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Sample records for gene-rich vertebrate regions

  1. Comparative analysis of chicken chromosome 28 provides new clues to the evolutionary fragility of gene-rich vertebrate regions

    PubMed Central

    Gordon, Laurie; Yang, Shan; Tran-Gyamfi, Mary; Baggott, Dan; Christensen, Mari; Hamilton, Aaron; Crooijmans, Richard; Groenen, Martien; Lucas, Susan; Ovcharenko, Ivan; Stubbs, Lisa

    2007-01-01

    The chicken genome draft sequence has provided a valuable resource for studies of an important agricultural and experimental model species and an important data set for comparative analysis. However, some of the most gene-rich segments are missing from chicken genome draft assemblies, limiting the analysis of a substantial number of genes and preventing a closer look at regions that are especially prone to syntenic rearrangements. To facilitate the functional and evolutionary analysis of one especially gene-rich, rearrangement-prone genomic region, we analyzed sequence from BAC clones spanning chicken microchromosome GGA28; as a complement we also analyzed a gene-sparse, stable region from GGA11. In these two regions we documented the conservation and lineage-specific gain and loss of protein-coding genes and precisely mapped the locations of 31 major human-chicken syntenic breakpoints. Altogether, we identified 72 lineage-specific genes, many of which are found at or near syntenic breaks, implicating evolutionary breakpoint regions as major sites of genetic innovation and change. Twenty-two of the 31 breakpoint regions have been reused repeatedly as rearrangement breakpoints in vertebrate evolution. Compared with stable GC-matched regions, GGA28 is highly enriched in CpG islands, as are break-prone intervals identified elsewhere in the chicken genome; evolutionary breakpoints are further enriched in GC content and CpG islands, highlighting a potential role for these features in genome instability. These data support the hypothesis that chromosome rearrangements have not occurred randomly over the course of vertebrate evolution but are focused preferentially within “fragile” regions with unusual DNA sequence characteristics. PMID:17921355

  2. Leukemia breakpoint region in 3q21 is gene rich.

    PubMed

    Rynditch, A; Pekarsky, Y; Schnittger, S; Gardiner, K

    1997-07-01

    Rearrangements of the long arm of human chromosome 3, including reciprocal translocations, inversions and deletion/duplication of bands 3q21-3q26, as well as deletions of 3q21 and reciprocal translocations between 3q21 and other chromosomes, are well documented in leukemia. Previous studies showed that the breakpoints within 3q21 cluster within a 10-40 kb region but no candidate genes were described. In this work, we have identified partial cDNAs corresponding to five to nine new transcripts from an 80 kb P1 clone that spans ten breakpoints. These transcripts, with one exception, appear to be expressed only at low levels in the set of cancer cell lines examined. Four transcripts are located between the previously mapped Ribophorin I gene and the most centromeric breakpoint; three map directly within the 20 kb spanning nine independent breakpoints. These data (i) show that among characterized leukemia breakpoint regions 3q21 is unusually gene rich, (ii) provide new candidates for relevance to leukemia in 3q21, and (iii) suggest possibilities for chromatin configuration effects. PMID:9249066

  3. Saturation mapping of a gene-rich recombination hot spot region in wheat.

    PubMed Central

    Faris, J D; Haen, K M; Gill, B S

    2000-01-01

    Physical mapping of wheat chromosomes has revealed small chromosome segments of high gene density and frequent recombination interspersed with relatively large regions of low gene density and infrequent recombination. We constructed a detailed genetic and physical map of one highly recombinant region on the long arm of chromosome 5B. This distally located region accounts for 4% of the physical size of the long arm and at least 30% of the recombination along the entire chromosome. Multiple crossovers occurred within this region, and the degree of recombination is at least 11-fold greater than the genomic average. Characteristics of the region such as gene order and frequency of recombination appear to be conserved throughout the evolution of the Triticeae. The region is more prone to chromosome breakage by gametocidal gene action than gene-poor regions, and evidence for genomic instability was implied by loss of gene collinearity for six loci among the homeologous regions. These data suggest that a unique level of chromatin organization exists within gene-rich recombination hot spots. The many agronomically important genes in this region should be accessible by positional cloning. PMID:10655233

  4. Comparative genomics of Lupinus angustifolius gene-rich regions: BAC library exploration, genetic mapping and cytogenetics

    PubMed Central

    2013-01-01

    Background The narrow-leafed lupin, Lupinus angustifolius L., is a grain legume species with a relatively compact genome. The species has 2n = 40 chromosomes and its genome size is 960 Mbp/1C. During the last decade, L. angustifolius genomic studies have achieved several milestones, such as molecular-marker development, linkage maps, and bacterial artificial chromosome (BAC) libraries. Here, these resources were integratively used to identify and sequence two gene-rich regions (GRRs) of the genome. Results The genome was screened with a probe representing the sequence of a microsatellite fragment length polymorphism (MFLP) marker linked to Phomopsis stem blight resistance. BAC clones selected by hybridization were subjected to restriction fingerprinting and contig assembly, and 232 BAC-ends were sequenced and annotated. BAC fluorescence in situ hybridization (BAC-FISH) identified eight single-locus clones. Based on physical mapping, cytogenetic localization, and BAC-end annotation, five clones were chosen for sequencing. Within the sequences of clones that hybridized in FISH to a single-locus, two large GRRs were identified. The GRRs showed strong and conserved synteny to Glycine max duplicated genome regions, illustrated by both identical gene order and parallel orientation. In contrast, in the clones with dispersed FISH signals, more than one-third of sequences were transposable elements. Sequenced, single-locus clones were used to develop 12 genetic markers, increasing the number of L. angustifolius chromosomes linked to appropriate linkage groups by five pairs. Conclusions In general, probes originating from MFLP sequences can assist genome screening and gene discovery. However, such probes are not useful for positional cloning, because they tend to hybridize to numerous loci. GRRs identified in L. angustifolius contained a low number of interspersed repeats and had a high level of synteny to the genome of the model legume G. max. Our results showed that

  5. Gene-rich chromosomal regions are preferentially localized in the lamin B deficient nuclear blebs of atypical progeria cells

    PubMed Central

    Bercht Pfleghaar, Katrin; Taimen, Pekka; Butin-Israeli, Veronika; Shimi, Takeshi; Langer-Freitag, Sabine; Markaki, Yolanda; Goldman, Anne E; Wehnert, Manfred; Goldman, Robert D

    2015-01-01

    More than 20 mutations in the gene encoding A-type lamins (LMNA) cause progeria, a rare premature aging disorder. The major pathognomonic hallmarks of progeria cells are seen as nuclear deformations or blebs that are related to the redistribution of A- and B-type lamins within the nuclear lamina. However, the functional significance of these progeria-associated blebs remains unknown. We have carried out an analysis of the structural and functional consequences of progeria-associated nuclear blebs in dermal fibroblasts from a progeria patient carrying a rare point mutation p.S143F (C428T) in lamin A/C. These blebs form microdomains that are devoid of major structural components of the nuclear envelope (NE)/lamina including B-type lamins and nuclear pore complexes (NPCs) and are enriched in A-type lamins. Using laser capture microdissection and comparative genomic hybridization (CGH) analyses, we show that, while these domains are devoid of centromeric heterochromatin and gene-poor regions of chromosomes, they are enriched in gene-rich chromosomal regions. The active form of RNA polymerase II is also greatly enriched in blebs as well as nascent RNA but the nuclear co-activator SKIP is significantly reduced in blebs compared to other transcription factors. Our results suggest that the p.S143F progeria mutation has a severe impact not only on the structure of the lamina but also on the organization of interphase chromatin domains and transcription. These structural defects are likely to contribute to gene expression changes reported in progeria and other types of laminopathies. PMID:25738644

  6. Identification and physical localization of useful genes and markers to a major gene-rich region on wheat group 1S chromosomes.

    PubMed Central

    Sandhu, D; Champoux, J A; Bondareva, S N; Gill, K S

    2001-01-01

    The short arm of Triticeae homeologous group 1 chromosomes is known to contain many agronomically important genes. The objectives of this study were to physically localize gene-containing regions of the group 1 short arm, enrich these regions with markers, and study the distribution of genes and recombination. We focused on the major gene-rich region ("1S0.8 region") and identified 75 useful genes along with 93 RFLP markers by comparing 35 different maps of Poaceae species. The RFLP markers were tested by gel blot DNA analysis of wheat group 1 nullisomic-tetrasomic lines, ditelosomic lines, and four single-break deletion lines for chromosome arm 1BS. Seventy-three of the 93 markers mapped to group 1 and detected 91 loci on chromosome 1B. Fifty-one of these markers mapped to two major gene-rich regions physically encompassing 14% of the short arm. Forty-one marker loci mapped to the 1S0.8 region and 10 to 1S0.5 region. Two cDNA markers mapped in the centromeric region and the remaining 24 loci were on the long arm. About 82% of short arm recombination was observed in the 1S0.8 region and 17% in the 1S0.5 region. Less than 1% recombination was observed for the remaining 85% of the physical arm length. PMID:11290727

  7. Fine structure mapping of a gene-rich region of wheat carrying Ph1, a suppressor of crossing over between homoeologous chromosomes

    PubMed Central

    Sidhu, Gaganpreet K.; Rustgi, Sachin; Shafqat, Mustafa N.; von Wettstein, Diter; Gill, Kulvinder S.

