebrate tissues and discuss the evolution of the compact ascidian genome. Copyright 2005 Wiley-Liss, Inc.

The Genomic and Genetic Toolbox of the Teleost Medaka (Oryzias latipes)

PubMed Central

Kirchmaier, Stephan; Naruse, Kiyoshi; Wittbrodt, Joachim; Loosli, Felix

2015-01-01

The Japanese medaka, Oryzias latipes, is a vertebrate teleost model with a long history of genetic research. A number of unique features and established resources distinguish medaka from other vertebrate model systems. A large number of laboratory strains from different locations are available. Due to a high tolerance to inbreeding, many highly inbred strains have been established, thus providing a rich resource for genetic studies. Furthermore, closely related species native to different habitats in Southeast Asia permit comparative evolutionary studies. The transparency of embryos, larvae, and juveniles allows a detailed in vivo analysis of development. New tools to study diverse aspects of medaka biology are constantly being generated. Thus, medaka has become an important vertebrate model organism to study development, behavior, and physiology. In this review, we provide a comprehensive overview of established genetic and molecular-genetic tools that render medaka fish a full-fledged vertebrate system. PMID:25855651

Spontaneous Bilateral Vertebral Artery Dissection During a Basketball Game

PubMed Central

Mas Rodriguez, Manuel F.; Berrios, Rafael Arias; Ramos, Edwardo

2016-01-01

Spontaneous vertebral artery dissection accounts for 2% of all ischemic strokes and can occur as a consequence of sports events. We present an unusual case of spontaneous bilateral vertebral artery dissection in a 30-year-old male patient during a basketball game. He developed severe dysphagia, right hemiparesis, and balance dysfunction. We also present a review of the pathology, diagnosis, symptomatology, treatment, prognosis, and occurrence of this entity in sports. PMID:26733592

Neurocytotoxic effects of iron-ions on the developing brain measured in vivo using medaka (Oryzias latipes), a vertebrate model

PubMed Central

Yasuda, Takako; Oda, Shoji; Yasuda, Hiroshi; Hibi, Yusuke; Anzai, Kazunori; Mitani, Hiroshi

2011-01-01

Purpose: Exposure to heavy-ion radiation is considered a critical health risk on long-term space missions. The developing central nervous system (CNS) is a highly radiosensitive tissue; however, the biological effects of heavy-ion radiation, which are greater than those of low-linear energy transfer (LET) radiation, are not well studied, especially in vivo in intact organisms. Here, we examined the effects of iron-ions on the developing CNS using vertebrate organism, fish embryos of medaka (Oryzias latipes). Materials and methods: Medaka embryos at developmental stage 28 were irradiated with iron-ions at various doses of 0-1.5 Gy. At 24 h after irradiation, radiation-induced apoptosis was examined using an acridine orange (AO) assay and histo-logically. To estimate the relative biological effectiveness (RBE), we quantified only characteristic AO-stained rosette-shaped apoptosis in the developing optic tectum (OT). At the time of hatching, morphological abnormalities in the irradiated brain were examined histologically. Results: The dose-response curve utilizing an apoptotic index for the iron-ion irradiated embryos was much steeper than that for X-ray irradiated embryos, with RBE values of 3.7-4.2. Histological examinations of irradiated medaka brain at 24 h after irradiation showed AO-positive rosette-shaped clusters as aggregates of condensed nuclei, exhibiting a circular hole, mainly in the marginal area of the OT and in the retina. However, all of the irradiated embryos hatched normally without apparent histological abnormalities in their brains. Conclusion: Our present study indicates that the medaka embryo is a useful model for evaluating neurocytotoxic effects on the developing CNS induced by exposure to heavy iron-ions relevant to the aerospace radiation environment. PMID:21770703

Depression of the Thoracolumbar Posterior Vertebral Body on the Estimation of Cement Leakage in Vertebroplasty and Kyphoplasty Operations

PubMed Central

Chen, Hao; Jia, Pu; Bao, Li; Feng, Fei; Yang, He; Li, Jin-Jun; Tang, Hai

2015-01-01

Background: The cross-section of thoracolumbar vertebral body is kidney-shaped with depressed posterior boundary. The anterior wall of the vertebral canal is separated from the posterior wall of the vertebral body on the lateral X-ray image. This study was designed to determine the sagittal distance between the anterior border of the vertebral canal and the posterior border of the vertebral body (DBCV) and to analyze the potential role of DBCV in the estimation of cement leakage during percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP). Methods: We retrospectively recruited 233 patients who had osteoporotic vertebral compression fractures and were treated with PVP or PKP. Computed tomography images of T11–L2 normal vertebrae were measured to obtain DBCV. The distance from cement to the posterior wall of the vertebral body (DCPW) of thoracolumbar vertebrae was measured from C-arm images. The selected vertebrae were divided into two groups according to DCPW, with the fracture levels, fracture grades and leakage rates of the two groups compared. A relative operating characteristic (ROC) curve was applied to determine whether the DCPW difference can be used to estimate the degree of cement leakage. The data were processed by statistical software SPSS version 21.0 using independent sample t-test and Chi-square tests. Results: The maximum DBCV was 6.40 mm and the average DBCV was 3.74 ± 0.95 mm. DBCV appeared to be longer in males than in females, but the difference was not statistically significant. The average DCPW of type-B leakage vertebrae (2.59 ± 1.20 mm) was shorter than that of other vertebrae (7.83 ± 2.38 mm, P < 0.001). The leakage rate of group DCPW ≤6.40 mm was lower than that of group DCPW >6.40 mm for type-C and type-S, but much higher for type-B. ROC curve revealed that DCPW only has a predictive value for type-B leakage (area under the curve: 0.98, 95% confidence interval: 0.95–0.99, P < 0.001), and when the cut-off value was 4.05 mm, the diagnostic sensitivity and the specificity were 94.87% and 93.02%, respectively. Conclusions: Depression of the thoracolumbar posterior vertebral body may be informative for the estimation of cement location on C-arm images. To reduce type-B leakage, DCPW should be made longer than DBCV on C-arm images for safety during PVP or PKP. PMID:26612289

Depression of the Thoracolumbar Posterior Vertebral Body on the Estimation of Cement Leakage in Vertebroplasty and Kyphoplasty Operations.

PubMed

Chen, Hao; Jia, Pu; Bao, Li; Feng, Fei; Yang, He; Li, Jin-Jun; Tang, Hai

2015-12-05

The cross-section of thoracolumbar vertebral body is kidney-shaped with depressed posterior boundary. The anterior wall of the vertebral canal is separated from the posterior wall of the vertebral body on the lateral X-ray image. This study was designed to determine the sagittal distance between the anterior border of the vertebral canal and the posterior border of the vertebral body (DBCV) and to analyze the potential role of DBCV in the estimation of cement leakage during percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP). We retrospectively recruited 233 patients who had osteoporotic vertebral compression fractures and were treated with PVP or PKP. Computed tomography images of T11-L2 normal vertebrae were measured to obtain DBCV. The distance from cement to the posterior wall of the vertebral body (DCPW) of thoracolumbar vertebrae was measured from C-arm images. The selected vertebrae were divided into two groups according to DCPW, with the fracture levels, fracture grades and leakage rates of the two groups compared. A relative operating characteristic (ROC) curve was applied to determine whether the DCPW difference can be used to estimate the degree of cement leakage. The data were processed by statistical software SPSS version 21.0 using independent sample t-test and Chi-square tests. The maximum DBCV was 6.40 mm and the average DBCV was 3.74 ± 0.95 mm. DBCV appeared to be longer in males than in females, but the difference was not statistically significant. The average DCPW of type-B leakage vertebrae (2.59 ± 1.20 mm) was shorter than that of other vertebrae (7.83 ± 2.38 mm, P < 0.001). The leakage rate of group DCPW ≤6.40 mm was lower than that of group DCPW >6.40 mm for type-C and type-S, but much higher for type-B. ROC curve revealed that DCPW only has a predictive value for type-B leakage (area under the curve: 0.98, 95% confidence interval: 0.95-0.99, P < 0.001), and when the cut-off value was 4.05 mm, the diagnostic sensitivity and the specificity were 94.87% and 93.02%, respectively. Depression of the thoracolumbar posterior vertebral body may be informative for the estimation of cement location on C-arm images. To reduce type-B leakage, DCPW should be made longer than DBCV on C-arm images for safety during PVP or PKP.

Congenital costo-vertebral fibrous band and congenital kyphoscoliosis: a previously unreported combination.

PubMed

Eid, Tony; Ghostine, Bachir; Kreichaty, Gaby; Daher, Paul; Ghanem, Ismat

2013-05-01

Congenital kyphoscoliosis (CKS) results from abnormal vertebral chondrification. Congenital fibrous bands occur in several locations with variable impact on vertebral development. We report a previously unreported case of a female infant with CKS presenting with an L2 hypoplastic vertebra and a costo-vertebral fibrous band extending to the skin in the form of a dimple. We also describe the therapeutic approach, consisting of surgical excision of the fibrous band and postoperative fulltime bracing, with a 7-year follow-up. We recommend a high index of suspicion in any unusual presentation of CKS and insist on case by case management in such cases.

The zebrafish eye—a paradigm for investigating human ocular genetics

PubMed Central

Richardson, R; Tracey-White, D; Webster, A; Moosajee, M

2017-01-01

Although human epidemiological and genetic studies are essential to elucidate the aetiology of normal and aberrant ocular development, animal models have provided us with an understanding of the pathogenesis of multiple developmental ocular malformations. Zebrafish eye development displays in depth molecular complexity and stringent spatiotemporal regulation that incorporates developmental contributions of the surface ectoderm, neuroectoderm and head mesenchyme, similar to that seen in humans. For this reason, and due to its genetic tractability, external fertilisation, and early optical clarity, the zebrafish has become an invaluable vertebrate system to investigate human ocular development and disease. Recently, zebrafish have been at the leading edge of preclinical therapy development, with their amenability to genetic manipulation facilitating the generation of robust ocular disease models required for large-scale genetic and drug screening programmes. This review presents an overview of human and zebrafish ocular development, genetic methodologies employed for zebrafish mutagenesis, relevant models of ocular disease, and finally therapeutic approaches, which may have translational leads in the future. PMID:27612182

Sequencing of the sea lamprey (Petromyzon marinus) genome provides insights into vertebrate evolution

PubMed Central

Smith, Jeramiah J; Kuraku, Shigehiro; Holt, Carson; Sauka-Spengler, Tatjana; Jiang, Ning; Campbell, Michael S; Yandell, Mark D; Manousaki, Tereza; Meyer, Axel; Bloom, Ona E; Morgan, Jennifer R; Buxbaum, Joseph D; Sachidanandam, Ravi; Sims, Carrie; Garruss, Alexander S; Cook, Malcolm; Krumlauf, Robb; Wiedemann, Leanne M; Sower, Stacia A; Decatur, Wayne A; Hall, Jeffrey A; Amemiya, Chris T; Saha, Nil R; Buckley, Katherine M; Rast, Jonathan P; Das, Sabyasachi; Hirano, Masayuki; McCurley, Nathanael; Guo, Peng; Rohner, Nicolas; Tabin, Clifford J; Piccinelli, Paul; Elgar, Greg; Ruffier, Magali; Aken, Bronwen L; Searle, Stephen MJ; Muffato, Matthieu; Pignatelli, Miguel; Herrero, Javier; Jones, Matthew; Brown, C Titus; Chung-Davidson, Yu-Wen; Nanlohy, Kaben G; Libants, Scot V; Yeh, Chu-Yin; McCauley, David W; Langeland, James A; Pancer, Zeev; Fritzsch, Bernd; de Jong, Pieter J; Zhu, Baoli; Fulton, Lucinda L; Theising, Brenda; Flicek, Paul; Bronner, Marianne E; Warren, Wesley C; Clifton, Sandra W; Wilson, Richard K; Li, Weiming

2013-01-01

Lampreys are representatives of an ancient vertebrate lineage that diverged from our own ~500 million years ago. By virtue of this deeply shared ancestry, the sea lamprey (P. marinus) genome is uniquely poised to provide insight into the ancestry of vertebrate genomes and the underlying principles of vertebrate biology. Here, we present the first lamprey whole-genome sequence and assembly. We note challenges faced owing to its high content of repetitive elements and GC bases, as well as the absence of broad-scale sequence information from closely related species. Analyses of the assembly indicate that two whole-genome duplications likely occurred before the divergence of ancestral lamprey and gnathostome lineages. Moreover, the results help define key evolutionary events within vertebrate lineages, including the origin of myelin-associated proteins and the development of appendages. The lamprey genome provides an important resource for reconstructing vertebrate origins and the evolutionary events that have shaped the genomes of extant organisms. PMID:23435085

Did the first chordates organize without the organizer?

PubMed

Kourakis, Matthew J; Smith, William C

2005-09-01

Models of vertebrate development frequently portray the organizer as acting on a largely unpatterned embryo to induce major components of the body plan, such as the neural plate and somites. Recent experiments examining the molecular and genetic basis of major inductive events of vertebrate embryogenesis force a re-examination of this view. These newer observations, along with a proposed revised fate map for the frog Xenopus laevis, suggest a possible reconciliation between the seemingly disparate mechanisms present in the ontogeny of the common chordate body plan of vertebrate and invertebrate chordates. Here, we review data from vertebrates and from an ascidian urochordate and propose that the organizer was not present at the base of the chordate lineage, but could have been a later innovation in the lineage leading to vertebrates, where its role was more permissive than instructive.

A Common Fold Mediates Vertebrate Defense and Bacterial Attack

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

Rosado, Carlos J.; Buckle, Ashley M.; Law, Ruby H.P.

2008-10-02

Proteins containing membrane attack complex/perforin (MACPF) domains play important roles in vertebrate immunity, embryonic development, and neural-cell migration. In vertebrates, the ninth component of complement and perforin form oligomeric pores that lyse bacteria and kill virus-infected cells, respectively. However, the mechanism of MACPF function is unknown. We determined the crystal structure of a bacterial MACPF protein, Plu-MACPF from Photorhabdus luminescens, to 2.0 angstrom resolution. The MACPF domain reveals structural similarity with poreforming cholesterol-dependent cytolysins (CDCs) from Gram-positive bacteria. This suggests that lytic MACPF proteins may use a CDC-like mechanism to form pores and disrupt cell membranes. Sequence similarity between bacterialmore » and vertebrate MACPF domains suggests that the fold of the CDCs, a family of proteins important for bacterial pathogenesis, is probably used by vertebrates for defense against infection.« less

Generation of monoclonal antibodies to vertebrate albumins for analysis of arthropod blood meals.

PubMed

Schwab, Lori Kae; Nardi, James B; Holly, Theresa; Wang, Liping; Frye, Janie; Novak, Robert J

2011-06-01

An immunoassay using monoclonal antibodies (MAbs) that are specific for different vertebrate taxa (from class to species) has been developed that simplifies and facilitates analysis of vertebrate blood meals from arthropod vectors. The MAbs have been prepared against the single protein albumin, the most abundant protein in vertebrate sera. A panel of these antibodies has been generated against albumins from 33 species of vertebrates, representing four classes, 15 orders, and 25 families. Immunoreactivity of albumin in mosquito blood meals can be detected as late as 48 h after feeding. Immunoassays with MAbs can be carried out in the field as well as the laboratory. Used in conjunction with nucleic acid assays or used alone with an appropriate assortment of antibodies, the assay is simple, sensitive, and unambiguous. © 2011 The Society for Vector Ecology.

Computerized detection of vertebral compression fractures on lateral chest radiographs: Preliminary results with a tool for early detection of osteoporosis

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

Kasai, Satoshi; Li Feng; Shiraishi, Junji

Vertebral fracture (or vertebral deformity) is a very common outcome of osteoporosis, which is one of the major public health concerns in the world. Early detection of vertebral fractures is important because timely pharmacologic intervention can reduce the risk of subsequent additional fractures. Chest radiographs are used routinely for detection of lung and heart diseases, and vertebral fractures can be visible on lateral chest radiographs. However, investigators noted that about 50% of vertebral fractures visible on lateral chest radiographs were underdiagnosed or under-reported, even when the fractures were severe. Therefore, our goal was to develop a computerized method for detectionmore » of vertebral fractures on lateral chest radiographs in order to assist radiologists' image interpretation and thus allow the early diagnosis of osteoporosis. The cases used in this study were 20 patients with severe vertebral fractures and 118 patients without fractures, as confirmed by the consensus of two radiologists. Radiologists identified the locations of fractured vertebrae, and they provided morphometric data on the vertebral shape for evaluation of the accuracy of detecting vertebral end plates by computer. In our computerized method, a curved search area, which included a number of vertebral end plates, was first extracted automatically, and was straightened so that vertebral end plates became oriented horizontally. Edge candidates were enhanced by use of a horizontal line-enhancement filter in the straightened image, and a multiple thresholding technique, followed by feature analysis, was used for identification of the vertebral end plates. The height of each vertebra was determined from locations of identified vertebral end plates, and fractured vertebrae were detected by comparison of the measured vertebral height with the expected height. The sensitivity of our computerized method for detection of fracture cases was 95% (19/20), with 1.03 (139/135) false-positive fractures per image. The accuracy of identifying vertebral end plates, marked by radiologists in a morphometric study, was 76.6% (400/522) and 70.9% (420/592) for cases used for training and those for testing, respectively. We prepared 32 additional fracture cases for a validation test, and we examined the detection accuracy of our computerized method. The sensitivity for these cases was 75% (24/32) at 1.03 (33/32) false-positive fractures per image. Our preliminary results show that the automated computerized scheme for detecting vertebral fractures on lateral chest radiographs has the potential to assist radiologists in detecting vertebral fractures.« less

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

Dynan, William S.

The goal of this study was to examine long-term effects of low-dose radiation exposure. One of the hypotheses was that radiation exposure would accelerate the normal aging process. The study was jointly funded by NASA and examined both low-LET radiation (γ-rays) and high-LET radiation (1000 MeV/nucleon 56Fe ions) at doses of 0.1 Gy and up. The work used the Japanese medaka fish (Oryzias latipes), as a vertebrate model organism that can be maintained in large numbers at low cost for lifetime studies. Like other small laboratory fish, Japanese medaka share many anatomical and histological characteristics with other vertebrates, and amore » variety of genetic and genomic resources are available. Some work also used the zebrafish (Danio rerio), another widely used laboratory model organism.« less

Computer-assisted analysis of cervical vertebral bone age using cephalometric radiographs in Brazilian subjects.

PubMed

Caldas, Maria de Paula; Ambrosano, Gláucia Maria Bovi; Haiter Neto, Francisco

2010-01-01

The aims of this study were to develop a computerized program for objectively evaluating skeletal maturation on cephalometric radiographs, and to apply the new method to Brazilian subjects. The samples were taken from the patient files of Oral Radiological Clinics from the North, Northeast, Midwest and South regions of the country. A total of 717 subjects aged 7.0 to 15.9 years who had lateral cephalometric radiographs and hand-wrist radiographs were selected. A cervical vertebral computerized analysis was created in the Radiocef Studio 2 computer software for digital cephalometric analysis, and cervical vertebral bone age was calculated using the formulas developed by Caldas et al.17 (2007). Hand-wrist bone age was evaluated by the TW3 method. Analysis of variance (ANOVA) and the Tukey test were used to compare cervical vertebral bone age, hand-wrist bone age and chronological age (P < 0.05). No significant difference was found between cervical vertebral bone age and chronological age in all regions studied. When analyzing bone age, it was possible to observe a statistically significant difference between cervical vertebral bone age and hand-wrist bone age for female and male subjects in the North and Northeast regions, as well as for male subjects in the Midwest region. No significant difference was observed between bone age and chronological age in all regions except for male subjects in the North and female subjects in the Northeast. Using cervical vertebral bone age, it might be possible to evaluate skeletal maturation in an objective manner using cephalometric radiographs.

Expression patterns of Eph genes in the "dual visual development" of the lamprey and their significance in the evolution of vision in vertebrates.

PubMed

Suzuki, Daichi G; Murakami, Yasunori; Yamazaki, Yuji; Wada, Hiroshi

2015-01-01

Image-forming vision is crucial to animals for recognizing objects in their environment. In vertebrates, this type of vision is achieved with paired camera eyes and topographic projection of the optic nerve. Topographic projection is established by an orthogonal gradient of axon guidance molecules, such as Ephs. To explore the evolution of image-forming vision in vertebrates, lampreys, which belong to the basal lineage of vertebrates, are key animals because they show unique "dual visual development." In the embryonic and pre-ammocoete larval stage (the "primary" phase), photoreceptive "ocellus-like" eyes develop, but there is no retinotectal optic nerve projection. In the late ammocoete larval stage (the "secondary" phase), the eyes grow and form into camera eyes, and retinotectal projection is newly formed. After metamorphosis, this retinotectal projection in adult lampreys is topographic, similar to that of gnathostomes. In this study, we explored the involvement of Ephs in lamprey "dual visual development" and establishment of the image-form vision. We found that gnathostome-like orthogonal gradient expression was present in the retina during the "secondary" phase; i.e., EphB showed a gradient of expression along the dorsoventral axis, while EphC was expressed along the anteroposterior axis. However, no orthogonal gradient expression was observed during the "primary" phase. These observations suggest that Ephs are likely recruited de novo for the guidance of topographical "second" optic nerve projection. Transformations during lamprey "dual visual development" may represent "recapitulation" from a protochordate-like ancestor to a gnathostome-like vertebrate ancestor. © 2015 Wiley Periodicals, Inc.

Beyond the binding site: in vivo identification of tbx2, smarca5 and wnt5b as molecular targets of CNBP during embryonic development.

PubMed

Armas, Pablo; Margarit, Ezequiel; Mouguelar, Valeria S; Allende, Miguel L; Calcaterra, Nora B

2013-01-01

CNBP is a nucleic acid chaperone implicated in vertebrate craniofacial development, as well as in myotonic dystrophy type 2 (DM2) and sporadic inclusion body myositis (sIBM) human muscle diseases. CNBP is highly conserved among vertebrates and has been implicated in transcriptional regulation; however, its DNA binding sites and molecular targets remain elusive. The main goal of this work was to identify CNBP DNA binding sites that might reveal target genes involved in vertebrate embryonic development. To accomplish this, we used a recently described yeast one-hybrid assay to identify DNA sequences bound in vivo by CNBP. Bioinformatic analyses revealed that these sequences are G-enriched and show high frequency of putative G-quadruplex DNA secondary structure. Moreover, an in silico approach enabled us to establish the CNBP DNA-binding site and to predict CNBP putative targets based on gene ontology terms and synexpression with CNBP. The direct interaction between CNBP and candidate genes was proved by EMSA and ChIP assays. Besides, the role of CNBP upon the identified genes was validated in loss-of-function experiments in developing zebrafish. We successfully confirmed that CNBP up-regulates tbx2b and smarca5, and down-regulates wnt5b gene expression. The highly stringent strategy used in this work allowed us to identify new CNBP target genes functionally important in different contexts of vertebrate embryonic development. Furthermore, it represents a novel approach toward understanding the biological function and regulatory networks involving CNBP in the biology of vertebrates.

Beyond the Binding Site: In Vivo Identification of tbx2, smarca5 and wnt5b as Molecular Targets of CNBP during Embryonic Development

PubMed Central

Mouguelar, Valeria S.; Allende, Miguel L.; Calcaterra, Nora B.

2013-01-01

CNBP is a nucleic acid chaperone implicated in vertebrate craniofacial development, as well as in myotonic dystrophy type 2 (DM2) and sporadic inclusion body myositis (sIBM) human muscle diseases. CNBP is highly conserved among vertebrates and has been implicated in transcriptional regulation; however, its DNA binding sites and molecular targets remain elusive. The main goal of this work was to identify CNBP DNA binding sites that might reveal target genes involved in vertebrate embryonic development. To accomplish this, we used a recently described yeast one-hybrid assay to identify DNA sequences bound in vivo by CNBP. Bioinformatic analyses revealed that these sequences are G-enriched and show high frequency of putative G-quadruplex DNA secondary structure. Moreover, an in silico approach enabled us to establish the CNBP DNA-binding site and to predict CNBP putative targets based on gene ontology terms and synexpression with CNBP. The direct interaction between CNBP and candidate genes was proved by EMSA and ChIP assays. Besides, the role of CNBP upon the identified genes was validated in loss-of-function experiments in developing zebrafish. We successfully confirmed that CNBP up-regulates tbx2b and smarca5, and down-regulates wnt5b gene expression. The highly stringent strategy used in this work allowed us to identify new CNBP target genes functionally important in different contexts of vertebrate embryonic development. Furthermore, it represents a novel approach toward understanding the biological function and regulatory networks involving CNBP in the biology of vertebrates. PMID:23667590

Characterization of the Trunk Neural Crest in the bamboo shark, Chiloscyllium punctatum

PubMed Central

Juarez, Marilyn; Reyes, Michelle; Coleman, Tiffany; Rotenstein, Lisa; Sao, Sothy; Martinez, Darwin; Jones, Matthew; Mackelprang, Rachel; de Bellard, Maria Elena

2013-01-01

The neural crest is a population of mesenchymal cells that after migrating from the neural tube give rise to a structures and cell-types: jaw, part of the peripheral ganglia and melanocytes. Although much is known about neural crest development in jawed vertebrates, a clear picture of trunk neural crest development for elasmobranchs is yet to be developed. Here we present a detailed study of trunk neural crest development in the bamboo shark, Chiloscyllium punctatum. Vital labeling with DiI and in situ hybridization using cloned Sox8 and Sox9 probes demonstrated that trunk neural crest cells follow a pattern similar to the migratory paths already described in zebrafish and amphibians. We found shark trunk neural crest along the rostral side of the somites, the ventromedial pathway, branchial arches, gut, sensory ganglia and nerves. Interestingly, Chiloscyllium punctatum Sox8 and Sox9 sequences aligned with vertebrate SoxE genes, but appeared to be more ancient than the corresponding vertebrate paralogs. The expression of these two SoxE genes in trunk neural crest cells, especially Sox9, matched the Sox10 migratory patterns observed in teleosts. Interestingly, we observed DiI cells and Sox9 labeling along the lateral line, suggesting that in C. punctatum, glial cells in the lateral line are likely of neural crest origin. Though this has been observed in other vertebrates, we are the first to show that the pattern is present in cartilaginous fishes. These findings demonstrate that trunk neural crest cell development in Chiloscyllium punctatum follows the same highly conserved migratory pattern observed in jawed vertebrates PMID:23640803

Remodeling of the notochord during development of vertebral fusions in Atlantic salmon (Salmo salar).

PubMed

Ytteborg, Elisabeth; Torgersen, Jacob Seilø; Pedersen, Mona E; Baeverfjord, Grete; Hannesson, Kirsten O; Takle, Harald

2010-12-01

Histological characterization of spinal fusions in Atlantic salmon (Salmo salar) has demonstrated shape alterations of vertebral body endplates, a reduced intervertebral space, and replacement of intervertebral cells by ectopic bone. However, the significance of the notochord during the fusion process has not been addressed. We have therefore investigated structural and cellular events in the notochord during the development of vertebral fusions. In order to induce vertebral fusions, Atlantic salmon were exposed to elevated temperatures from fertilization until they attained a size of 15g. Based on results from radiography, intermediate and terminal stages of the fusion process were investigated by immunohistochemistry and real-time quantitative polymerase chain reaction. Examination of structural extracellular matrix proteins such as Perlecan, Aggrecan, Elastin, and Laminin revealed reduced activity and reorganization at early stages in the pathology. Staining for elastic fibers visualized a thinner elastic membrane surrounding the notochord of developing fusions, and immunohistochemistry for Perlecan showed that the notochordal sheath was stretched during fusion. These findings in the outer notochord correlated with the loss of Aggrecan- and Substance-P-positive signals and the further loss of vacuoles from the chordocytes in the central notochord. At more progressed stages of fusion, chordocytes condensed, and the expression of Aggrecan and Substance P reappeared. The hyperdense regions seem to be of importance for the formation of notochordal tissue into bone. Thus, the remodeling of notochord integrity by reduced elasticity, structural alterations, and cellular changes is probably involved in the development of vertebral fusions.

Relationships among diet, physical activity, and dual plane dual-energy X-ray absorptiometry bone outcomes in pre-pubertalgirls.

PubMed

Ren, Jie; Brann, Lynn S; Bruening, Kay S; Scerpella, Tamara A; Dowthwaite, Jodi N

2017-12-01

In pre-pubertal girls, nutrient intakes and non-aquatic organized activity were evaluated as factors in vertebral body bone mass, structure, and strength. Activity, vitamin B 12 , and dietary fiber predicted bone outcomes most consistently. Exercise and vitamin B 12 appear beneficial, whereas high fiber intake appears to be adverse for vertebral body development. Childhood development sets the baseline for adult fracture risk. Most studies evaluate development using postero-anterior (PA) dual-energy X-ray absorptiometry (DXA) areal bone mineral density, bone mineral content, and bone mineral apparent density. In a prior analysis, we demonstrated that PA DXA reflects posterior element properties, rather than vertebral body fracture sites, such that loading is associated with subtle differences in vertebral body geometry, not 3D density. The current analysis is restricted to pre-pubertal girls, for a focused exploration of key nutrient intakes and physical activity as factors in dual plane indices of vertebral body geometry, density, and strength. This cross-sectional analysis used paired PA and supine lateral (LAT) lumbar spine DXA scans to assess "3D" vertebral body bone mineral apparent density (PALATBMAD), "3D" index of structural strength in axial compression (PALATIBS), and fracture risk index (PALATFRI). Diet data were collected using the Youth/Adolescent Questionnaire (YAQ, 1995); organized physical activity was recorded via calendar-based form. Pearson correlations and backward stepwise multiple linear regression analyzed associations among key nutrients, physical activity, and bone outcomes. After accounting for activity and key covariates, fiber, unsupplemented vitamin B 12 , zinc, carbohydrate, vitamin C, unsupplemented magnesium, and unsupplemented calcium intake explained significant variance for one or more bone outcomes (p < 0.05). After adjustment for influential key nutrients and covariates, activity exposure was associated with postero-anterior (PA) areal bone mineral density, PA bone mineral content, PA width, lateral (LAT) BMC, "3D" bone cross-sectional area (coronal plane), "3D" PALATIBS, and PALATFRI benefits (p < 0.05). Physical activity, fiber intake, and unsupplemented B 12 intake appear to influence vertebral body bone mass, density, geometry, and strength in well-nourished pre-pubertal girls; high fiber intakes may adversely affect childhood vertebral body growth.

Treatment of tuberculous aortic pseudoaneurysm associated with vertebral tuberculosis: A case series and a literature review.

PubMed

Xue, Jing; Yao, Yimin; Liu, Limin

2018-04-01

Tuberculous aortic pseudoaneurysm associated with vertebral tuberculosis is a rare disease but with very high mortality. We review the literature and find 19 reports with 22 patients. Here we report three cases with vertebral tuberculosis, who also have tuberculous pseudoaneurysm of the aorta. These patients were treated by different methods. We try to analyze the epidemiology, pathogenesis, presentation, and management of this disease to find the best treatment. The patients presented with different symptoms such as pain (chest, abdominal or back), fever, blood volume reduction or hemorrhagic shock symptoms. Large mass also could be observed by imaging. In addition to clinical manifestations, enhanced computed tomography or magnetic resonance imaging could also help the diagnosis of this disease. Tuberculous aortic pseudoaneurysm associated with vertebral tuberculosis. Three patients were treated with anti-tuberculosis(TB) drugs or combined with different sequences surgical treatment: Case 1 refused to receive pseudoaneurysm surgery and only had anti-TB drug treatment; Case 2 received thoracic spinal surgery first; Case 3 received endovascular stent grafting. Two patients (case 1 and case 2) who refused to undergo aneurysm surgery died. The last patient (case 3) underwent endovascular repair and antibiotic therapy for tuberculosis, and the postoperative course was uneventful; the patient recovered and survived. Once the diagnosis of tuberculous pseudoaneurysm is confirmed, surgical treatment should be provided immediately combined with anti-tuberculosis drugs. The aim of the treatment is to save lives, prevent relapse, and facilitate the return to normal life, regardless of the size of the pseudoaneurysm. The pseudoaneurysm should be treated first to prevent aneurysm rupture before the vertebral tuberculosis surgery.

The Left Atrio-Vertebral Ratio: a new simple means for assessing left atrial enlargement on Computed Tomography.

PubMed

Montillet, Marie; Baqué-Juston, Marie; Tasu, Jean-Pierre; Bertrand, Sandra; Berthier, Frédéric; Zarqane, Naïma; Brunner, Philippe

2018-03-01

The purpose of this study is to describe a new method to quickly estimate left atrial enlargement (LAE) on Computed Tomography. Left atrial (LA) volume was assessed with a 3D-threshold Hounsfield unit detection technique, including left atrial appendage and excluding pulmonary venous confluence, in 201 patients with ECG-gated 128-slice dual-source CT and indexed to body surface area. LA and vertebral axial diameter and area were measured at the bottom level of the right inferior pulmonary vein ostium. Ratio of LA diameter and surface on vertebra (LAVD and LAVA) were compared to LA volume. In accordance with the literature, a cutoff value of 78 ml/m 2 was chosen for maximal normal LA volume. 18% of LA was enlarged. The best cutoff values for LAE assessment were 2.5 for LAVD (AUC: 0.65; 95% CI: 0.58-0.73; sensitivity: 57%; specificity: 71%), and 3 for LAVA (AUC: 0.78; 95% CI: 0.72-0.84; sensitivity: 67%; specificity: 79%), with higher accuracy for LAVA (P=0.015). Inter-observer and intra-observer variability were either good or excellent for LAVD and LAVA (respective intraclass coefficients: 0.792 and 0.910; 0.912 and 0.937). A left atrium area superior to three times the vertebral area indicates LAE with high specificity. • Left atrial enlargement is a frequent condition associated with poor cardiac outcome. • Left atrial enlargement is highly time-consuming to diagnose on CT. • The left atrio-vertebral ratio quickly assesses left atrial enlargement. • A left atrial area > three times vertebral area is highly specific.

Morphological changes of the caudal cervical intervertebral foramina due to flexion-extension and compression-traction movements in the canine cervical vertebral column.

PubMed

Ramos, Renato M; da Costa, Ronaldo C; Oliveira, Andre L A; Kodigudla, Manoj K; Goel, Vijay K

2015-08-06

Previous studies in humans have reported that the dimensions of the intervertebral foramina change significantly with movement of the spine. Cervical spondylomyelopathy (CSM) in dogs is characterized by dynamic and static compressions of the neural components, leading to variable degrees of neurologic deficits and neck pain. Studies suggest that intervertebral foraminal stenosis has implications in the pathogenesis of CSM. The dimensions of the cervical intervertebral foramina may significantly change during neck movements. This could have implication in the pathogenesis of CSM and other diseases associated with radiculopathy such as intervertebral disc disease. The purpose of this study was to quantify the morphological changes in the intervertebral foramina of dogs during flexion, extension, traction, and compression of the canine cervical vertebral column. All vertebral columns were examined with magnetic resonance imaging prior to biomechanic testing. Eight normal vertebral columns were placed in Group 1 and eight vertebral columns with intervertebral disc degeneration or/and protrusion were assigned to Group 2. Molds of the left and right intervertebral foramina from C4-5, C5-6 and C6-7 were taken during all positions and loading modes. Molds were frozen and vertical (height) and horizontal (width) dimensions of the foramina were measured. Comparisons were made between neutral to flexion and extension, flexion to extension, and traction to compression in neutral position. Extension decreased all the foraminal dimensions significantly, whereas flexion increased all the foraminal dimensions significantly. Compression decreased all the foraminal dimensions significantly, and traction increased the foraminal height, but did not significantly change the foraminal width. No differences in measurements were seen between groups. Our results show movement-related changes in the dimensions of the intervertebral foramina, with significant foraminal narrowing in extension and compression.

A Symptomatic Case of Thoracic Vertebral Hemangioma Causing Lower Limb Spastic Paresis

PubMed Central

Alfawareh, Mohammad; Alotaibi, Tariq; Labeeb, Abdallah; Audat, Ziad

2016-01-01

Patient: Male, 18 Final Diagnosis: Hemangioma Symptoms: Pain • weaknes of lower limbs Medication: — Clinical Procedure: Decompression and fixation Specialty: Neurosurgery Objective: Unusual clinical course Background: Despite being the most common tumor of the spine, vertebral hemangioma is rarely symptomatic in adults. In fact, only 0.9–1.2% of all vertebral hemangiomas may be symptomatic. When hemangiomas occur in the thoracic vertebrae, they are more likely to be symptomatic due to the narrow vertebral canal dimensions that mandate more aggressive management prior to the onset of severe neurological sequelae. Case Report: An 18-year-old male presented to the emergency room with a one-month history of mild to moderate midthoracic back pain, radiating to both lower limbs. It was associated with both lower limb weakness and decreased sensation. There was no history of bowel or bladder incontinence. Neurological examination revealed lower limb weakness with power 3/5, exaggerated deep tendon reflexes, bilateral sustained clonus, impaired sensation below the umbilicus, spasticity, and a positive Babinski sign. A CT scan showed a diffuse body lesion at the 8th thoracic vertebra with coarse trabeculations, corduroy appearance, or jail-bar sign. The patient underwent decompression and fixation. Biopsy of permanent samples showed proliferation of blood vessels with dilated spaces and no malignant cells, consistent with hemangioma. Postoperatively, spasticity improved, and the patient regained normal power. Conclusions: Symptomatic vertebral hemangiomas are rare but should be considered as a differential diagnosis. They can present with severe neurological symptoms. When managed appropriately, patients regain full motor and sensory function. Decompression resulted in quick relief of symptoms, which was followed by an extensive rehabilitation program. PMID:27795545

Skeletal morphogenesis of the vertebral column of the miniature hylid frog Acris crepitans, with comments on anomalies.

PubMed

Pugener, L Analía; Maglia, Anne M

2009-01-01

Although the vertebral columns of anurans have received much study in the last 150 years, few detailed descriptions exist of the skeletal morphogenesis of this anatomical unit. Herein, the ontogeny of the vertebral skeleton of the hylid frog Acris crepitans is described based on cleared and double-stained specimens, radiographs, and 3D reconstructions generated from synchrotron microCT scans. The adult axial formula is 1-7-1-1, and the vertebral centra are epichordal and procoelous. The neural arches are nonimbricate, and there is a medial articulation between the laminae of Presacrals I and II. Free ribs are absent. The sacral diapophyses are uniform in width or slightly expanded distally. The urostyle is slender, round in cross section, and about equal in length to the presacral region. Presacral vertebrae are the first to form, developing in a cephalic-to-caudal sequence. However, development and growth are decoupled and growth is fastest initially in the posterior presacrals and sacrum. In addition, there is a time lag between the formation of the presacral/sacral region and the postsacral region. More than 8.5% of the specimens examined have vertebral anomalies, and about 50% display small variants from the typical vertebral column morphology. However, these malformations do not seem to have been so severe as to have affected survival. 2008 Wiley-Liss, Inc.

A sonographic approach to prenatal classification of congenital spine anomalies

PubMed Central

Robertson, Meiri; Sia, Sock Bee

2015-01-01

Abstract Objective: To develop a classification system for congenital spine anomalies detected by prenatal ultrasound. Methods: Data were collected from fetuses with spine abnormalities diagnosed in our institution over a five‐year period between June 2005 and June 2010. The ultrasound images were analysed to determine which features were associated with different congenital spine anomalies. Findings of the prenatal ultrasound images were correlated with other prenatal imaging, post mortem findings, post mortem imaging, neonatal imaging, karyotype, and other genetic workup. Data from published case reports of prenatal diagnosis of rare congenital spine anomalies were analysed to provide a comprehensive work. Results: During the study period, eighteen cases of spine abnormalities were diagnosed in 7819 women. The mean gestational age at diagnosis was 18.8w ± 2.2 SD. While most cases represented open NTD, a spectrum of vertebral abnormalities were diagnosed prenatally. These included hemivertebrae, block vertebrae, cleft or butterfly vertebrae, sacral agenesis, and a lipomeningocele. The most sensitive features for diagnosis of a spine abnormality included flaring of the vertebral arch ossification centres, abnormal spine curvature, and short spine length. While reported findings at the time of diagnosis were often conservative, retrospective analysis revealed good correlation with radiographic imaging. 3D imaging was found to be a valuable tool in many settings. Conclusions: Analysis of the study findings showed prenatal ultrasound allowed detection of disruption to the normal appearances of the fetal spine. Using the three features of flaring of the vertebral arch ossification centres, abnormal spine curvature, and short spine length, an algorithm was devised to aid with the diagnosis of spine anomalies for those who perform and report prenatal ultrasound. PMID:28191204

Spaceflight effects on biomechanical and biochemical properties of rat vertebrae

NASA Technical Reports Server (NTRS)

Zernicke, R. F.; Vailas, A. C.; Grindeland, R. E.; Kaplansky, A.; Salem, G. J.; Martinez, D. A.

1990-01-01

The biomechanical and biochemical responses of lumbar vertebral bodies during a 12.5-day spaceflight (Cosmos 1887 biosatellite) were determined for rapidly growing rats (90-day-old, Czechoslovakian-Wistar). By use of age-matched vivarium controls (normal cage environment) and synchronous controls (simulated flight conditions), as well as a basal control group (killed before lift-off on the 1st day of flight), the combined influences of growth and space-flight could be examined. Centra of the sixth lumbar vertebrae (L6) were compressed to 50% strain at a fast strain rate while immersed in physiological buffer (37 degrees C). The body masses of vivarium and synchronous controls were significantly heavier than either the flight or basal controls. The flight group had an L6 vertebral body compressional stiffness that was 39% less than the vivarium controls, 47% less than the synchronous control, and 16% less than the basal controls. In addition, the average initial maximum load of the flight L6 was 22% less than vivarium controls and 18% less than the synchronous controls, whereas the linear compressional load of the flight group averaged 34% less than the vivarium and 25% less than the synchronous groups. The structural properties of the vertebrae from the 12.5-day-younger basal group closely resembled the flight vertebrae. Calcium, phosphorous, and hydroxyproline concentrations were not significantly different among the groups. Nevertheless, the lack of strength and stiffness development in spaceflight, coupled with a smaller proportion of mature hydroxypyridinoline cross-links, suggested that the 12.5 days of spaceflight slowed the maturation of trabecular bone in the vertebral bodies of rapidly growing rats.

Spermatogonial Stem Cell Niche and Spermatogonial Stem Cell Transplantation in Zebrafish

PubMed Central

Nóbrega, Rafael Henrique; Greebe, Caaj Douwe; van de Kant, Henk; Bogerd, Jan; de França, Luiz Renato; Schulz, Rüdiger W.

2010-01-01

Background Spermatogonial stem cells (SSCs) are the foundation of spermatogenesis, and reside within a specific microenvironment in the testes called “niche” which regulates stem cell properties, such as, self-renewal, pluripotency, quiescence and their ability to differentiate. Methodology/Principal Findings Here, we introduce zebrafish as a new model for the study of SSCs in vertebrates. Using 5′-bromo-2′-deoxyuridine (BrdU), we identified long term BrdU-retaining germ cells, type A undifferentiated spermatogonia as putative stem cells in zebrafish testes. Similar to rodents, these cells were preferentially located near the interstitium, suggesting that the SSC niche is related to interstitial elements and might be conserved across vertebrates. This localization was also confirmed by analyzing the topographical distribution of type A undifferentiated spermatogonia in normal, vasa::egfp and fli::egfp zebrafish testes. In the latter one, the topographical arrangement suggested that the vasculature is important for the SSC niche, perhaps as a supplier of nutrients, oxygen and/or signaling molecules. We also developed an SSC transplantation technique for both male and female recipients as an assay to evaluate the presence, biological activity, and plasticity of the SSC candidates in zebrafish. Conclusions/Significance We demonstrated donor-derived spermato- and oogenesis in male and female recipients, respectively, indicating the stemness of type A undifferentiated spermatogonia and their plasticity when placed into an environment different from their original niche. Similar to other vertebrates, the transplantation efficiency was low. This might be attributed to the testicular microenvironment created after busulfan depletion in the recipients, which may have caused an imbalance between factors regulating self-renewal or differentiation of the transplanted SSCs. PMID:20862221

Aspergillus terreus infection of pseudoaneurysm of aortofemoral vascular graft with contiguous vertebral osteomyelitis.

PubMed

Glotzbach, R E

1982-02-01

This is a case report of a patient who developed several unusual complications of an aortofemoral vascular graft. These were thrombosis, pseudoaneurysm, and infection. There was an Aspergillus terreus infection of the pseudoaneurysm of the vascular prosthesis. A contiguous vertebral osteomyelitis due to A. terreus subsequently developed. This represented a localized, invasive form of aspergillosis.

Dynamic Viral Dissemination in Mice Infected with Yellow Fever Virus Strain 17D

PubMed Central

Erickson, Andrea K.

2013-01-01

Arboviruses such as yellow fever virus (YFV) are transmitted between arthropod vectors and vertebrate hosts. While barriers limiting arbovirus population diversity have been observed in mosquitoes, whether barriers exist in vertebrate hosts is unclear. To investigate whether arboviruses encounter bottlenecks during dissemination in the vertebrate host, we infected immunocompetent mice and immune-deficient mice lacking alpha/beta interferon (IFN-α/β) receptors (IFNAR−/− mice) with a pool of genetically marked viruses to evaluate dissemination and host barriers. We used the live attenuated vaccine strain YFV-17D, which contains many mutations compared with virulent YFV. We found that intramuscularly injected immunocompetent mice did not develop disease and that viral dissemination was restricted. Conversely, 32% of intramuscularly injected IFNAR−/− mice developed disease. By following the genetically marked viruses over time, we found broad dissemination in IFNAR−/− mice followed by clearance. The patterns of viral dissemination were similar in mice that developed disease and mice that did not develop disease. Unlike our previous results with poliovirus, these results suggest that YFV-17D encounters no major barriers during dissemination within a vertebrate host in the absence of the type I IFN response. PMID:24027319

Highly conserved elements discovered in vertebrates are present in non-syntenic loci of tunicates, act as enhancers and can be transcribed during development

PubMed Central

Sanges, Remo; Hadzhiev, Yavor; Gueroult-Bellone, Marion; Roure, Agnes; Ferg, Marco; Meola, Nicola; Amore, Gabriele; Basu, Swaraj; Brown, Euan R.; De Simone, Marco; Petrera, Francesca; Licastro, Danilo; Strähle, Uwe; Banfi, Sandro; Lemaire, Patrick; Birney, Ewan; Müller, Ferenc; Stupka, Elia

2013-01-01

Co-option of cis-regulatory modules has been suggested as a mechanism for the evolution of expression sites during development. However, the extent and mechanisms involved in mobilization of cis-regulatory modules remains elusive. To trace the history of non-coding elements, which may represent candidate ancestral cis-regulatory modules affirmed during chordate evolution, we have searched for conserved elements in tunicate and vertebrate (Olfactores) genomes. We identified, for the first time, 183 non-coding sequences that are highly conserved between the two groups. Our results show that all but one element are conserved in non-syntenic regions between vertebrate and tunicate genomes, while being syntenic among vertebrates. Nevertheless, in all the groups, they are significantly associated with transcription factors showing specific functions fundamental to animal development, such as multicellular organism development and sequence-specific DNA binding. The majority of these regions map onto ultraconserved elements and we demonstrate that they can act as functional enhancers within the organism of origin, as well as in cross-transgenesis experiments, and that they are transcribed in extant species of Olfactores. We refer to the elements as ‘Olfactores conserved non-coding elements’. PMID:23393190

Developmental evolutionary biology of the vertebrate ear: conserving mechanoelectric transduction and developmental pathways in diverging morphologies

NASA Technical Reports Server (NTRS)

Fritzsch, B.; Beisel, K. W.; Bermingham, N. A.

2000-01-01

This brief overview shows that a start has been made to molecularly dissect vertebrate ear development and its evolutionary conservation to the development of the insect hearing organ. However, neither the patterning process of the ear nor the patterning process of insect sensory organs is sufficiently known at the moment to provide more than a first glimpse. Moreover, hardly anything is known about otocyst development of the cephalopod molluscs, another triploblast lineage that evolved complex 'ears'. We hope that the apparent conserved functional and cellular components present in the ciliated sensory neurons/hair cells will also be found in the genes required for vertebrate ear and insect sensory organ morphogenesis (Fig. 3). Likewise, we expect that homologous pre-patterning genes will soon be identified for the non-sensory cell development, which is more than a blocking of neuronal development through the Delta/Notch signaling system. Generation of the apparently unique ear could thus represent a multiplication of non-sensory cells by asymmetric and symmetric divisions as well as modification of existing patterning process by implementing novel developmental modules. In the final analysis, the vertebrate ear may come about by increasing the level of gene interactions in an already existing and highly conserved interactive cascade of bHLH genes. Since this was apparently achieved in all three lineages of triploblasts independently (Fig. 3), we now need to understand how much of the morphogenetic cascades are equally conserved across phyla to generate complex ears. The existing mutations in humans and mice may be able to point the direction of future research to understand the development of specific cell types and morphologies in the formation of complex arthropod, cephalopod, and vertebrate 'ears'.

Anomalous Origin of the Right Vertebral Artery: Incidence and Significance.

PubMed

Maiti, Tanmoy Kumar; Konar, Subhas Kanti; Bir, Shyamal; Nanda, Anil; Cuellar, Hugo

2016-05-01

Detailed knowledge about anatomic variations of the aortic arch and its multiple branches is extremely important to endovascular and diagnostic radiologists. It is often hypothesized that anomalous origin and distribution of large aortic vessels may alter the cerebral hemodynamics and potentially lead to a vascular pathology. In this article, we describe a case of anomalous origin of the right vertebral artery, which was detected during an intervention. We further reviewed the available literature of anomalous origin of the right vertebral artery. The probable embryologic development and clinical significance are discussed. The incidence of anomalous origin of a vertebral artery seems to be underestimated in recent literature. A careful review of the literature shows more than 100 such cases. The right vertebral artery can arise from the aortic arch or one of its branches. Dual origin of the vertebral artery is not uncommon. The embryologic developmental hypotheses are contradictory and complex. Anomalous origin of the right vertebral artery may not be the sole reason behind a disease process. However, it can certainly lead to a misdiagnosis during diagnostic vascular studies. Detailed information is essential for any surgery or endovascular intervention in this location. Copyright © 2015 Elsevier Inc. All rights reserved.

VERTEBRAL DYSPLASIA IN YOUNG FISH EXPOSED TO THE HERBICIDE TRIFLURALIN

EPA Science Inventory

Sheepshead minnows, Cyprinodon variegatus Lacepede, exposed to 5-5 to 31 micrograms/l of the herbicide trifluralin, throughout their first 28 days of life, developed a heretofore, undescribed vertebral dysplasia. This dysplasia consisted of semisymmetrical hypertrophy of vertebra...

Vertebral Development in Paleozoic and Mesozoic Tetrapods Revealed by Paleohistological Data

PubMed Central

Danto, Marylène; Witzmann, Florian; Fröbisch, Nadia B.

2016-01-01

Basal tetrapods display a wide spectrum of vertebral centrum morphologies that can be used to distinguish different tetrapod groups. The vertebral types range from multipartite centra in stem-tetrapods, temnospondyls, and seymouriamorphs up to monospondylous centra in lepospondyls and have been drawn upon for reconstructing major evolutionary trends in tetrapods that are now considered textbook knowledge. Two modes of vertebral formation have been postulated: the multipartite vertebrae formed first as cartilaginous elements with subsequent ossification. The monospondylous centrum, in contrast, was formed by direct ossification without a cartilaginous precursor. This study describes centrum morphogenesis in basal tetrapods for the first time, based on bone histology. Our results show that the intercentra of the investigated stem-tetrapods consist of a small band of periosteal bone and a dense network of endochondral bone. In stereospondyl temnospondyls, high amounts of calcified cartilage are preserved in the endochondral trabeculae. Notably, the periosteal region is thickened and highly vascularized in the plagiosaurid stereospondyls. Among “microsaur” lepospondyls, the thickened periosteal region is composed of compact bone and the notochordal canal is surrounded by large cell lacunae. In nectridean lepospondyls, the periosteal region has a spongy structure with large intertrabecular spaces, whereas the endochondral region has a highly cancellous structure. Our observations indicate that regardless of whether multipartite or monospondylous, the centra of basal tetrapods display first endochondral and subsequently periosteal ossification. A high interspecific variability is observed in growth rate, organization, and initiation of periosteal ossification. Moreover, vertebral development and structure reflect different lifestyles. The bottom-dwelling Plagiosauridae increase their skeletal mass by hyperplasy of the periosteal region. In nectrideans, the skeletal mass decreases, as the microstructure is spongy and lightly built. Additionally, we observed that vertebral structure is influenced by miniaturization in some groups. The phylogenetic information that can be drawn from vertebral development, however, is limited. PMID:27074015

Single olfactory organ associated with prosencephalic malformation and cyclopia in a Xenopus laevis tadpole.

PubMed

Magrassi, L; Graziadei, P P

1987-06-02

A cyclops Xenopus laevis tadpole with a single olfactory organ is described. At a stage comparable to 48, the telencephalon was severely atrophic and only the region where the olfactory fibres terminated appeared to have the cytoarchitecture of the olfactory bulb. In this animal the central nervous system (CNS) appeared normally developed only posterior to the preoptic area. The hypothesis of a diencephalic origin of the region where the olfactory fibres terminated is discussed in the light of our previous results of olfactory placode transplantation. By analogy between this case and other malformations (cyclopia, holoprosencephaly) in higher vertebrates and humans, the need is emphasized for a more precise anatomical description of the olfactory input in related malformations.

Evidence that the notochord may be pivotal in the development of sacral and anorectal malformations.

PubMed

Qi, Bao Quan; Beasley, Spencer W; Frizelle, Francis A

2003-09-01

The notochord is known to organize normal development of central axial structures, such as the spinal cord, vertebral column, and anorectum, but its role in abnormal development of these organs has not been well documented. The current study has used Ethylenethiourea to induce anorectal malformations in fetal rats, allowing investigation of abnormalities of the notochord and their relationship to the axial structural abnormalities that occur. Timed-mated pregnant rats were fed Ethylenethiourea by gavage on gestational day 10. Their embryos were harvested on gestational days 13 to 16 and sectioned in either the transverse or sagittal plane. Sections were stained with H and E and examined serially. Anorectal malformations were identified in 29 of 34 embryos and neural tube defects in 24, ranging from an accessory neural tube to lumbo-sacral rachischisis. There was no tail or only a rudimentary tail in the majority of embryos. Abnormalities of the notochord in the lumbo-sacral area included ventro-dorsal branching, ventral deviation, and ectopic notochordal tissue. Most abnormal notochord branches and ectopic notochordal tissue were abnormally close to or in contact with the wall of the cloaca or neural tube. Given the known role of the notochord in controlling normal development, this study would suggest that abnormal notochord development may be pivotal in producing neural tube defects and anorectal malformations, possibly by altering sonic hedgehog signalling.

[Study of incidence of osteoporotic fractures in a cohort of individuals older than 50 years from Asturias, Spain, after a 6 year follow-up period].

PubMed

Naves Díaz, M; Díaz López, J B; Gómez Alonso, C; Altadill Arregui, A; Rodríguez Rebollar, A; Cannata Andía, J B

2000-11-18

The present work, performed as follow-up of the prevalence study of vertebral fractures (EVOS Study), evaluates in a 6 year period the incidence of vertebral fractures and other osteoporotic fractures in Oviedo (Asturias, Spain) in people older than 50 years. The study was performed in a cohort from the Oviedo's local registry in 1986. 624 men and women were followed by 3 postal questionnaires. The first questionnaire referred to the history of falls and fractures that happened during the follow-up period performed. Between the 2nd and 3rd follow-up subjects were invited to repeat the X-rays previously performed in the initial study. The incidence of osteoporotic fractures was higher in women than in men. In both sexes, vertebral fracture was the one which reached the highest incidence. Compared with men, Colles' fracture in women occurred earlier, with 5 times higher incidence. The incidence of hip fracture was twice higher in women than in men. A prevalent vertebral fractures increased until 5 times the incidence of vertebral and hip fracture. Among the osteoporotic fractures, vertebral fracture had a highest incidence values in both sexes. Although vertebral and hip fractures were twice incident in women compared with men, the incidence of Colles fracture was five times higher in women. A pre-existing vertebral fracture is an important risk factor to develop a new vertebral or hip fracture.

Evolution of the new vertebrate head by co-option of an ancient chordate skeletal tissue.

PubMed

Jandzik, David; Garnett, Aaron T; Square, Tyler A; Cattell, Maria V; Yu, Jr-Kai; Medeiros, Daniel M

2015-02-26

A defining feature of vertebrates (craniates) is a pronounced head that is supported and protected by a robust cellular endoskeleton. In the first vertebrates, this skeleton probably consisted of collagenous cellular cartilage, which forms the embryonic skeleton of all vertebrates and the adult skeleton of modern jawless and cartilaginous fish. In the head, most cellular cartilage is derived from a migratory cell population called the neural crest, which arises from the edges of the central nervous system. Because collagenous cellular cartilage and neural crest cells have not been described in invertebrates, the appearance of cellular cartilage derived from neural crest cells is considered a turning point in vertebrate evolution. Here we show that a tissue with many of the defining features of vertebrate cellular cartilage transiently forms in the larvae of the invertebrate chordate Branchiostoma floridae (Florida amphioxus). We also present evidence that during evolution, a key regulator of vertebrate cartilage development, SoxE, gained new cis-regulatory sequences that subsequently directed its novel expression in neural crest cells. Together, these results suggest that the origin of the vertebrate head skeleton did not depend on the evolution of a new skeletal tissue, as is commonly thought, but on the spread of this tissue throughout the head. We further propose that the evolution of cis-regulatory elements near an ancient regulator of cartilage differentiation was a major factor in the evolution of the vertebrate head skeleton.

Zebrafish pit1 mutants lack three pituitary cell types and develop severe dwarfism.

PubMed

Nica, Gabriela; Herzog, Wiebke; Sonntag, Carmen; Hammerschmidt, Matthias

2004-05-01

The Pou domain transcription factor Pit-1 is required for lineage determination and cellular commitment processes during mammalian adenohypophysis development. Here we report the cloning and mutational analysis of a pit1 homolog from zebrafish. Compared with mouse, zebrafish pit1 starts to be expressed at a much earlier stage of adenohypophysis development. However, as in the mouse, expression is restricted to a subset of pituitary cell types, excluding proopiomelanocortin (pomc)-expressing cells (corticotropes, melanotropes) and possibly gonadotropes. We could identify two N-ethyl-N-nitrosourea-induced zebrafish pit1 null mutants. Most mutants die during larval stages, whereas survivors develop severe dwarfism. Mutant larvae lack lactotropes, somatotropes, and thyrotropes, although the adenohypophysis is of normal size, without any sign of increased apoptosis rates. Instead, mutant embryos initiate ectopic expression of pomc in pit1-positive cells, leading to an expansion of the Pomc lineage. Similarly, the number of gonadotropes seems increased, as indicated by the expression of gsualpha, a marker for thyrotropes and gonadotropes. In pit1 mutants, the total number of gsualpha-positive cells is normal despite the loss of gsualpha and tshbeta coexpressing cells. Together, these data suggest a transfating of the Pit1 lineage to the Pomc and possibly the gonadotroph lineages in the mutant, and a pomc- and gonadotropin-repressive role of Pit1 during normal zebrafish development. This is different from mouse, for which a repressive role of Pit-1 has only been reported for the gonadotropin Lhbeta, but not for Pomc. In sum, our data point to both conserved and class-specific aspects of Pit1 function during pituitary development in different vertebrate species.

Case studies of spinal deformities in ornamental koi, Cyprinus carpio L.

PubMed

Chin, H N; Loh, R; Hong, Y C; Gibson-Kueh, S

2017-01-01

This is a study of vertebral deformities in ornamental koi based on computed radiography and skeletons cleaned by dermestid beetles (Dermestes maculatus). All koi developed gradual onset of swimming abnormalities as adults. Extensive intervertebral osteophyte formation correlated with age of fish and was associated with hindquarter paresis in one koi. Vertebral compression and fusion were the most common spinal deformities occurring at multiple sites, similar to findings in other farmed fish. Site-specific spinal deformities were thought to develop due to differences in swimming behaviour and rates of vertebral growth. One koi had offspring with spinal deformities. Spinal deformities are significant problems in both European and Australian food fish hatcheries. The heritability of vertebral deformities in farmed fish is reportedly low unless there is concurrent poor husbandry or nutritional deficiencies. The specific aetiologies for vertebral deformities in koi in this study could not be ascertained. Current knowledge on spinal deformities in the better studied European food fish species suggests multifactorial aetiologies. Future research should include prospective longitudinal studies of larger numbers of koi from hatch and consideration of all potential risk factors such as husbandry, nutrition, temperature, photoperiod and genetics. © 2016 John Wiley & Sons Ltd.

Late development of hagfish vertebral elements.

PubMed

Ota, Kinya G; Fujimoto, Satoko; Oisi, Yasuhiro; Kuratani, Shigeru

2013-05-01

It has been demonstrated recently that hagfishes, one of two groups of extant jawless vertebrates, have cartilaginous vertebral elements. Embryological and gene expression analyses have also shown that this group of animals develops a sclerotome, the potential primordium of the axial skeleton. However, it has not been shown unequivocally that the hagfish sclerotome truly differentiates into cartilage, because access to late-stage embryos and information about the cartilaginous extracellular matrix (ECM) are lacking for these animals. Here we investigated the expression patterns of the biglycan/decorin (BGN/DCN) gene in the inshore hagfish, Eptatretus burgeri. The homologue of this gene encodes the major noncollagenous component of the cartilaginous ECM among gnathostomes. We clearly identified the expression of this gene in adult vertebral tissues and in embryonic mesenchymal cells on the ventral aspect of the notochord. Taking into account that the sclerotome in the gnathostomes expresses BGN/DCN gene during the chondrogenesis, it is highly expected the hagfish BGN/DCN-positive mesenchymal cells are derived from the sclerotomes. We propose that hagfishes and gnathostomes share conserved developmental mechanisms not only in their somite differentiation, but also in chondrogenesis of their vertebral elements. Copyright © 2013 Wiley Periodicals, Inc.

An Ancient Gene Network Is Co-opted for Teeth on Old and New Jaws

PubMed Central

Fraser, Gareth J; Hulsey, C. Darrin; Bloomquist, Ryan F; Uyesugi, Kristine; Manley, Nancy R; Streelman, J. Todd

2009-01-01

Vertebrate dentitions originated in the posterior pharynx of jawless fishes more than half a billion years ago. As gnathostomes (jawed vertebrates) evolved, teeth developed on oral jaws and helped to establish the dominance of this lineage on land and in the sea. The advent of oral jaws was facilitated, in part, by absence of hox gene expression in the first, most anterior, pharyngeal arch. Much later in evolutionary time, teleost fishes evolved a novel toothed jaw in the pharynx, the location of the first vertebrate teeth. To examine the evolutionary modularity of dentitions, we asked whether oral and pharyngeal teeth develop using common or independent gene regulatory pathways. First, we showed that tooth number is correlated on oral and pharyngeal jaws across species of cichlid fishes from Lake Malawi (East Africa), suggestive of common regulatory mechanisms for tooth initiation. Surprisingly, we found that cichlid pharyngeal dentitions develop in a region of dense hox gene expression. Thus, regulation of tooth number is conserved, despite distinct developmental environments of oral and pharyngeal jaws; pharyngeal jaws occupy hox-positive, endodermal sites, and oral jaws develop in hox-negative regions with ectodermal cell contributions. Next, we studied the expression of a dental gene network for tooth initiation, most genes of which are similarly deployed across the two disparate jaw sites. This collection of genes includes members of the ectodysplasin pathway, eda and edar, expressed identically during the patterning of oral and pharyngeal teeth. Taken together, these data suggest that pharyngeal teeth of jawless vertebrates utilized an ancient gene network before the origin of oral jaws, oral teeth, and ectodermal appendages. The first vertebrate dentition likely appeared in a hox-positive, endodermal environment and expressed a genetic program including ectodysplasin pathway genes. This ancient regulatory circuit was co-opted and modified for teeth in oral jaws of the first jawed vertebrate, and subsequently deployed as jaws enveloped teeth on novel pharyngeal jaws. Our data highlight an amazing modularity of jaws and teeth as they coevolved during the history of vertebrates. We exploit this diversity to infer a core dental gene network, common to the first tooth and all of its descendants. PMID:19215146

Evolutionary biology of plant defenses against herbivory and their predictive implications for endocrine disruptor susceptibility in vertebrates.