    2008-01-01

    The wheat gene-rich region (GRR) 5L0.5 contains many important genes, including Ph1, the principal regulator of chromosome pairing. Comparative marker analysis identified 32 genes for the GRR controlling important agronomic traits. Detailed characterization of this region was accomplished by first physically localizing 213 wheat group 5L-specific markers, using group 5 nulli-tetrasomics, three Ph1 gene deletion/insertion mutants, and nine terminal deletion lines with their breakpoints around the 5L0.5 region. The Ph1 gene was localized to a much smaller region within the GRR (Ph1 gene region). Of the 61 markers that mapped in the four subregions of the GRR, 9 mapped in the Ph1 gene region. High stringency sequence comparison (e < 1 ×10−25) of 157 group 5L-specific wheat ESTs identified orthologs for 80% sequences in rice and 71% in Arabidopsis. Rice orthologs were present on all rice chromosomes, although most (34%) were on rice chromosome 9 (R9). No single collinear region was identified in Arabidopsis even for a smaller region, such as the Ph1 gene region. Seven of the nine Ph1 gene region markers mapped within a 450-kb region on R9 with the same gene order. Detailed domain/motif analysis of the 91 putative genes present in the 450-kb region identified 26 candidates for the Ph1 gene, including genes involved in chromatin reorganization, microtubule attachment, acetyltransferases, methyltransferases, DNA binding, and meiosis/anther specific proteins. Five of these genes shared common domains/motifs with the meiosis specific genes Zip1, Scp1, Cor1, RAD50, RAD51, and RAD57. Wheat and Arabidopsis homologs for these rice genes were identified. PMID:18398005

  8. Identification and high-density mapping of gene-rich regions in chromosome group 1 of wheat.

    PubMed

    Gill, K S; Gill, B S; Endo, T R; Taylor, T

    1996-12-01

    We studied the distribution of genes and recombination in wheat (Triticum aestivum) group 1 chromosomes by comparing high-density physical and genetic maps. Physical maps of chromosomes 1A, 1B, and 1D were generated by mapping 50 DNA markers on 56 single-break deletion lines. A consensus physical map was compared with the 1D genetic map of Triticum tauschii (68 markers) and a Triticeae group 1 consensus map (288 markers) to generate a cytogenetic ladder map (CLM). Most group 1 markers (86%) were present in five clusters that encompassed only 10% of the group 1 chromosome. This distribution may reflect that of genes because more than half of the probes were cDNA clones and 30% were PstI genomic. All 14 agronomically important genes in group 1 chromosomes were present in these clusters. Most recombination occurred in gene-cluster regions. Markers fell at an average distance of 244 kb in these regions. The CLM involving the Triticeae consensus genetic map revealed that the above distribution of genes and recombination is the same in other Triticeae species. Because of a significant number of common markers, our CLM can be used for comparative mapping and to estimate physical distances among markers in many Poaceae species including rice and maize. PMID:8978071

  9. Male-specific region of the bovine Y chromosome is gene rich with a high transcriptomic activity in testis development.

    PubMed

    Chang, Ti-Cheng; Yang, Yang; Retzel, Ernest F; Liu, Wan-Sheng

    2013-07-23

    The male-specific region of the mammalian Y chromosome (MSY) contains clusters of genes essential for male reproduction. The highly repetitive and degenerative nature of the Y chromosome impedes genomic and transcriptomic characterization. Although the Y chromosome sequence is available for the human, chimpanzee, and macaque, little is known about the annotation and transcriptome of nonprimate MSY. Here, we investigated the transcriptome of the MSY in cattle by direct testis cDNA selection and RNA-seq approaches. The bovine MSY differs radically from the primate Y chromosomes with respect to its structure, gene content, and density. Among the 28 protein-coding genes/families identified on the bovine MSY (12 single- and 16 multicopy genes), 16 are bovid specific. The 1,274 genes identified in this study made the bovine MSY gene density the highest in the genome; in comparison, primate MSYs have only 31-78 genes. Our results, along with the highly transcriptional activities observed from these Y-chromosome genes and 375 additional noncoding RNAs, challenge the widely accepted hypothesis that the MSY is gene poor and transcriptionally inert. The bovine MSY genes are predominantly expressed and are differentially regulated during the testicular development. Synonymous substitution rate analyses of the multicopy MSY genes indicated that two major periods of expansion occurred during the Miocene and Pliocene, contributing to the adaptive radiation of bovids. The massive amplification and vigorous transcription suggest that the MSY serves as a genomic niche regulating male reproduction during bovid expansion. PMID:23842086

  10. Regions identity between the genome of vertebrates and non-retroviral families of insect viruses

    PubMed Central

    2011-01-01

    Background The scope of our understanding of the evolutionary history between viruses and animals is limited. The fact that the recent availability of many complete insect virus genomes and vertebrate genomes as well as the ability to screen these sequences makes it possible to gain a new perspective insight into the evolutionary interaction between insect viruses and vertebrates. This study is to determine the possibility of existence of sequence identity between the genomes of insect viruses and vertebrates, attempt to explain this phenomenon in term of genetic mobile element, and try to investigate the evolutionary relationship between these short regions of identity among these species. Results Some of studied insect viruses contain variable numbers of short regions of sequence identity to the genomes of vertebrate with nucleotide sequence length from 28 bp to 124 bp. They are found to locate in multiple sites of the vertebrate genomes. The ontology of animal genes with identical regions involves in several processes including chromatin remodeling, regulation of apoptosis, signaling pathway, nerve system development and some enzyme-like catalysis. Phylogenetic analysis reveals that at least some short regions of sequence identity in the genomes of vertebrate are derived the ancestral of insect viruses. Conclusion Short regions of sequence identity were found in the vertebrates and insect viruses. These sequences played an important role not only in the long-term evolution of vertebrates, but also in promotion of insect virus. This typical win-win strategy may come from natural selection. PMID:22073942

  11. ECRbase: Database of Evolutionary Conserved Regions, Promoters, and Transcription Factor Binding Sites in Vertebrate Genomes

    DOE Data Explorer

    Loots, Gabriela G. [LLNL; Ovcharenko, I. [LLNL

    Evolutionary conservation of DNA sequences provides a tool for the identification of functional elements in genomes. This database of evolutionary conserved regions (ECRs) in vertebrate genomes features a database of syntenic blocks that recapitulate the evolution of rearrangements in vertebrates and a comprehensive collection of promoters in all vertebrate genomes generated using multiple sources of gene annotation. The database also contains a collection of annotated transcription factor binding sites (TFBSs) in evolutionary conserved and promoter elements. ECRbase currently includes human, rhesus macaque, dog, opossum, rat, mouse, chicken, frog, zebrafish, and fugu genomes. (taken from paper in Journal: Bioinformatics, November 7, 2006, pp. 122-124

  12. ECRbase: Database of Evolutionary Conserved Regions, Promoters, and Transcription Factor Binding Sites in Vertebrate Genomes

    SciTech Connect

    Loots, G; Ovcharenko, I

    2006-08-08

    Evolutionary conservation of DNA sequences provides a tool for the identification of functional elements in genomes. We have created a database of evolutionary conserved regions (ECRs) in vertebrate genomes entitled ECRbase that is constructed from a collection of pairwise vertebrate genome alignments produced by the ECR Browser database. ECRbase features a database of syntenic blocks that recapitulate the evolution of rearrangements in vertebrates and a collection of promoters in all vertebrate genomes presented in the database. The database also contains a collection of annotated transcription factor binding sites (TFBS) in all ECRs and promoter elements. ECRbase currently includes human, rhesus macaque, dog, opossum, rat, mouse, chicken, frog, zebrafish, and two pufferfish genomes. It is freely accessible at http://ECRbase.dcode.org.

  13. The evolution of vertebrate somatostatin receptors and their gene regions involves extensive chromosomal rearrangements

    PubMed Central

    2012-01-01

    Background Somatostatin and its related neuroendocrine peptides have a wide variety of physiological functions that are mediated by five somatostatin receptors with gene names SSTR1-5 in mammals. To resolve their evolution in vertebrates we have investigated the SSTR genes and a large number of adjacent gene families by phylogeny and conserved synteny analyses in a broad range of vertebrate species. Results We find that the SSTRs form two families that belong to distinct paralogons. We observe not only chromosomal similarities reflecting the paralogy relationships between the SSTR-bearing chromosome regions, but also extensive rearrangements between these regions in teleost fish genomes, including fusions and translocations followed by reshuffling through intrachromosomal rearrangements. These events obscure the paralogy relationships but are still tractable thanks to the many genomes now available. We have identified a previously unrecognized SSTR subtype, SSTR6, previously misidentified as either SSTR1 or SSTR4. Conclusions Two ancestral SSTR-bearing chromosome regions were duplicated in the two basal vertebrate tetraploidizations (2R). One of these ancestral SSTR genes generated SSTR2, -3 and -5, the other gave rise to SSTR1, -4 and -6. Subsequently SSTR6 was lost in tetrapods and SSTR4 in teleosts. Our study shows that extensive chromosomal rearrangements have taken place between related chromosome regions in teleosts, but that these events can be resolved by investigating several distantly related species. PMID:23194088

  14. Evidence from cyclostomes for complex regionalization of the ancestral vertebrate brain.

    PubMed

    Sugahara, Fumiaki; Pascual-Anaya, Juan; Oisi, Yasuhiro; Kuraku, Shigehiro; Aota, Shin-ichi; Adachi, Noritaka; Takagi, Wataru; Hirai, Tamami; Sato, Noboru; Murakami, Yasunori; Kuratani, Shigeru

    2016-03-01

    The vertebrate brain is highly complex, but its evolutionary origin remains elusive. Because of the absence of certain developmental domains generally marked by the expression of regulatory genes, the embryonic brain of the lamprey, a jawless vertebrate, had been regarded as representing a less complex, ancestral state of the vertebrate brain. Specifically, the absence of a Hedgehog- and Nkx2.1-positive domain in the lamprey subpallium was thought to be similar to mouse mutants in which the suppression of Nkx2-1 leads to a loss of the medial ganglionic eminence. Here we show that the brain of the inshore hagfish (Eptatretus burgeri), another cyclostome group, develops domains equivalent to the medial ganglionic eminence and rhombic lip, resembling the gnathostome brain. Moreover, further investigation of lamprey larvae revealed that these domains are also present, ruling out the possibility of convergent evolution between hagfish and gnathostomes. Thus, brain regionalization as seen in crown gnathostomes is not an evolutionary innovation of this group, but dates back to the latest vertebrate ancestor before the divergence of cyclostomes and gnathostomes more than 500 million years ago. PMID:26878236

  15. Early vertebrate chromosome duplications and the evolution of the neuropeptide Y receptor gene regions

    PubMed Central

    2008-01-01

    Background One of the many gene families that expanded in early vertebrate evolution is the neuropeptide (NPY) receptor family of G-protein coupled receptors. Earlier work by our lab suggested that several of the NPY receptor genes found in extant vertebrates resulted from two genome duplications before the origin of jawed vertebrates (gnathostomes) and one additional genome duplication in the actinopterygian lineage, based on their location on chromosomes sharing several gene families. In this study we have investigated, in five vertebrate genomes, 45 gene families with members close to the NPY receptor genes in the compact genomes of the teleost fishes Tetraodon nigroviridis and Takifugu rubripes. These correspond to Homo sapiens chromosomes 4, 5, 8 and 10. Results Chromosome regions with conserved synteny were identified and confirmed by phylogenetic analyses in H. sapiens, M. musculus, D. rerio, T. rubripes and T. nigroviridis. 26 gene families, including the NPY receptor genes, (plus 3 described recently by other labs) showed a tree topology consistent with duplications in early vertebrate evolution and in the actinopterygian lineage, thereby supporting expansion through block duplications. Eight gene families had complications that precluded analysis (such as short sequence length or variable number of repeated domains) and another eight families did not support block duplications (because the paralogs in these families seem to have originated in another time window than the proposed genome duplication events). RT-PCR carried out with several tissues in T. rubripes revealed that all five NPY receptors were expressed in the brain and subtypes Y2, Y4 and Y8 were also expressed in peripheral organs. Conclusion We conclude that the phylogenetic analyses and chromosomal locations of these gene families support duplications of large blocks of genes or even entire chromosomes. Thus, these results are consistent with two early vertebrate tetraploidizations forming a

  16. Regional variations in the compressive properties of lumbar vertebral trabeculae. Effects of disc degeneration

    SciTech Connect

    Keller, T.S.; Hansson, T.H.; Abram, A.C.; Spengler, D.M.; Panjabi, M.M. )

    1989-09-01

    The compressive mechanical properties of human lumbar vertebral trabeculae were examined on the basis of anatomic origin, bone density, and intervertebral disc properties. Trabecular bone compressive strength and stiffness increased with increasing bone density, the latter proportional to strength and stiffness to the one-half power. Regional variations within each segment were found, the most prevalent differences occurring in regions of bone overlying the disc nucleus in comparison with bone overlying the disc anulus. For normal discs, the ratio of strength of bone overlying the disc nucleus to bone overlying the disc anulus was 1.25, decreasing to 1.0 for moderately degenerated discs. These results suggest that an interdependency of trabecular bone properties and intervertebral disc properties may exist.

  17. Evolution of the vertebrate genome as reflected in paralogous chromosomal regions in man and the house mouse

    SciTech Connect

    Lundin, L.G. )

    1993-04-01

    Gene constellations on several human chromosomes are interpreted as indications of large regional duplications that took place during evolution of the vertebrate genome. Four groups of paralogous chromosomal regions in man and the house mouse are suggested and are believed to be conserved remnants of the two or three rounds of tetraploidization that are likely to have occurred during evolution of the vertebrates. The phenomenon of differential silencing of genes is described. The importance of conservation of linkage of particular genes is discussed in relation to genetic regulation and cell differentiation. 120 refs., 5 tabs.

  18. A procephalic territory in Drosophila exhibiting similarities and dissimilarities compared to the vertebrate midbrain/hindbrain boundary region

    PubMed Central

    Urbach, Rolf

    2007-01-01

    Background In vertebrates, the primordium of the brain is subdivided by the expression of Otx genes (forebrain/anterior midbrain), Hox genes (posterior hindbrain), and the genes Pax2, Pax5 and Pax8 (intervening region). The latter includes the midbrain/hindbrain boundary (MHB), which acts as a key organizer during brain patterning. Recent studies in Drosophila revealed that orthologous sets of genes are expressed in a similar tripartite pattern in the late embryonic brain, which suggested correspondence between the Drosophila deutocerebral/tritocerebral boundary region and the vertebrate MHB. To gain more insight into the evolution of brain regions, and particularly the MHB, I examined the expression of a comprehensive array of MHB-specific gene orthologs in the procephalic neuroectoderm and in individually identified neuroblasts during early embryonic stages 8–11, at which the segmental organization of the brain is most clearly displayed. Results and conclusion I show that the early embryonic brain exhibits an anterior Otx/otd domain and a posterior Hox1/lab domain, but that Pax2/5/8 orthologs are not expressed in the neuroectoderm and neuroblasts of the intervening territory. Furthermore, the expression domains of Otx/otd and Gbx/unpg exhibit a small common interface within the anterior deutocerebrum. In contrast to vertebrates, Fgf8-related genes are not expressed posterior to the otd/unpg interface. However, at the otd/unpg interface the early expression of other MHB-specific genes (including btd, wg, en), and of dorsoventral patterning genes, closely resembles the situation at the vertebrate MHB. Altogether, these results suggest the existence of an ancestral territory within the primordium of the deutocerebrum and adjacent protocerebrum, which might be the evolutionary equivalent of the region of the vertebrate MHB. However, lack of expression of Pax2/5/8 and Fgf8-related genes, and significant differences in the expression onset of other key regulators at

  19. Photoelastic analisys in the lower region of vertebral body L4

    PubMed Central

    Fakhouri, Sarah Fakher; Zamarioli, Ariane; Shimano, Marcos Massao; Defino, Helton Luiz Aparecido; Araujo, Cleudmar Amaral; Shimano, Antonio Carlos

    2012-01-01

    Objective To analyze the shear forces on the vertebral body L4 when submitted to a compression force by means of transmission photoelasticity. Methods Twelve photoelastic models were divided into three groups, with four models per group, according to the positioning of the sagittal section vertebrae L4-L5 (sections A, B and C). The simulation was performed using a 15N compression force, and the fringe orders were evaluated in the vertebral body L4 by the Tardy compensation method. Results Photoelastic analysis showed, in general, a homogeneous distribution in the vertebral bodies. The shear forces were higher in section C than B, and higher in B than A. Conclusion The posterior area of L4, mainly in section C, showed higher shear concentrations, corresponding to a more susceptible area for bone fracture and spondylolisthesis. Economic and Decision Analyses - Development of an Economic or Decision Model. Level I PMID:24453574

  20. Vertebrate fossils and trace fossils in Upper Jurassic-Lower cretaceous red beds in the Atacama region, Chile

    NASA Astrophysics Data System (ADS)

    Bell, C. M.; Suárez, M.

    Pterosaur, dinosaur, and crocodile bones are recorded here for the first time in Upper Jurassic-Lower Cretaceous red beds in the Atacama region east of Copiapó, Chile. Trace fossils produced by vertebrate animals include the footprints of theropod dinosaurs and the depressions of sandstone laminae interpreted as burrows and foot impressions. The fossils occur in the 1500-meter-thick Quebrada Monardes Formation, which consists predominantly of the aeolian and alluvial deposits of a semi-arid terrestrial environment. Vertebrate fossils are very rare in Chile. Dinosaur bones and footprints have previously been recorded at only seven locations, and pterosaur remains at only one location. The newly discovered dinosaur bones are the oldest to be described in Chile.

  1. HNK-1 immunoreactivity during early morphogenesis of the head region in a nonmodel vertebrate, crocodile embryo.

    PubMed

    Kundrát, Martin

    2008-11-01

    The present study examines HNK-1 immunoidentification of a population of the neural crest (NC) during early head morphogenesis in the nonmodel vertebrate, the crocodile (Crocodylus niloticus) embryos. Although HNK-1 is not an exclusive NC marker among vertebrates, temporospatial immunoreactive patterns found in the crocodile are almost consistent with NC patterns derived from gene expression studies known in birds (the closest living relatives of crocodiles) and mammals. In contrast to birds, the HNK-1 epitope is immunoreactive in NC cells at the neural fold level in crocodile embryos and therefore provides sufficient base to assess early migratory events of the cephalic NC. I found that crocodile NC forms three classic migratory pathways in the head: mandibular, hyoid, and branchial. Further, I demonstrate that, besides this classic phenotype, there is also a forebrain-derived migratory population, which consolidates into a premandibular stream in the crocodile. In contrast to the closely related chick model, crocodilian premandibular and mandibular NC cells arise from the open neural tube suggesting that species-specific heterochronic behavior of NC may be involved in the formation of different vertebrate facial phenotypes. PMID:18668221

  2. HNK-1 immunoreactivity during early morphogenesis of the head region in a nonmodel vertebrate, crocodile embryo

    NASA Astrophysics Data System (ADS)

    Kundrát, Martin

    2008-11-01

    The present study examines HNK-1 immunoidentification of a population of the neural crest (NC) during early head morphogenesis in the nonmodel vertebrate, the crocodile ( Crocodylus niloticus) embryos. Although HNK-1 is not an exclusive NC marker among vertebrates, temporospatial immunoreactive patterns found in the crocodile are almost consistent with NC patterns derived from gene expression studies known in birds (the closest living relatives of crocodiles) and mammals. In contrast to birds, the HNK-1 epitope is immunoreactive in NC cells at the neural fold level in crocodile embryos and therefore provides sufficient base to assess early migratory events of the cephalic NC. I found that crocodile NC forms three classic migratory pathways in the head: mandibular, hyoid, and branchial. Further, I demonstrate that, besides this classic phenotype, there is also a forebrain-derived migratory population, which consolidates into a premandibular stream in the crocodile. In contrast to the closely related chick model, crocodilian premandibular and mandibular NC cells arise from the open neural tube suggesting that species-specific heterochronic behavior of NC may be involved in the formation of different vertebrate facial phenotypes.