PubMed Central

Wynne-Edwards, K E

2001-01-01

Hormone disruption is a major, underappreciated component of the plant chemical arsenal, and the historical coevolution between hormone-disrupting plants and herbivores will have both increased the susceptibility of carnivores and diversified the sensitivities of herbivores to man-made endocrine disruptors. Here I review diverse evidence of the influence of plant secondary compounds on vertebrate reproduction, including human reproduction. Three of the testable hypotheses about the evolutionary responses of vertebrate herbivores to hormone-disrupting challenges from their diet are developed. Specifically, the hypotheses are that a) vertebrate herbivores will express steroid hormone receptors in the buccal cavity and/or the vomeronasal organ; b) absolute sex steroid concentrations will be lower in carnivores than in herbivores; and c) herbivore steroid receptors should be more diverse in their binding affinities than carnivore lineages. The argument developed in this review, if empirically validated by support for the specific hypotheses, suggests that a) carnivores will be more susceptible than herbivores to endocrine-disrupting compounds of anthropogenic origin entering their bodies, and b) diverse herbivore lineages will be variably susceptible to any given natural or synthetic contaminant. As screening methods for hormone-disrupting potential are compared and adopted, comparative endocrine physiology research is urgently needed to develop models that predict the broad applicability of those screening results in diverse vertebrate species. PMID:11401754

The APC/C Ubiquitin Ligase: From Cell Biology to Tumorigenesis

PubMed Central

Penas, Clara; Ramachandran, Vimal; Ayad, Nagi George

2011-01-01

The ubiquitin proteasome system (UPS) is required for normal cell proliferation, vertebrate development, and cancer cell transformation. The UPS consists of multiple proteins that work in concert to target a protein for degradation via the 26S proteasome. Chains of an 8.5-kDa protein called ubiquitin are attached to substrates, thus allowing recognition by the 26S proteasome. Enzymes called ubiquitin ligases or E3s mediate specific attachment to substrates. Although there are over 600 different ubiquitin ligases, the Skp1–Cullin–F-box (SCF) complexes and the anaphase promoting complex/cyclosome (APC/C) are the most studied. SCF involvement in cancer has been known for some time while APC/C’s cancer role has recently emerged. In this review we will discuss the importance of APC/C to normal cell proliferation and development, underscoring its possible contribution to transformation. We will also examine the hypothesis that modulating a specific interaction of the APC/C may be therapeutically attractive in specific cancer subtypes. Finally, given that the APC/C pathway is relatively new as a cancer target, therapeutic interventions affecting APC/C activity may be beneficial in cancers that are resistant to classical chemotherapy. PMID:22655255

Automated quantification of lumbar vertebral kinematics from dynamic fluoroscopic sequences

NASA Astrophysics Data System (ADS)

Camp, Jon; Zhao, Kristin; Morel, Etienne; White, Dan; Magnuson, Dixon; Gay, Ralph; An, Kai-Nan; Robb, Richard

2009-02-01

We hypothesize that the vertebra-to-vertebra patterns of spinal flexion and extension motion of persons with lower back pain will differ from those of persons who are pain-free. Thus, it is our goal to measure the motion of individual lumbar vertebrae noninvasively from dynamic fluoroscopic sequences. Two-dimensional normalized mutual information-based image registration was used to track frame-to-frame motion. Software was developed that required the operator to identify each vertebra on the first frame of the sequence using a four-point "caliper" placed at the posterior and anterior edges of the inferior and superior end plates of the target vertebrae. The program then resolved the individual motions of each vertebra independently throughout the entire sequence. To validate the technique, 6 cadaveric lumbar spine specimens were potted in polymethylmethacrylate and instrumented with optoelectric sensors. The specimens were then placed in a custom dynamic spine simulator and moved through flexion-extension cycles while kinematic data and fluoroscopic sequences were simultaneously acquired. We found strong correlation between the absolute flexionextension range of motion of each vertebra as recorded by the optoelectric system and as determined from the fluoroscopic sequence via registration. We conclude that this method is a viable way of noninvasively assessing twodimensional vertebral motion.

Congenital cervical kyphosis in two young sighthounds.

PubMed

Forterre, F; Casoni, D; Tomek, A; Karli, P; Howard, J; Precht, C

2015-01-01

Cervical vertebral (C) malformation is rarely reported in large breed dogs. Congenital cervical kyphosis (CCK) may result from defects of vertebral segmentation, failure of formation or both. This report describes two cases of C3-C4 CCK in young sighthounds, treated surgically. An 18-month-old female Deerhound and a six-week-old female Borzoi dog were presented because of the complaints of reluctance to exercise and signs of of neck pain. Both dogs were neurologically normal. Diagnostic imaging revealed C3-C4 deformity, moderate kyphosis, and spinal canal stenosis associated with chronic spinal cord pressure atrophy. Both dogs underwent surgical treatment. A staged two-step surgery starting with dorsal decompression was elected in the Deerhound. After the first surgical procedure, the dog developed focal myelomalacia and phrenic nerve paralysis and was euthanatized. A ventral distraction-fusion technique with two locking plates was performed in the Borzoi. This patient recovered uneventfully and long-term follow-up computed tomography revealed complete spondylodesis. Until now, CCK has only been described in sighthounds. Congenital cervical kyphosis might be considered a differential diagnosis in these breeds that are presented with signs of cervical pain. Ventral realignment-fusion and bone grafting may be considered for surgical treatment, although the earliest age at which this procedure can and should be performed remains unclear.

Tonic and Phasic Receptor Neurons in the Vertebrate Olfactory Epithelium

PubMed Central

Madrid, Rodolfo; Sanhueza, Magdalena; Alvarez, Osvaldo; Bacigalupo, Juan

2003-01-01

Olfactory receptor neurons (ORNs) respond to odorants with characteristic patterns of action potentials that are relevant for odor coding. Prolonged odorant exposures revealed three populations of dissociated toad ORNs, which were mimicked by depolarizing currents: tonic (TN, displaying sustained firing, 49% of 102 cells), phasic (PN, exhibiting brief action potential trains, 36%) and intermediate neurons (IN, generating trains longer than PN, 15%). We studied the biophysical properties underlying the differences between TNs and PNs, the most extreme cases among ORNs. TNs and PNs possessed similar membrane capacitances (∼4 pF), but they differed in resting potential (−82 versus −64 mV), input resistance (4.2 versus 2.9 GΩ) and unspecific current, Iu (TNs: 0 < Iu ≤ 1 pA/pF; and PNs: Iu > 1 pA/pF). Firing behavior did not correlate with differences in voltage-gated conductances. We developed a mathematical model that accurately simulates tonic and phasic patterns. Whole cell recordings from rat ORNs in fragments (∼4 mm2) of olfactory epithelium showed that such a tissue normally contains tonic and phasic receptor neurons, suggesting that this feature is common across a wide range of vertebrates. Our findings show that the individual passive electrical properties can govern the firing patterns of ORNs. PMID:12770919

Gap Junctional Communication in Morphogenesis

PubMed Central

Levin, Michael

2007-01-01

Gap junctions permit the direct passage of small molecules from the cytosol of one cell to that of its neighbor, and thus form a system of cell-cell communication that exists alongside familiar secretion/receptor signaling. Because of the rich potential for regulation of junctional conductance, and directional and molecular gating (specificity), gap junctional communication (GJC) plays a crucial role in many aspects of normal tissue physiology. However, the most exciting role for GJC is in the regulation of information flow that takes place during embryonic development, regeneration, and tumor progression. The molecular mechanisms by which GJC establishes local and long-range instructive morphogenetic cues are just beginning to be understood. This review summarizes the current knowledge of the involvement of GJC in the patterning of both vertebrate and invertebrate systems and discusses in detail several morphogenetic systems in which the properties of this signaling have been molecularly characterized. One model consistent with existing data in the fields of vertebrate left-right patterning and anterior-posterior polarity in flatworm regeneration postulates electrophoretically-guided movement of small molecule morphogens through long-range GJC paths. The discovery of mechanisms controlling embryonic and regenerative GJC-mediated signaling, and identification of the downstream targets of GJC-permeable molecules, represent exciting next areas of research in this fascinating field. PMID:17481700

Oligodendrocyte ablation affects the coordinated interaction between granule and Purkinje neurons during cerebellum development

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

Collin, Ludovic; Doretto, Sandrine; Department of Psychiatry and Human Behavior, University of California Irvine, 3226 Gillespie Neuroscience Research Facility, Irvine CA 92697

2007-08-01

Oligodendrocytes (OLs) are the glial cells of the central nervous system (CNS) classically known to be devoted to the formation of myelin sheaths around most axons of the vertebrate brain. We have addressed the role of these cells during cerebellar development, by ablating OLs in vivo. Previous analyses had indicated that OL ablation during the first six postnatal days results into a striking cerebellar phenotype, whose major features are a strong reduction of granule neurons and aberrant Purkinje cells development. These two cell types are highly interconnected during cerebellar development through the production of molecules that help their proliferation, differentiationmore » and maintenance. In this article, we present data showing that OL ablation has major effects on the physiology of Purkinje (PC) and granule cells (GC). In particular, OL ablation results into a reduction of sonic hedgehog (Shh), Brain Derived Neurotrophic Factor (BDNF), and Reelin (Rln) expression. These results indicate that absence of OLs profoundly alters the normal cerebellar developmental program.« less

Fibroblast growth factor receptor signaling is essential for lens fiber cell differentiation.

PubMed

Zhao, Haotian; Yang, Tianyu; Madakashira, Bhavani P; Thiels, Cornelius A; Bechtle, Chad A; Garcia, Claudia M; Zhang, Huiming; Yu, Kai; Ornitz, David M; Beebe, David C; Robinson, Michael L

2008-06-15

The vertebrate lens provides an excellent model to study the mechanisms that regulate terminal differentiation. Although fibroblast growth factors (FGFs) are thought to be important for lens cell differentiation, it is unclear which FGF receptors mediate these processes during different stages of lens development. Deletion of three FGF receptors (Fgfr1-3) early in lens development demonstrated that expression of only a single allele of Fgfr2 or Fgfr3 was sufficient for grossly normal lens development, while mice possessing only a single Fgfr1 allele developed cataracts and microphthalmia. Profound defects were observed in lenses lacking all three Fgfrs. These included lack of fiber cell elongation, abnormal proliferation in prospective lens fiber cells, reduced expression of the cell cycle inhibitors p27(kip1) and p57(kip2), increased apoptosis and aberrant or reduced expression of Prox1, Pax6, c-Maf, E-cadherin and alpha-, beta- and gamma-crystallins. Therefore, while signaling by FGF receptors is essential for lens fiber differentiation, different FGF receptors function redundantly.

Ensembl genomes 2016: more genomes, more complexity

USDA-ARS?s Scientific Manuscript database

Ensembl Genomes (http://www.ensemblgenomes.org) is an integrating resource for genome-scale data from non-vertebrate species, complementing the resources for vertebrate genomics developed in the context of the Ensembl project (http://www.ensembl.org). Together, the two resources provide a consistent...

Zebrafish blowout provides genetic evidence for Patched1-mediated negative regulation of Hedgehog signaling within the proximal optic vesicle of the vertebrate eye.

PubMed

Lee, Jiwoon; Willer, Jason R; Willer, Gregory B; Smith, Kierann; Gregg, Ronald G; Gross, Jeffrey M

2008-07-01

In this study, we have characterized the ocular defects in the recessive zebrafish mutant blowout that presents with a variably penetrant coloboma phenotype. blowout mutants develop unilateral or bilateral colobomas and as a result, the retina and retinal pigmented epithelium are not contained within the optic cup. Colobomas result from defects in optic stalk morphogenesis whereby the optic stalk extends into the retina and impedes the lateral edges of the choroid fissure from meeting and fusing. The expression domain of the proximal optic vesicle marker pax2a is expanded in blowout at the expense of the distal optic vesicle marker pax6, suggesting that the initial patterning of the optic vesicle into proximal and distal territories is disrupted in blowout. Later aspects of distal optic cup formation (i.e. retina development) are normal in blowout mutants, however. Positional cloning of blowout identified a nonsense mutation in patched1, a negative regulator of the Hedgehog pathway, as the underlying cause of the blowout phenotype. Expanded domains of expression of the Hedgehog target genes patched1 and patched2 were observed in blowout, consistent with a loss of Patched1 function and upregulation of Hedgehog pathway activity. Moreover, colobomas in blowout could be suppressed by pharmacologically inhibiting the Hedgehog pathway with cyclopamine, and maximal rescue occurred when embryos were exposed to cyclopamine between 5.5 and 13 hours post-fertilization. These observations highlight the critical role that Hedgehog pathway activity plays in mediating patterning of the proximal/distal axis of the optic vesicle during the early phases of eye development and they provide genetic confirmation for the integral role that patched1-mediated negative regulation of Hedgehog signaling plays during vertebrate eye development.

Zebrafish blowout provides genetic evidence for Patched1 mediated negative regulation of Hedgehog signaling within the proximal optic vesicle of the vertebrate eye

PubMed Central

Lee, Jiwoon; Willer, Jason R.; Willer, Gregory B.; Smith, Kierann; Gregg, Ronald G.; Gross, Jeffrey M.

2008-01-01

In this study we have characterized the ocular defects in the recessive zebrafish mutant blowout that presents with a variably penetrant coloboma phenotype. blowout mutants develop unilateral or bilateral colobomas and as a result, the retina and retinal pigmented epithelium are not contained within the optic cup. Colobomas result from defects in optic stalk morphogenesis whereby the optic stalk extends into the retina and impedes the lateral edges of the choroid fissure from meeting and fusing. The expression domain of the proximal optic vesicle marker pax2a is expanded in blowout at the expense of the distal optic vesicle marker pax6, suggesting that the initial patterning of the optic vesicle into proximal and distal territories is disrupted in blowout. Later aspects of distal optic cup formation (i.e. retina development) are normal in blowout mutants, however. Positional cloning of blowout identified a nonsense mutation in patched1, a negative regulator of the Hedgehog pathway, as the underlying cause of the blowout phenotype. Expanded domains of expression of the Hedgehog target genes patched1 and patched2 were observed in blowout, consistent with a loss of Patched1 function and upregulation of Hedgehog pathway activity. Moreover, colobomas in blowout could be suppressed by pharmacologically inhibiting the Hedgehog pathway with cyclopamine, and maximal rescue occurred when embryos were exposed to cyclopamine between 5.5 and 13 hours post fertilization. These observations highlight the critical role that Hedgehog pathway activity plays in mediating patterning of the proximal/distal axis of the optic vesicle during the early phases of eye development and they provide genetic confirmation for the integral role that patched1-mediated negative regulation of Hedgehog signaling plays during vertebrate eye development. PMID:18479681

Perchlorate disrupts embryonic androgen synthesis and reproductive development in threespine stickleback without changing whole-body levels of thyroid hormone

PubMed Central

Petersen, Ann M.; Dillon, Danielle; Bernhardt, Richard A.; Torunsky, Roberta; Postlethwait, John H.; von Hippel, Frank A.; Buck, C. Loren; Cresko, William A.

2014-01-01

Perchlorate, an environmental contaminant, disrupts normal functioning of the thyroid. We previously showed that perchlorate disrupts behavior and gonad development, and induces external morphological changes in a vertebrate model organism, the threespine stickleback. Whether perchlorate alters these phenotypes via a thyroid-mediated mechanism, and the extent to which the effects depend on dose, are unknown. To address these questions, we chronically exposed stickleback to control conditions and to three concentrations of perchlorate (10, 30 and 100 ppm) at various developmental stages from fertilization to reproductive maturity. Adults chronically exposed to perchlorate had increased numbers of thyroid follicles and decreased numbers of thyrocytes. Surprisingly, T4 and T3 levels in larval, juvenile, and adult whole fish chronically exposed to perchlorate did not differ from controls, except at the lowest perchlorate dose, suggesting a non-monotonic dose response curve. We found no detectable abnormalities in external phenotype at any dose of perchlorate, indicating that the increased number of thyroid follicles compensated for the disruptive effects of these doses. In contrast to external morphology, gonadal development was altered substantially, with the highest dose of perchlorate causing the largest effects. Perchlorate increased the number both of early stage ovarian follicles in females and of advanced spermatogenic stages in males. Perchlorate also disrupted embryonic androgen levels. We conclude that chronic perchlorate exposure may not result in lasting adult gross morphological changes but can produce lasting modifications to gonads when compensation of T3 and T4 levels occurs by thyroid follicle hyperplasia. Perchlorate may therefore affect vertebrate development via both thyroidal and non-thyroidal mechanisms. PMID:25448260

HuD and the Survival Motor Neuron Protein Interact in Motoneurons and Are Essential for Motoneuron Development, Function, and mRNA Regulation.

PubMed

Hao le, Thi; Duy, Phan Q; An, Min; Talbot, Jared; Iyer, Chitra C; Wolman, Marc; Beattie, Christine E

2017-11-29

Motoneurons establish a critical link between the CNS and muscles. If motoneurons do not develop correctly, they cannot form the required connections, resulting in movement defects or paralysis. Compromised development can also lead to degeneration because the motoneuron is not set up to function properly. Little is known, however, regarding the mechanisms that control vertebrate motoneuron development, particularly the later stages of axon branch and dendrite formation. The motoneuron disease spinal muscular atrophy (SMA) is caused by low levels of the survival motor neuron (SMN) protein leading to defects in vertebrate motoneuron development and synapse formation. Here we show using zebrafish as a model system that SMN interacts with the RNA binding protein (RBP) HuD in motoneurons in vivo during formation of axonal branches and dendrites. To determine the function of HuD in motoneurons, we generated zebrafish HuD mutants and found that they exhibited decreased motor axon branches, dramatically fewer dendrites, and movement defects. These same phenotypes are present in animals expressing low levels of SMN, indicating that both proteins function in motoneuron development. HuD binds and transports mRNAs and one of its target mRNAs, Gap43 , is involved in axonal outgrowth. We found that Gap43 was decreased in both HuD and SMN mutants. Importantly, transgenic expression of HuD in motoneurons of SMN mutants rescued the motoneuron defects, the movement defects, and Gap43 mRNA levels. These data support that the interaction between SMN and HuD is critical for motoneuron development and point to a role for RBPs in SMA. SIGNIFICANCE STATEMENT In zebrafish models of the motoneuron disease spinal muscular atrophy (SMA), motor axons fail to form the normal extent of axonal branches and dendrites leading to decreased motor function. SMA is caused by low levels of the survival motor neuron (SMN) protein. We show in motoneurons in vivo that SMN interacts with the RNA binding protein, HuD. Novel mutants reveal that HuD is also necessary for motor axonal branch and dendrite formation. Data also revealed that both SMN and HuD affect levels of an mRNA involved in axonal growth. Moreover, expressing HuD in SMN-deficient motoneurons can rescue the motoneuron development and motor defects caused by low levels of SMN. These data support that SMN:HuD complexes are essential for normal motoneuron development and indicate that mRNA handling is a critical component of SMA. Copyright © 2017 the authors 0270-6474/17/3711559-13$15.00/0.

Cytodifferentiation of hair cells during the development of a basal chordate.

PubMed

Gasparini, Fabio; Caicci, Federico; Rigon, Francesca; Zaniolo, Giovanna; Burighel, Paolo; Manni, Lucia

2013-10-01

Tunicates are unique animals for studying the origin and evolution of vertebrates because they are considered vertebrates' closest living relatives and share the vertebrate body plan and many specific features. Both possess neural placodes, transient thickenings of the cranial ectoderm that give rise to various types of sensory cells, including axonless secondary mechanoreceptors. In vertebrates, these are represented by the hair cells of the inner ear and the lateral line, which have an apical apparatus typically bearing cilia and stereovilli. In tunicates, they are found in the coronal organ, which is a mechanoreceptor located at the base of the oral siphon along the border of the velum and tentacles and is formed of cells bearing a row of cilia and short microvilli. The coronal organ represents the best candidate homolog for the vertebrate lateral line. To further understand the evolution of secondary sensory cells, we analysed the development and cytodifferentiation of coronal cells in the tunicate ascidian Ciona intestinalis for the first time. Here, coronal sensory cells can be identified as early as larval metamorphosis, before tentacles form, as cells with short cilia and microvilli. Sensory cells gradually differentiate, acquiring hair cell features with microvilli containing actin and myosin VIIa; in the meantime, the associated supporting cells develop. The coronal organ grows throughout the animal's lifespan, accompanying the growth of the tentacle crown. Anti-phospho Histone H3 immunostaining indicates that both hair cells and supporting cells can proliferate. This finding contributes to the understanding of the evolution of secondary sensory cells, suggesting that both ancestral cell types were able to proliferate and that this property was progressively restricted to supporting cells in vertebrates and definitively lost in mammals. Copyright © 2013 Elsevier B.V. All rights reserved.

Does Subjective Sleep Affect Bone Mineral Density in Older People with Minimal Health Disorders? The PROOF Cohort.

PubMed

Saint Martin, Magali; Labeix, Pierre; Garet, Martin; Thomas, Thierry; Barthélémy, Jean-Claude; Collet, Philippe; Roche, Frédéric; Sforza, Emilia

2016-11-15

Clinical and epidemiological studies suggest a relation between bone mineral density (BMD) and self-assessment of sleep with an effect on bone formation and osteoporosis (OS) risk in short and long sleepers. This study explores this association in a large sample of older subjects. We examined 500 participants without insomnia complaints aged 65.7 ± 0.8 y. Each participant had a full evaluation including anthropometric measurement, clinical examination and measurements of BMD at the lumbar spine and femoral sites by dual-energy X-ray absorptiometry. The daily energy expenditure (DEE) was measured by the Population Physical Activity Questionnaire. Sleep duration and quality were evaluated by the Pittsburgh Sleep Quality Index. The subjects were stratified into three groups according to sleep duration, i.e., short (< 6 h), normal (6-8 h), and long (≥ 8 h) sleepers. Osteopenia was found in 40% of the subjects at the femoral level and 43% at the vertebral level. The prevalence of OS was lower both at femoral (8%) and vertebral (12%) levels. Short, normal, and long sleepers accounted for 29%, 40%, and 31% of subjects, respectively. After adjustments for metabolic, anthropometric, and DEE, multinomial logistic regression analysis indicated that long sleepers were more likely to have femoral neck OS with a slight effect of DEE at vertebral spine. In a sample of older subjects, self-reported long sleep was the best predictor of OS risk at the femoral level. This finding suggests an association between OS and self-reported sleep duration in older subjects. NCT 00759304 and NCT 00766584. © 2016 American Academy of Sleep Medicine

Use of cervical vertebral dimensions for assessment of children growth.

PubMed

Caldas, Maria de Paula; Ambrosano, Gláucia Maria Bovi; Haiter-Neto, Francisco

2007-04-01

The purpose of this study was to investigate whether skeletal maturation using cephalometric radiographs could be used in a Brazilian population. The study population was selected from the files of the Oral Radiological Clinic of the Dental School of Piracicaba, Brazil and consisted of 128 girls and 110 boys (7.0 to 15.9 years old) who had cephalometric and hand-wrist radiographs taken on the same day. Cervical vertebral bone age was evaluated using the method described by Mito and colleagues in 2002. Bone age was assessed by the Tanner-Whitehouse (TW3) method and was used as a gold standard to determine the reliability of cervical vertebral bone age. An analysis of variance and Tukey's post-hoc test were used to compare cervical vertebral bone age, bone age and chronological age at 5% significance level. The analysis of the Brazilian female children data showed that there was a statistically significant difference (p<0.05) between cervical vertebral bone age and chronological age and between bone age and chronological age. However no statistically significant difference (p>0.05) was found between cervical vertebral bone age and bone age. Differently, the analysis of the male children data revealed a statistically significant difference (p<0.05) between cervical vertebral bone age and bone age and between cervical vertebral bone age and chronological age (p<0.05). The findings of the present study suggest that the method for objectively evaluating skeletal maturation on cephalometric radiographs by determination of vertebral bone age can be applied to Brazilian females only. The development of a new method to objectively evaluate cervical vertebral bone age in males is needed.

Risk of Vertebral Fracture in Patients Diagnosed with a Depressive Disorder: A Nationwide Population-Based Cohort Study

PubMed Central

Lee, Shyh-Chyang; Hu, Li-Yu; Huang, Min-Wei; Shen, Cheng-Che; Huang, Wei-Lun; Lu, Ti; Hsu, Chiao-Lin; Pan, Chih-Chuan

2017-01-01

OBJECTIVE: Previous studies have reported that depression may play a crucial role in the occurrence of vertebral fractures. However, a clear correlation between depressive disorders and osteoporotic fractures has not been established. We explored the association between depressive disorders and subsequent new-onset vertebral fractures. Additionally, we aimed to identify the potential risk factors for vertebral fracture in patients with a depressive disorder. METHODS: We studied patients listed in the Taiwan National Health Insurance Research Database who were diagnosed with a depressive disorder by a psychiatrist. The comparison cohort consisted of age- and sex-matched patients without a depressive disorder. The incidence rate and hazard ratios of subsequent vertebral fracture were evaluated. We used Cox regression analysis to evaluate the risk of vertebral fracture among patients with a depressive disorder. RESULTS: The total number of patients with and without a depressive disorder was 44,812. The incidence risk ratio (IRR) between these 2 cohorts indicated that depressive disorder patients had a higher risk of developing a subsequent vertebral fracture (IRR=1.41, 95% confidence interval [CI]=1.26–1.57, p<0.001). In the multivariate analysis, the depressive disorder cohort showed a higher risk of vertebral fracture than the comparison cohort (adjusted hazard ratio=1.24, 95% CI=1.11–1.38, p<0.001). Being older than 50 years, having a lower monthly income, and having hypertension, diabetes mellitus, cerebrovascular disease, chronic obstructive pulmonary disease, autoimmune disease, or osteoporosis were considered predictive factors for vertebral fracture in patients with depressive disorders. CONCLUSIONS: Depressive disorders may increase the risk of a subsequent new-onset vertebral fracture. PMID:28226032

Risk of Vertebral Fracture in Patients Diagnosed with a Depressive Disorder: A Nationwide Population-Based Cohort Study.

PubMed

Lee, Shyh-Chyang; Hu, Li-Yu; Huang, Min-Wei; Shen, Cheng-Che; Huang, Wei-Lun; Lu, Ti; Hsu, Chiao-Lin; Pan, Chih-Chuan

2017-01-01

Previous studies have reported that depression may play a crucial role in the occurrence of vertebral fractures. However, a clear correlation between depressive disorders and osteoporotic fractures has not been established. We explored the association between depressive disorders and subsequent new-onset vertebral fractures. Additionally, we aimed to identify the potential risk factors for vertebral fracture in patients with a depressive disorder. We studied patients listed in the Taiwan National Health Insurance Research Database who were diagnosed with a depressive disorder by a psychiatrist. The comparison cohort consisted of age- and sex-matched patients without a depressive disorder. The incidence rate and hazard ratios of subsequent vertebral fracture were evaluated. We used Cox regression analysis to evaluate the risk of vertebral fracture among patients with a depressive disorder. The total number of patients with and without a depressive disorder was 44,812. The incidence risk ratio (IRR) between these 2 cohorts indicated that depressive disorder patients had a higher risk of developing a subsequent vertebral fracture (IRR=1.41, 95% confidence interval [CI]=1.26-1.57, p<0.001). In the multivariate analysis, the depressive disorder cohort showed a higher risk of vertebral fracture than the comparison cohort (adjusted hazard ratio=1.24, 95% CI=1.11-1.38, p<0.001). Being older than 50 years, having a lower monthly income, and having hypertension, diabetes mellitus, cerebrovascular disease, chronic obstructive pulmonary disease, autoimmune disease, or osteoporosis were considered predictive factors for vertebral fracture in patients with depressive disorders. Depressive disorders may increase the risk of a subsequent new-onset vertebral fracture.

Environmental contaminant exposure data and monitoring priorities for wild terrestrial vertebrates at national parks in coastal and estuarine habitat

USGS Publications Warehouse

Rattner, B.A.; Ackerson, B.K.; Eisenreich, K.M.; McKernan, M.A.; Harmon, David

2006-01-01

The Biomonitoring of Environmental Status and Trends (BEST) Project of the U.S. Geological Survey (USGS) assesses the exposure and effects of environmental contaminants on select species and habitats in the United States. One of the many BEST Project activities entails the development of decision-support tools to assist in the identification of chemical threats to species and lands under the stewardship of the Department of the Interior. Although there are many ecotoxicological monitoring programs that focus on aquatic species and habitats, there are currently no large-scale efforts that are focused on terrestrial vertebrates in the United States. Nonetheless, organochlorine contaminants, metals, and new pollutants continue to pose hazards to terrestrial vertebrates at many spatial scales (ranging from small hazardous-waste-site point sources to entire watersheds). To evaluate and prioritize pollutant hazards for terrestrial vertebrates, a ?Contaminant Exposure and EffectsTerrestrial Vertebrates? (CEE-TV) database (www.pwrc.usgs.gov/contaminants-online) was developed. The CEE-TV database has been used to conduct simple searches for exposure and biological effects information for a given species or location, identification of temporal contaminant exposure trends, information gap analyses for national wildlife refuge and national park units, and ranking of terrestrial vertebrate ecotoxicological information needs based on data density and water quality problems. Despite widespread concerns about environmental contamination, during the past decade only about one-half of the coastal National Park units appear to have terrestrial vertebrate ecotoxicological data. Based upon known environmental contaminant hazards, it is recommended that regionalized monitoring programs or efforts focused on lands managed by the Department of the Interior should be undertaken to prevent serious natural resource problems.

C1-C2 instability with severe occipital headache in the setting of vertebral artery facet complex erosion.

PubMed

Taher, Fadi; Bokums, Kristaps; Aichmair, Alexander; Hughes, Alexander P

2014-05-01

An exact understanding of patient vertebral artery anatomy is essential to safely place screws at the atlanto-axial level in posterior arthrodesis. We aim to report a case of erosion of the left vertebral artery into the C1-C2 facet complex with resultant rotatory and lateral listhesis presenting with severe occipital headache. This represents a novel etiology for this diagnosis and our report illustrates technical considerations when instrumenting the C1-C2 segment. We report a case of severe occipital headache due to C1-C2 instability with resultant left C2 nerve compression in the setting of erosion of the vertebral artery into the C1-C2 facet complex. A 68-year-old woman presented with a 12-month history of progressively debilitating headache and neck pain with atlanto-axial instability. Computed tomography (CT) angiography demonstrated erosion of the left vertebral artery into the left C1-C2 facet complex. In addition, the tortuous vertebral arteries had eroded into the C2 pedicles, eliminating the possibility for posterior pedicle screw placement. The patient underwent posterior arthrodesis of C1-C2 utilizing bilateral lateral mass fixation into C1 and bilateral trans-laminar fixation into C2 with resolution of all preoperative complaints. This study constitutes the first report of a tortuous vertebral artery causing the partial destruction of a C1-C2 facet complex, as well as instability, with the clinical presentation of severe occipital headache. It hereby presents a novel etiology for both the development of C1-C2 segment instability as well as the development of occipital headache. Careful evaluation of such lesions utilizing CT angiography is important when formulating a surgical plan.

Origin of the vertebrate body plan via mechanically biased conservation of regular geometrical patterns in the structure of the blastula.

PubMed

Edelman, David B; McMenamin, Mark; Sheesley, Peter; Pivar, Stuart

2016-09-01

We present a plausible account of the origin of the archetypal vertebrate bauplan. We offer a theoretical reconstruction of the geometrically regular structure of the blastula resulting from the sequential subdivision of the egg, followed by mechanical deformations of the blastula in subsequent stages of gastrulation. We suggest that the formation of the vertebrate bauplan during development, as well as fixation of its variants over the course of evolution, have been constrained and guided by global mechanical biases. Arguably, the role of such biases in directing morphology-though all but neglected in previous accounts of both development and macroevolution-is critical to any substantive explanation for the origin of the archetypal vertebrate bauplan. We surmise that the blastula inherently preserves the underlying geometry of the cuboidal array of eight cells produced by the first three cleavages that ultimately define the medial-lateral, dorsal-ventral, and anterior-posterior axes of the future body plan. Through graphical depictions, we demonstrate the formation of principal structures of the vertebrate body via mechanical deformation of predictable geometrical patterns during gastrulation. The descriptive rigor of our model is supported through comparisons with previous characterizations of the embryonic and adult vertebrate bauplane. Though speculative, the model addresses the poignant absence in the literature of any plausible account of the origin of vertebrate morphology. A robust solution to the problem of morphogenesis-currently an elusive goal-will only emerge from consideration of both top-down (e.g., the mechanical constraints and geometric properties considered here) and bottom-up (e.g., molecular and mechano-chemical) influences. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Hox genes and chordate evolution.

PubMed

Holland, P W; Garcia-Fernàndez, J

1996-02-01

Hox genes are implicated in the control of axial patterning during embryonic development of many, perhaps all, animals. Here we review recent data on Hox gene diversity, genomic organization, and embryonic expression in chordates (including tunicates, amphioxus, hagfish, lampreys, teleosts) plus their putative sister group, the hemichordates. We consider the potential of comparative Hox gene data to resolve some outstanding controversies in chordate phylogeny. The use of Hox gene expression patterns to identify homologies between body plans both within the vertebrates and between the chordate subphyla is also discussed. Homology between the vertebrate hindbrain and an extensive region of amphioxus neural tube is suggested by comparison of Hox-3 homologues and strengthened by new data on amphioxus Hox-1 gene expression reported here. Finally, we give two examples of how Hox genes are giving glimpses into chordate developmental evolution. The first relates changes in Hox gene expression to transposition of vertebral of vertebral identities; the second describes a correlation between vertebrate origins and Hox gene cluster duplication. We suggest that the simultaneous duplication of many classes of genes, often interacting in gene networks, allowed the elaboration of new developmental control mechanisms at vertebrate origins.

Developmental mechanisms of intervertebral disc and vertebral column formation.

PubMed

Lawson, Lisa Y; Harfe, Brian D

2017-11-01

The vertebral column consists of repeating units of ossified vertebrae that are adjoined by fibrocartilagenous intervertebral discs. These structures form from the embryonic notochord and somitic mesoderm. In humans, congenital malformations of the vertebral column include scoliosis, kyphosis, spina bifida, and Klippel Feil syndrome. In adulthood, a common malady affecting the vertebral column includes disc degeneration and associated back pain. Indeed, recent reports estimate that low back pain is the number one cause of disability worldwide. Our review provides an overview of the molecular mechanisms underlying vertebral column morphogenesis and intervertebral disc development and maintenance, with an emphasis on what has been gleaned from recent genetic studies in mice. The aim of this review is to provide a developmental framework through which vertebral column formation can be understood so that ultimately, research scientists and clinicians alike can restore disc health with appropriately designed gene and cell-based therapies. WIREs Dev Biol 2017, 6:e283. doi: 10.1002/wdev.283 For further resources related to this article, please visit the WIREs website. © 2017 Wiley Periodicals, Inc.

REPRODUCTIVE AND DEVELOPMENTAL EFFECTS OF CONTAMINANTS IN OVIPAROUS VERTEBRATES: WORKSHOP SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS

EPA Science Inventory

Oviparous vertebrates generally occupy important niches in aquatic as well as terrestrial systems, and reproductive and developmental effects on these species can be of relatively great ecological significance. Because these organisms have critical windows of development, they ma...

Ensembl Genomes 2013: scaling up access to genome-wide data

USDA-ARS?s Scientific Manuscript database

Ensembl Genomes (http://www.ensemblgenomes.org) is an integrating resource for genome-scale data from non-vertebrate species. The project exploits and extends technologies for genome annotation, analysis and dissemination, developed in the context of the vertebrate-focused Ensembl project, and provi...

A median third eye: pineal gland retraces evolution of vertebrate photoreceptive organs.

PubMed

Mano, Hiroaki; Fukada, Yoshitaka

2007-01-01

In many vertebrates, the pineal gland serves as a photoreceptive neuroendocrine organ. Morphological and functional similarities between the pineal and retinal photoreceptor cells indicate their close evolutionary relationship, and hence the comparative studies on the pineal gland and the retina are the keys to deciphering the evolutionary traces of the vertebrate photoreceptive organs. Several studies have suggested common genetic and molecular mechanisms responsible for their similarities, but largely unknown are those underlying pineal-specific development and physiological functions. Recent studies have identified several cis-acting DNA elements that participate in transcriptional control of the pineal-specific genes. Genetic approaches in the zebrafish have also contributed to elucidating the genetic network regulating the pineal development and neurogenesis. These efforts toward elucidating the molecular instrumentation intrinsic to the pineal gland, back to back with those to the retina, should lead to a comprehensive understanding of the evolutionary history of the vertebrate photoreceptive structures. This article summarizes the current status of research on these topics.

The vertebrates from the Lower Ladinian (Middle Triassic) bonebed of Lamerden (Germany) as palaeoenvironment indicators in the Germanic Basin

NASA Astrophysics Data System (ADS)

Diedrich, Cajus G.

2015-11-01

A marine/limnic vertebrate fauna is described from the enodis/posseckeri Bonebed mixed in a bivalve shell-rich bioclastic carbonate rudstone at the eastern coastal margin of the Rhenish Massif mainland at Lamerden (Germany) within the western Germanic Basin (Central Europe). The condensation layer is of Fassanian (Ladinian, Middle Triassic) in age. The vertebrate biodiversity includes five different shark, and several actinopterygian fish species represented by teeth and scales. Abundant isolated bones from a small- and a large-sized pachypleurosaur Neusticosaurus species, which can be composed as incomplete skeletons, originate from dense populations of different individual age stages. Important facies indicator reptiles are from the thalattosaur Blezingeria ichthyospondyla which postcranial skeleton is reconstructed hypothetically using additional postcranial bones from similar aged various German localities. The vertebrate biodiversity of the enodis/posseckeri bonebed of Lamerden reflect a limnic/fluvial freshwater influenced fauna (amphibians/terrestrial and marine reptiles) with dominance of normal saline marine influences. Macroalgae meadow adapted placodont reptiles are absent in Lamerden, as well as open marine-adapted ichthyosaurs, supporting a lagoon with fresh water influence position at the Rhenish Massif mainland coast. In those contemporanous brackish lagoons, which seem to be isochronous to northern Tethys lagoons of the Kalschieferzone at the Monte San Giorgio (Switzerland/Italy), small pachypleurosaurs were abundant prey in both regions for reptile predators, especially large paraxial swimming alligator habitus-like Paranothosaurus, which even contain stomach contents of pachypleurosaurs.

Development and assessment of a digital X-ray software tool to determine vertebral rotation in adolescent idiopathic scoliosis.

PubMed

Eijgenraam, Susanne M; Boselie, Toon F M; Sieben, Judith M; Bastiaenen, Caroline H G; Willems, Paul C; Arts, Jacobus J; Lataster, Arno

2017-02-01

The amount of vertebral rotation in the axial plane is of key importance in the prognosis and treatment of adolescent idiopathic scoliosis (AIS). Current methods to determine vertebral rotation are either designed for use in analogue plain radiographs and not useful in digital images, or lack measurement precision and are therefore less suitable for the follow-up of rotation in AIS patients. This study aimed to develop a digital X-ray software tool with high measurement precision to determine vertebral rotation in AIS, and to assess its (concurrent) validity and reliability. In this study a combination of basic science and reliability methodology applied in both laboratory and clinical settings was used. Software was developed using the algorithm of the Perdriolle torsion meter for analogue AP plain radiographs of the spine. Software was then assessed for (1) concurrent validity and (2) intra- and interobserver reliability. Plain radiographs of both human cadaver vertebrae and outpatient AIS patients were used. Concurrent validity was measured by two independent observers, both experienced in the assessment of plain radiographs. Reliability-measurements were performed by three independent spine surgeons. Pearson correlation of the software compared with the analogue Perdriolle torsion meter for mid-thoracic vertebrae was 0.98, for low-thoracic vertebrae 0.97 and for lumbar vertebrae 0.97. Measurement exactness of the software was within 5° in 62% of cases and within 10° in 97% of cases. Intraclass correlation coefficient (ICC) for inter-observer reliability was 0.92 (0.91-0.95), ICC for intra-observer reliability was 0.96 (0.94-0.97). We developed a digital X-ray software tool to determine vertebral rotation in AIS with a substantial concurrent validity and reliability, which may be useful for the follow-up of vertebral rotation in AIS patients. Copyright © 2015 Elsevier Inc. All rights reserved.

Left-right asymmetry and cardiac looping: implications for cardiac development and congenital heart disease.

PubMed

Kathiriya, I S; Srivastava, D

2000-01-01

Proper morphogenesis and positioning of internal organs requires delivery and interpretation of precise signals along the anterior-posterior, dorsal-ventral, and left-right axes. An elegant signaling cascade determines left- versus right-sided identity in visceral organs in a concordant fashion, resulting in a predictable left-right (LR) organ asymmetry in all vertebrates. The complex morphogenesis of the heart and its connections to the vasculature are particularly dependent upon coordinated LR signaling pathways. Disorganization of LR signals can result in myriad congenital heart defects that are a consequence of abnormal looping and remodeling of the primitive heart tube into a multi-chambered organ. A framework for understanding how LR asymmetric signals contribute to normal organogenesis has emerged and begins to explain the basis of many human diseases of LR asymmetry. Here we review the impact of LR signaling pathways on cardiac development and congenital heart disease.

The large Maf factor Traffic Jam controls gonad morphogenesis in Drosophila.

PubMed

Li, Michelle A; Alls, Jeffrey D; Avancini, Rita M; Koo, Karen; Godt, Dorothea

2003-11-01

Interactions between somatic and germline cells are critical for the normal development of egg and sperm. Here we show that the gene traffic jam (tj) produces a soma-specific factor that controls gonad morphogenesis and is required for female and male fertility. tj encodes the only large Maf factor in Drosophila melanogaster, an orthologue of the atypical basic Leu zipper transcription factors c-Maf and MafB/Kreisler in vertebrates. Expression of tj occurs in somatic gonadal cells that are in direct contact with germline cells throughout development. In tj mutant gonads, somatic cells fail to inter-mingle and properly envelop germline cells, causing an early block in germ cell differentiation. In addition, tj mutant somatic cells show an increase in the level of expression for several adhesion molecules. We propose that tj is a critical modulator of the adhesive properties of somatic cells, facilitating germline-soma interactions that are essential for germ cell differentiation.

"Serpentine-like syndrome"-A very rare multiple malformation syndrome characterised by brachioesophagus and vertebral anomalies.

PubMed

Beleza-Meireles, Ana; Steenhaut, Patricia; Hocq, Catheline; Clapuyt, Philippe; Bernard, Pierre; Debauche, Christian; Sznajer, Yves

2017-02-01

"Serpentine-like syndrome" is a severe and rare association of multiple congenital malformations, characterised by brachioesophagus, secondary intrathoracic stomach, and vertebral anomalies. Other associated anomalies have been described, such as malposition and herniation of abdominal organs. We report the natural history of a baby girl born at 29 weeks of gestation with intra uterine growth restriction, short neck, large rachischisis from cervical to thoracic spine, a very short oesophagus, thoracic stomach associated with a midline diaphragmatic hernia, malrotated gut and median cleft lip. Most of these anomalies were detected antenatally. Molecular karyotype was normal. She died at age 12 days. To our knowledge, the present patient represents the 8th report of a case of "Serpentine-like syndrome". Brachioesophagus and congenital vertebral anomalies, in particular rachischisis, are the cardinal features of this condition. All reported cases have been sporadic and the cause is still unknown. We believe that the specificity of the presentation as well as the similarities between available descriptions of patients suggests a common, yet to identify, molecular cause, possibly involving a developmental "toolkit"/homeobox gene or related pathways. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Case report: Teriparatide treatment in a case of severe pregnancy -and lactation- associated osteoporosis.

PubMed

Lampropoulou-Adamidou, Kalliopi; Trovas, George; Stathopoulos, Ioannis P; Papaioannou, Nikolaos A

2012-01-01

Pregnancy- and lactation-associated osteoporosis (PLO) is an uncommon disease. The majority of cases are seen in the third trimester or early post-partum in primagravid women and the prominent clinical feature of PLO is severe and prolonged back pain and height loss. The prevalence and aetiology of this disorder are as yet unclear and there are no guidelines for its treatment. We report the outcomes of teriparatide (TRP) treatment in a woman suffering from severe PLO with 6 vertebral fragility fractures, severe back pain and very low BMD. Thirteen months after the initiation of therapy, the patient was almost free of back pain. There was no new clinical vertebral fracture. Her laboratory tests were all normal. BMD increased by 24.4% at the lumbar spine, 9.9% and 4.6% at the left and the right total hip and 12.6% and 7.8% at the left and right femur neck, respectively. TRP treatment simultaneously with weaning and calcium and vitamin D supplementation seems to considerably increase BMD, improve severe back pain and quality of life and prevent further occurrence of vertebral fractures, making TRP a helpful tool in restoring bone strength in PLO patients.

The behavior of larval zebrafish reveals stressor-mediated anorexia during early vertebrate development.

PubMed

De Marco, Rodrigo J; Groneberg, Antonia H; Yeh, Chen-Min; Treviño, Mario; Ryu, Soojin

2014-01-01

The relationship between stress and food consumption has been well documented in adults but less so in developing vertebrates. Here we demonstrate that an encounter with a stressor can suppress food consumption in larval zebrafish. Furthermore, we provide indication that food intake suppression cannot be accounted for by changes in locomotion, oxygen consumption and visual responses, as they remain unaffected after exposure to a potent stressor. We also show that feeding reoccurs when basal levels of cortisol (stress hormone in humans and teleosts) are re-established. The results present evidence that the onset of stress can switch off the drive for feeding very early in vertebrate development, and add a novel endpoint for analyses of metabolic and behavioral disorders in an organism suitable for high-throughput genetics and non-invasive brain imaging.

The loss and recovery of vertebrate vision examined in microplates.

PubMed

Thorn, Robert J; Clift, Danielle E; Ojo, Oladele; Colwill, Ruth M; Creton, Robbert

2017-01-01

Regenerative medicine offers potentially ground-breaking treatments of blindness and low vision. However, as new methodologies are developed, a critical question will need to be addressed: how do we monitor in vivo for functional success? In the present study, we developed novel behavioral assays to examine vision in a vertebrate model system. In the assays, zebrafish larvae are imaged in multiwell or multilane plates while various red, green, blue, yellow or cyan objects are presented to the larvae on a computer screen. The assays were used to examine a loss of vision at 4 or 5 days post-fertilization and a gradual recovery of vision in subsequent days. The developed assays are the first to measure the loss and recovery of vertebrate vision in microplates and provide an efficient platform to evaluate novel treatments of visual impairment.

The behavior of larval zebrafish reveals stressor-mediated anorexia during early vertebrate development

PubMed Central

De Marco, Rodrigo J.; Groneberg, Antonia H.; Yeh, Chen-Min; Treviño, Mario; Ryu, Soojin

2014-01-01

The relationship between stress and food consumption has been well documented in adults but less so in developing vertebrates. Here we demonstrate that an encounter with a stressor can suppress food consumption in larval zebrafish. Furthermore, we provide indication that food intake suppression cannot be accounted for by changes in locomotion, oxygen consumption and visual responses, as they remain unaffected after exposure to a potent stressor. We also show that feeding reoccurs when basal levels of cortisol (stress hormone in humans and teleosts) are re-established. The results present evidence that the onset of stress can switch off the drive for feeding very early in vertebrate development, and add a novel endpoint for analyses of metabolic and behavioral disorders in an organism suitable for high-throughput genetics and non-invasive brain imaging. PMID:25368561

Detection of degenerative change in lateral projection cervical spine x-ray images

NASA Astrophysics Data System (ADS)

Jebri, Beyrem; Phillips, Michael; Knapp, Karen; Appelboam, Andy; Reuben, Adam; Slabaugh, Greg

2015-03-01

Degenerative changes to the cervical spine can be accompanied by neck pain, which can result from narrowing of the intervertebral disc space and growth of osteophytes. In a lateral x-ray image of the cervical spine, degenerative changes are characterized by vertebral bodies that have indistinct boundaries and limited spacing between vertebrae. In this paper, we present a machine learning approach to detect and localize degenerative changes in lateral x-ray images of the cervical spine. Starting from a user-supplied set of points in the center of each vertebral body, we fit a central spline, from which a region of interest is extracted and image features are computed. A Random Forest classifier labels regions as degenerative change or normal. Leave-one-out cross-validation studies performed on a dataset of 103 patients demonstrates performance of above 95% accuracy.

Pigmented anatomy in Carboniferous cyclostomes and the evolution of the vertebrate eye.

PubMed

Gabbott, Sarah E; Donoghue, Philip C J; Sansom, Robert S; Vinther, Jakob; Dolocan, Andrei; Purnell, Mark A

2016-08-17

The success of vertebrates is linked to the evolution of a camera-style eye and sophisticated visual system. In the absence of useful data from fossils, scenarios for evolutionary assembly of the vertebrate eye have been based necessarily on evidence from development, molecular genetics and comparative anatomy in living vertebrates. Unfortunately, steps in the transition from a light-sensitive 'eye spot' in invertebrate chordates to an image-forming camera-style eye in jawed vertebrates are constrained only by hagfish and lampreys (cyclostomes), which are interpreted to reflect either an intermediate or degenerate condition. Here, we report-based on evidence of size, shape, preservation mode and localized occurrence-the presence of melanosomes (pigment-bearing organelles) in fossil cyclostome eyes. Time of flight secondary ion mass spectrometry analyses reveal secondary ions with a relative intensity characteristic of melanin as revealed through principal components analyses. Our data support the hypotheses that extant hagfish eyes are degenerate, not rudimentary, that cyclostomes are monophyletic, and that the ancestral vertebrate had a functional visual system. We also demonstrate integument pigmentation in fossil lampreys, opening up the exciting possibility of investigating colour patterning in Palaeozoic vertebrates. The examples we report add to the record of melanosome preservation in Carboniferous fossils and attest to surprising durability of melanosomes and biomolecular melanin. © 2016 The Authors.

Pigmented anatomy in Carboniferous cyclostomes and the evolution of the vertebrate eye

PubMed Central

Gabbott, Sarah E.; Sansom, Robert S.; Vinther, Jakob; Dolocan, Andrei; Purnell, Mark A.

2016-01-01

The success of vertebrates is linked to the evolution of a camera-style eye and sophisticated visual system. In the absence of useful data from fossils, scenarios for evolutionary assembly of the vertebrate eye have been based necessarily on evidence from development, molecular genetics and comparative anatomy in living vertebrates. Unfortunately, steps in the transition from a light-sensitive ‘eye spot’ in invertebrate chordates to an image-forming camera-style eye in jawed vertebrates are constrained only by hagfish and lampreys (cyclostomes), which are interpreted to reflect either an intermediate or degenerate condition. Here, we report—based on evidence of size, shape, preservation mode and localized occurrence—the presence of melanosomes (pigment-bearing organelles) in fossil cyclostome eyes. Time of flight secondary ion mass spectrometry analyses reveal secondary ions with a relative intensity characteristic of melanin as revealed through principal components analyses. Our data support the hypotheses that extant hagfish eyes are degenerate, not rudimentary, that cyclostomes are monophyletic, and that the ancestral vertebrate had a functional visual system. We also demonstrate integument pigmentation in fossil lampreys, opening up the exciting possibility of investigating colour patterning in Palaeozoic vertebrates. The examples we report add to the record of melanosome preservation in Carboniferous fossils and attest to surprising durability of melanosomes and biomolecular melanin. PMID:27488650

Treatment Challenges of a Primary Vertebral Artery Aneurysm Causing Recurrent Ischemic Strokes.

PubMed

Strambo, Davide; Peruzzotti-Jametti, Luca; Semerano, Aurora; Fanelli, Giovanna; Simionato, Franco; Chiesa, Roberto; Rinaldi, Enrico; Martinelli, Vittorio; Comi, Giancarlo; Bacigaluppi, Marco; Sessa, Maria

2017-01-01

Background . Extracranial vertebral artery aneurysms are a rare cause of embolic stroke; surgical and endovascular therapy options are debated and long-term complication may occur. Case Report . A 53-year-old man affected by neurofibromatosis type 1 (NF1) came to our attention for recurrent vertebrobasilar embolic strokes, caused by a primary giant, partially thrombosed, fusiform aneurysm of the left extracranial vertebral artery. The aneurysm was treated by endovascular approach through deposition of Guglielmi Detachable Coils in the proximal segment of the left vertebral artery. Six years later the patient presented stroke recurrence. Cerebral angiography and Color Doppler Ultrasound well characterized the unique hemodynamic condition developed over the years responsible for the new embolic event: the aneurysm had been revascularized from its distal portion by reverse blood flow coming from the patent vertebrobasilar axis. A biphasic Doppler signal in the left vertebral artery revealed a peculiar behavior of the blood flow, alternately directed to the aneurysm and backwards to the basilar artery. Surgical ligation of the distal left vertebral artery and excision of the aneurysm were thus performed. Conclusion . This is the first described case of NF1-associated extracranial vertebral artery aneurysm presenting with recurrent embolic stroke. Complete exclusion of the aneurysm from the blood circulation is advisable to achieve full resolution of the embolic source.

Selection of reference genes for microRNA analysis associated to early stress response to handling and confinement in Salmo salar.

PubMed

Zavala, Eduardo; Reyes, Daniela; Deerenberg, Robert; Vidal, Rodrigo

2017-05-11

MicroRNAs are key non-coding RNA molecules that play a relevant role in the regulation of gene expression through translational repression and/or transcript cleavage during normal development and physiological adaptation processes like stress. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) has become the approach normally used to determine the levels of microRNAs. However, this approach needs the use of endogenous reference. An improper selection of endogenous references can result in confusing interpretation of data. The aim of this study was to identify and validate appropriate endogenous reference miRNA genes for normalizing RT-qPCR survey of miRNAs expression in four different tissues of Atlantic salmon, under handling and confinement stress conditions associated to early or primary stress response. Nine candidate reference normalizers, including microRNAs and nuclear genes, normally used in vertebrate microRNA expression studies were selected from literature, validated by RT-qPCR and analyzed by the algorithms geNorm and NormFinder. The results revealed that the ssa-miR-99-5p gene was the most stable overall and that ssa-miR-99-5p and ssa-miR-23a-5p genes were the best combination. Moreover, the suitability of ssa-miR-99-5p and ssa-miR-23a-5p as endogeneuos reference genes was demostrated by the expression analysis of ssa-miR-193-5p gene.

Research information needs on terrestrial vertebrate species of the interior Columbia basin and northern portions of the Klamath and Great Basins: a research, development, and application database.

Treesearch

Bruce G. Marcot

1997-01-01

Research information needs on selected invertebrates and all vertebrates of the interior Columbia River basin and adjacent areas in the United States were collected into a research, development, and application database as part of the Interior Columbia Basin Ecosystem Management Project. The database includes 482 potential research study topics on 232 individual...

The notochord: structure and functions.

PubMed

Corallo, Diana; Trapani, Valeria; Bonaldo, Paolo

2015-08-01

The notochord is an embryonic midline structure common to all members of the phylum Chordata, providing both mechanical and signaling cues to the developing embryo. In vertebrates, the notochord arises from the dorsal organizer and it is critical for proper vertebrate development. This evolutionary conserved structure located at the developing midline defines the primitive axis of embryos and represents the structural element essential for locomotion. Besides its primary structural function, the notochord is also a source of developmental signals that patterns surrounding tissues. Among the signals secreted by the notochord, Hedgehog proteins play key roles during embryogenesis. The Hedgehog signaling pathway is a central regulator of embryonic development, controlling the patterning and proliferation of a wide variety of organs. In this review, we summarize the current knowledge on notochord structure and functions, with a particular emphasis on the key developmental events that take place in vertebrates. Moreover, we discuss some genetic studies highlighting the phenotypic consequences of impaired notochord development, which enabled to understand the molecular basis of different human congenital defects and diseases.

Analysis of Long Bone and Vertebral Failure Patterns.

DTIC Science & Technology

1982-09-30

processes further supported the findings of • :the scanning electron microscopy studies . In the impacted animals, the cartilage surface was eroded... cartilage matrix. In the six years post-impaction group, the articular cartilage had converted to fibrocartilage instead of normal hyaline cartilage . The...columns of four rhesus monkeys have been collected and are being processed for study with light microscopy and scanning electron microscopy. The baboon

Reduced Bone Density and Vertebral Fractures in Smokers. Men and COPD Patients at Increased Risk

PubMed Central

Jaramillo, Joshua D.; Wilson, Carla; Stinson, Douglas J.; Lynch, David A.; Bowler, Russell P.; Lutz, Sharon; Bon, Jessica M.; Arnold, Ben; McDonald, Merry-Lynn N.; Washko, George R.; Wan, Emily S.; DeMeo, Dawn L.; Foreman, Marilyn G.; Soler, Xavier; Lindsay, Sarah E.; Lane, Nancy E.; Genant, Harry K.; Silverman, Edwin K.; Hokanson, John E.; Make, Barry J.; Crapo, James D.

2015-01-01

Rationale: Former smoking history and chronic obstructive pulmonary disease (COPD) are potential risk factors for osteoporosis and fractures. Under existing guidelines for osteoporosis screening, women are included but men are not, and only current smoking is considered. Objectives: To demonstrate the impact of COPD and smoking history on the risk of osteoporosis and vertebral fracture in men and women. Methods: Characteristics of participants with low volumetric bone mineral density (vBMD) were identified and related to COPD and other risk factors. We tested associations of sex and COPD with both vBMD and fractures adjusting for age, race, body mass index (BMI), smoking, and glucocorticoid use. Measurements and Main Results: vBMD by calibrated quantitative computed tomography (QCT), visually scored vertebral fractures, and severity of lung disease were determined from chest CT scans of 3,321 current and ex-smokers in the COPDGene study. Low vBMD as a surrogate for osteoporosis was calculated from young adult normal values. Male smokers had a small but significantly greater risk of low vBMD (2.5 SD below young adult mean by calibrated QCT) and more fractures than female smokers. Low vBMD was present in 58% of all subjects, was more frequent in those with worse COPD, and rose to 84% among subjects with very severe COPD. Vertebral fractures were present in 37% of all subjects and were associated with lower vBMD at each Global Initiative for Chronic Obstructive Lung Disease stage of severity. Vertebral fractures were most common in the midthoracic region. COPD and especially emphysema were associated with both low vBMD and vertebral fractures after adjustment for steroid use, age, pack-years of smoking, current smoking, and exacerbations. Airway disease was associated with higher bone density after adjustment for other variables. Calibrated QCT identified more subjects with abnormal values than the standard dual-energy X-ray absorptiometry in a subset of subjects and correlated well with prevalent fractures. Conclusions: Male smokers, with or without COPD, have a significant risk of low vBMD and vertebral fractures. COPD was associated with low vBMD after adjusting for race, sex, BMI, smoking, steroid use, exacerbations, and age. Screening for low vBMD by using QCT in men and women who are smokers will increase opportunities to identify and treat osteoporosis in this at-risk population. PMID:25719895

Reduced Bone Density and Vertebral Fractures in Smokers. Men and COPD Patients at Increased Risk.

PubMed

Jaramillo, Joshua D; Wilson, Carla; Stinson, Douglas S; Stinson, Douglas J; Lynch, David A; Bowler, Russell P; Lutz, Sharon; Bon, Jessica M; Arnold, Ben; McDonald, Merry-Lynn N; Washko, George R; Wan, Emily S; DeMeo, Dawn L; Foreman, Marilyn G; Soler, Xavier; Lindsay, Sarah E; Lane, Nancy E; Genant, Harry K; Silverman, Edwin K; Hokanson, John E; Make, Barry J; Crapo, James D; Regan, Elizabeth A

2015-05-01

Former smoking history and chronic obstructive pulmonary disease (COPD) are potential risk factors for osteoporosis and fractures. Under existing guidelines for osteoporosis screening, women are included but men are not, and only current smoking is considered. To demonstrate the impact of COPD and smoking history on the risk of osteoporosis and vertebral fracture in men and women. Characteristics of participants with low volumetric bone mineral density (vBMD) were identified and related to COPD and other risk factors. We tested associations of sex and COPD with both vBMD and fractures adjusting for age, race, body mass index (BMI), smoking, and glucocorticoid use. vBMD by calibrated quantitative computed tomography (QCT), visually scored vertebral fractures, and severity of lung disease were determined from chest CT scans of 3,321 current and ex-smokers in the COPDGene study. Low vBMD as a surrogate for osteoporosis was calculated from young adult normal values. Male smokers had a small but significantly greater risk of low vBMD (2.5 SD below young adult mean by calibrated QCT) and more fractures than female smokers. Low vBMD was present in 58% of all subjects, was more frequent in those with worse COPD, and rose to 84% among subjects with very severe COPD. Vertebral fractures were present in 37% of all subjects and were associated with lower vBMD at each Global Initiative for Chronic Obstructive Lung Disease stage of severity. Vertebral fractures were most common in the midthoracic region. COPD and especially emphysema were associated with both low vBMD and vertebral fractures after adjustment for steroid use, age, pack-years of smoking, current smoking, and exacerbations. Airway disease was associated with higher bone density after adjustment for other variables. Calibrated QCT identified more subjects with abnormal values than the standard dual-energy X-ray absorptiometry in a subset of subjects and correlated well with prevalent fractures. Male smokers, with or without COPD, have a significant risk of low vBMD and vertebral fractures. COPD was associated with low vBMD after adjusting for race, sex, BMI, smoking, steroid use, exacerbations, and age. Screening for low vBMD by using QCT in men and women who are smokers will increase opportunities to identify and treat osteoporosis in this at-risk population.

Undiagnosed vertebral hemangioma causing a lumbar compression fracture and epidural hematoma in a parturient undergoing vaginal delivery under epidural analgesia: a case report.

PubMed

Staikou, Chryssoula; Stamelos, Matthaios; Boutas, Ioannis; Koutoulidis, Vassileios

2015-08-01

Vertebral hemangiomas are benign vascular tumours of the bony spine which are usually asymptomatic. Pregnancy-related anatomical and hormonal changes may lead to expansion of hemangiomas and development of neurological symptoms. We present an unusual case of vertebral fracture due to an undiagnosed hemangioma presenting as postpartum back pain following epidural analgesia. A multiparous female with an unremarkable history developed intense lumbar pain after vaginal delivery under epidural analgesia. The pain was attributed to tissue trauma associated with the epidural technique. The patient had no clinical improvement with analgesics, and her symptoms deteriorated over the following days. A magnetic resonance imaging scan revealed an acute fracture of the second lumbar vertebra (L2) with epidural extension and mild compression of the dural sac, suggesting hemangioma as the underlying cause. The patient underwent successful spinal surgery with pedicle screw fixation to stabilize the fracture. Vertebral fractures secondary to acute expansion of a vertebral hemangioma rarely occur during vaginal delivery. In such cases, the labour epidural technique and analgesia may challenge the physician in making the diagnosis. Postpartum severe back pain should be thoroughly investigated even in the absence of neurological deficits, and osseous spinal pathology should be considered in the differential diagnosis.