  3. The vertebrate ancestral repertoire of visual opsins, transducin alpha subunits and oxytocin/vasopressin receptors was established by duplication of their shared genomic region in the two rounds of early vertebrate genome duplications

    PubMed Central

    2013-01-01

    Background Vertebrate color vision is dependent on four major color opsin subtypes: RH2 (green opsin), SWS1 (ultraviolet opsin), SWS2 (blue opsin), and LWS (red opsin). Together with the dim-light receptor rhodopsin (RH1), these form the family of vertebrate visual opsins. Vertebrate genomes contain many multi-membered gene families that can largely be explained by the two rounds of whole genome duplication (WGD) in the vertebrate ancestor (2R) followed by a third round in the teleost ancestor (3R). Related chromosome regions resulting from WGD or block duplications are said to form a paralogon. We describe here a paralogon containing the genes for visual opsins, the G-protein alpha subunit families for transducin (GNAT) and adenylyl cyclase inhibition (GNAI), the oxytocin and vasopressin receptors (OT/VP-R), and the L-type voltage-gated calcium channels (CACNA1-L). Results Sequence-based phylogenies and analyses of conserved synteny show that the above-mentioned gene families, and many neighboring gene families, expanded in the early vertebrate WGDs. This allows us to deduce the following evolutionary scenario: The vertebrate ancestor had a chromosome containing the genes for two visual opsins, one GNAT, one GNAI, two OT/VP-Rs and one CACNA1-L gene. This chromosome was quadrupled in 2R. Subsequent gene losses resulted in a set of five visual opsin genes, three GNAT and GNAI genes, six OT/VP-R genes and four CACNA1-L genes. These regions were duplicated again in 3R resulting in additional teleost genes for some of the families. Major chromosomal rearrangements have taken place in the teleost genomes. By comparison with the corresponding chromosomal regions in the spotted gar, which diverged prior to 3R, we could time these rearrangements to post-3R. Conclusions We present an extensive analysis of the paralogon housing the visual opsin, GNAT and GNAI, OT/VP-R, and CACNA1-L gene families. The combined data imply that the early vertebrate WGD events contributed to the

  4. Solving a sequencing problem in the vertebrate mitochondrial control region using phylogenetic comparisons.

    PubMed

    Feinstein, Julie; Cracraft, Joel

    2004-01-01

    The mitochondrial control region (mtCR) of the bird-of-paradise, Phonygammus keraudrenii, the Trumpet Manucode, contains a unique arrangement of homopolymers and short tandem repeats. Homopolymers occur within a few hundred bases of each other, trapping sequence information between unsequenceable barriers. A comparative strategy, involving other manucode species, allowed the prediction of primer sites in the inaccessible region. The method is suggested for similar sequencing problems. PMID:15621664

  5. Vertebral Morphometry.

    PubMed

    Chou, Sharon H; Vokes, Tamara

    2016-01-01

    There is as yet no agreement about the criteria by which to arrive at an imaging diagnosis of a vertebral fracture. Because high-grade fractures result in alterations in vertebral shape, 1 possible avenue of diagnosis has been to quantitate changes in vertebral shape. The result has been a variety of methods for the relative and absolute measurements of vertebral dimensions. Such measurements have also lent themselves to automated computed analysis. The number of techniques reflects the absence of any consensus about the best. The semiquantitative technique proposed by Genant has become the most widely used and has served the field well for comparative purposes. Its use in higher grade fractures has been widely endorsed, if some concepts (e.g., short vertebral height-vertebrae) are at variance with lower grades of fracturing. Vertebral morphometry may be the only recourse in high volume epidemiological and interventional studies. PMID:26349790

  6. Salamander Hox clusters contain repetitive DNA and expanded non-coding regions: a typical Hox structure for non-mammalian tetrapod vertebrates?

    PubMed Central

    2013-01-01

    Hox genes encode transcription factors that regulate embryonic and post-embryonic developmental processes. The expression of Hox genes is regulated in part by the tight, spatial arrangement of conserved coding and non-coding sequences. The potential for evolutionary changes in Hox cluster structure is thought to be low among vertebrates; however, recent studies of a few non-mammalian taxa suggest greater variation than originally thought. Using next generation sequencing of large genomic fragments (>100 kb) from the red spotted newt (Notophthalamus viridescens), we found that the arrangement of Hox cluster genes was conserved relative to orthologous regions from other vertebrates, but the length of introns and intergenic regions varied. In particular, the distance between hoxd13 and hoxd11 is longer in newt than orthologous regions from vertebrate species with expanded Hox clusters and is predicted to exceed the length of the entire HoxD clusters (hoxd13–hoxd4) of humans, mice, and frogs. Many repetitive DNA sequences were identified for newt Hox clusters, including an enrichment of DNA transposon-like sequences relative to non-coding genomic fragments. Our results suggest that Hox cluster expansion and transposon accumulation are common features of non-mammalian tetrapod vertebrates. PMID:23561734

  7. Vertebrate Dissimilarity Due to Turnover and Richness Differences in a Highly Beta-Diverse Region: The Role of Spatial Grain Size, Dispersal Ability and Distance

    PubMed Central

    Calderón-Patrón, Jaime M.; Moreno, Claudia E.; Pineda-López, Rubén; Sánchez-Rojas, Gerardo; Zuria, Iriana

    2013-01-01

    We explore the influence of spatial grain size, dispersal ability, and geographic distance on the patterns of species dissimilarity of terrestrial vertebrates, separating the dissimilarity explained by species replacement (turnover) from that resulting from richness differences. With data for 905 species of terrestrial vertebrates distributed in the Isthmus of Tehuantepec, classified into five groups according to their taxonomy and dispersal ability, we calculated total dissimilarity and its additive partitioning as two components: dissimilarity derived from turnover and dissimilarity derived from richness differences. These indices were compared using fine (10 x 10 km), intermediate (20 x 20 km) and coarse (40 x 40 km) grain grids, and were tested for any correlations with geographic distance. The results showed that total dissimilarity is high for the terrestrial vertebrates in this region. Total dissimilarity, and dissimilarity due to turnover are correlated with geographic distance, and the patterns are clearer when the grain is fine, which is consistent with the distance-decay pattern of similarity. For all terrestrial vertebrates tested on the Isthmus of Tehuantepec both the dissimilarity derived from turnover and the dissimilarity resulting from richness differences make important contributions to total dissimilarity, and dispersal ability does not seem to influence the dissimilarity patterns. These findings support the idea that conservation efforts in this region require a system of interconnected protected areas that embrace the environmental, climatic and biogeographic heterogeneity of the area. PMID:24324840

  8. Phylogeography of a widespread terrestrial vertebrate in a barely-studied Palearctic region: green toads (Bufo viridis subgroup) indicate glacial refugia in Eastern Central Asia.

    PubMed

    Zhang, Yi-Jun; Stöck, Matthias; Zhang, Peng; Wang, Xiu-Ling; Zhou, Hui; Qu, Liang-Hu

    2008-11-01

    The phylogeography of western Palearctic species is relatively well studied, but data on Eastern Central Asia are scarce. We present one of the first data sets from a widespread terrestrial vertebrate (Bufo pewzowi) inhabiting Eastern Central Asian mountains and deserts to gain knowledge on its phylogeography in this region. We applied combined phylogenetic and demographic analyses to understand the evolutionary history using mitochondrial DNA D-loop variation of toads from 37 locations. Genetic structure of Bufo pewzowi is strongly affected by landscape: we found three haplotype groups in eastern Kazakhstan, Dzungaria and Tarim Basin, divided by the Tian Shan and Dzungarian Alatau ranges. A vicariant hypothesis may explain divergence among groups. The divergence time of the three major clades was estimated about 0.9 million years ago (confidence interval 0.5-1.4), and is discussed with respect to Quaternary uplifting and glaciation in the Tian Shan. Demographic analyses provided evidence for both historical bottlenecks and population expansions and suggested Pleistocene signatures. Glacial refugia were inferred in the Tarim Basin (around the Turpan depression), in southern Dzungaria (Urumqui region), at the northern foot of the Tian Shan (Gongnaisi) and perhaps at the Altai range (Terekti). Regional Post-Last Glacial Maximum dispersal patterns are proposed. A taxonomic hypothesis is presented. This study provides a detailed history of how a widespread terrestrial vertebrate responded to geological change and Quaternary glacial events in Eastern Central Asia and may have significance for future phylogeographic research in this understudied region. PMID:18301990

  9. Evolution of vertebrate IgM: complete amino acid sequence of the constant region of Ambystoma mexicanum mu chain deduced from cDNA sequence.

    PubMed

    Fellah, J S; Wiles, M V; Charlemagne, J; Schwager, J

    1992-10-01

    cDNA clones coding for the constant region of the Mexican axolotl (Ambystoma mexicanum) mu heavy immunoglobulin chain were selected from total spleen RNA, using a cDNA polymerase chain reaction technique. The specific 5'-end primer was an oligonucleotide homologous to the JH segment of Xenopus laevis mu chain. One of the clones, JHA/3, corresponded to the complete constant region of the axolotl mu chain, consisting of a 1362-nucleotide sequence coding for a polypeptide of 454 amino acids followed in 3' direction by a 179-nucleotide untranslated region and a polyA+ tail. The axolotl C mu is divided into four typical domains (C mu 1-C mu 4) and can be aligned with the Xenopus C mu with an overall identity of 56% at the nucleotide level. Percent identities were particularly high between C mu 1 (59%) and C mu 4 (71%). The C-terminal 20-amino acid segment which constitutes the secretory part of the mu chain is strongly homologous to the equivalent sequences of chondrichthyans and of other tetrapods, including a conserved N-linked oligosaccharide, the penultimate cysteine and the C-terminal lysine. The four C mu domains of 13 vertebrate species ranging from chondrichthyans to mammals were aligned and compared at the amino acid level. The significant number of mu-specific residues which are conserved into each of the four C mu domains argues for a continuous line of evolution of the vertebrate mu chain. This notion was confirmed by the ability to reconstitute a consistent vertebrate evolution tree based on the phylogenic parsimony analysis of the C mu 4 sequences. PMID:1382992

  10. Contaminant exposure and potential effects on terrestrial vertebrates residing in the National Capital Region network and Mid-Atlantic network

    USGS Publications Warehouse

    Rattner, B.A.; Ackerson, B.K.

    2006-01-01

    Based upon these and other findings, ecotoxicological monitoring and research investigations of terrestrial vertebrates are warranted at several National Parks. These include Shenandoah National Park, Richmond National Battlefield, Chesapeake & Ohio Canal National Historic Park, Valley Forge National Historic Park, Hopewell Furnace National Historic Site, Monocacy National Battlefield, and Harpers Ferry National Historic Park. The types of investigations vary according to the species present at these parks and potential contaminant threats, but should focus on contemporary use pesticides and herbicides, polychlorinated biphenyls, mercury, lead, and perhaps, emerging contaminants including antibiotics, flame retardants, pharmaceuticals, and surfactants. Other management recommendations include additional training for natural resource staff members in the area of ecotoxicology, inclusion of terrestrial vertebrate contaminant monitoring and the Contaminant Assessment Process (U.S. Geological Survey Biomonitoring of Environmental Status and Trends Project) into the National Park Service Vital Signs Program, development of protocols for hand ling and toxicological analysis of dead or seemingly affected wildlife, consideration of some alternative methods and compounds for pest management and weed control

  11. DNA Sequence Characterization of a Gene-rich Region in Rye

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aluminum toxicity, affecting approximately half of the world’s arable land, severely hinders the ability of crop plants to utilize moisture and nutrients by restricting root growth and function. Among the cultivated cereals, rye is the most Al-tolerant of the cereals and represents an important pote...

  12. Vertebrate Reproduction.

    PubMed

    Kornbluth, Sally; Fissore, Rafael

    2015-10-01

    Vertebrate reproduction requires a myriad of precisely orchestrated events-in particular, the maternal production of oocytes, the paternal production of sperm, successful fertilization, and initiation of early embryonic cell divisions. These processes are governed by a host of signaling pathways. Protein kinase and phosphatase signaling pathways involving Mos, CDK1, RSK, and PP2A regulate meiosis during maturation of the oocyte. Steroid signals-specifically testosterone-regulate spermatogenesis, as does signaling by G-protein-coupled hormone receptors. Finally, calcium signaling is essential for both sperm motility and fertilization. Altogether, this signaling symphony ensures the production of viable offspring, offering a chance of genetic immortality. PMID:26430215

  13. Vertebrate skeletogenesis.

    PubMed

    Lefebvre, Véronique; Bhattaram, Pallavi

    2010-01-01

    Vertebrate skeletogenesis consists in elaborating an edifice of more than 200 pieces of bone and cartilage. Each skeletal piece is crafted at a distinct location in the body, is articulated with others, and reaches a specific size, shape, and tissue composition according to both species instructions and individual determinants. This complex, customized body frame fulfills multiple essential tasks. It confers morphological features, allows controlled postures and movements, protects vital organs, houses hematopoiesis, stores minerals, and adsorbs toxins. This review provides an overview of the multiple facets of this ingenious process for experts as well as nonexperts of skeletogenesis. We explain how the developing vertebrate uses both specific and ubiquitously expressed genes to generate multipotent mesenchymal cells, specify them to a skeletogenic fate, control their survival and proliferation, and direct their differentiation into cartilage, bone, and joint cells. We review milestone discoveries made toward uncovering the intricate networks of regulatory factors that are involved in these processes, with an emphasis on signaling pathways and transcription factors. We describe numerous skeletal malformation and degeneration diseases that occur in humans as a result of mutations in regulatory genes, and explain how these diseases both help and motivate us to further decipher skeletogenic processes. Upon discussing current knowledge and gaps in knowledge in the control of skeletogenesis, we highlight ultimate research goals and propose research priorities and approaches for future endeavors. PMID:20691853

  14. Three-dimensional structure of the M-region (bare zone) of vertebrate striated muscle myosin filaments by single-particle analysis.

    PubMed

    Al-Khayat, Hind A; Kensler, Robert W; Morris, Edward P; Squire, John M

    2010-11-12

    The rods of anti-parallel myosin molecules overlap at the centre of bipolar myosin filaments to produce an M-region (bare zone) that is free of myosin heads. Beyond the M-region edges, myosin molecules aggregate in a parallel fashion to yield the bridge regions of the myosin filaments. Adjacent myosin filaments in striated muscle A-bands are cross-linked by the M-band. Vertebrate striated muscle myosin filaments have a 3-fold rotational symmetry around their long axes. In addition, at the centre of the M-region, there are three 2-fold axes perpendicular to the filament long axis, giving the whole filament dihedral 32-point group symmetry. Here we describe the three-dimensional structure obtained by a single-particle analysis of the M-region of myosin filaments from goldfish skeletal muscle under relaxing conditions and as viewed in negative stain. This is the first single-particle reconstruction of isolated M-regions. The resulting three-dimensional reconstruction reveals details to about 55 Å resolution of the density distribution in the five main nonmyosin densities in the M-band (M6', M4', M1, M4 and M6) and in the myosin head crowns (P1, P2 and P3) at the M-region edges. The outermost crowns in the reconstruction were identified specifically by their close similarity to the corresponding crown levels in our previously published bridge region reconstructions. The packing of myosin molecules into the M-region structure is discussed, and some unidentified densities are highlighted. PMID:20851129

  15. Conserved localization of Pax6 and Pax7 transcripts in the brain of representatives of sarcopterygian vertebrates during development supports homologous brain regionalization

    PubMed Central

    Moreno, Nerea; Joven, Alberto; Morona, Ruth; Bandín, Sandra; López, Jesús M.; González, Agustín

    2014-01-01

    Many of the genes involved in brain patterning during development are highly conserved in vertebrates and similarities in their expression patterns help to recognize homologous cell types or brain regions. Among these genes, Pax6 and Pax7 are expressed in regionally restricted patterns in the brain and are essential for its development. In the present immunohistochemical study we analyzed the distribution of Pax6 and Pax7 cells in the brain of six representative species of tetrapods and lungfishes, the closest living relatives of tetrapods, at several developmental stages. The distribution patterns of these transcription factors were largely comparable across species. In all species only Pax6 was expressed in the telencephalon, including the olfactory bulbs, septum, striatum, and amygdaloid complex. In the diencephalon, Pax6 and Pax7 were distinct in the alar and basal parts, mainly in prosomeres 1 and 3. Pax7 specifically labeled cells in the optic tectum (superior colliculus) and Pax6, but not Pax7, cells were found in the tegmentum. Pax6 was found in most granule cells of the cerebellum and Pax7 labeling was detected in cells of the ventricular zone of the rostral alar plate and in migrated cells in the basal plate, including the griseum centrale and the interpeduncular nucleus. Caudally, Pax6 cells formed a column, whereas the ventricular zone of the alar plate expressed Pax7. Since the observed Pax6 and Pax7 expression patterns are largely conserved they can be used to identify subdivisions in the brain across vertebrates that are not clearly discernible with classical techniques. PMID:25147506

  16. Building the Vertebrate Spine

    NASA Astrophysics Data System (ADS)

    Pourquié, Olivier

    2008-03-01

    to scoliosis in humans. Finally, the subsequent regional differentiation of the precursors of the vertebrae is controlled by Hox genes, whose collinear expression controls both gastrulation of somite precursors and their subsequent patterning into region-specific types of structures. Therefore somite development provides an outstanding paradigm to study patterning and differentiation in vertebrate embryos.

  17. 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…

  18. Climate change and marine vertebrates.

    PubMed

    Sydeman, William J; Poloczanska, Elvira; Reed, Thomas E; Thompson, Sarah Ann

    2015-11-13

    Climate change impacts on vertebrates have consequences for marine ecosystem structures and services. We review marine fish, mammal, turtle, and seabird responses to climate change and discuss their potential for adaptation. Direct and indirect responses are demonstrated from every ocean. Because of variation in research foci, observed responses differ among taxonomic groups (redistributions for fish, phenology for seabirds). Mechanisms of change are (i) direct physiological responses and (ii) climate-mediated predator-prey interactions. Regional-scale variation in climate-demographic functions makes range-wide population dynamics challenging to predict. The nexus of metabolism relative to ecosystem productivity and food webs appears key to predicting future effects on marine vertebrates. Integration of climate, oceanographic, ecosystem, and population models that incorporate evolutionary processes is needed to prioritize the climate-related conservation needs for these species. PMID:26564847

  19. The vertebral column of Australopithecus sediba.

    PubMed

    Williams, Scott A; Ostrofsky, Kelly R; Frater, Nakita; Churchill, Steven E; Schmid, Peter; Berger, Lee R

    2013-04-12

    Two partial vertebral columns of Australopithecus sediba grant insight into aspects of early hominin spinal mobility, lumbar curvature, vertebral formula, and transitional vertebra position. Au. sediba likely possessed five non-rib-bearing lumbar vertebrae and five sacral elements, the same configuration that occurs modally in modern humans. This finding contrasts with other interpretations of early hominin regional vertebral numbers. Importantly, the transitional vertebra is distinct from and above the last rib-bearing vertebra in Au. sediba, resulting in a functionally longer lower back. This configuration, along with a strongly wedged last lumbar vertebra and other indicators of lordotic posture, would have contributed to a highly flexible spine that is derived compared with earlier members of the genus Australopithecus and similar to that of the Nariokotome Homo erectus skeleton. PMID:23580532

  20. [Vertebral hydatidosis: case report].

    PubMed

    Varela, R; Santelices, J P; Cuzmar, D; Aldunate, J T; Plaza-Guzmán, N; Lizama-Calvo, P

    2015-01-01

    Hydatidosis caused by echinococcus granulosus may affect any organ in the body, with the lungs and the liver as the most commonly affected organs. Vertebral compromise resulting from echinococcus granulosus has a low prevalence and accounts for less than 1% of bone compromise. We report the case of a 50 year-old female who presented at the Trauma Service with progressive low back pain with 5 months of duration that irradiated to the right lower limb, and led to neurologic compromise of the limb. Imaging studies showed spondylodiscitis at T12-L1, confirmed by a biopsy. Treatment of this condition is both orthopedic and surgical. The recurrence rate is high, between 30 and 40%. The objective of describing this case is to propose the differential diagnosis of a vertebral mass of unknown origin and provide details as to how to manage this condition. PMID:27012085

  1. Viruses of lower vertebrates.

    PubMed

    Essbauer, S; Ahne, W

    2001-08-01

    Viruses of lower vertebrates recently became a field of interest to the public due to increasing epizootics and economic losses of poikilothermic animals. These were reported worldwide from both wildlife and collections of aquatic poikilothermic animals. Several RNA and DNA viruses infecting fish, amphibians and reptiles have been studied intensively during the last 20 years. Many of these viruses induce diseases resulting in important economic losses of lower vertebrates, especially in fish aquaculture. In addition, some of the DNA viruses seem to be emerging pathogens involved in the worldwide decline in wildlife. Irido-, herpes- and polyomavirus infections may be involved in the reduction in the numbers of endangered amphibian and reptile species. In this context the knowledge of several important RNA viruses such as orthomyxo-, paramyxo-, rhabdo-, retro-, corona-, calici-, toga-, picorna-, noda-, reo- and birnaviruses, and DNA viruses such as parvo-, irido-, herpes-, adeno-, polyoma- and poxviruses, is described in this review. PMID:11550762

  2. Head segmentation in vertebrates

    PubMed Central

    Kuratani, Shigeru; Schilling, Thomas

    2008-01-01

    Classic theories of vertebrate head segmentation clearly exemplify the idealistic nature of comparative embryology prior to the 20th century. Comparative embryology aimed at recognizing the basic, primary structure that is shared by all vertebrates, either as an archetype or an ancestral developmental pattern. Modern evolutionary developmental (Evo-Devo) studies are also based on comparison, and therefore have a tendency to reduce complex embryonic anatomy into overly simplified patterns. Here again, a basic segmental plan for the head has been sought among chordates. We convened a symposium that brought together leading researchers dealing with this problem, in a number of different evolutionary and developmental contexts. Here we give an overview of the outcome and the status of the field in this modern era of Evo-Devo. We emphasize the fact that the head segmentation problem is not fully resolved, and we discuss new directions in the search for hints for a way out of this maze. PMID:20607135

  3. [A vertebral arteriovenous fistula diagnosed by auscultation].