Rotational vertebral artery occlusion: mechanisms and long-term outcome.

PubMed

Choi, Kwang-Dong; Choi, Jae-Hwan; Kim, Ji-Soo; Kim, Hyo Jung; Kim, Min-Ji; Lee, Tae-Hong; Lee, Hyung; Moon, In Soo; Oh, Hui Jong; Kim, Jae-Il

2013-07-01

To elucidate the mechanisms and prognosis of rotational vertebral artery occlusion (RVAO). We analyzed clinical and radiological characteristics, patterns of induced nystagmus, and outcome in 21 patients (13 men, aged 29-77 years) with RVAO documented by dynamic cerebral angiography during an 8-year period at 3 University Hospitals in Korea. The follow-up periods ranged from 5 to 91 months (median, 37.5 months). Most patients (n=19; 90.5%) received conservative treatments. All the patients developed vertigo accompanied by tinnitus (38%), fainting (24%), or blurred vision (19%). Only 12 (57.1%) patients showed the typical pattern of RVAO during dynamic cerebral angiography, a compression of the dominant vertebral artery at the C1-2 level during contralateral head rotation. The induced nystagmus was mostly downbeat with horizontal and torsional components beating toward the compressed vertebral artery side. None of the patients with conservative treatments developed posterior circulation stroke, and 4 of them (21.1%) showed resolution of symptoms during the follow-ups. RVAO has various patterns of vertebral artery compression, and favorable long-term outcome with conservative treatments. In most patients with RVAO, the symptoms may be ascribed to asymmetrical excitation of the bilateral labyrinth induced by transient ischemia or by disinhibition from inferior cerebellar hypoperfusion. Conservative management might be considered as the first-line treatment of RVAO.

Conserved developmental expression of Fezf in chordates and Drosophila and the origin of the Zona Limitans Intrathalamica (ZLI) brain organizer

PubMed Central

2010-01-01

Background The zona limitans intrathalamica (ZLI) and the isthmus organizer (IsO) are two major secondary organizers of vertebrate brain development. These organizers are located at the interface of the expression domains of key patterning genes (Fezf-Irx and Otx-Gbx, respectively). To gain insights into the evolutionary origin of the ZLI, we studied Fezf in bilaterians. Results In this paper, we identified a conserved sequence motif (Fezf box) in all bilaterians. We report the expression pattern of Fezf in amphioxus and Drosophila and compare it with those of Gbx, Otx and Irx. We found that the relative expression patterns of these genes in vertebrates are fully conserved in amphioxus and flies, indicating that the genetic subdivisions defining the location of both secondary organizers in early vertebrate brain development were probably present in the last common ancestor of extant bilaterians. However, in contrast to vertebrates, we found that Irx-defective flies do not show an affected Fezf expression pattern. Conclusions The absence of expression of the corresponding morphogens from cells at these conserved genetic boundaries in invertebrates suggests that the organizing properties might have evolved specifically in the vertebrate lineage by the recruitment of key morphogens to these conserved genetic locations. PMID:20849572

Ocular abnormalities in mice lacking the immunoglobulin superfamily member Cdo.

PubMed

Zhang, Wei; Mulieri, Philip J; Gaio, Ursula; Bae, Gyu-Un; Krauss, Robert S; Kang, Jong-Sun

2009-10-01

Vertebrate eye development requires a series of complex morphogenetic and inductive events to produce a lens vesicle centered within the bilayered optic cup and a posteriorly positioned optic stalk. Multiple congenital eye defects, including microphthalmia and coloboma, result from defects in early eye morphogenesis. Cdo is a multifunctional cell surface immunoglobulin superfamily member that interacts with and mediates signaling by cadherins and netrins to regulate myogenesis. In addition, Cdo plays an essential role in early forebrain development by functioning as coreceptor for sonic hedgehog. It is reported here that Cdo is expressed in a dynamic, but dorsally restricted, fashion during early eye development, and that mice lacking Cdo display multiple eye defects. Anomalies seen in Cdo(-/-) mice include coloboma (failure to close the optic fissure); failure to form a proper boundary between the retinal pigmented epithelium and optic stalk; defective lens formation, including failure to separate from the surface ectoderm; and microphthalmia. Consistent with this wide array of defects, developing eyes of Cdo(-/-) mice show altered expression of several regulators of dorsoventral eye patterning, including Pax6, Pax2, and Tbx5. Taken together, these findings show that Cdo is required for normal eye development and is required for normal expression of patterning genes in both the ventral and dorsal domains. The multiple eye development defects seen in Cdo(-/-) mice suggest that mutations in human Cdo could contribute to congenital eye anomalies, such as Jacobsen syndrome, which is frequently associated with ocular defects, including coloboma and Peters' anomaly.

DNA methylation in amphioxus: from ancestral functions to new roles in vertebrates.

PubMed

Albalat, Ricard; Martí-Solans, Josep; Cañestro, Cristian

2012-03-01

In vertebrates, DNA methylation is an epigenetic mechanism that modulates gene transcription, and plays crucial roles during development, cell fate maintenance, germ cell pluripotency and inheritable genome imprinting. DNA methylation might also play a role as a genome defense mechanism against the mutational activity derived from transposon mobility. In contrast to the heavily methylated genomes in vertebrates, most genomes in invertebrates are poorly or just moderately methylated, and the function of DNA methylation remains unclear. Here, we review the DNA methylation system in the cephalochordate amphioxus, which belongs to the most basally divergent group of our own phylum, the chordates. First, surveys of the amphioxus genome database reveal the presence of the DNA methylation machinery, DNA methyltransferases and methyl-CpG-binding domain proteins. Second, comparative genomics and analyses of conserved synteny between amphioxus and vertebrates provide robust evidence that the DNA methylation machinery of amphioxus represents the ancestral toolkit of chordates, and that its expansion in vertebrates was originated by the two rounds of whole-genome duplication that occurred in stem vertebrates. Third, in silico analysis of CpGo/e ratios throughout the amphioxus genome suggests a bimodal distribution of DNA methylation, consistent with a mosaic pattern comprising domains of methylated DNA interspersed with domains of unmethylated DNA, similar to the situation described in ascidians, but radically different to the globally methylated vertebrate genomes. Finally, we discuss potential roles of the DNA methylation system in amphioxus in the context of chordate genome evolution and the origin of vertebrates.

Phylostratigraphic Profiles in Zebrafish Uncover Chordate Origins of the Vertebrate Brain

PubMed Central

Šestak, Martin Sebastijan; Domazet-Lošo, Tomislav

2015-01-01

An elaborated tripartite brain is considered one of the important innovations of vertebrates. Other extant chordate groups have a more basic brain organization. For instance, cephalochordates possess a relatively simple brain possibly homologous to the vertebrate forebrain and hindbrain, whereas tunicates display the tripartite organization, but without the specialized brain centers. The difference in anatomical complexity is even more pronounced if one compares chordates with other deuterostomes that have only a diffuse nerve net or alternatively a rather simple central nervous system. To gain a new perspective on the evolutionary roots of the complex vertebrate brain, we made here a phylostratigraphic analysis of gene expression patterns in the developing zebrafish (Danio rerio). The recovered adaptive landscape revealed three important periods in the evolutionary history of the zebrafish brain. The oldest period corresponds to preadaptive events in the first metazoans and the emergence of the nervous system at the metazoan–eumetazoan transition. The origin of chordates marks the next phase, where we found the overall strongest adaptive imprint in almost all analyzed brain regions. This finding supports the idea that the vertebrate brain evolved independently of the brains within the protostome lineage. Finally, at the origin of vertebrates we detected a pronounced signal coming from the dorsal telencephalon, in agreement with classical theories that consider this part of the cerebrum a genuine vertebrate innovation. Taken together, these results reveal a stepwise adaptive history of the vertebrate brain where most of its extant organization was already present in the chordate ancestor. PMID:25415965

Development of a Complete Life Cycle Sediment Toxicity Test for the Sheepshead Minnow (Cyprinodon variegatus)

EPA Science Inventory

Existing sediment toxicity test methods are limited to acute and chronic exposure of invertebrates and acute exposure of vertebrates, with limited guidance on the chronic exposure of vertebrates, specifically fishes. A series of life stage-specific studies were conducted to dete...

Vertebrate development: the subtle art of germ-layer specification.

PubMed

Stemple, D L

2001-10-30

Nodal signalling is essential for vertebrate germ-layer formation. How this single signal can generate such a diverse array of tissues remains a mystery and is an area of intense research. Three recent reports reveal unanticipated subtleties to the process and provide new mechanisms for generating distinct responses.

Latent Inhibition in an Insect: The Role of Aminergic Signaling

ERIC Educational Resources Information Center

Fernandez, Vanesa M.; Giurfa, Martin; Devaud, Jean-Marc; Farina, Walter M.

2012-01-01

Latent inhibition (LI) is a decrement in learning performance that results from the nonreinforced pre-exposure of the to-be-conditioned stimulus, in both vertebrates and invertebrates. In vertebrates, LI development involves dopamine and serotonin; in invertebrates there is yet no information. We studied differential olfactory conditioning of the…

Presence/absence as a metric for monitoring vertebrate populations

Treesearch

Len Ruggiero; Dean Pearson

2000-01-01

Developing cost effective methods for monitoring vertebrate populations is a persistent problem in wildlife biology. Population demographic data is too costly and time intensive to acquire, so researchers have begun investigating presence/absence sampling as a means for monitoring wildlife populations. We examined three important assumptions regarding the probability...

Fishing for an ECG: A Student-Directed Electrocardiographic Laboratory Using Rainbow Trout

ERIC Educational Resources Information Center

Cotter, Paul A.; Rodnick, Kenneth J.

2007-01-01

Cardiac physiology is emphasized in many undergraduate physiology courses, but few nonmammalian vertebrate model systems exist that 1) can be studied fairly noninvasively, 2) are well suited for controlled experimentation, and 3) emphasize principles characteristic of the vertebrate heart. We have developed an inquiry-based…

Calcineurin/NFAT signaling in osteoblasts regulates bone mass.

PubMed

Winslow, Monte M; Pan, Minggui; Starbuck, Michael; Gallo, Elena M; Deng, Lei; Karsenty, Gerard; Crabtree, Gerald R

2006-06-01

Development and repair of the vertebrate skeleton requires the precise coordination of bone-forming osteoblasts and bone-resorbing osteoclasts. In diseases such as osteoporosis, bone resorption dominates over bone formation, suggesting a failure to harmonize osteoclast and osteoblast function. Here, we show that mice expressing a constitutively nuclear NFATc1 variant (NFATc1(nuc)) in osteoblasts develop high bone mass. NFATc1(nuc) mice have massive osteoblast overgrowth, enhanced osteoblast proliferation, and coordinated changes in the expression of Wnt signaling components. In contrast, viable NFATc1-deficient mice have defects in skull bone formation in addition to impaired osteoclast development. NFATc1(nuc) mice have increased osteoclastogenesis despite normal levels of RANKL and OPG, indicating that an additional NFAT-regulated mechanism influences osteoclastogenesis in vivo. Calcineurin/NFATc signaling in osteoblasts controls the expression of chemoattractants that attract monocytic osteoclast precursors, thereby coupling bone formation and bone resorption. Our results indicate that NFATc1 regulates bone mass by functioning in both osteoblasts and osteoclasts.

The N-Methyl-D-Aspartate Receptor in Heart Development: A Gene Knockdown Model Using siRNA

PubMed Central

Lie, Octavian V.; Bennett, Gregory D.; Rosenquist, Thomas H

2009-01-01

Antagonists of the N-methyl-D-aspartate receptor (NMDAR) may disrupt the development of the cardiac neural crest (CNC) and contribute to conotruncal heart defects. To test this interaction, a loss-of-function model was generated using small interfering RNAs (siRNA) directed against the critical NR1-subunit of this receptor in avian embryos. The coding sequence of the chicken NR1-gene and predicted protein sequences were characterized and found to be homologous with other vertebrate species. Analysis of its spatiotemporal expression demonstrated its expression within the neural tube at pre-migratory CNC sites. siRNA targeted to the NR1-mRNA in pre-migratory CNC lead to a significant decrease in NR1 protein expression. However, embryo survival and heart development were not adversely affected. These results indicate that the CNC may function normally in the absence of functional NMDAR, and that NMDAR antagonists may have a complex impact upon the CNC that transcends impairment of a single receptor type. PMID:19737608

Understanding the relationship between DNA methylation and histone lysine methylation☆

PubMed Central

Rose, Nathan R.; Klose, Robert J.

2014-01-01

DNA methylation acts as an epigenetic modification in vertebrate DNA. Recently it has become clear that the DNA and histone lysine methylation systems are highly interrelated and rely mechanistically on each other for normal chromatin function in vivo. Here we examine some of the functional links between these systems, with a particular focus on several recent discoveries suggesting how lysine methylation may help to target DNA methylation during development, and vice versa. In addition, the emerging role of non-methylated DNA found in CpG islands in defining histone lysine methylation profiles at gene regulatory elements will be discussed in the context of gene regulation. This article is part of a Special Issue entitled: Methylation: A Multifaceted Modification — looking at transcription and beyond. PMID:24560929

The floor plate is sufficient for development of the sclerotome and spine without the notochord.

PubMed

Ando, Takashi; Semba, Kei; Suda, Hiroko; Sei, Akira; Mizuta, Hiroshi; Araki, Masatake; Abe, Kuniya; Imai, Kenji; Nakagata, Naomi; Araki, Kimi; Yamamura, Ken-ichi

2011-01-01

Danforth'sshort-tail (Sd) mouse is a semi-dominant mutation affecting the development of the vertebral column. Although the notochord degenerates completely by embryonic day 9.5, the vertebral column exists up to the lumber region, suggesting that the floor plate can substitute for notochord function. We previously established the mutant mouse line, Skt(Gt), through gene trap mutagenesis and identified the novel gene, Skt, which was mapped 0.95cM distal to the Sd locus. Taking advantage of the fact that monitoring notochordal development and genotyping of the Sd locus can be performed using the Skt(Gt) allele, we assessed the development of the vertebra, notochord, somite, floor plate and sclerotome in +-+/+-Skt(Gt), Sd-+/+-+, Sd-Skt(Gt)/+-+, Sd-Skt(Gt)/+-Skt(Gt), Sd-+/Sd-+ and Sd-Skt(Gt)/Sd-Skt(Gt) embryos. In Sd homozygous mutants with a C57BL/6 genetic background, the vertebral column was truncated in the 6th thoracic vertebra, which was more severe than previously reported. The floor plate and sclerotome developed to the level of somite before notochord degeneration and the number of remaining vertebrae corresponded well with the level of development of the floor plate and sclerotome. Defects to the sclerotome and subsequent vertebral development were not due to failure of somitogenesis. Taken together, these results suggest that the notochord induced floor plate development before degeneration, and that the remaining floor plate is sufficient for maintenance of differentiation of the somite into the sclerotome and vertebra in the absence of the notochord. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

A proposed radiographic classification scheme for congenital thoracic vertebral malformations in brachycephalic "screw-tailed" dog breeds.

PubMed

Gutierrez-Quintana, Rodrigo; Guevar, Julien; Stalin, Catherine; Faller, Kiterie; Yeamans, Carmen; Penderis, Jacques

2014-01-01

Congenital vertebral malformations are common in brachycephalic "screw-tailed" dog breeds such as French bulldogs, English bulldogs, Boston terriers, and pugs. The aim of this retrospective study was to determine whether a radiographic classification scheme developed for use in humans would be feasible for use in these dog breeds. Inclusion criteria were hospital admission between September 2009 and April 2013, neurologic examination findings available, diagnostic quality lateral and ventro-dorsal digital radiographs of the thoracic vertebral column, and at least one congenital vertebral malformation. Radiographs were retrieved and interpreted by two observers who were unaware of neurologic status. Vertebral malformations were classified based on a classification scheme modified from a previous human study and a consensus of both observers. Twenty-eight dogs met inclusion criteria (12 with neurologic deficits, 16 with no neurologic deficits). Congenital vertebral malformations affected 85/362 (23.5%) of thoracic vertebrae. Vertebral body formation defects were the most common (butterfly vertebrae 6.6%, ventral wedge-shaped vertebrae 5.5%, dorsal hemivertebrae 0.8%, and dorso-lateral hemivertebrae 0.5%). No lateral hemivertebrae or lateral wedge-shaped vertebrae were identified. The T7 vertebra was the most commonly affected (11/28 dogs), followed by T8 (8/28 dogs) and T12 (8/28 dogs). The number and type of vertebral malformations differed between groups (P = 0.01). Based on MRI, dorsal, and dorso-lateral hemivertebrae were the cause of spinal cord compression in 5/12 (41.6%) of dogs with neurologic deficits. Findings indicated that a modified human radiographic classification system of vertebral malformations is feasible for use in future studies of brachycephalic "screw-tailed" dogs. © 2014 American College of Veterinary Radiology.

Identification of Ohnolog Genes Originating from Whole Genome Duplication in Early Vertebrates, Based on Synteny Comparison across Multiple Genomes.

PubMed

Singh, Param Priya; Arora, Jatin; Isambert, Hervé

2015-07-01

Whole genome duplications (WGD) have now been firmly established in all major eukaryotic kingdoms. In particular, all vertebrates descend from two rounds of WGDs, that occurred in their jawless ancestor some 500 MY ago. Paralogs retained from WGD, also coined 'ohnologs' after Susumu Ohno, have been shown to be typically associated with development, signaling and gene regulation. Ohnologs, which amount to about 20 to 35% of genes in the human genome, have also been shown to be prone to dominant deleterious mutations and frequently implicated in cancer and genetic diseases. Hence, identifying ohnologs is central to better understand the evolution of vertebrates and their susceptibility to genetic diseases. Early computational analyses to identify vertebrate ohnologs relied on content-based synteny comparisons between the human genome and a single invertebrate outgroup genome or within the human genome itself. These approaches are thus limited by lineage specific rearrangements in individual genomes. We report, in this study, the identification of vertebrate ohnologs based on the quantitative assessment and integration of synteny conservation between six amniote vertebrates and six invertebrate outgroups. Such a synteny comparison across multiple genomes is shown to enhance the statistical power of ohnolog identification in vertebrates compared to earlier approaches, by overcoming lineage specific genome rearrangements. Ohnolog gene families can be browsed and downloaded for three statistical confidence levels or recompiled for specific, user-defined, significance criteria at http://ohnologs.curie.fr/. In the light of the importance of WGD on the genetic makeup of vertebrates, our analysis provides a useful resource for researchers interested in gaining further insights on vertebrate evolution and genetic diseases.

Identification of Ohnolog Genes Originating from Whole Genome Duplication in Early Vertebrates, Based on Synteny Comparison across Multiple Genomes

PubMed Central

Singh, Param Priya; Arora, Jatin; Isambert, Hervé

2015-01-01

Whole genome duplications (WGD) have now been firmly established in all major eukaryotic kingdoms. In particular, all vertebrates descend from two rounds of WGDs, that occurred in their jawless ancestor some 500 MY ago. Paralogs retained from WGD, also coined ‘ohnologs’ after Susumu Ohno, have been shown to be typically associated with development, signaling and gene regulation. Ohnologs, which amount to about 20 to 35% of genes in the human genome, have also been shown to be prone to dominant deleterious mutations and frequently implicated in cancer and genetic diseases. Hence, identifying ohnologs is central to better understand the evolution of vertebrates and their susceptibility to genetic diseases. Early computational analyses to identify vertebrate ohnologs relied on content-based synteny comparisons between the human genome and a single invertebrate outgroup genome or within the human genome itself. These approaches are thus limited by lineage specific rearrangements in individual genomes. We report, in this study, the identification of vertebrate ohnologs based on the quantitative assessment and integration of synteny conservation between six amniote vertebrates and six invertebrate outgroups. Such a synteny comparison across multiple genomes is shown to enhance the statistical power of ohnolog identification in vertebrates compared to earlier approaches, by overcoming lineage specific genome rearrangements. Ohnolog gene families can be browsed and downloaded for three statistical confidence levels or recompiled for specific, user-defined, significance criteria at http://ohnologs.curie.fr/. In the light of the importance of WGD on the genetic makeup of vertebrates, our analysis provides a useful resource for researchers interested in gaining further insights on vertebrate evolution and genetic diseases. PMID:26181593

Ontogenetic niche shifts in dinosaurs influenced size, diversity and extinction in terrestrial vertebrates.

PubMed

Codron, Daryl; Carbone, Chris; Müller, Dennis W H; Clauss, Marcus

2012-08-23

Given the physiological limits to egg size, large-bodied non-avian dinosaurs experienced some of the most extreme shifts in size during postnatal ontogeny found in terrestrial vertebrate systems. In contrast, mammals--the other dominant vertebrate group since the Mesozoic--have less complex ontogenies. Here, we develop a model that quantifies the impact of size-specific interspecies competition on abundances of differently sized dinosaurs and mammals, taking into account the extended niche breadth realized during ontogeny among large oviparous species. Our model predicts low diversity at intermediate size classes (between approx. 1 and 1000 kg), consistent with observed diversity distributions of dinosaurs, and of Mesozoic land vertebrates in general. It also provides a mechanism--based on an understanding of different ecological and evolutionary constraints across vertebrate groups--that explains how mammals and birds, but not dinosaurs, were able to persist beyond the Cretaceous-Tertiary (K-T) boundary, and how post-K-T mammals were able to diversify into larger size categories.

Ontogenetic niche shifts in dinosaurs influenced size, diversity and extinction in terrestrial vertebrates

PubMed Central

Codron, Daryl; Carbone, Chris; Müller, Dennis W. H.; Clauss, Marcus

2012-01-01

Given the physiological limits to egg size, large-bodied non-avian dinosaurs experienced some of the most extreme shifts in size during postnatal ontogeny found in terrestrial vertebrate systems. In contrast, mammals—the other dominant vertebrate group since the Mesozoic—have less complex ontogenies. Here, we develop a model that quantifies the impact of size-specific interspecies competition on abundances of differently sized dinosaurs and mammals, taking into account the extended niche breadth realized during ontogeny among large oviparous species. Our model predicts low diversity at intermediate size classes (between approx. 1 and 1000 kg), consistent with observed diversity distributions of dinosaurs, and of Mesozoic land vertebrates in general. It also provides a mechanism—based on an understanding of different ecological and evolutionary constraints across vertebrate groups—that explains how mammals and birds, but not dinosaurs, were able to persist beyond the Cretaceous–Tertiary (K–T) boundary, and how post-K–T mammals were able to diversify into larger size categories. PMID:22513279

VerSeDa: vertebrate secretome database

PubMed Central

Cortazar, Ana R.; Oguiza, José A.

2017-01-01

Based on the current tools, de novo secretome (full set of proteins secreted by an organism) prediction is a time consuming bioinformatic task that requires a multifactorial analysis in order to obtain reliable in silico predictions. Hence, to accelerate this process and offer researchers a reliable repository where secretome information can be obtained for vertebrates and model organisms, we have developed VerSeDa (Vertebrate Secretome Database). This freely available database stores information about proteins that are predicted to be secreted through the classical and non-classical mechanisms, for the wide range of vertebrate species deposited at the NCBI, UCSC and ENSEMBL sites. To our knowledge, VerSeDa is the only state-of-the-art database designed to store secretome data from multiple vertebrate genomes, thus, saving an important amount of time spent in the prediction of protein features that can be retrieved from this repository directly. Database URL: VerSeDa is freely available at http://genomics.cicbiogune.es/VerSeDa/index.php PMID:28365718

A platform for rapid exploration of aging and diseases in a naturally short-lived vertebrate

PubMed Central

Harel, Itamar; Benayoun, Bérénice A.; Machado, Ben; Singh, Param Priya; Hu, Chi-Kuo; Pech, Matthew F.; Valenzano, Dario R.; Zhang, Elisa; Sharp, Sabrina C.; Artandi, Steven E.; Brunet, Anne

2015-01-01

Summary Aging is a complex process that affects multiple organs. Modeling aging and age-related diseases in the lab is challenging because classical vertebrate models have relatively long lifespans. Here we develop the first platform for rapid exploration of age-dependent traits and diseases in vertebrates, using the naturally short-lived African turquoise killifish. We provide an integrative genomic and genome-editing toolkit in this organism using our de novo-assembled genome and the CRISPR/Cas9 technology. We mutate many genes encompassing the hallmarks of aging, and for a subset, we produce stable lines within 2–3 months. As a proof-of-principle, we show that fish deficient for the protein subunit of telomerase exhibit the fastest onset of telomere-related pathologies among vertebrates. We further demonstrate the feasibility of creating specific genetic variants. This genome-to-phenotype platform represents a unique resource for studying vertebrate aging and disease in a high throughput manner and for investigating candidates arising from human genome-wide studies. PMID:25684364

VerSeDa: vertebrate secretome database.

PubMed

Cortazar, Ana R; Oguiza, José A; Aransay, Ana M; Lavín, José L

2017-01-01

Based on the current tools, de novo secretome (full set of proteins secreted by an organism) prediction is a time consuming bioinformatic task that requires a multifactorial analysis in order to obtain reliable in silico predictions. Hence, to accelerate this process and offer researchers a reliable repository where secretome information can be obtained for vertebrates and model organisms, we have developed VerSeDa (Vertebrate Secretome Database). This freely available database stores information about proteins that are predicted to be secreted through the classical and non-classical mechanisms, for the wide range of vertebrate species deposited at the NCBI, UCSC and ENSEMBL sites. To our knowledge, VerSeDa is the only state-of-the-art database designed to store secretome data from multiple vertebrate genomes, thus, saving an important amount of time spent in the prediction of protein features that can be retrieved from this repository directly. VerSeDa is freely available at http://genomics.cicbiogune.es/VerSeDa/index.php. © The Author(s) 2017. Published by Oxford University Press.

Ascidians and the plasticity of the chordate developmental program.

PubMed

Lemaire, Patrick; Smith, William C; Nishida, Hiroki

2008-07-22

Little is known about the ancient chordates that gave rise to the first vertebrates, but the descendants of other invertebrate chordates extant at the time still flourish in the ocean. These invertebrates include the cephalochordates and tunicates, whose larvae share with vertebrate embryos a common body plan with a central notochord and a dorsal nerve cord. Tunicates are now thought to be the sister group of vertebrates. However, research based on several species of ascidians, a diverse and wide-spread class of tunicates, revealed that the molecular strategies underlying their development appear to diverge greatly from those found in vertebrates. Furthermore, the adult body plan of most tunicates, which arises following an extensive post-larval metamorphosis, shows little resemblance to the body plan of any other chordate. In this review, we compare the developmental strategies of ascidians and vertebrates and argue that the very divergence of these strategies reveals the surprising level of plasticity of the chordate developmental program and is a rich resource to identify core regulatory mechanisms that are evolutionarily conserved in chordates. Further, we propose that the comparative analysis of the architecture of ascidian and vertebrate gene regulatory networks may provide critical insight into the origin of the chordate body plan.

A comparative examination of neural circuit and brain patterning between the lamprey and amphioxus reveals the evolutionary origin of the vertebrate visual center.

PubMed

Suzuki, Daichi G; Murakami, Yasunori; Escriva, Hector; Wada, Hiroshi

2015-02-01

Vertebrates are equipped with so-called camera eyes, which provide them with image-forming vision. Vertebrate image-forming vision evolved independently from that of other animals and is regarded as a key innovation for enhancing predatory ability and ecological success. Evolutionary changes in the neural circuits, particularly the visual center, were central for the acquisition of image-forming vision. However, the evolutionary steps, from protochordates to jaw-less primitive vertebrates and then to jawed vertebrates, remain largely unknown. To bridge this gap, we present the detailed development of retinofugal projections in the lamprey, the neuroarchitecture in amphioxus, and the brain patterning in both animals. Both the lateral eye in larval lamprey and the frontal eye in amphioxus project to a light-detecting visual center in the caudal prosencephalic region marked by Pax6, which possibly represents the ancestral state of the chordate visual system. Our results indicate that the visual system of the larval lamprey represents an evolutionarily primitive state, forming a link from protochordates to vertebrates and providing a new perspective of brain evolution based on developmental mechanisms and neural functions. © 2014 Wiley Periodicals, Inc.

Pathologic fracture of the thoracic spine in a male master ultra-marathoner due to the combination of a vertebral hemangioma and osteopenia.

PubMed

Knechtle, Beat; Nikolaidis, Pantelis T; Lutz, Bruno; Rosemann, Thomas; Baerlocher, Christian B

2017-01-01

Vertebral hemangiomas are the most common benign vertebral neoplasms and are generally asymptomatic. In the present study, we report the case of a 52-year-old male master ultra-marathoner suffering from a pathologic fracture of the thoracic spine due to a vertebral hemangioma. A further examination in the athlete revealed an accompanying osteopenia, which was most likely due to a deficiency in both vitamin D and testosterone. The treatment of the fracture consisted of percutaneous vertebroplasty. Shortly after the operation the athlete was able to continue running. The most likely reason for the pathologic fracture of the vertebral body was the combination of the vertebral hemangioma and osteopenia. The further treatment consisted of supplementation of both vitamin D and testosterone. Athletes and physicians should be aware that male master ultra-marathoners older than 50 years might suffer from osteopenia, where a deficiency in vitamin D and testosterone could be contributing factors for osteopenia development in general. Copyright © 2017 The Lithuanian University of Health Sciences. Production and hosting by Elsevier Sp. z o.o. All rights reserved.

Reconstruction of the vertebrate ancestral genome reveals dynamic genome reorganization in early vertebrates.

PubMed

Nakatani, Yoichiro; Takeda, Hiroyuki; Kohara, Yuji; Morishita, Shinichi

2007-09-01

Although several vertebrate genomes have been sequenced, little is known about the genome evolution of early vertebrates and how large-scale genomic changes such as the two rounds of whole-genome duplications (2R WGD) affected evolutionary complexity and novelty in vertebrates. Reconstructing the ancestral vertebrate genome is highly nontrivial because of the difficulty in identifying traces originating from the 2R WGD. To resolve this problem, we developed a novel method capable of pinning down remains of the 2R WGD in the human and medaka fish genomes using invertebrate tunicate and sea urchin genes to define ohnologs, i.e., paralogs produced by the 2R WGD. We validated the reconstruction using the chicken genome, which was not considered in the reconstruction step, and observed that many ancestral proto-chromosomes were retained in the chicken genome and had one-to-one correspondence to chicken microchromosomes, thereby confirming the reconstructed ancestral genomes. Our reconstruction revealed a contrast between the slow karyotype evolution after the second WGD and the rapid, lineage-specific genome reorganizations that occurred in the ancestral lineages of major taxonomic groups such as teleost fishes, amphibians, reptiles, and marsupials.

Evolutionary Genomics and Adaptive Evolution of the Hedgehog Gene Family (Shh, Ihh and Dhh) in Vertebrates

PubMed Central

Pereira, Joana; Johnson, Warren E.; O’Brien, Stephen J.; Jarvis, Erich D.; Zhang, Guojie; Gilbert, M. Thomas P.; Vasconcelos, Vitor; Antunes, Agostinho

2014-01-01

The Hedgehog (Hh) gene family codes for a class of secreted proteins composed of two active domains that act as signalling molecules during embryo development, namely for the development of the nervous and skeletal systems and the formation of the testis cord. While only one Hh gene is found typically in invertebrate genomes, most vertebrates species have three (Sonic hedgehog – Shh; Indian hedgehog – Ihh; and Desert hedgehog – Dhh), each with different expression patterns and functions, which likely helped promote the increasing complexity of vertebrates and their successful diversification. In this study, we used comparative genomic and adaptive evolutionary analyses to characterize the evolution of the Hh genes in vertebrates following the two major whole genome duplication (WGD) events. To overcome the lack of Hh-coding sequences on avian publicly available databases, we used an extensive dataset of 45 avian and three non-avian reptilian genomes to show that birds have all three Hh paralogs. We find suggestions that following the WGD events, vertebrate Hh paralogous genes evolved independently within similar linkage groups and under different evolutionary rates, especially within the catalytic domain. The structural regions around the ion-binding site were identified to be under positive selection in the signaling domain. These findings contrast with those observed in invertebrates, where different lineages that experienced gene duplication retained similar selective constraints in the Hh orthologs. Our results provide new insights on the evolutionary history of the Hh gene family, the functional roles of these paralogs in vertebrate species, and on the location of mutational hotspots. PMID:25549322

Pharmacological induction of skin pigmentation unveils the neuroendocrine circuit regulated by light.

PubMed

Bertolesi, Gabriel E; Vazhappilly, Sherene T; Hehr, Carrie L; McFarlane, Sarah

2016-03-01

Light-regulated skin colour change is an important physiological process in invertebrates and lower vertebrates, and includes daily circadian variation and camouflage (i.e. background adaptation). The photoactivation of melanopsin-expressing retinal ganglion cells (mRGCs) in the eye initiates an uncharacterized neuroendocrine circuit that regulates melanin dispersion/aggregation through the secretion of alpha-melanocyte-stimulating hormone (α-MSH). We developed experimental models of normal or enucleated Xenopus embryos, as well as in situ cultures of skin of isolated dorsal head and tails, to analyse pharmacological induction of skin pigmentation and α-MSH synthesis. Both processes are triggered by a melanopsin inhibitor, AA92593, as well as chloride channel modulators. The AA9253 effect is eye-dependent, while functional data in vivo point to GABAA receptors expressed on pituitary melanotrope cells as the chloride channel blocker target. Based on the pharmacological data, we suggest a neuroendocrine circuit linking mRGCs with α-MSH secretion, which is used normally during background adaptation. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Evolution and Development of Ventricular Septation in the Amniote Heart

PubMed Central

Poelmann, Robert E.; Groot, Adriana C. Gittenberger-de; Vicente-Steijn, Rebecca; Wisse, Lambertus J.; Bartelings, Margot M.; Everts, Sonja; Hoppenbrouwers, Tamara; Kruithof, Boudewijn P. T.; Jensen, Bjarke; de Bruin, Paul W.; Hirasawa, Tatsuya; Kuratani, Shigeru; Vonk, Freek; van de Put, Jeanne M. M. S.; de Bakker, Merijn A.; Richardson, Michael K.

2014-01-01

During cardiogenesis the epicardium, covering the surface of the myocardial tube, has been ascribed several functions essential for normal heart development of vertebrates from lampreys to mammals. We investigated a novel function of the epicardium in ventricular development in species with partial and complete septation. These species include reptiles, birds and mammals. Adult turtles, lizards and snakes have a complex ventricle with three cava, partially separated by the horizontal and vertical septa. The crocodilians, birds and mammals with origins some 100 million years apart, however, have a left and right ventricle that are completely separated, being a clear example of convergent evolution. In specific embryonic stages these species show similarities in development, prompting us to investigate the mechanisms underlying epicardial involvement. The primitive ventricle of early embryos becomes septated by folding and fusion of the anterior ventricular wall, trapping epicardium in its core. This folding septum develops as the horizontal septum in reptiles and the anterior part of the interventricular septum in the other taxa. The mechanism of folding is confirmed using DiI tattoos of the ventricular surface. Trapping of epicardium-derived cells is studied by transplanting embryonic quail pro-epicardial organ into chicken hosts. The effect of decreased epicardium involvement is studied in knock-out mice, and pro-epicardium ablated chicken, resulting in diminished and even absent septum formation. Proper folding followed by diminished ventricular fusion may explain the deep interventricular cleft observed in elephants. The vertical septum, although indistinct in most reptiles except in crocodilians and pythonidsis apparently homologous to the inlet septum. Eventually the various septal components merge to form the completely septated heart. In our attempt to discover homologies between the various septum components we aim to elucidate the evolution and development of this part of the vertebrate heart as well as understand the etiology of septal defects in human congenital heart malformations. PMID:25192012

One-stage posterior instrumentation surgery for the treatment of osteoporotic vertebral collapse with neurological deficits

PubMed Central

Ito, Manabu; Abumi, Kuniyoshi; Kotani, Yoshihisa; Takahata, Masahiko; Hojo, Yoshihiro; Minami, Akio

2010-01-01

The number of reports describing osteoporotic vertebral fracture has increased as the number of elderly people has grown. Anterior decompression and fusion alone for the treatment of vertebral collapse is not easy for patients with comorbid medical problems and severe bone fragility. The purpose of the present study was to evaluate the efficacy of one-stage posterior instrumentation surgery for the treatment of osteoporotic vertebral collapse with neurological deficits. A consecutive series of 21 patients who sustained osteoporotic vertebral collapse with neurological deficits were managed with posterior decompression and short-segmental pedicle screw instrumentation augmented with ultra-high molecular weight polyethylene (UHMWP) cables with or without vertebroplasty using calcium phosphate cement. The mean follow-up was 42 months. All patients showed neurologic recovery. Segmental kyphotic angle at the instrumented level was significantly improved from an average preoperative kyphosis of 22.8–14.7 at a final follow-up. Spinal canal occupation was significantly reduced from an average before surgery of 40.4–19.1% at the final follow-up. Two patients experienced loosening of pedicle screws and three patients developed subsequent vertebral compression fractures within adjacent segments. However, these patients were effectively treated in a conservative fashion without any additional surgery. Our results indicated that one-stage posterior instrumentation surgery augmented with UHMWP cables could provide significant neurological improvement in the treatment of osteoporotic vertebral collapse. PMID:20157741

One-stage posterior instrumentation surgery for the treatment of osteoporotic vertebral collapse with neurological deficits.

PubMed

Sudo, Hideki; Ito, Manabu; Abumi, Kuniyoshi; Kotani, Yoshihisa; Takahata, Masahiko; Hojo, Yoshihiro; Minami, Akio

2010-06-01

The number of reports describing osteoporotic vertebral fracture has increased as the number of elderly people has grown. Anterior decompression and fusion alone for the treatment of vertebral collapse is not easy for patients with comorbid medical problems and severe bone fragility. The purpose of the present study was to evaluate the efficacy of one-stage posterior instrumentation surgery for the treatment of osteoporotic vertebral collapse with neurological deficits. A consecutive series of 21 patients who sustained osteoporotic vertebral collapse with neurological deficits were managed with posterior decompression and short-segmental pedicle screw instrumentation augmented with ultra-high molecular weight polyethylene (UHMWP) cables with or without vertebroplasty using calcium phosphate cement. The mean follow-up was 42 months. All patients showed neurologic recovery. Segmental kyphotic angle at the instrumented level was significantly improved from an average preoperative kyphosis of 22.8-14.7 at a final follow-up. Spinal canal occupation was significantly reduced from an average before surgery of 40.4-19.1% at the final follow-up. Two patients experienced loosening of pedicle screws and three patients developed subsequent vertebral compression fractures within adjacent segments. However, these patients were effectively treated in a conservative fashion without any additional surgery. Our results indicated that one-stage posterior instrumentation surgery augmented with UHMWP cables could provide significant neurological improvement in the treatment of osteoporotic vertebral collapse.

Id expression in amphioxus and lamprey highlights the role of gene cooption during neural crest evolution

NASA Technical Reports Server (NTRS)

Meulemans, Daniel; McCauley, David; Bronner-Fraser, Marianne

2003-01-01

Neural crest cells are unique to vertebrates and generate many of the adult structures that differentiate them from their closest invertebrate relatives, the cephalochordates. Id genes are robust markers of neural crest cells at all stages of development. We compared Id gene expression in amphioxus and lamprey to ask if cephalochordates deploy Id genes at the neural plate border and dorsal neural tube in a manner similar to vertebrates. Furthermore, we examined whether Id expression in these cells is a basal vertebrate trait or a derived feature of gnathostomes. We found that while expression of Id genes in the mesoderm and endoderm is conserved between amphioxus and vertebrates, expression in the lateral neural plate border and dorsal neural tube is a vertebrate novelty. Furthermore, expression of lamprey Id implies that recruitment of Id genes to these cells occurred very early in the vertebrate lineage. Based on expression in amphioxus we postulate that Id cooption conferred sensory cell progenitor-like properties upon the lateral neurectoderm, and pharyngeal mesoderm-like properties upon cranial neural crest. Amphioxus Id expression is also consistent with homology between the anterior neurectoderm of amphioxus and the presumptive placodal ectoderm of vertebrates. These observations support the idea that neural crest evolution was driven in large part by cooption of multipurpose transcriptional regulators from other tissues and cell types.

Evolution and development of the vertebrate neck

PubMed Central

Ericsson, Rolf; Knight, Robert; Johanson, Zerina

2013-01-01

Muscles of the vertebrate neck include the cucullaris and hypobranchials. Although a functional neck first evolved in the lobe-finned fishes (Sarcopterygii) with the separation of the pectoral/shoulder girdle from the skull, the neck muscles themselves have a much earlier origin among the vertebrates. For example, lampreys possess hypobranchial muscles, and may also possess the cucullaris. Recent research in chick has established that these two muscles groups have different origins, the hypobranchial muscles having a somitic origin but the cucullaris muscle deriving from anterior lateral plate mesoderm associated with somites 1–3. Additionally, the cucullaris utilizes genetic pathways more similar to the head than the trunk musculature. Although the latter results are from experiments in the chick, cucullaris homologues occur in a variety of more basal vertebrates such as the sharks and zebrafish. Data are urgently needed from these taxa to determine whether the cucullaris in these groups also derives from lateral plate mesoderm or from the anterior somites, and whether the former or the latter represent the basal vertebrate condition. Other lateral plate mesoderm derivatives include the appendicular skeleton (fins, limbs and supporting girdles). If the cucullaris is a definitive lateral plate-derived structure it may have evolved in conjunction with the shoulder/limb skeleton in vertebrates and thereby provided a greater degree of flexibility to the heads of predatory vertebrates. PMID:22697305

The pre-vertebrate origins of neurogenic placodes.

PubMed

Abitua, Philip Barron; Gainous, T Blair; Kaczmarczyk, Angela N; Winchell, Christopher J; Hudson, Clare; Kamata, Kaori; Nakagawa, Masashi; Tsuda, Motoyuki; Kusakabe, Takehiro G; Levine, Michael

2015-08-27

The sudden appearance of the neural crest and neurogenic placodes in early branching vertebrates has puzzled biologists for over a century. These embryonic tissues contribute to the development of the cranium and associated sensory organs, which were crucial for the evolution of the vertebrate "new head". A previous study suggests that rudimentary neural crest cells existed in ancestral chordates. However, the evolutionary origins of neurogenic placodes have remained obscure owing to a paucity of embryonic data from tunicates, the closest living relatives to those early vertebrates. Here we show that the tunicate Ciona intestinalis exhibits a proto-placodal ectoderm (PPE) that requires inhibition of bone morphogenetic protein (BMP) and expresses the key regulatory determinant Six1/2 and its co-factor Eya, a developmental process conserved across vertebrates. The Ciona PPE is shown to produce ciliated neurons that express genes for gonadotropin-releasing hormone (GnRH), a G-protein-coupled receptor for relaxin-3 (RXFP3) and a functional cyclic nucleotide-gated channel (CNGA), which suggests dual chemosensory and neurosecretory activities. These observations provide evidence that Ciona has a neurogenic proto-placode, which forms neurons that appear to be related to those derived from the olfactory placode and hypothalamic neurons of vertebrates. We discuss the possibility that the PPE-derived GnRH neurons of Ciona resemble an ancestral cell type, a progenitor to the complex neuronal circuit that integrates sensory information and neuroendocrine functions in vertebrates.

Epitope-blocking enzyme-linked immunosorbent assay for detection of antibodies to Ross River virus in vertebrate sera.

PubMed

Oliveira, Nidia M M; Broom, Annette K; Mackenzie, John S; Smith, David W; Lindsay, Michael D A; Kay, Brian H; Hall, Roy A

2006-07-01

We describe the development of an epitope-blocking enzyme-linked immunosorbent assay (ELISA) for the sensitive and rapid detection of antibodies to Ross River virus (RRV) in human sera and known vertebrate host species. This ELISA provides an alternative method for the serodiagnosis of RRV infections.

Use of survey data to develop sediment criteria for protecting aquatic vertebrates in mountain streams

EPA Science Inventory

We examined the relationship of aquatic vertebrate taxa abundances and an index of biotic integrity (IBI) to reachwide measures of areal percent streambed surficial fines (≤ 0.06 mm) and sand and fines (≤ 2 mm), based on data collected from 557 wadeable streams in the Western Mou...

Eimeria that infect fish are diverse and are related to, but distinct from, those that infect terrestrial vertebrates

USDA-ARS?s Scientific Manuscript database

The Eimeria are ubiquitous Apicoplexan parasites (family: coccidia) of the gut epithelium of vertebrates which complete their development in a single host species and whose sporocysts may be recognized by the presence of a Stieda body through which their sporozoites excyst. Their diversity and rel...

AQUATIC VERTEBRATE ASSEMBLAGES AT LEAST- AND MOST-IMPACTED STREAM AND RIVER SITES IN THE WESTERN FORESTED MOUNTAINS AGGREGATE ECOREGIONS

EPA Science Inventory

In the West, development of indicators of aquatic vertebrate assemblages condition in streams and rivers is challenged by low species richness (often < 3 species), by strong natural gradients (e.g., elevation), by human impact gradients that often co-vary with natural gradients, ...

Spatial coordination of compensatory eye movements in vertebrates: form and function.

PubMed

Graf, W

1988-01-01

The semicircular canals of the labyrinth of vertebrates provide one way of motion detection in three-dimensional space. The fully developed form of the vertebrate labyrinth consists of six semicircular canals, three on each side of the head, whose spatial arrangement (vertical canals are placed diagonally in the head, horizontal canals are oriented earth horizontally) follows three interconnected principles: 1) bilateral symmetry, 2) push-pull operational mode, and 3) mutual orthogonality. Other sensory and motor systems related to vestibular reflexes, such as the extraocular muscles or the "optokinetic" coordinate axes encoded in the activity of the visually driven cells of the accessory optic system, share the same geometrical framework. This framework is also reflected in the anatomical networks mediating compensatory eye movements, linking each of the semicircular canals to a particular set of extraocular muscles (so-called principal vestibuloocular reflex connections to yoke muscles). These classical vestibulo-oculomotor relationships have been verified at many levels of the vertebrate hierarchy, including lateral- and frontal-eyed animals. The particular spatial orientation of the semicircular canals requires further comment and phylogenetic evaluation. The spatial arrangement of the vertical canals is already present in fossil ostracoderms, and is also exemplified in lampreys, the modern forms of once abundant agnathan species that populated the Silurian and Devonian oceans. The lampreys and ostracoderms lack horizontal canals, which appear later in all descendent vertebrates. The fully developed vertebrate labyrinth with its six semicircular canals displays distinct differences that are obvious when comparing distant taxa (e.g. elasmobranchs versus other vertebrates). Whereas the common crus of the semicircular canals in teleosts through mammals is formed between the anterior and the posterior semicircular canal, it occurs between the anterior and the horizontal canal in elasmobranchs. However, despite this morphological difference, these two vertebrate labyrinth prototypes constitute a functionally identical solution. A similar analysis holds for certain invertebrate species (crab, octopus, squid), which display an even wider variety in the physical expressions of movement detection systems when compared to vertebrates. Although the physical expressions of motion detection systems differ in the animal kingdom, the functional solutions (providing the best signal-to-noise ratio) with adherence to bilateral symmetry, push-pull operational mode, and mutual orthogonality are identical.(ABSTRACT TRUNCATED AT 400 WORDS)

Cement pulmonary embolism after vertebroplasty.

PubMed

Sifuentes Giraldo, Walter Alberto; Lamúa Riazuelo, José Ramón; Gallego Rivera, José Ignacio; Vázquez Díaz, Mónica

2013-01-01

In recent years, the use of vertebral cementing techniques for vertebroplasty and kyphoplasty has spread for the treatment of pain associated with osteoporotic vertebral compression fractures. This is also associated with the increased incidence of complications related with these procedures, the most frequent being originated by leakage of cementation material. Cement can escape into the vertebral venous system and reach the pulmonary circulation through the azygous system and cava vein, producing a cement embolism. This is a frequent complication, occurring in up to 26% of patients undergoing vertebroplasty but, since most patients have no clinical or hemodynamical repercussion, this event usually goes unnoticed. However, some serious, and even fatal cases, have been reported. We report the case of a 74-year-old male patient who underwent vertebroplasty for persistent pain associated with osteoporotic L3 vertebral fracture and who developed a cement leak into the cava vein and right pulmonary artery during the procedure. Although he developed a pulmonary cement embolism, the patient remained asymptomatic and did not present complications during follow-up. Copyright © 2012 Elsevier España, S.L. All rights reserved.

Synchrotron imaging reveals bone healing and remodelling strategies in extinct and extant vertebrates

PubMed Central

Anné, Jennifer; Edwards, Nicholas P.; Wogelius, Roy A.; Tumarkin-Deratzian, Allison R.; Sellers, William I.; van Veelen, Arjen; Bergmann, Uwe; Sokaras, Dimosthenis; Alonso-Mori, Roberto; Ignatyev, Konstantin; Egerton, Victoria M.; Manning, Phillip L.

2014-01-01

Current understanding of bone healing and remodelling strategies in vertebrates has traditionally relied on morphological observations through the histological analysis of thin sections. However, chemical analysis may also be used in such interpretations, as different elements are known to be absorbed and used by bone for different physiological purposes such as growth and healing. These chemical signatures are beyond the detection limit of most laboratory-based analytical techniques (e.g. scanning electron microscopy). However, synchrotron rapid scanning–X-ray fluorescence (SRS–XRF) is an elemental mapping technique that uniquely combines high sensitivity (ppm), excellent sample resolution (20–100 µm) and the ability to scan large specimens (decimetre scale) approximately 3000 times faster than other mapping techniques. Here, we use SRS–XRF combined with microfocus elemental mapping (2–20 µm) to determine the distribution and concentration of trace elements within pathological and normal bone of both extant and extinct archosaurs (Cathartes aura and Allosaurus fragilis). Results reveal discrete chemical inventories within different bone tissue types and preservation modes. Chemical inventories also revealed detail of histological features not observable in thin section, including fine structures within the interface between pathological and normal bone as well as woven texture within pathological tissue. PMID:24806709

Are evolutionary hypotheses for motion sickness "just-so" stories?

PubMed

Oman, Charles M

2012-01-01

Vertebrates have evolved rapidly conditionable nausea and vomiting reflexes mediated by gut and brainstem receptors, clearly as a defense against neurotoxin ingestion. In 1977 Treisman proposed that sensory orientation linkages to emetic centers evolved for the same reason, and that motion sickness was an accidental byproduct. It was an "adaptationist" explanation for motion sickness, since it assumed that evolution has shaped all phenotypic traits for survival advantage. Treisman's "poison" theory is plausible, and frequently cited as the accepted scientific explanation for motion sickness. However, alternative explanations have been proposed. The creation of hypotheses is an essential part of science - provided they are testable. This paper reviews the evidence for the Poison theory and several other adaptationist explanations. These hypotheses are certainly not "just-so stories", but supporting evidence is equivocal, and contradictory evidence exists Parsimony suggests an alternative "pluralistic" view: The vertebrate reticular formation maintains oxygenated blood flow to the brain, discriminates unexpected sensory stimuli- including postural disturbances, and detects and expels ingested neurotoxins. The three systems share neuroarchitectural elements but normally function independently. Brainstem sensory conflict neurons normally discriminate brief postural disturbances, but can be abnormally stimulated during prolonged passive transport (e.g. by boat, beginning about 150-200 generations ago). Sensory conflict signals cross couple into the neurotoxin expulsion and avoidance system, producing an arguably maladaptive emetic phenotype.

Selection of reliable reference genes for normalization of quantitative RT-PCR from different developmental stages and tissues in amphioxus

PubMed Central

Zhang, Qi-Lin; Zhu, Qian-Hua; Liao, Xin; Wang, Xiu-Qiang; Chen, Tao; Xu, Han-Ting; Wang, Juan; Yuan, Ming-Long; Chen, Jun-Yuan

2016-01-01

Amphioxus is a closest living proxy to the ancestor of cephalochordates with vertebrates, and key animal for novel understanding in the evolutionary origin of vertebrate body plan, genome, tissues and immune system. Reliable analyses using quantitative real-time PCR (qRT-PCR) for answering these scientific questions is heavily dependent on reliable reference genes (RGs). In this study, we evaluated stability of thirteen candidate RGs in qRT-PCR for different developmental stages and tissues of amphioxus by four independent (geNorm, NormFinder, BestKeeper and deltaCt) and one comparative algorithms (RefFinder). The results showed that the top two stable RGs were the following: (1) S20 and 18 S in thirteen developmental stages, (2) EF1A and ACT in seven normal tissues, (3) S20 and L13 in both intestine and hepatic caecum challenged with lipopolysaccharide (LPS), and (4) S20 and EF1A in gill challenged with LPS. The expression profiles of two target genes (EYA and HHEX) in thirteen developmental stages were used to confirm the reliability of chosen RGs. This study identified optimal RGs that can be used to accurately measure gene expression under these conditions, which will benefit evolutionary and functional genomics studies in amphioxus. PMID:27869224

Fgf8 and Fgf3 are required for zebrafish ear placode induction, maintenance and inner ear patterning.

PubMed

Léger, Sophie; Brand, Michael

2002-11-01

The vertebrate inner ear develops from initially 'simple' ectodermal placode and vesicle stages into the complex three-dimensional structure which is necessary for the senses of hearing and equilibrium. Although the main morphological events in vertebrate inner ear development are known, the genetic mechanisms controlling them are scarcely understood. Previous studies have suggested that the otic placode is induced by signals from the chordamesoderm and the hindbrain, notably by fibroblast growth factors (Fgfs) and Wnt proteins. Here we study the role of Fgf8 as a bona-fide hindbrain-derived signal that acts in conjunction with Fgf3 during placode induction, maintenance and otic vesicle patterning. Acerebellar (ace) is a mutant in the fgf8 gene that results in a non-functional Fgf8 product. Homozygous mutants for acerebellar (ace) have smaller ears that typically have only one otolith, abnormal semi-circular canals, and behavioral defects. Using gene expression markers for the otic placode, we find that ace/fgf8 and Fgf-signaling are required for normal otic placode formation and maintenance. Conversely, misexpression of fgf8 or Fgf8-coated beads implanted into the vicinity of the otic placode can increase ear size and marker gene expression, although competence to respond to the induction appears restricted. Cell transplantation experiments and expression analysis suggest that Fgf8 is required in the hindbrain in the rhombomere 4-6 area to restore normal placode development in ace mutants, in close neighbourhood to the forming placode, but not in mesodermal tissues. Fgf3 and Fgf8 are expressed in hindbrain rhombomere 4 during the stages that are critical for placode induction. Joint inactivation of Fgf3 and Fgf8 by mutation or antisense-morpholino injection causes failure of placode formation and results in ear-less embryos, mimicking the phenotype we observe after pharmacological inhibition of Fgf-signaling. Fgf8 and Fgf3 together therefore act during induction and differentiation of the ear placode. In addition to the early requirement for Fgf signaling, the abnormal differentiation of inner ear structures and mechanosensory hair cells in ace mutants, pharmacological inhibition of Fgf signaling, and the expression of fgf8 and fgf3 in the otic vesicle demonstrate independent Fgf function(s) during later development of the otic vesicle and lateral line organ. We furthermore addressed a potential role of endomesomerm by studying mzoep mutant embryos that are depleted of head endomesodermal tissue, including chordamesoderm, due to a lack of Nodal-pathway signaling. In these embryos, early placode induction proceeds largely normally, but the ear placode extends abnormally to midline levels at later stages, suggesting a role for the midline in restricting placode development to dorsolateral levels. We suggest a model of zebrafish inner ear development with several discrete steps that utilize sequential Fgf signals during otic placode induction and vesicle patterning. Copyright 2002 Elsevier Science Ireland Ltd.

3-M syndrome: description of six new patients with review of the literature.

PubMed

van der Wal, G; Otten, B J; Brunner, H G; van der Burgt, I

2001-10-01

3-M syndrome combines pre- and postnatal growth retardation and dysmorphic facial features with autosomal recessive inheritance. Six new patients with 3-M syndrome are described and compared with 28 cases from the literature. Our six patients have a growth pattern, which parallels that of Silver-Russell syndrome (SRS). Final height is ISD less in 3-M syndrome than in SRS. Growth hormone treatment significantly increased final height in two of our patients. 3-M syndrome can be differentiated from other types of dwarfism by clinical criteria and by the demonstration of characteristically slender long bones and foreshortened vertebral bodies. We propose that calculating the metacarpal and vertebral indices can be used to measure and document this important diagnostic feature. While the gonadal status of female patients with 3-M syndrome is completely normal, male patients have a gonadal dysfunction and sub- or infertility.

The relation between height, foot length, pelvic adequacy and mode of delivery.

PubMed

Van Bogaert, L J

1999-02-01

To investigate the value of maternal height and foot length as predictors of pelvic adequacy and to evaluate the influence of body components' proportions on the mode of delivery. Retrospective study of the anthropometry of women having normal vertex deliveries (NVD), caesarean sections (CS) and vaginal birth after caesarean (VBAC). NVD patients were taller, had a longer vertebral column, longer lower limbs and longer feet than CS and than VBAC patients. The anthropometric measurements of VBAC patients yielded values intermediate between CS and NVD patients. The ratios of height to any of the other measured variables (vertebral column, lower limb and foot length) were similar in the three groups indicating that the body proportions were the same. Maternal height and foot length are of limited value as predictors of pelvic (in-)adequacy. The anthropometric features of women delivered by CS only are similar to those of women having a vaginal birth after Caesarean.

The scaling and temperature dependence of vertebrate metabolism

PubMed Central

White, Craig R; Phillips, Nicole F; Seymour, Roger S

2005-01-01

Body size and temperature are primary determinants of metabolic rate, and the standard metabolic rate (SMR) of animals ranging in size from unicells to mammals has been thought to be proportional to body mass (M) raised to the power of three-quarters for over 40 years. However, recent evidence from rigorously selected datasets suggests that this is not the case for birds and mammals. To determine whether the influence of body mass on the metabolic rate of vertebrates is indeed universal, we compiled SMR measurements for 938 species spanning six orders of magnitude variation in mass. When normalized to a common temperature of 38 °C, the SMR scaling exponents of fish, amphibians, reptiles, birds and mammals are significantly heterogeneous. This suggests both that there is no universal metabolic allometry and that models that attempt to explain only quarter-power scaling of metabolic rate are unlikely to succeed. PMID:17148344

Incidence of Vertebral Fractures in Women with Systemic Lupus Erythematosus After 8 Years of Follow-Up.

PubMed

García-Carrasco, Mario; Mendoza-Pinto, Claudia; León-Vázquez, María de la Luz; Méndez-Martínez, Socorro; Etchegaray-Morales, Ivet; Montiel-Jarquín, Álvaro; Enriquez-Guerra, Miguel Angel; Muñóz-Guarneros, Margarita; Gálvez-Romero, José Luis; Soto-Santillán, Pamela; Cervera, Ricard

2017-09-01

The aim of this study was to evaluate possible associations between potential risk factors and the occurrence of established vertebral fractures (VF) in Mexican patients with systemic lupus erythematosus (SLE). Consecutive patients with SLE were enrolled in a prospective, observational study from 2006 to 2015. Information on potential risk factors, including demographics, clinical data, and bone mineral density (BMD) at the lumbar spine and hip on dual-energy X-ray absorptiometry was collected at baseline and follow-up. Semiquantitative analysis was used to determine incident VF on lateral thoracic and lumbar radiographs, defined as any vertebral body graded normal at baseline and at least mildly deformed (20-25% reduction or more in any vertebral height) during follow-up. Differences in baseline characteristics were assessed in patients with and without new radiographic VF. Of 110 SLE patients included, with a median follow-up of 8 (IQR 8-9) years, 22 (20%) had radiographic VF at baseline; 35 (32%) patients had a new VF. The annual incidence rate of new morphometric VF was 3.5 (95% CI 2.4-4.91) per 100 patient/years. Most fractures were mild or moderate and biconcave shaped. Incident VF were significantly associated with baseline BMD at the total hip and longer disease duration. Cumulative glucocorticoid dose, postmenopausal status, and previous prevalent VF were not associated with VF. In this SLE cohort in daily clinical practice, new VF were frequently present in SLE patients, especially those with longer disease duration and low-hip BMD.

Effect of teriparatide on pregnancy and lactation-associated osteoporosis with multiple vertebral fractures.

PubMed

Choe, Eun Yeong; Song, Je Eun; Park, Kyeong Hye; Seok, Hannah; Lee, Eun Jig; Lim, Sung-Kil; Rhee, Yumie

2012-09-01

Pregnancy and lactation-associated osteoporosis (PLO) is very rare, but it can cause severe vertebral compression fractures with disabling back pain. PLO patients have commonly been treated with antiresorptive agents against high bone turnover. There are, however, some concerns regarding the use of bisphosphonates: (1) PLO occurs during the first pregnancy with a high possibility of recurrence during the second pregnancy, (2) long-term outcomes of bisphosphonates in PLO are lacking, and (3) there is a possibility of bisphosphonates accumulated in the bones crossing the placenta. Therefore, alternative therapies must be considered. We analyzed the effect of teriparatide (TPTD), the human recombinant parathyroid hormone (1-34), for 18 months in three women with PLO. Multiple vertebral fractures with severe back pain appeared within 6 months after their first childbirth. Two of them had a family history of osteoporosis. Lactation was discontinued immediately after diagnosis of PLO. Calcium carbonate, cholecalciferol, and TPTD were prescribed. The back pain immediately resolved. Bone mineral density (BMD) increased by 14.5-25.0% (mean 19.5%) at the lumbar spine and by 9.5-16.7% (mean 13.1%) at the femoral neck, after 18 months of treatment. The final Z scores in these PLO patients were nearly normalized. Two women had a second baby without any complication. BMD significantly improved after 18 months of treatment with TPTD without further fractures. In conclusion, TPTD should be considered to avoid long-term morbidity in young patients with PLO and is highly encouraged for use in PLO patients with multiple vertebral fractures.

Breaking evolutionary and pleiotropic constraints in mammals: On sloths, manatees and homeotic mutations

PubMed Central

2011-01-01

Background Mammals as a rule have seven cervical vertebrae, except for sloths and manatees. Bateson proposed that the change in the number of cervical vertebrae in sloths is due to homeotic transformations. A recent hypothesis proposes that the number of cervical vertebrae in sloths is unchanged and that instead the derived pattern is due to abnormal primaxial/abaxial patterning. Results We test the detailed predictions derived from both hypotheses for the skeletal patterns in sloths and manatees for both hypotheses. We find strong support for Bateson's homeosis hypothesis. The observed vertebral and rib patterns cannot be explained by changes in primaxial/abaxial patterning. Vertebral patterns in sloths and manatees are similar to those in mice and humans with abnormal numbers of cervical vertebrae: incomplete and asymmetric homeotic transformations are common and associated with skeletal abnormalities. In sloths the homeotic vertebral shift involves a large part of the vertebral column. As such, similarity is greatest with mice mutant for genes upstream of Hox. Conclusions We found no skeletal abnormalities in specimens of sister taxa with a normal number of cervical vertebrae. However, we always found such abnormalities in conspecifics with an abnormal number, as in many of the investigated dugongs. These findings strongly support the hypothesis that the evolutionary constraints on changes of the number of cervical vertebrae in mammals is due to deleterious pleitropic effects. We hypothesize that in sloths and manatees low metabolic and activity rates severely reduce the usual stabilizing selection, allowing the breaking of the pleiotropic constraints. This probably also applies to dugongs, although to a lesser extent. PMID:21548920

Phylostratigraphic profiles in zebrafish uncover chordate origins of the vertebrate brain.