    PubMed

    Iglesias Escalera, G; Diaz-Delgado Peñas, R; Carrasco Marina, M Ll; Maraña Perez, A; Ialeggio, D

    2015-01-01

    Cervical artery fistulas are rare arteriovenous malformations. The etiology of the vertebral arteriovenous fistulas (AVF) can be traumatic or spontaneous. They tend to be asymptomatic or palpation or continuous vibration in the cervical region. An arteriography is necessary for a definitive diagnosis. The treatment is complete embolization of the fistula. We present the case of a two year-old male, where the mother described it «like a washing machine in his head». On palpation during the physical examination, there was a continuous vibration, and a continuous murmur in left cervical region. A vascular malformation in vertebral region was clinically suspected, and confirmed with angio-MRI and arteriography. AVF are rare in childhood. They should be suspected in the presence of noises, palpation or continuous vibration in the cervical region. Early diagnosis can prevent severe complications in asymptomatic children. PMID:24598790

  4. Reintroduction of locally extinct vertebrates impacts arid soil fungal communities.

    PubMed

    Clarke, Laurence J; Weyrich, Laura S; Cooper, Alan

    2015-06-01

    Introduced species have contributed to extinction of native vertebrates in many parts of the world. Changes to vertebrate assemblages are also likely to alter microbial communities through coextinction of some taxa and the introduction of others. Many attempts to restore degraded habitats involve removal of exotic vertebrates (livestock and feral animals) and reintroduction of locally extinct species, but the impact of such reintroductions on microbial communities is largely unknown. We used high-throughput DNA sequencing of the fungal internal transcribed spacer I (ITS1) region to examine whether replacing exotic vertebrates with reintroduced native vertebrates led to changes in soil fungal communities at a reserve in arid central Australia. Soil fungal diversity was significantly different between dune and swale (interdune) habitats. Fungal communities also differed significantly between sites with exotic or reintroduced native vertebrates after controlling for the effect of habitat. Several fungal operational taxonomic units (OTUs) found exclusively inside the reserve were present in scats from reintroduced native vertebrates, providing a direct link between the vertebrate assemblage and soil microbial communities. Our results show that changes to vertebrate assemblages through local extinctions and the invasion of exotic species can alter soil fungal communities. If local extinction of one or several species results in the coextinction of microbial taxa, the full complement of ecological interactions may never be restored. PMID:25943906

  5. Correlation between Hox code and vertebral morphology in archosaurs.

    PubMed

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

    2015-07-01

    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

  6. 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

  7. Mechanotransduction During Vertebrate Neurulation.

    PubMed

    Sokol, Sergei Y

    2016-01-01

    Vertebrate neural tube formation is a complex morphogenetic process, which involves hundreds of genes dynamically coordinating various behaviors in different cell populations of neural tissue. The challenge remains to determine the relative contributions of physical forces and biochemical signaling events to neural tube closure and accompanying cell fate specification. Planar cell polarity (PCP) molecules are prime candidate factors for the production of actomyosin-dependent mechanical signals necessary for morphogenesis. Conversely, physical forces may contribute to the polarized distribution of PCP proteins. Understanding mechanosensory and mechanotransducing properties of diverse molecules should help define the direction and amplitude of physical stresses that are critical for neurulation. PMID:26969989

  8. Non-contiguous multifocal vertebral osteomyelitis caused by Serratia marcescens.

    PubMed

    Lau, Jen Xin; Li, Jordan Yuanzhi; Yong, Tuck Yean

    2015-03-01

    Serratia marcescens is a common nosocomial infection but a rare cause of osteomyelitis and more so of vertebral osteomyelitis. Vertebral osteomyelitis caused by this organism has been reported in few studies. We report a case of S. marcescens vertebral discitis and osteomyelitis affecting multiple non-contiguous vertebras. Although Staphylococcus aureus is the most common cause of vertebral osteomyelitis, rare causes, such as S. marcescens, need to be considered, especially when risk factors such as intravenous heroin use, post-spinal surgery and immunosuppression are present. Therefore, blood culture and where necessary biopsy of the infected region should be undertaken to establish the causative organism and determine appropriate antibiotic susceptibility. Prompt diagnosis of S. marcescens vertebral osteomyelitis followed by the appropriate treatment can achieve successful outcomes. PMID:24533544

  9. Vertebral Angiosarcoma. Case Study.

    PubMed

    Guzik, Grzegorz

    2015-01-01

    Bone angiosarcomas, especially vertebral angiosarcomas, are very rare. There are no studies based on large clinical samples in the literature, and only a few single case reports can be found. The symptoms of the disease are not specific. It is usually detected incidentally or at a late stage when pathological vertebral fractures or neurological complications occur. Diagnostic imaging and history help to recognize the tumour behind the symptoms, but do not allow accurate clinical diagnosis. The basis for a diagnosis is the histopathological examination supported by immunohistochemistry (IHC) assays. The case of a 26-year-old woman with an angiosarcoma involving the eighth thoracic vertebra we report reflects diagnostic problems adversely affecting the efficacy and accuracy of treatment offered to patients. The patient underwent three surgeries of the spine, including two biopsies. A needle biopsy did not provide sufficient information for the diagnosis. An open excisional biopsy, which at the same time temporarily reduced neurological deficits in the patient, was the only chance to obtain an accurate diagnosis. The third surgery was posterior decompression of the spinal cord due to the rapidly escalating paraparesis. It was not until 8 weeks later that the final diagnosis was established. At that time, the patient could not be qualified for any supplementary treatment. The patient died in hospital 6 months after the onset of disease. PMID:26468177

  10. Height and body mass index in Oslo, Norway, compared to other regions of Europe: do they explain differences in the incidence of hip fracture? European Vertebral Osteoporosis Study Group.

    PubMed

    Meyer, H E; Falch, J A; O'Neill, T; Tverdal, A; Varlow, J

    1995-10-01

    Lean body stature and tallness have both been identified as risk factors for hip fracture. In this study, height and weight data from a multinational multicenter study were used to compare Oslo, which has some of the highest incidence rates of hip fracture ever reported, to other regions of Europe, with respect to height and body mass index. More than 17,000 subjects in six age strata (50-54, 55-59, 60-64, 65-69, 70-74, 75+ years) from 36 centers in 19 European countries were enrolled in the European Vertebral Osteoporosis Study (EVOS), which included standardized height and weight measurements. We found that men in Oslo were 4.3 cm taller than men in western Europe, 5.0 cm taller than men in eastern Europe, and 8.6 cm taller than men in southern Europe. Oslo women were also taller, by 2.2 cm compared to women in western Europe, 2.7 cm compared to women in eastern Europe, and 5.2 cm compared to women in southern Europe. In all age groups, except women aged 55-59 years, mean body mass index (BMI) was lowest in Oslo. Nearly twice as many had a BMI less than 22.0 kg/m2 in Oslo compared to the other regions combined (11.1% vs. 6.6% in men and 19.2% vs. 9.9% in women). This study indicates that the people of Oslo are taller and leaner than people in other regions of Europe. This may in part explain the higher incidence of hip fracture in the population of Oslo. PMID:8573406

  11. The epidemiology of vertebral fractures. European Vertebral Osteoporosis Study Group.

    PubMed

    Cooper, C; O'Neill, T; Silman, A

    1993-01-01

    Vertebral fractures are recognised as a hallmark of osteoporosis, yet little is known of their epidemiology. This deficiency limits accurate characterisation of the public health importance of osteoporosis. Assessment of the impact of vertebral fractures has been hampered by the absence of formal criteria for identifying fractures on a thoracolumbar radiograph. Initial methods relying upon subjective radiological assessments have given way to morphometric measurements of vertebral heights, with deformities defined according to various algorithms. These methods have been used in a series of studies performed in Rochester, MN, to determine the incidence, outcome, and time trends of vertebral deformities. The results suggest a prevalence rate of vertebral deformity of 25.3 per 100 Rochester women aged 50 years and over (95% CI, 22.3-28.2), with an estimated incidence of 17.8 per 1,000 person-years. The incidence of clinically diagnosed vertebral fractures among women in the same population was 5.3 per 1,000 person-years, suggesting that around 30% of such deformities in women receive clinical attention. Morphometric measurement on the radiographs of women with clinically diagnosed fractures revealed that 80% had grade 2 ( > 4 SD) deformities. Comparable data on the occurrence and health impact of vertebral deformities throughout Europe are urgently required. The European Vertebral Osteoporosis Study (EVOS) is a multicentre epidemiological study that aims to address this issue. It is designed as a radiographic prevalence study in 34 European centres.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8110529

  12. Vertebral fracture classification

    NASA Astrophysics Data System (ADS)

    de Bruijne, Marleen; Pettersen, Paola C.; Tankó, László B.; Nielsen, Mads

    2007-03-01

    A novel method for classification and quantification of vertebral fractures from X-ray images is presented. Using pairwise conditional shape models trained on a set of healthy spines, the most likely unfractured shape is estimated for each of the vertebrae in the image. The difference between the true shape and the reconstructed normal shape is an indicator for the shape abnormality. A statistical classification scheme with the two shapes as features is applied to detect, classify, and grade various types of deformities. In contrast with the current (semi-)quantitative grading strategies this method takes the full shape into account, it uses a patient-specific reference by combining population-based information on biological variation in vertebra shape and vertebra interrelations, and it provides a continuous measure of deformity. Good agreement with manual classification and grading is demonstrated on 204 lateral spine radiographs with in total 89 fractures.