PubMed

Šestak, Martin Sebastijan; Domazet-Lošo, Tomislav

2015-02-01

An elaborated tripartite brain is considered one of the important innovations of vertebrates. Other extant chordate groups have a more basic brain organization. For instance, cephalochordates possess a relatively simple brain possibly homologous to the vertebrate forebrain and hindbrain, whereas tunicates display the tripartite organization, but without the specialized brain centers. The difference in anatomical complexity is even more pronounced if one compares chordates with other deuterostomes that have only a diffuse nerve net or alternatively a rather simple central nervous system. To gain a new perspective on the evolutionary roots of the complex vertebrate brain, we made here a phylostratigraphic analysis of gene expression patterns in the developing zebrafish (Danio rerio). The recovered adaptive landscape revealed three important periods in the evolutionary history of the zebrafish brain. The oldest period corresponds to preadaptive events in the first metazoans and the emergence of the nervous system at the metazoan-eumetazoan transition. The origin of chordates marks the next phase, where we found the overall strongest adaptive imprint in almost all analyzed brain regions. This finding supports the idea that the vertebrate brain evolved independently of the brains within the protostome lineage. Finally, at the origin of vertebrates we detected a pronounced signal coming from the dorsal telencephalon, in agreement with classical theories that consider this part of the cerebrum a genuine vertebrate innovation. Taken together, these results reveal a stepwise adaptive history of the vertebrate brain where most of its extant organization was already present in the chordate ancestor. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Convergent evolution of hemoglobin switching in jawed and jawless vertebrates.

PubMed

Rohlfing, Kim; Stuhlmann, Friederike; Docker, Margaret F; Burmester, Thorsten

2016-02-01

During development, humans and other jawed vertebrates (Gnathostomata) express distinct hemoglobin genes, resulting in different hemoglobin tetramers. Embryonic and fetal hemoglobin have higher oxygen affinities than the adult hemoglobin, sustaining the oxygen demand of the developing organism. Little is known about the expression of hemoglobins during development of jawless vertebrates (Agnatha). We identified three hemoglobin switches in the life cycle of the sea lamprey. Three hemoglobin genes are specifically expressed in the embryo, four genes in the filter feeding larva (ammocoete), and nine genes correspond to the adult hemoglobin chains. During the development from the parasitic to the reproductive adult, the composition of hemoglobin changes again, with a massive increase of chain aHb1. A single hemoglobin chain is expressed constitutively in all stages. We further showed the differential expression of other globin genes: Myoglobin 1 is most highly expressed in the reproductive adult, myoglobin 2 expression peaks in the larva. Globin X1 is restricted to the embryo; globin X2 was only found in the reproductive adult. Cytoglobin is expressed at low levels throughout the life cycle. Because the hemoglobins of jawed and jawless vertebrates evolved independently from a common globin ancestor, hemoglobin switching must also have evolved convergently in these taxa. Notably, the ontogeny of sea lamprey hemoglobins essentially recapitulates their phylogeny, with the embryonic hemoglobins emerging first, followed by the evolution of larval and adult hemoglobins.

Cerberus-Nodal-Lefty-Pitx signaling cascade controls left-right asymmetry in amphioxus.

PubMed

Li, Guang; Liu, Xian; Xing, Chaofan; Zhang, Huayang; Shimeld, Sebastian M; Wang, Yiquan

2017-04-04

Many bilaterally symmetrical animals develop genetically programmed left-right asymmetries. In vertebrates, this process is under the control of Nodal signaling, which is restricted to the left side by Nodal antagonists Cerberus and Lefty. Amphioxus, the earliest diverging chordate lineage, has profound left-right asymmetry as a larva. We show that Cerberus , Nodal , Lefty , and their target transcription factor Pitx are sequentially activated in amphioxus embryos. We then address their function by transcription activator-like effector nucleases (TALEN)-based knockout and heat-shock promoter (HSP)-driven overexpression. Knockout of Cerberus leads to ectopic right-sided expression of Nodal , Lefty , and Pitx , whereas overexpression of Cerberus represses their left-sided expression. Overexpression of Nodal in turn represses Cerberus and activates Lefty and Pitx ectopically on the right side. We also show Lefty represses Nodal , whereas Pitx activates Nodal These data combine in a model in which Cerberus determines whether the left-sided gene expression cassette is activated or repressed. These regulatory steps are essential for normal left-right asymmetry to develop, as when they are disrupted embryos may instead form two phenotypic left sides or two phenotypic right sides. Our study shows the regulatory cassette controlling left-right asymmetry was in place in the ancestor of amphioxus and vertebrates. This includes the Nodal inhibitors Cerberus and Lefty, both of which operate in feedback loops with Nodal and combine to establish asymmetric Pitx expression. Cerberus and Lefty are missing from most invertebrate lineages, marking this mechanism as an innovation in the lineage leading to modern chordates.

Retinoid quantification by HPLC/MS(n)

NASA Technical Reports Server (NTRS)

McCaffery, Peter; Evans, James; Koul, Omanand; Volpert, Amy; Reid, Kevin; Ullman, M. David

2002-01-01

Retinoic acid (RA) mediates most of the biological effects of vitamin A that are essential for vertebrate survival. It acts through binding to receptors that belong to the nuclear receptor transcription factor superfamily (Mangelsdorf et al. 1994). It is also a highly potent vertebrate teratogen. To determine the function and effects of endogenous and exogenous RA, it is important to have a highly specific, sensitive, accurate, and precise analytical procedure. Current analyses of RA and other retinoids are labor intensive, of poor sensitivity, have limited specificity, or require compatibility with RA reporter cell lines (Chen et al. 1995. BIOCHEM: Pharmacol. 50: 1257-1264; Creech Kraft et al. 1994. BIOCHEM: J. 301: 111-119; Lanvers et al. 1996. J. Chromatogr. B Biomed. Appl. 685: 233-240; Maden et al. 1998. DEVELOPMENT: 125: 4133-4144; Wagner et al. 1992. DEVELOPMENT: 116: 55-66). This paper describes an HPLC/mass spectrometry/mass spectrometry product ion scan (HPLC/MS(n)) procedure for the analysis of retinoids that employs atmospheric pressure chemical ionization MS. The retinoids are separated by normal-phase column chromatography with a linear hexane-isopropanol-dioxane gradient. Each retinoid is detected by a unique series of MS(n) functions set at optimal collision-induced dissociation energy (30% to 32%) for all MS(n) steps. The scan events are divided into three segments, based on HPLC elution order, to maximize the mass spectrometer duty cycle. The all-trans, 9-cis, and 13-cis RA isomers are separated, if desired, by an isocratic hexane-dioxane-isopropanol mobile phase. This paper describes an HPLC/MS(n) procedure possessing high sensitivity and specificity for retinoids.

Molecular cloning of Foxl2 gene and the effects of endocrine-disrupting chemicals on its mRNA level in rare minnow, Gobiocypris rarus.

PubMed

Wang, Houpeng; Wu, Tingting; Qin, Fang; Wang, Lihong; Wang, Zaizhao

2012-06-01

Endocrine-disrupting chemicals (EDCs) can affect normal sexual differentiation in fish. Foxl2, one forkhead transcription factor, plays an important role in ovarian differentiation in the early development of the female gonad in mammals and fish. How EDCs affect Foxl2 expression is little known. In this study, we isolated a Foxl2 cDNA from the ovary of rare minnow Gobiocypris rarus and examined its expression during early development stages and in different adult tissues. Then, we analyzed Foxl2 expression in G. rarus juvenile following 3-day exposure to 17α- ethinylestradiol (EE2), 4-n-nonylphenol (NP), and bisphenol A (BPA). Alignment of known Foxl2 sequences among vertebrates showed high identity in forkhead domain and C-terminal region with other vertebrate proteins. Quantitative RT-PCR analysis showed that Foxl2 expression was linear decrease and cyp19a1a, the downstream target gene of Foxl2, had no correlation with Foxl2 from 18 to 50 days post fertilization (dpf). Among different adult tissues, Foxl2 is mainly expressed in ovary, brain, gill, eye, and male spleen. In the 3-day exposure, the juvenile fish to EDCs, 0.1 nM EE2, and 1 nM BPA significantly up-regulated the expression of Foxl2 gene, while NP had no effect on Foxl2 expression. Altogether, these results provide basic data for further study on how Foxl2 mediates EDCs impact on the sexual differentiation in G. rarus.

[Spinal manipulative therapy and cervical artery dissections].

PubMed

Saxler, G; Schopphoff, E; Quitmann, H; Quint, U

2005-06-01

Severe complications after cervical spine manipulation are rare. As experts for medical treatment errors, we received between July 2002 and February 2004 cases with serious complications in the central nervous system after manipulation. 5 vertebral artery dissections with subsequent brain infarction were registered. In all cases, the patients showed complete persisting remission of symptoms. In addition, a kinematic estimation model was developed to study the possible causes of vertebral artery damage. We were able to demonstrate that material extension is dependent on cervical rotation and the "free length" of the vertebral artery in the upper cervical spine.

100 years of Drosophila research and its impact on vertebrate neuroscience: a history lesson for the future.

PubMed

Bellen, Hugo J; Tong, Chao; Tsuda, Hiroshi

2010-07-01

Discoveries in fruit flies have greatly contributed to our understanding of neuroscience. The use of an unparalleled wealth of tools, many of which originated between 1910–1960, has enabled milestone discoveries in nervous system development and function. Such findings have triggered and guided many research efforts in vertebrate neuroscience. After 100 years, fruit flies continue to be the choice model system for many neuroscientists. The combinational use of powerful research tools will ensure that this model organism will continue to lead to key discoveries that will impact vertebrate neuroscience.

100 years of Drosophila research and its impact on vertebrate neuroscience: a history lesson for the future

PubMed Central

Bellen, Hugo J; Tong, Chao; Tsuda, Hiroshi

2014-01-01

Discoveries in fruit flies have greatly contributed to our understanding of neuroscience. The use of an unparalleled wealth of tools, many of which originated between 1910–1960, has enabled milestone discoveries in nervous system development and function. Such findings have triggered and guided many research efforts in vertebrate neuroscience. After 100 years, fruit flies continue to be the choice model system for many neuroscientists. The combinational use of powerful research tools will ensure that this model organism will continue to lead to key discoveries that will impact vertebrate neuroscience. PMID:20383202

A comparative meta-analysis of maximal aerobic metabolism of vertebrates: implications for respiratory and cardiovascular limits to gas exchange.

PubMed

Hillman, Stanley S; Hancock, Thomas V; Hedrick, Michael S

2013-02-01

Maximal aerobic metabolic rates (MMR) in vertebrates are supported by increased conductive and diffusive fluxes of O(2) from the environment to the mitochondria necessitating concomitant increases in CO(2) efflux. A question that has received much attention has been which step, respiratory or cardiovascular, provides the principal rate limitation to gas flux at MMR? Limitation analyses have principally focused on O(2) fluxes, though the excess capacity of the lung for O(2) ventilation and diffusion remains unexplained except as a safety factor. Analyses of MMR normally rely upon allometry and temperature to define these factors, but cannot account for much of the variation and often have narrow phylogenetic breadth. The unique aspect of our comparative approach was to use an interclass meta-analysis to examine cardio-respiratory variables during the increase from resting metabolic rate to MMR among vertebrates from fish to mammals, independent of allometry and phylogeny. Common patterns at MMR indicate universal principles governing O(2) and CO(2) transport in vertebrate cardiovascular and respiratory systems, despite the varied modes of activities (swimming, running, flying), different cardio-respiratory architecture, and vastly different rates of metabolism (endothermy vs. ectothermy). Our meta-analysis supports previous studies indicating a cardiovascular limit to maximal O(2) transport and also implicates a respiratory system limit to maximal CO(2) efflux, especially in ectotherms. Thus, natural selection would operate on the respiratory system to enhance maximal CO(2) excretion and the cardiovascular system to enhance maximal O(2) uptake. This provides a possible evolutionary explanation for the conundrum of why the respiratory system appears functionally over-designed from an O(2) perspective, a unique insight from previous work focused solely on O(2) fluxes. The results suggest a common gas transport blueprint, or Bauplan, in the vertebrate clade.

The painted turtle, Chrysemys picta: a model system for vertebrate evolution, ecology, and human health.

PubMed

Valenzuela, Nicole

2009-07-01

Painted turtles (Chrysemys picta) are representatives of a vertebrate clade whose biology and phylogenetic position hold a key to our understanding of fundamental aspects of vertebrate evolution. These features make them an ideal emerging model system. Extensive ecological and physiological research provide the context in which to place new research advances in evolutionary genetics, genomics, evolutionary developmental biology, and ecological developmental biology which are enabled by current resources, such as a bacterial artificial chromosome (BAC) library of C. picta, and the imminent development of additional ones such as genome sequences and cDNA and expressed sequence tag (EST) libraries. This integrative approach will allow the research community to continue making advances to provide functional and evolutionary explanations for the lability of biological traits found not only among reptiles but vertebrates in general. Moreover, because humans and reptiles share a common ancestor, and given the ease of using nonplacental vertebrates in experimental biology compared with mammalian embryos, painted turtles are also an emerging model system for biomedical research. For example, painted turtles have been studied to understand many biological responses to overwintering and anoxia, as potential sentinels for environmental xenobiotics, and as a model to decipher the ecology and evolution of sexual development and reproduction. Thus, painted turtles are an excellent reptilian model system for studies with human health, environmental, ecological, and evolutionary significance.

Risk Prediction of New Adjacent Vertebral Fractures After PVP for Patients with Vertebral Compression Fractures: Development of a Prediction Model

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

Zhong, Bin-Yan; He, Shi-Cheng; Zhu, Hai-Dong

PurposeWe aim to determine the predictors of new adjacent vertebral fractures (AVCFs) after percutaneous vertebroplasty (PVP) in patients with osteoporotic vertebral compression fractures (OVCFs) and to construct a risk prediction score to estimate a 2-year new AVCF risk-by-risk factor condition.Materials and MethodsPatients with OVCFs who underwent their first PVP between December 2006 and December 2013 at Hospital A (training cohort) and Hospital B (validation cohort) were included in this study. In training cohort, we assessed the independent risk predictors and developed the probability of new adjacent OVCFs (PNAV) score system using the Cox proportional hazard regression analysis. The accuracy ofmore » this system was then validated in both training and validation cohorts by concordance (c) statistic.Results421 patients (training cohort: n = 256; validation cohort: n = 165) were included in this study. In training cohort, new AVCFs after the first PVP treatment occurred in 33 (12.9%) patients. The independent risk factors were intradiscal cement leakage and preexisting old vertebral compression fracture(s). The estimated 2-year absolute risk of new AVCFs ranged from less than 4% in patients with neither independent risk factors to more than 45% in individuals with both factors.ConclusionsThe PNAV score is an objective and easy approach to predict the risk of new AVCFs.« less

Outgroup, alignment and modelling improvements indicate that two TNFSF13-like genes existed in the vertebrate ancestor.

PubMed

Redmond, Anthony K; Pettinello, Rita; Dooley, Helen

2017-03-01

The molecular machinery required for lymphocyte development and differentiation appears to have emerged concomitantly with distinct B- and T-like lymphocyte subsets in the ancestor of all vertebrates. The TNFSF superfamily (TNFSF) members BAFF (TNFSF13/Blys) and APRIL (TNFSF13) are key regulators of B cell development survival, and activation in mammals, but the temporal emergence of these molecules, and their precise relationship to the newly identified TNFSF gene BALM (BAFF and APRIL-like molecule), have not yet been elucidated. Here, to resolve the early evolutionary history of this family, we improved outgroup sampling and alignment quality, and applied better fitting substitution models compared to past studies. Our analyses reveal that BALM is a definitive TNFSF13 family member, which split from BAFF in the gnathostome (jawed vertebrate) ancestor. Most importantly, however, we show that both the APRIL and BAFF lineages existed in the ancestors of all extant vertebrates. This implies that APRIL has been lost, or is yet to be found, in cyclostomes (jawless vertebrates). Our results suggest that lineage-specific gene duplication and loss events have caused lymphocyte regulation, despite shared origins, to become secondarily distinct between gnathostomes and cyclostomes. Finally, the structure of lamprey BAFF-like, and its phylogenetic placement as sister to BAFF and BALM, but not the more slowly evolving APRIL, indicates that the primordial lymphocyte regulator was more APRIL-like than BAFF-like.

PERCHLORATE INDUCES HERMAPHRODITISM IN THREESPINE STICKLEBACKS

PubMed Central

Bernhardt, Richard R.; von Hippel, Frank A.; Cresko, William A.

2011-01-01

Recently, concern regarding perchlorate contamination has arisen in many contexts. Perchlorate has many military, commercial, and domestic applications, and it has been found in milk, drinking and irrigation water, and produce. Perchlorate is harmful at low levels, yet it remains unregulated in the United States while the U.S. Environmental Protection Agency attempts to establish acceptable exposure levels. The present study investigated potential reproductive effects on vertebrates using a model fish species, the threespine stickleback (Gasterosteus aculeatus). Sticklebacks were raised from syngamy through sexual maturity in untreated water and in three target concentrations of sodium perchlorate–treated water. Perchlorate was found to interfere with the expression of nuptial coloration, courtship behavior, and normal sexual development. Genetic testing revealed that some females were masculinized to the extent that they produced both sperm and eggs, and histological analysis showed that these individuals had intersexual gonads (ovotestes) containing both oocytes and cells undergoing spermatogenesis. In vitro fertilizations revealed that those gametes were capable of self- and cross-fertilization. However, crosses using sperm derived from genetic females died either during the blastula phase or near the onset of organogenesis. Sperm derived from genetic males produced viable fry when crossed with eggs derived from genetic females from all treatments. To our knowledge, the present study provides the first evidence that perchlorate produces androgenic effects and is capable of inducing functional hermaphroditism in a nonhermaphroditic vertebrate. PMID:16916028

Cloning of a neonatal calcium atpase isoform (SERCA 1B) from extraocular muscle of adult blue marlin (Makaira nigricans).

PubMed

Londraville, R L; Cramer, T D; Franck, J P; Tullis, A; Block, B A

2000-10-01

Complete cDNAs for the fast-twitch Ca2+ -ATPase isoform (SERCA 1) were cloned and sequenced from blue marlin (Makaira nigricans) extraocular muscle (EOM). Complete cDNAs for SERCA 1 were also cloned from fast-twitch skeletal muscle of the same species. The two sequences are identical over the coding region except for the last five codons on the carboxyl end; EOM SERCA 1 cDNA codes for 996 amino acids and the fast-twitch cDNAs code for 991 aa. Phylogenetic analysis revealed that EOM SERCA 1 clusters with an isoform of Ca2+ -ATPase normally expressed in early development of mammals (SERCA 1B). This is the first report of SERCA 1B in an adult vertebrate. RNA hybridization assays indicate that 1B expression is limited to extraocular muscles. Because EOM gives rise to the thermogenic heater organ in marlin, we investigated whether SERCA 1B may play a role in heat generation, or if 1B expression is common in EOM among vertebrates. Chicken also expresses SERCA 1B in EOM, but rat expresses SERCA 1A; because SERCA 1B is not specific to heater tissue we conclude it is unlikely that it plays a specific role in intracellular heat production. Comparative sequence analysis does reveal, however, several sites that may be the source of functional differences between fish and mammalian SERCAs.

A new molecular logic for BMP-mediated dorsoventral patterning in the leech Helobdella.

PubMed

Kuo, Dian-Han; Weisblat, David A

2011-08-09

Bone morphogenetic protein (BMP) signaling is broadly implicated in dorsoventral (DV) patterning of bilaterally symmetric animals [1-3], and its role in axial patterning apparently predates the birth of Bilateria [4-7]. In fly and vertebrate embryos, BMPs and their antagonists (primarily Sog/chordin) diffuse and interact to generate signaling gradients that pattern fields of cells [8-10]. Work in other species reveals diversity in essential facets of this ancient patterning process, however. Here, we report that BMP signaling patterns the DV axis of segmental ectoderm in the leech Helobdella, a clitellate annelid (superphylum Lophotrochozoa) featuring stereotyped developmental cell lineages, but the detailed mechanisms of DV patterning in Helobdella differ markedly from fly and vertebrates. In Helobdella, BMP2/4s are expressed broadly, rather than in dorsal territory, whereas a dorsally expressed BMP5-8 specifies dorsal fate by short-range signaling. A BMP antagonist, gremlin, is upregulated by BMP5-8 in dorsolateral, rather than ventral territory, and yet the BMP-antagonizing activity of gremlin is required for normal ventral cell fates. Gremlin promotes ventral fates without disrupting dorsal fates by selectively inhibiting BMP2/4s, not BMP5-8. Thus, DV patterning in the development of the leech revealed unexpected evolutionary plasticity of the conserved BMP patterning system, presumably reflecting its adaptation to different modes of embryogenesis. Copyright © 2011 Elsevier Ltd. All rights reserved.

Scube3 Is Expressed in Multiple Tissues during Development but Is Dispensable for Embryonic Survival in the Mouse

PubMed Central

Xavier, Guilherme M.; Panousopoulos, Leonidas; Cobourne, Martyn T.

2013-01-01

The vertebrate Scube family consists of three independent members Scube1-3; which encode secreted cell surface-associated membrane glycoproteins that share a domain organization of at least five recognizable motifs and the ability to both homo- and heterodimerize. There is recent biochemical evidence to suggest that Scube2 is directly involved in Hedgehog signaling, acting co-operatively with Dispatched to mediate the release in soluble form of cholesterol and palmitate-modified Hedgehog ligand during long-range activity. Indeed, in the zebrafish myotome, all three Scube proteins can subtly promote Hedgehog signal transduction in a non-cell autonomous manner. In order to further investigate the role of Scube genes during development, we have generated mice with targeted inactivation of Scube3. Despite a dynamic developmental expression pattern, with transcripts present in neuroectoderm, endoderm and endochondral tissues, particularly within the craniofacial region; an absence of Scube3 function results in no overt embryonic phenotype in the mouse. Mutant mice are born at expected Mendelian ratios, are both viable and fertile, and seemingly retain normal Hedgehog signaling activity in craniofacial tissues. These findings suggest that in the mouse, Scube3 is dispensable for normal development; however, they do not exclude the possibility of a co-operative role for Scube3 with other Scube members during embryogenesis or a potential role in adult tissue homeostasis over the long-term. PMID:23383134

Development and evolution of the vertebrate primary mouth

PubMed Central

Soukup, Vladimír; Horácek, Ivan; Cerny, Robert

2013-01-01

The vertebrate oral region represents a key interface between outer and inner environments, and its structural and functional design is among the limiting factors for survival of its owners. Both formation of the respective oral opening (primary mouth) and establishment of the food-processing apparatus (secondary mouth) require interplay between several embryonic tissues and complex embryonic rearrangements. Although many aspects of the secondary mouth formation, including development of the jaws, teeth or taste buds, are known in considerable detail, general knowledge about primary mouth formation is regrettably low. In this paper, primary mouth formation is reviewed from a comparative point of view in order to reveal its underestimated morphogenetic diversity among, and also within, particular vertebrate clades. In general, three main developmental modes were identified. The most common is characterized by primary mouth formation via a deeply invaginated ectodermal stomodeum and subsequent rupture of the bilaminar oral membrane. However, in salamander, lungfish and also in some frog species, the mouth develops alternatively via stomodeal collar formation contributed both by the ecto- and endoderm. In ray-finned fishes, on the other hand, the mouth forms via an ectoderm wedge and later horizontal detachment of the initially compressed oral epithelia with probably a mixed germ-layer derivation. A very intriguing situation can be seen in agnathan fishes: whereas lampreys develop their primary mouth in a manner similar to the most common gnathostome pattern, hagfishes seem to undergo a unique oropharyngeal morphogenesis when compared with other vertebrates. In discussing the early formative embryonic correlates of primary mouth formation likely to be responsible for evolutionary–developmental modifications of this area, we stress an essential role of four factors: first, positioning and amount of yolk tissue; closely related to, second, endoderm formation during gastrulation, which initiates the process and constrains possible evolutionary changes within this area; third, incipient structure of the stomodeal primordium at the anterior neural plate border, where the ectoderm component of the prospective primary mouth is formed; and fourth, the prime role of Pitx genes for establishment and later morphogenesis of oral region both in vertebrates and non-vertebrate chordates. PMID:22804777

Developmental mechanisms of macroevolutionary change in the tetrapod axis: A case study of Sauropterygia

PubMed Central

Soul, Laura C.; Benson, Roger B. J.

2017-01-01

Understanding how developmental processes change on macroevolutionary timescales to generate body plan disparity is fundamental to the study of vertebrate evolution. Adult morphology of the vertebral column directly reflects the mechanisms that generate vertebral counts (somitogenesis) and their regionalisation (homeotic effects) during embryonic development. Sauropterygians were a group of Mesozoic marine reptiles that exhibited an extremely high disparity of presacral vertebral/somite counts. Using phylogenetic comparative methods, we demonstrate that somitogenesis and homeotic effects evolved in a co‐ordinated way among sauropterygians, contrasting with the wider pattern in tetrapods, in which somitogenetic and homeotic shifts are uncorrelated. Changes in sauropterygian body proportions were primarily enabled by homeotic shifts, with a lesser, but important, contribution from differences in postpatterning growth among somites. High body plan plasticity was present in Triassic sauropterygians and was maintained among their Jurassic and Cretaceous descendants. The extreme disparity in the body plan of plesiosaurian sauropterygians did not result from accelerated rates of evolutionary change in neck length, but instead reflect this ancestral versatility of sauropterygian axial development. Our results highlight variation in modes of axial development among tetrapods, and show that heterogeneous statistical models can uncover novel macroevolutionary patterns for animal body plans and the developmental mechanisms that control them. PMID:28240769

An ancient dental gene set governs development and continuous regeneration of teeth in sharks.

PubMed

Rasch, Liam J; Martin, Kyle J; Cooper, Rory L; Metscher, Brian D; Underwood, Charlie J; Fraser, Gareth J

2016-07-15

The evolution of oral teeth is considered a major contributor to the overall success of jawed vertebrates. This is especially apparent in cartilaginous fishes including sharks and rays, which develop elaborate arrays of highly specialized teeth, organized in rows and retain the capacity for life-long regeneration. Perpetual regeneration of oral teeth has been either lost or highly reduced in many other lineages including important developmental model species, so cartilaginous fishes are uniquely suited for deep comparative analyses of tooth development and regeneration. Additionally, sharks and rays can offer crucial insights into the characters of the dentition in the ancestor of all jawed vertebrates. Despite this, tooth development and regeneration in chondrichthyans is poorly understood and remains virtually uncharacterized from a developmental genetic standpoint. Using the emerging chondrichthyan model, the catshark (Scyliorhinus spp.), we characterized the expression of genes homologous to those known to be expressed during stages of early dental competence, tooth initiation, morphogenesis, and regeneration in bony vertebrates. We have found that expression patterns of several genes from Hh, Wnt/β-catenin, Bmp and Fgf signalling pathways indicate deep conservation over ~450 million years of tooth development and regeneration. We describe how these genes participate in the initial emergence of the shark dentition and how they are redeployed during regeneration of successive tooth generations. We suggest that at the dawn of the vertebrate lineage, teeth (i) were most likely continuously regenerative structures, and (ii) utilised a core set of genes from members of key developmental signalling pathways that were instrumental in creating a dental legacy redeployed throughout vertebrate evolution. These data lay the foundation for further experimental investigations utilizing the unique regenerative capacity of chondrichthyan models to answer evolutionary, developmental, and regenerative biological questions that are impossible to explore in classical models. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

The diving paradox: new insights into the role of the dive response in air-breathing vertebrates.

PubMed

Davis, Randall W; Polasek, Lori; Watson, Rebecca; Fuson, Amanda; Williams, Terrie M; Kanatous, Shane B

2004-07-01

When aquatic reptiles, birds and mammals submerge, they typically exhibit a dive response in which breathing ceases, heart rate slows, and blood flow to peripheral tissues is reduced. The profound dive response that occurs during forced submergence sequesters blood oxygen for the brain and heart while allowing peripheral tissues to become anaerobic, thus protecting the animal from immediate asphyxiation. However, the decrease in peripheral blood flow is in direct conflict with the exercise response necessary for supporting muscle metabolism during submerged swimming. In free diving animals, a dive response still occurs, but it is less intense than during forced submergence, and whole-body metabolism remains aerobic. If blood oxygen is not sequestered for brain and heart metabolism during normal diving, then what is the purpose of the dive response? Here, we show that its primary role may be to regulate the degree of hypoxia in skeletal muscle so that blood and muscle oxygen stores can be efficiently used. Paradoxically, the muscles of diving vertebrates must become hypoxic to maximize aerobic dive duration. At the same time, morphological and enzymatic adaptations enhance intracellular oxygen diffusion at low partial pressures of oxygen. Optimizing the use of blood and muscle oxygen stores allows aquatic, air-breathing vertebrates to exercise for prolonged periods while holding their breath.

Mutations in zebrafish pitx2 model congenital malformations in Axenfeld-Rieger syndrome but do not disrupt left-right placement of visceral organs.

PubMed

Ji, Yongchang; Buel, Sharleen M; Amack, Jeffrey D

2016-08-01

Pitx2 is a conserved homeodomain transcription factor that has multiple functions during embryonic development. Mutations in human PITX2 cause autosomal dominant Axenfeld-Rieger syndrome (ARS), characterized by congenital eye and tooth malformations. Pitx2(-/-) knockout mouse models recapitulate aspects of ARS, but are embryonic lethal. To date, ARS treatments remain limited to managing individual symptoms due to an incomplete understanding of PITX2 function. In addition to regulating eye and tooth development, Pitx2 is a target of a conserved Nodal (TGFβ) signaling pathway that mediates left-right (LR) asymmetry of visceral organs. Based on its highly conserved asymmetric expression domain, the Nodal-Pitx2 axis has long been considered a common denominator of LR development in vertebrate embryos. However, functions of Pitx2 during asymmetric organ morphogenesis are not well understood. To gain new insight into Pitx2 function we used genome editing to create mutations in the zebrafish pitx2 gene. Mutations in the pitx2 homeodomain caused phenotypes reminiscent of ARS, including aberrant development of the cornea and anterior chamber of the eye and reduced or absent teeth. Intriguingly, LR asymmetric looping of the heart and gut was normal in pitx2 mutants. These results suggest conserved roles for Pitx2 in eye and tooth development and indicate Pitx2 is not required for asymmetric looping of zebrafish visceral organs. This work establishes zebrafish pitx2 mutants as a new animal model for investigating mechanisms underlying congenital malformations in ARS and high-throughput drug screening for ARS therapeutics. Additionally, pitx2 mutants present a unique opportunity to identify new genes involved in vertebrate LR patterning. We show Nodal signaling-independent of Pitx2-controls asymmetric expression of the fatty acid elongase elovl6 in zebrafish, pointing to a potential novel pathway during LR organogenesis. Copyright © 2016 Elsevier Inc. All rights reserved.

DAX1/NR0B1 was expressed during mammalian gonadal development and gametogenesis before it was recruited to the eutherian X chromosome.

PubMed

Stickels, Robert; Clark, Kevin; Heider, Thomas N; Mattiske, Deidre M; Renfree, Marilyn B; Pask, Andrew J

2015-01-01

The nuclear receptor subfamily 0, group B, member 1 (NR0B1) gene is an orphan nuclear receptor that is X-linked in eutherian mammals and plays a critical role in the establishment and function of the hypothalamic-pituitary-adrenal-gonadal axis. Duplication or overexpression of NR0B1 in eutherian males causes male to female sex reversal, and mutation and deletions of NR0B1 cause testicular defects. Thus, gene dosage is critical for the function of NR0B1 in normal gonadogenesis. However, NR0B1 is autosomal in all noneutherian vertebrates, including marsupials and monotreme mammals, and two active copies of the gene are compatible with both male and female gonadal development. In the current study, we examined the evolution and expression of autosomal NR0B1 during gonadal development in a marsupial (the tammar wallaby) as compared to the role of its X-linked orthologues in a eutherian (the mouse). We show that NR0B1 underwent rapid evolutionary change when it relocated from its autosomal position in the nonmammalian vertebrates, monotremes, and marsupials to an X-linked location in eutherian mammals. Despite the acquisition of a novel genomic location and a unique N-terminal domain, NR0B1 protein distribution was remarkably similar between mice and marsupials both throughout gonadal development and during gamete formation. A conserved accumulation of NR0B1 protein was observed in developing oocytes, where its function appears to be critical in the early embryo, prior to zygotic genome activation. Together these findings suggest that NR0B1 had a conserved role in gonadogenesis that existed long before it moved to the X chromosome and despite undergoing significant evolutionary change. © 2015 by the Society for the Study of Reproduction, Inc.