  13. Chemical ecology of vertebrate carrion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vertebrate carrion is a nutrient-rich, ephemeral resource that is utilized by many different organisms ranging from vertebrate and invertebrate scavengers to microbes. The organisms that consume carrion play an important ecological role, as decomposition is vital to ecosystem function. Without the...

  14. A revised metric for quantifying body shape in vertebrates.

    PubMed

    Collar, David C; Reynaga, Crystal M; Ward, Andrea B; Mehta, Rita S

    2013-08-01

    Vertebrates exhibit tremendous diversity in body shape, though quantifying this variation has been challenging. In the past, researchers have used simplified metrics that either describe overall shape but reveal little about its anatomical basis or that characterize only a subset of the morphological features that contribute to shape variation. Here, we present a revised metric of body shape, the vertebrate shape index (VSI), which combines the four primary morphological components that lead to shape diversity in vertebrates: head shape, length of the second major body axis (depth or width), and shape of the precaudal and caudal regions of the vertebral column. We illustrate the usefulness of VSI on a data set of 194 species, primarily representing five major vertebrate clades: Actinopterygii, Lissamphibia, Squamata, Aves, and Mammalia. We quantify VSI diversity within each of these clades and, in the course of doing so, show how measurements of the morphological components of VSI can be obtained from radiographs, articulated skeletons, and cleared and stained specimens. We also demonstrate that head shape, secondary body axis, and vertebral characteristics are important independent contributors to body shape diversity, though their importance varies across vertebrate groups. Finally, we present a functional application of VSI to test a hypothesized relationship between body shape and the degree of axial bending associated with locomotor modes in ray-finned fishes. Altogether, our study highlights the promise VSI holds for identifying the morphological variation underlying body shape diversity as well as the selective factors driving shape evolution. PMID:23746908

  15. Thyroglobulin Represents a Novel Molecular Architecture of Vertebrates.

    PubMed

    Holzer, Guillaume; Morishita, Yoshiaki; Fini, Jean-Baptiste; Lorin, Thibault; Gillet, Benjamin; Hughes, Sandrine; Tohmé, Marie; Deléage, Gilbert; Demeneix, Barbara; Arvan, Peter; Laudet, Vincent

    2016-08-01

    Thyroid hormones modulate not only multiple functions in vertebrates (energy metabolism, central nervous system function, seasonal changes in physiology, and behavior) but also in some non-vertebrates where they control critical post-embryonic developmental transitions such as metamorphosis. Despite their obvious biological importance, the thyroid hormone precursor protein, thyroglobulin (Tg), has been experimentally investigated only in mammals. This may bias our view of how thyroid hormones are produced in other organisms. In this study we searched genomic databases and found Tg orthologs in all vertebrates including the sea lamprey (Petromyzon marinus). We cloned a full-size Tg coding sequence from western clawed frog (Xenopus tropicalis) and zebrafish (Danio rerio). Comparisons between the representative mammal, amphibian, teleost fish, and basal vertebrate indicate that all of the different domains of Tg, as well as Tg regional structure, are conserved throughout the vertebrates. Indeed, in Xenopus, zebrafish, and lamprey Tgs, key residues, including the hormonogenic tyrosines and the disulfide bond-forming cysteines critical for Tg function, are well conserved despite overall divergence of amino acid sequences. We uncovered upstream sequences that include start codons of zebrafish and Xenopus Tgs and experimentally proved that these are full-length secreted proteins, which are specifically recognized by antibodies against rat Tg. By contrast, we have not been able to find any orthologs of Tg among non-vertebrate species. Thus, Tg appears to be a novel protein elaborated as a single event at the base of vertebrates and virtually unchanged thereafter. PMID:27311711

  16. Vertebral osteomyelitis: disk hypodensity on CT

    SciTech Connect

    Larde, D.; Mathieu, D.; Frija, J.; Gaston, A.; Vasile, N.

    1982-11-01

    The importance and role of computed tomography (CT) are discussed on the basis of 36 cases of vertebral osteomyelitis. The bone images themselves, the detection of lumbar disk hypodensity, and the exploration of soft paraspinal regions in the search for an abscess are factors that contribute to the superiority of this method in difficult cases. In cases where the diagnosis is already known, CT offers an excellent method to assess the extent of the lesions. Its accuracy, coupled with its rapidity and noninvasive nature, affects the role of conventional tomography, a method that is incomplete and involves higher radiation doses. CT offers an excellent method for follow-up after treatment of vertebral osteomyelitis.

  17. Mitotic chromosome condensation in vertebrates

    SciTech Connect

    Vagnarelli, Paola

    2012-07-15

    Work from several laboratories over the past 10-15 years has revealed that, within the interphase nucleus, chromosomes are organized into spatially distinct territories [T. Cremer, C. Cremer, Chromosome territories, nuclear architecture and gene regulation in mammalian cells, Nat. Rev. Genet. 2 (2001) 292-301 and T. Cremer, M. Cremer, S. Dietzel, S. Muller, I. Solovei, S. Fakan, Chromosome territories-a functional nuclear landscape, Curr. Opin. Cell Biol. 18 (2006) 307-316]. The overall compaction level and intranuclear location varies as a function of gene density for both entire chromosomes [J.A. Croft, J.M. Bridger, S. Boyle, P. Perry, P. Teague,W.A. Bickmore, Differences in the localization and morphology of chromosomes in the human nucleus, J. Cell Biol. 145 (1999) 1119-1131] and specific chromosomal regions [N.L. Mahy, P.E. Perry, S. Gilchrist, R.A. Baldock, W.A. Bickmore, Spatial organization of active and inactive genes and noncoding DNA within chromosome territories, J. Cell Biol. 157 (2002) 579-589] (Fig. 1A, A'). In prophase, when cyclin B activity reaches a high threshold, chromosome condensation occurs followed by Nuclear Envelope Breakdown (NEB) [1]. At this point vertebrate chromosomes appear as compact structures harboring an attachment point for the spindle microtubules physically recognizable as a primary constriction where the two sister chromatids are held together. The transition from an unshaped interphase chromosome to the highly structured mitotic chromosome (compare Figs. 1A and B) has fascinated researchers for several decades now; however a definite picture of how this process is achieved and regulated is not yet in our hands and it will require more investigation to comprehend the complete process. From a biochemical point of view a vertebrate mitotic chromosomes is composed of DNA, histone proteins (60%) and non-histone proteins (40%) [6]. I will discuss below what is known to date on the contribution of these two different classes of

  18. An amphioxus Krox gene: insights into vertebrate hindbrain evolution.

    PubMed

    Knight, R D; Panopoulou, G D; Holland, P W; Shimeld, S M

    2000-10-01

    The transcription factor Krox-20 has roles in the maintenance of segmentation and specification of segment identity in the vertebrate hindbrain. Overt hindbrain segmentation is a vertebrate novelty, and is not seen in invertebrate chordates such as amphioxus and tunicates. To test if the roles of Krox-20 are also derived, we cloned a Krox-20 related gene, AmphiKrox, from amphioxus. AmphiKrox is related to a small family of vertebrate Krox genes and is expressed in the most anterior region of the amphioxus brain and in the club shaped gland, a secretory organ that develops in the anterior pharynx. Neither expression domain overlaps with the expression of AmphiHox-1, -2, -3 or -4, suggesting that the roles of Krox-20 in hindbrain segmentation and in Hox gene regulation were acquired concomitant with the duplication of Krox genes in vertebrate evolution. PMID:11180801

  19. Lymphatic regulation in nonmammalian vertebrates.

    PubMed

    Hedrick, Michael S; Hillman, Stanley S; Drewes, Robert C; Withers, Philip C

    2013-08-01

    All vertebrate animals share in common the production of lymph through net capillary filtration from their closed circulatory system into their tissues. The balance of forces responsible for net capillary filtration and lymph formation is described by the Starling equation, but additional factors such as vascular and interstitial compliance, which vary markedly among vertebrates, also have a significant impact on rates of lymph formation. Why vertebrates show extreme variability in rates of lymph formation and how nonmammalian vertebrates maintain plasma volume homeostasis is unclear. This gap hampers our understanding of the evolution of the lymphatic system and its interaction with the cardiovascular system. The evolutionary origin of the vertebrate lymphatic system is not clear, but recent advances suggest common developmental factors for lymphangiogenesis in teleost fishes, amphibians, and mammals with some significant changes in the water-land transition. The lymphatic system of anuran amphibians is characterized by large lymphatic sacs and two pairs of lymph hearts that return lymph into the venous circulation but no lymph vessels per se. The lymphatic systems of reptiles and some birds have lymph hearts, and both groups have extensive lymph vessels, but their functional role in both lymph movement and plasma volume homeostasis is almost completely unknown. The purpose of this review is to present an evolutionary perspective in how different vertebrates have solved the common problem of the inevitable formation of lymph from their closed circulatory systems and to point out the many gaps in our knowledge of this evolutionary progression. PMID:23640588

  20. Automatic vertebral identification using surface-based registration

    NASA Astrophysics Data System (ADS)

    Herring, Jeannette L.; Dawant, Benoit M.