The Development of Children's Ideas on Animal Classification, Form and Function; Is School Experience Becoming Increasingly Impoverished?

ERIC Educational Resources Information Center

Braund, Martin

This paper begins with a review of previous research into children's classification schema, specifically with regard to the concept of vertebrate/invertebrate, before citing the details of more recent findings with primary aged children. This research explores the concept of vertebrate/invertebrate and how ideas progress across primary and…

Video Views and Reviews: Neurulation and the Fashioning of the Vertebrate Central Nervous System

ERIC Educational Resources Information Center

Watters, Christopher

2006-01-01

The central nervous system (CNS) is the first adult organ system to appear during vertebrate development, and the process of its emergence is commonly called neurulation. Such biological "urgency" is perhaps not surprising given the structural and functional complexity of the CNS and the importance of neural function to adaptive behavior and…

Plasticity of Neurovestibular Systems Following Micro- and Hyper-Gravity Exposure and Readaptation to Earth's 1G

NASA Technical Reports Server (NTRS)

Boyle, Richard D.

2012-01-01

The gravity-sensing organs sense the sum of inertial force due to head translation and head orientation relative to gravity. Normally gravity is constant, and yet the neural sensors show remarkable plasticity. When the force of gravity changes, such as in spaceflight or during centrifugation, the neurovestibular system responds by regulating its neural output, and this response is similar for the vertebrate utricular nerve afferents and for the statocyst hair cell in invertebrates. First, we examine the response of utricular afferents in toadfish following exposure to G on two orbital missions (STS-90 and 95). Within the first day after landing, magnitude of neural response to an applied acceleration was significantly elevated, and re-adaptation back to control values occurred within approximately 30 hours. Time course of return to normal approximately parallels the decrease in vestibular disorientation in astronauts following return. Next, we use well-controlled hyper-G experiments in the vertebrate model to address: If G leads to adaptation and subsequent re-adaptation neural processes, does the transfer from 1G to hyper-G impart the opposite effects and do the effects accompanying transfer from the hyper-G back to the 1G conditions resemble as an analog the transfer from 1G to the microG Results show a biphasic pattern in reaction to 3G exposures: an initial sensitivity up-regulation (3- and 4-day) followed by a significant decrease after longer exposure. Return to control values is on the order of 4-8 days. Utricular sensitivity is strongly regulated up or down by gravity load and the duration of exposure. Interestingly, we found no correlation of response and hair cell synaptic body counts despite the large gain difference between 4- and 16-Day subjects. Lastly, we examine responses of statocyst receptors in land snail following exposure to G on two unmanned Russian Orbital missions (Foton M-2 and -3). Here, we have the ability to measure the output directly from the hair cells. Similar to afferents in vertebrates the hair cells increased their response sensitivity to vestibular stimulation. Two major pieces of information are needed: the precise vertebrate hair cell response to altered gravity and the impact of longer duration exposures on sensory plasticity.

Bridging the Synaptic Gap: Neuroligins and Neurexin I in Apis mellifera

PubMed Central

Biswas, Sunita; Russell, Robyn J.; Jackson, Colin J.; Vidovic, Maria; Ganeshina, Olga; Oakeshott, John G.; Claudianos, Charles

2008-01-01

Vertebrate studies show neuroligins and neurexins are binding partners in a trans-synaptic cell adhesion complex, implicated in human autism and mental retardation disorders. Here we report a genetic analysis of homologous proteins in the honey bee. As in humans, the honeybee has five large (31–246 kb, up to 12 exons each) neuroligin genes, three of which are tightly clustered. RNA analysis of the neuroligin-3 gene reveals five alternatively spliced transcripts, generated through alternative use of exons encoding the cholinesterase-like domain. Whereas vertebrates have three neurexins the bee has just one gene named neurexin I (400 kb, 28 exons). However alternative isoforms of bee neurexin I are generated by differential use of 12 splice sites, mostly located in regions encoding LNS subdomains. Some of the splice variants of bee neurexin I resemble the vertebrate α- and β-neurexins, albeit in vertebrates these forms are generated by alternative promoters. Novel splicing variations in the 3′ region generate transcripts encoding alternative trans-membrane and PDZ domains. Another 3′ splicing variation predicts soluble neurexin I isoforms. Neurexin I and neuroligin expression was found in brain tissue, with expression present throughout development, and in most cases significantly up-regulated in adults. Transcripts of neurexin I and one neuroligin tested were abundant in mushroom bodies, a higher order processing centre in the bee brain. We show neuroligins and neurexins comprise a highly conserved molecular system with likely similar functional roles in insects as vertebrates, and with scope in the honeybee to generate substantial functional diversity through alternative splicing. Our study provides important prerequisite data for using the bee as a model for vertebrate synaptic development. PMID:18974885

Developing Novel Therapeutic Approaches in Small Cell Lung Carcinoma Using Genetically Engineered Mouse Models and Human Circulating Tumor Cells

DTIC Science & Technology

2016-12-01

developed expertise in live animal imaging to enable monitoring to tumors over time in these models. We have initiated treatment studies with chemotherapy...requested on 9/22/14 and reported in our first annual report. Significant changes in use or care of human subjects, vertebrate animals ...biohazards and/or select agents We have no additional changes to make in use of vertebrate animals , biohazards and/or select reagents beyond what was

Optomotor behaviour in Xenopus laevis tadpoles as a measure of the effect of gravity on visual and vestibular neural integration

NASA Technical Reports Server (NTRS)

Pronych, S. P.; Souza, K. A.; Neff, A. W.; Wassersug, R. J.

1996-01-01

The ability of aquatic vertebrates to maintain their position requires integration of visual and vestibular sensory information. To understand better how aquatic animals integrate such information, we measured the optomotor behaviour of Xenopus laevis tadpoles raised in growth chambers in microgravity (< 10(-3)g), normal gravity (1 g), hypergravity (3 g) and on a slowly rotating clinostat (simulated microgravity). The goal of this research was to determine how development in an altered gravitational force field affects the visual- and vestibular-dependent behaviour of tadpoles. This research represents the first time that the optomotor behaviour of an organism raised from fertilization in microgravity has been tested. Significant differences were observed in the optomotor behaviour among the four gravity treatments. When first exposed to normal gravity, the microgravity-raised tadpoles exhibited the strongest (or most positive) optomotor behaviour, while the 3 g centrifuge tadpoles showed no optomotor response. Some abnormal behaviours (such as erratic swimming, lying motionless and abnormal swimming posture) were observed in the tadpoles raised in altered gravity on the initial day of testing. One day later, the tadpoles raised in hypergravity did not differ significantly in their optomotor behaviour from control tadpoles raised in normal gravity. However, tadpoles raised in microgravity still displayed an exaggerated optomotor response. One week after the tadpoles had been introduced to normal gravity, there was no longer a significant difference in optomotor behaviour among the different gravity treatments. This convergence of optomotor behaviour by tadpoles from the different treatment reflects the acclimation of their vestibular systems to normal gravity.

Learning to Fish with Genetics: A Primer on the Vertebrate Model Danio rerio

PubMed Central

Holtzman, Nathalia G.; Iovine, M. Kathryn; Liang, Jennifer O.; Morris, Jacqueline

2016-01-01

In the last 30 years, the zebrafish has become a widely used model organism for research on vertebrate development and disease. Through a powerful combination of genetics and experimental embryology, significant inroads have been made into the regulation of embryonic axis formation, organogenesis, and the development of neural networks. Research with this model has also expanded into other areas, including the genetic regulation of aging, regeneration, and animal behavior. Zebrafish are a popular model because of the ease with which they can be maintained, their small size and low cost, the ability to obtain hundreds of embryos on a daily basis, and the accessibility, translucency, and rapidity of early developmental stages. This primer describes the swift progress of genetic approaches in zebrafish and highlights recent advances that have led to new insights into vertebrate biology. PMID:27384027

[Advances in congenital vertebral malformation caused by genomic copy number variation].

PubMed

Liu, Zhenlei; Wu, Nan; Wu, Zhihong; Zuo, Yuzhi; Qiu, Guixing

2016-04-01

Congenital vertebral malformation (CVM) is a congenital vertebral structural deformity caused by abnormal somitogenesis during embryonic development, of which the reason lies in gene mutation or abnormal regulation of the genes that coordinate somitogenesis during embryonic period. ICVAS had proposed a new classification algorithm for CVM, which facilitated exploration for its genetic etiology. Genomic Copy Number Variation (CNV) is a kind of DNA mutation, which is important for human evolution, phenotype polymorphism and diseases. Series of advances have been made on genetic causes of CVM, especially on CVM caused by CNV. CNVs of chromosome 16p11.2, 10q24.31, 17p11.2, 20p11, 22q11.2 and a few other regions are associated with CVM, indicating that gene dosage may play important roles in the development of the spinal cord.

AmphiPax3/7, an amphioxus paired box gene: insights into chordate myogenesis, neurogenesis, and the possible evolutionary precursor of definitive vertebrate neural crest.

PubMed

Holland, L Z; Schubert, M; Kozmik, Z; Holland, N D

1999-01-01

Amphioxus probably has only a single gene (AmphiPax3/7) in the Pax3/7 subfamily. Like its vertebrate homologs (Pax3 and Pax7), amphioxus AmphiPax3/7 is probably involved in specifying the axial musculature and muscularized notochord. During nervous system development, AmphiPax3/7 is first expressed in bilateral anteroposterior stripes along the edges of the neural plate. This early neural expression may be comparable to the transcription of Pax3 and Pax7 in some of the anterior neural crest cells of vertebrates. Previous studies by others and ourselves have demonstrated that several genes homologous to genetic markers for vertebrate neural crest are expressed along the neural plate-epidermis boundary in embryos of tunicates and amphioxus. Taken together, the early neural expression patterns of AmphiPax3/7 and other neural crest markers of amphioxus and tunicates suggest that cell populations that eventually gave rise to definitive vertebrate neural crest may have been present in ancestral invertebrate chordates. During later neurogenesis in amphioxus, AmphiPax3/7, like its vertebrate homologs, is expressed dorsally and dorsolaterally in the neural tube and may be involved in dorsoventral patterning. However, unlike its vertebrate homologs, AmphiPax3/7 is expressed only at the anterior end of the central nervous system instead of along much of the neuraxis; this amphioxus pattern may represent the loss of a primitive chordate character.

Linking vertebral number to performance of aquatic escape responses in the axolotl (Ambystoma mexicanum).

PubMed

Ackerly, Kerri L; Ward, Andrea B

2015-12-01

Environmental conditions during early development in ectothermic vertebrates can lead to variation in vertebral number among individuals of the same species. It is often seen that individuals of a species raised at cooler temperatures have more vertebrae than individuals raised at warmer temperatures, although the functional consequences of this variation in vertebral number on swimming performance are relatively unclear. To investigate this relationship, we tested how vertebral number in axolotls (Ambystoma mexicanum) affected performance of aquatic escape responses (C-starts). Axolotls were reared at four temperatures (12-24°C) encompassing their natural thermal range and then transitioned to a mean temperature (18°C) three months before C-starts were recorded. Our results showed variation in vertebral number, but that variation was not significantly affected by developmental temperature. C-start performance among axolotls was significantly correlated with caudal vertebral number, and individuals with more caudal vertebrae were able to achieve greater curvature more quickly during their responses than individuals with fewer vertebrae. However, our results show that these individuals did not achieve greater displacements or velocities, and that developmental temperature did not have any effect on C-start performance. We highlight that the most important aspects of escape swim performance (i.e., how far individuals get from a threat and how quickly they move the most important parts of the body away from that threat) are consistent across individuals regardless of developmental temperature and morphological variation. Copyright © 2015 Elsevier GmbH. All rights reserved.

A comparison of hand wrist bone analysis with two different cervical vertebral analysis in measuring skeletal maturation.

PubMed

Pichai, Saravanan; Rajesh, M; Reddy, Naveen; Adusumilli, Gopinath; Reddy, Jayaprakash; Joshi, Bhavana

2014-09-01

Skeletal maturation is an integral part of individual pattern of growth and development and is a continuous process. Peak growth velocity in standing height is the most valid representation of the rate of overall skeletal growth. Ossification changes of hand wrist and cervical vertebrae are the reliable indicators of growth status of individual. The objective of this study was to compare skeletal maturation as measured by hand wrist bone analysis and cervical vertebral analysis. Hand wrist radiographs and lateral cephalograms of 72 subjects aged between 7 and 16 years both male and female from the patients visiting Department of Orthodontics and Dentofacial Orthopedics, R.V. Dental College and Hospital. The 9 stages were reduced to 5 stages to compare with cervical vertebral maturation stage by Baccetti et al. The Bjork, Grave and Brown stages were reduced to six intervals to compare with cervical vertebral maturational index (CVMI) staging by Hassel and Farman. These measurements were then compared with the hand wrist bone analysis, and the results were statistically analyzed using the Mann-Whitney test. There was no significant difference between the hand wrist analysis and the two different cervical vertebral analyses for assessing skeletal maturation. There was no significant difference between the two cervical vertebral analyses, but the CVMI method, which is visual method is less time consuming. Vertebral analysis on a lateral cephalogram is as valid as the hand wrist bone analysis with the advantage of reducing the radiation exposure of growing subjects.

iDNA screening: Disease vectors as vertebrate samplers.

PubMed

Kocher, Arthur; de Thoisy, Benoit; Catzeflis, François; Valière, Sophie; Bañuls, Anne-Laure; Murienne, Jérôme

2017-11-01

In the current context of global change and human-induced biodiversity decline, there is an urgent need for developing sampling approaches able to accurately describe the state of biodiversity. Traditional surveys of vertebrate fauna involve time-consuming and skill-demanding field methods. Recently, the use of DNA derived from invertebrate parasites (leeches and blowflies) was suggested as a new tool for vertebrate diversity assessment. Bloodmeal analyses of arthropod disease vectors have long been performed to describe their feeding behaviour, for epidemiological purposes. On the other hand, this existing expertise has not yet been applied to investigate vertebrate fauna per se. Here, we evaluate the usefulness of hematophagous dipterans as vertebrate samplers. Blood-fed sand flies and mosquitoes were collected in Amazonian forest sites and analysed using high-throughput sequencing of short mitochondrial markers. Bloodmeal identifications highlighted contrasting ecological features and feeding behaviour among dipteran species, which allowed unveiling arboreal and terrestrial mammals of various body size, as well as birds, lizards and amphibians. Additionally, lower vertebrate diversity was found in sites undergoing higher levels of human-induced perturbation. These results suggest that, in addition to providing precious information on disease vector host use, dipteran bloodmeal analyses may represent a useful tool in the study of vertebrate communities. Although further effort is required to validate the approach and consider its application to large-scale studies, this first work opens up promising perspectives for biodiversity monitoring and eco-epidemiology. © 2017 John Wiley & Sons Ltd.

Leaping lopsided: a review of the current hypotheses regarding etiologies of limb malformations in frogs.

PubMed

Loeffler, I K; Stocum, D L; Fallon, J F; Meteyer, C U

2001-10-15

Recent progress in the investigation of limb malformations in free-living frogs has underlined the wide range in the types of limb malformations and the apparent spatiotemporal clustering of their occurrence. Here, we review the current understanding of normal and abnormal vertebrate limb development and regeneration and discuss some of the molecular events that may bring about limb malformation. Consideration of the differences between limb development and regeneration in amphibians has led us to the hypothesis that some of the observed limb malformations come about through misdirected regeneration. We report the results of a pilot study that supports this hypothesis. In this study, the distal aspect of the right hindlimb buds of X. laevis tadpoles was amputated at the pre-foot paddle stage. The tadpoles were raised in water from a pond in Minnesota at which 7% of surveyed newly metamorphosed feral frogs had malformations. Six percent (6 of 100) of the right limbs of the tadpoles raised in pond water developed abnormally. One truncated right limb was the only malformation in the control group, which was raised in dechlorinated municipal water. All unamputated limbs developed normally in both groups. Three major factors under consideration for effecting the limb malformations are discussed. These factors include environmental chemicals (primarily agrichemicals), encysted larvae (metacercariae) of trematode parasites, and increased levels of ultraviolet light. Emphasis is placed on the necessary intersection of environmental stressors and developmental events to bring about the specific malformations that are observed in free-living frog populations.

Leaping lopsided: a review of the current hypotheses regarding etiologies of limb malformations in frogs

USGS Publications Warehouse

Loeffler, I.K.; Stocum, D.L.; Fallon, J.F.; Meteyer, C.U.

2001-01-01

Recent progress in the investigation of limb malformations in free-living frogs has underlined the wide range in the types of limb malformations and the apparent spatiotemporal clustering of their occurrence. Here, we review the current understanding of normal and abnormal vertebrate limb development and regeneration and discuss some of the molecular events that may bring about limb malformation. Consideration of the differences between limb development and regeneration in amphibians has led us to the hypothesis that some of the observed limb malformations come about through misdirected regeneration. We report the results of a pilot study that supports this hypothesis. In this study, the distal aspect of the right hindlimb buds of X. laevis tadpoles was amputated at the pre-foot paddle stage. The tadpoles were raised in water from a pond in Minnesota at which 7% of surveyed newly metamorphosed feral frogs had malformations. Six percent (6 of 100) of the right limbs of the tadpoles raised in pond water developed abnormally. One truncated right limb was the only malformation in the control group, which was raised in dechlorinated municipal water. All unamputated limbs developed normally in both groups. Three major factors under consideration for effecting the limb malformations are discussed. These factors include environmental chemicals (primarily agrichemicals), encysted larvae (metacercariae) of trematode parasites, and increased levels of ultraviolet light. Emphasis is placed on the necessary intersection of environmental stressors and developmental events to bring about the specific malformations that are observed in free-living frog populations.

Changes in CSF flow after one-stage posterior vertebral column resection in scoliosis patients with syringomyelia and Chiari malformation type I.

PubMed

Wang, Yingsong; Xie, Jingming; Zhao, Zhi; Zhang, Ying; Li, Tao; Si, Yongyu

2013-05-01

Phase contrast-cine MRI (PC-cine MRI) studies in patients with syringomyelia and Chiari malformation Type I (CM-I) have demonstrated abnormal CSF flow across the foramen magnum, which can revert to normal after craniocervical decompression with syrinx shrinkage. In order to investigate the mechanisms leading to postoperative syringomyelia shrinkage, the authors studied the hydrodynamic changes of CSF flow in the craniocervical junction and spinal canal in patients with scoliosis associated with syringomyelia after one-stage deformity correction by posterior vertebral column resection. Preoperative and postoperative CSF flow dynamics at the levels of the foramen magnum, C-7, T-7 (or apex), and L-1 were assessed by electrocardiogram-synchronized cardiac-gated PC-cine MRI in 8 adolescent patients suffering from severe scoliosis with syringomyelia and CM-I (scoliosis group) and undergoing posterior vertebral column resection. An additional 8 patients with syringomyelia and CM-I without spinal deformity (syrinx group) and 8 healthy volunteers (control group) were also enrolled. Mean values were obtained for the following parameters: the duration of a CSF cycle, the duration of caudad CSF flow (CSF downflow [DF]) and cephalad CSF flow (CSF upflow [UF]), the ratio of DF duration to CSF cycle duration (DF%), and the ratio of UF duration to CSF cycle duration (UF%). The ratio of the stationary phase (SP) duration to CSF cycle duration was calculated (SP%). The maximum downflow velocities (VD max) and maximum upflow velocities (VU max) were measured. SPSS (version 14.0) was used for all statistical analysis. Patients in the scoliosis group underwent one-stage posterior vertebral column resection for deformity correction without suboccipital decompression. The mean preoperative coronal Cobb angle was 102.4° (range 76°-138°). The mean postoperative Cobb angle was 41.7° (range 12°-75°), with an average correction rate of 59.3%. During the follow-up, 1 patient with hypermyotonia experienced a significant decrease of muscle tension and 1 patient with reduced anal sphincter tone manifested recovery. A total of 5 patients demonstrated a significant decrease (> 30%) in syrinx size. With respect to changes in CSF flow dynamics, the syrinx group was characterized by slower and shorter downflow than the control group, and the difference was more significant at the foramen magnum and C-7 levels. In patients with scoliosis, CSF downflow at the foramen magnum level was significantly restricted, and a prolonged stationary phase indicated increased obstruction of CSF flow. After posterior vertebral column resection, the peak velocity of CSF flow at the foramen magnum increased, and the downflow phase duration was markedly prolonged. The parameters showed a return to almost normal CSF dynamics at the craniocervical region, and this improvement was maintained for 6-12 months of follow-up. There were distinct abnormalities of CSF flow at the craniocervical junction in patients with syringomyelia. Abnormal dynamics of downflow could be aggravated by associated severe spinal deformity and improved by correction via posterior vertebral column resection.

Vertebral metastases from neuroendocrine tumours: How to avoid false positives on 68Ga-DOTA-TOC PET using CT pattern analysis?

PubMed

Gauthé, Mathieu; Testart Dardel, Nathalie; Ruiz Santiago, Fernando; Ohnona, Jessica; Nataf, Valérie; Montravers, Françoise; Talbot, Jean-Noël

2018-03-12

To develop criteria to improve discrimination between vertebral metastases from neuroendocrine tumours (NETs) and benign bone lesions on PET combined with CT using DOTA-D-Phe 1 -Tyr 3 -octreotide labelled with gallium-68 ( 68 Ga-DOTA-TOC). In 535 NET patients, 68 Ga-DOTA-TOC PET/CT examinations were reviewed retrospectively for vertebral CT lesions and/or PET foci. For each vertebral PET abnormality, appearance on CT, biological volume (BV), standardized uptake value (SUV max ) and ratios to those of reference organs were determined. All vertebral abnormalities were characterized as a metastasis, a typical vertebral haemangioma (VH) or other benign lesion. In 79 patients (14.8 %), we found 107 metastases, 34 VHs and 31 other benign lesions in the spine. The optimal cut-off values to differentiate metastases from benign lesions were BV ≥0.72 cm 3 , SUVmax ≥2, SUVmax ratio to a reference vertebra ≥2.1, to liver ≥0.28 and to spleen ≥0.14. They corresponded to lesion-based 68 Ga-DOTA-TOC PET/CT sensitivity of 87 %, 98 %, 97 %, 99 % and 94 %, and specificity of 55 %, 100 %, 90 %, 97 %, 100 %, respectively. The high sensitivity of 68 Ga-DOTA-TOC-PET/CT in detecting NET vertebral metastases was confirmed; this study showed that specificity could be improved by combining CT features and quantifying 68 Ga-DOTA-TOC uptake. • Bone metastases in neuroendocrine tumours correlate with prognosis. • Benign bone lesions may mimic metastases on 68 Ga-DOTA-TOC PET/CT imaging. • The specific polka-dot CT pattern may be missing in some vertebral haemangiomas. • Lesion atypical for haemangiomas can be better characterized by quantifying 68 Ga-DOTA-TOC uptake.

The Evolution of Bony Vertebrate Enhancers at Odds with Their Coding Sequence Landscape.

PubMed

Yousaf, Aisha; Sohail Raza, Muhammad; Ali Abbasi, Amir

2015-08-06

Enhancers lie at the heart of transcriptional and developmental gene regulation. Therefore, changes in enhancer sequences usually disrupt the target gene expression and result in disease phenotypes. Despite the well-established role of enhancers in development and disease, evolutionary sequence studies are lacking. The current study attempts to unravel the puzzle of bony vertebrates' conserved noncoding elements (CNE) enhancer evolution. Bayesian phylogenetics of enhancer sequences spotlights promising interordinal relationships among placental mammals, proposing a closer relationship between humans and laurasiatherians while placing rodents at the basal position. Clock-based estimates of enhancer evolution provided a dynamic picture of interspecific rate changes across the bony vertebrate lineage. Moreover, coelacanth in the study augmented our appreciation of the vertebrate cis-regulatory evolution during water-land transition. Intriguingly, we observed a pronounced upsurge in enhancer evolution in land-dwelling vertebrates. These novel findings triggered us to further investigate the evolutionary trend of coding as well as CNE nonenhancer repertoires, to highlight the relative evolutionary dynamics of diverse genomic landscapes. Surprisingly, the evolutionary rates of enhancer sequences were clearly at odds with those of the coding and the CNE nonenhancer sequences during vertebrate adaptation to land, with land vertebrates exhibiting significantly reduced rates of coding sequence evolution in comparison to their fast evolving regulatory landscape. The observed variation in tetrapod cis-regulatory elements caused the fine-tuning of associated gene regulatory networks. Therefore, the increased evolutionary rate of tetrapods' enhancer sequences might be responsible for the variation in developmental regulatory circuits during the process of vertebrate adaptation to land. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Heterogeneous conservation of Dlx paralog co-expression in jawed vertebrates.

PubMed

Debiais-Thibaud, Mélanie; Metcalfe, Cushla J; Pollack, Jacob; Germon, Isabelle; Ekker, Marc; Depew, Michael; Laurenti, Patrick; Borday-Birraux, Véronique; Casane, Didier

2013-01-01

The Dlx gene family encodes transcription factors involved in the development of a wide variety of morphological innovations that first evolved at the origins of vertebrates or of the jawed vertebrates. This gene family expanded with the two rounds of genome duplications that occurred before jawed vertebrates diversified. It includes at least three bigene pairs sharing conserved regulatory sequences in tetrapods and teleost fish, but has been only partially characterized in chondrichthyans, the third major group of jawed vertebrates. Here we take advantage of developmental and molecular tools applied to the shark Scyliorhinus canicula to fill in the gap and provide an overview of the evolution of the Dlx family in the jawed vertebrates. These results are analyzed in the theoretical framework of the DDC (Duplication-Degeneration-Complementation) model. The genomic organisation of the catshark Dlx genes is similar to that previously described for tetrapods. Conserved non-coding elements identified in bony fish were also identified in catshark Dlx clusters and showed regulatory activity in transgenic zebrafish. Gene expression patterns in the catshark showed that there are some expression sites with high conservation of the expressed paralog(s) and other expression sites with events of paralog sub-functionalization during jawed vertebrate diversification, resulting in a wide variety of evolutionary scenarios within this gene family. Dlx gene expression patterns in the catshark show that there has been little neo-functionalization in Dlx genes over gnathostome evolution. In most cases, one tandem duplication and two rounds of vertebrate genome duplication have led to at least six Dlx coding sequences with redundant expression patterns followed by some instances of paralog sub-functionalization. Regulatory constraints such as shared enhancers, and functional constraints including gene pleiotropy, may have contributed to the evolutionary inertia leading to high redundancy between gene expression patterns.

Correlations between Cervical Vertebral Maturation (CVM) and Dental Development in Thai Cleft Patients.

PubMed

Chongcharueyskul, Pathomporn; Wangsrimonkol, Tasanee; Pisek, Poonsak; Pisek, Araya; Manosudprasit, Montian

2015-08-01

To examine correlations between cervical vertebral maturation stages (CVMs) and dental development stages, and cervical vertebral maturation (CVM) stage 6 and completion of root formation of mandibular third molar in Thai cleft patients. Lateral cephalograms of 366 cleft subjects aged 7-9 years were assessed for CVMs using Baccetti method. Calcication stages of all left mandibular teeth within each CVMs were assessed from panoramic films using Demirjian method. Spearman rank correlation coefficients comparing CVMs and teeth were 0.51-0.79 (p<0.001). Second molar had the highest and central incisor had the lowest correlations. In CVMs 6, 2.9% of third molars had completed root formation. However, only CVMs 6 could be predicted from third molar stage G that had a high likelihood ratio (30.94). Dental development was highly correlated with CVM in clefts. Third molar stage G could predict completed growth of mandible in individual patients, but it should be combined with other maturation indicators.

The neural crest, a multifaceted structure of the vertebrates.

PubMed

Dupin, Elisabeth; Le Douarin, Nicole M

2014-09-01

In this review, several features of the cells originating from the lateral borders of the primitive neural anlagen, the neural crest (NC) are considered. Among them, their multipotentiality, which together with their migratory properties, leads them to colonize the developing body and to participate in the development of many tissues and organs. The in vitro analysis of the developmental capacities of single NC cells (NCC) showed that they present several analogies with the hematopoietic cells whose differentiation involves the activity of stem cells endowed with different arrays of developmental potentialities. The permanence of such NC stem cells in the adult organism raises the problem of their role at that stage of life. The NC has appeared during evolution in the vertebrate phylum and is absent in their Protocordates ancestors. The major role of the NCC in the development of the vertebrate head points to a critical role for this structure in the remarkable diversification and radiation of this group of animals. © 2014 Wiley Periodicals, Inc.

Conserved Genetic Pathways Controlling the Development of the Diffuse Endocrine System in Vertebrates and Drosophila

PubMed Central

Hartenstein, Volker; Takashima, Shigeo; Adams, Katrina

2014-01-01

The midgut epithelium is formed by absorptive enterocytes, secretory cells and endocrine cells. Each of these lineages is derived from the pluripotent progenitors that constitute the embryonic endoderm; the mature midgut retains pools of self-renewing stem cells that continue to produce all lineages. Recent findings in vertebrates and Drosophila shed light on the genetic mechanism that specifies the fate of the different lineages. A pivotal role is played by the Notch signaling pathway that, in a manner that appears to be very similar to the way in which Notch signaling selects neural progenitors within the neurectoderm, distinguishes the fate of secretory/endocrine cells and enterocytes. Proneural genes encoding bHLH transcription factors are expressed and required in prospective endocrine cells; activation of the Notch pathways restricts the number of these cells and promotes enterocyte development. In this review we compare the development of the intestinal endocrine cells in vertebrates and insects and summarize recent findings dealing with genetic pathways controlling this cell type. PMID:20005229

Histology of the heterostracan dermal skeleton: Insight into the origin of the vertebrate mineralised skeleton.

PubMed

Keating, Joseph N; Marquart, Chloe L; Donoghue, Philip C J

2015-06-01

Living vertebrates are divided into those that possess a fully formed and fully mineralised skeleton (gnathostomes) versus those that possess only unmineralised cartilaginous rudiments (cyclostomes). As such, extinct phylogenetic intermediates of these living lineages afford unique insights into the evolutionary assembly of the vertebrate mineralised skeleton and its canonical tissue types. Extinct jawless and jawed fishes assigned to the gnathostome stem evidence the piecemeal assembly of skeletal systems, revealing that the dermal skeleton is the earliest manifestation of a homologous mineralised skeleton. Yet the nature of the primitive dermal skeleton, itself, is poorly understood. This is principally because previous histological studies of early vertebrates lacked a phylogenetic framework required to derive evolutionary hypotheses. Nowhere is this more apparent than within Heterostraci, a diverse clade of primitive jawless vertebrates. To this end, we surveyed the dermal skeletal histology of heterostracans, inferred the plesiomorphic heterostracan skeleton and, through histological comparison to other skeletonising vertebrate clades, deduced the ancestral nature of the vertebrate dermal skeleton. Heterostracans primitively possess a four-layered skeleton, comprising a superficial layer of odontodes composed of dentine and enameloid; a compact layer of acellular parallel-fibred bone containing a network of vascular canals that supply the pulp canals (L1); a trabecular layer consisting of intersecting radial walls composed of acellular parallel-fibred bone, showing osteon-like development (L2); and a basal layer of isopedin (L3). A three layered skeleton, equivalent to the superficial layer L2 and L3 and composed of enameloid, dentine and acellular bone, is possessed by the ancestor of heterostracans + jawed vertebrates. We conclude that an osteogenic component is plesiomorphic with respect to the vertebrate dermal skeleton. Consequently, we interpret the dermal skeleton of denticles in chondrichthyans and jawless thelodonts as independently and secondarily simplified. J. Morphol. 276:657-680, 2015. © 2015 The Authors Journal of Morphology Published by Wiley Periodicals, Inc. © 2015 The Authors Journal of Morphology Published by Wiley Periodicals, Inc.