    2000-06-01

    This work introduces an enhancement to currently existing methods of intra-operative vertebral registration by allowing the portion of the spinal column surface that correctly matches a set of physical vertebral points to be automatically selected from several possible choices. Automatic selection is made possible by the shape variations that exist among lumbar vertebrae. In our experiments, we register vertebral points representing physical space to spinal column surfaces extracted from computed tomography images. The vertebral points are taken from the posterior elements of a single vertebra to represent the region of surgical interest. The surface is extracted using an improved version of the fully automatic marching cubes algorithm, which results in a triangulated surface that contains multiple vertebrae. We find the correct portion of the surface by registering the set of physical points to multiple surface areas, including all vertebral surfaces that potentially match the physical point set. We then compute the standard deviation of the surface error for the set of points registered to each vertebral surface that is a possible match, and the registration that corresponds to the lowest standard deviation designates the correct match. We have performed our current experiments on two plastic spine phantoms and one patient.

  1. Health impact associated with vertebral deformities: results from the European Vertebral Osteoporosis Study (EVOS).

    PubMed

    Matthis, C; Weber, U; O'Neill, T W; Raspe, H

    1998-01-01

    To study the association between vertebral deformities and subjective health outcome indicators, including back pain and disability, a cross-sectional survey with spinal radiographs and personal interviews was carried out in 36 study centres in 19 European countries on a total of 15,570 men and women aged 50-79 years (population-based stratified random samples). No interventions were done. The main outcome measures were the presence and intensity of current and previous back pain, functional capacity (ADL questionnaire) and overall subjective health. The presence and intensity of back pain and functional and health impairments varied within wide ranges with no obvious regional pattern. However, the associations between negative health outcomes and vertebral deformity were homogeneous between countries and between centres within countries. In logistic regression analyses weak but significant associations between the presence of vertebral deformities and various health indicators were demonstrated. The magnitude of the associations increased with severity and number of deformities. Compared with subjects without deformities those with low-grade deformities had no or only a weakly elevated risk for back pain, disability and impaired subjective health (odds ratios (OR) 1.2-1.3). The odds ratios increased for individuals with single severe deformities (OR 1.3-2.1) and were highest in those with multiple severe deformities (OR 1.7-4.2). The associations between vertebral deformities and negative health outcomes were stronger in men than in women. In this cross-sectional study radiologically assessed vertebral deformities were therefore weakly associated with both current and previous back pain as well as with functional and health impairments in both women and men. Multiple severe deformities were associated with severe and disabling back pain with stronger effects in men. PMID:10024907

  2. Independent regulation of vertebral number and vertebral identity by microRNA-196 paralogs

    PubMed Central

    Wong, Siew Fen Lisa; Agarwal, Vikram; Mansfield, Jennifer H.; Denans, Nicolas; Schwartz, Matthew G.; Prosser, Haydn M.; Pourquié, Olivier; Bartel, David P.; Tabin, Clifford J.; McGlinn, Edwina

    2015-01-01

    The Hox genes play a central role in patterning the embryonic anterior-to-posterior axis. An important function of Hox activity in vertebrates is the specification of different vertebral morphologies, with an additional role in axis elongation emerging. The miR-196 family of microRNAs (miRNAs) are predicted to extensively target Hox 3′ UTRs, although the full extent to which miR-196 regulates Hox expression dynamics and influences mammalian development remains to be elucidated. Here we used an extensive allelic series of mouse knockouts to show that the miR-196 family of miRNAs is essential both for properly patterning vertebral identity at different axial levels and for modulating the total number of vertebrae. All three miR-196 paralogs, 196a1, 196a2, and 196b, act redundantly to pattern the midthoracic region, whereas 196a2 and 196b have an additive role in controlling the number of rib-bearing vertebra and positioning of the sacrum. Independent of this, 196a1, 196a2, and 196b act redundantly to constrain total vertebral number. Loss of miR-196 leads to a collective up-regulation of numerous trunk Hox target genes with a concomitant delay in activation of caudal Hox genes, which are proposed to signal the end of axis extension. Additionally, we identified altered molecular signatures associated with the Wnt, Fgf, and Notch/segmentation pathways and demonstrate that miR-196 has the potential to regulate Wnt activity by multiple mechanisms. By feeding into, and thereby integrating, multiple genetic networks controlling vertebral number and identity, miR-196 is a critical player defining axial formulae. PMID:26283362

  3. Recombination Drives Vertebrate Genome Contraction

    PubMed Central

    Nam, Kiwoong; Ellegren, Hans

    2012-01-01

    Selective and/or neutral processes may govern variation in DNA content and, ultimately, genome size. The observation in several organisms of a negative correlation between recombination rate and intron size could be compatible with a neutral model in which recombination is mutagenic for length changes. We used whole-genome data on small insertions and deletions within transposable elements from chicken and zebra finch to demonstrate clear links between recombination rate and a number of attributes of reduced DNA content. Recombination rate was negatively correlated with the length of introns, transposable elements, and intergenic spacer and with the rate of short insertions. Importantly, it was positively correlated with gene density, the rate of short deletions, the deletion bias, and the net change in sequence length. All these observations point at a pattern of more condensed genome structure in regions of high recombination. Based on the observed rates of small insertions and deletions and assuming that these rates are representative for the whole genome, we estimate that the genome of the most recent common ancestor of birds and lizards has lost nearly 20% of its DNA content up until the present. Expansion of transposable elements can counteract the effect of deletions in an equilibrium mutation model; however, since the activity of transposable elements has been low in the avian lineage, the deletion bias is likely to have had a significant effect on genome size evolution in dinosaurs and birds, contributing to the maintenance of a small genome. We also demonstrate that most of the observed correlations between recombination rate and genome contraction parameters are seen in the human genome, including for segregating indel polymorphisms. Our data are compatible with a neutral model in which recombination drives vertebrate genome size evolution and gives no direct support for a role of natural selection in this process. PMID:22570634

  4. Evolution of vertebrate retinal photoreception

    PubMed Central

    Lamb, Trevor D.

    2009-01-01

    Recent findings shed light on the steps underlying the evolution of vertebrate photoreceptors and retina. Vertebrate ciliary photoreceptors are not as wholly distinct from invertebrate rhabdomeric photoreceptors as is sometimes thought. Recent information on the phylogenies of ciliary and rhabdomeric opsins has helped in constructing the likely routes followed during evolution. Clues to the factors that led the early vertebrate retina to become invaginated can be obtained by combining recent knowledge about the origin of the pathway for dark re-isomerization of retinoids with knowledge of the inability of ciliary opsins to undergo photoreversal, along with consideration of the constraints imposed under the very low light levels in the deep ocean. Investigation of the origin of cell classes in the vertebrate retina provides support for the notion that cones, rods and bipolar cells all originated from a primordial ciliary photoreceptor, whereas ganglion cells, amacrine cells and horizontal cells all originated from rhabdomeric photoreceptors. Knowledge of the molecular differences between cones and rods, together with knowledge of the scotopic signalling pathway, provides an understanding of the evolution of rods and of the rods' retinal circuitry. Accordingly, it has been possible to propose a plausible scenario for the sequence of evolutionary steps that led to the emergence of vertebrate photoreceptors and retina. PMID:19720653

  5. Medical treatment of vertebral osteoporosis.

    PubMed

    Lippuner, K

    2003-10-01

    Although osteoporosis is a systemic disease, vertebral fractures due to spinal bone loss are a frequent, sometimes early and often neglected complication of the disease, generally associated with considerable disability and pain. As osteoporotic vertebral fractures are an important predictor of future fracture risk, including at the hip, medical management is targeted at reducing fracture risk. A literature search for randomized, double-blind, prospective, controlled clinical studies addressing medical treatment possibilities of vertebral fractures in postmenopausal Caucasian women was performed on the leading medical databases. For each publication, the number of patients with at least one new vertebral fracture and the number of randomized patients by treatment arm was retrieved. The relative risk (RR) and the number needed to treat (NNT, i.e. the number of patients to be treated to avoid one radiological vertebral fracture over the duration of the study), together with the respective 95% confidence intervals (95%CI) were calculated for each study. Treatment of steroid-induced osteoporosis and treatment of osteoporosis in men were reviewed separately, based on the low number of publications available. Forty-five publications matched with the search criteria, allowing for analysis of 15 different substances tested regarding their anti-fracture efficacy at the vertebral level. Bisphosphonates, mainly alendronate and risedronate, were reported to have consistently reduced the risk of a vertebral fracture over up to 50 months of treatment in four (alendronate) and two (risedronate) publications. Raloxifene reduced vertebral fracture risk in one study over 36 months, which was confirmed by 48 months' follow-up data. Parathormone (PTH) showed a drastic reduction in vertebral fracture risk in early studies, while calcitonin may also be a treatment option to reduce fracture risk. For other substances published data are conflicting (calcitriol, fluoride) or insufficient

  6. De Novo Genesis of Enhancers in Vertebrates

    PubMed Central

    Eichenlaub, Michael P.; Ettwiller, Laurence

    2011-01-01

    Evolutionary innovation relies partially on changes in gene regulation. While a growing body of evidence demonstrates that such innovation is generated by functional changes or translocation of regulatory elements via mobile genetic elements, the de novo generation of enhancers from non-regulatory/non-mobile sequences has, to our knowledge, not previously been demonstrated. Here we show evidence for the de novo genesis of enhancers in vertebrates. For this, we took advantage of the massive gene loss following the last whole genome duplication in teleosts to systematically identify regions that have lost their coding capacity but retain sequence conservation with mammals. We found that these regions show enhancer activity while the orthologous coding regions have no regulatory activity. These results demonstrate that these enhancers have been de novo generated in fish. By revealing that minor changes in non-regulatory sequences are sufficient to generate new enhancers, our study highlights an important playground for creating new regulatory variability and evolutionary innovation. PMID:22069375

  7. Cystic Abnormalities of the Spinal Cord and Vertebral Column.

    PubMed

    da Costa, Ronaldo C; Cook, Laurie B

    2016-03-01

    Cystic lesions of the vertebral column and spinal cord are important differential diagnoses in dogs with signs of spinal cord disease. Synovial cysts are commonly associated with degenerative joint disease and usually affect the cervical and lumbosacral regions. Arachnoid diverticulum (previously known as cyst) is seen in the cervical region of large breed dogs and thoracolumbar region of small breed dogs. This article reviews the causes, diagnosis, and treatment of these and other, less common, cystic lesions. PMID:26706913

  8. 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…

  9. Vertebral Augmentation for Osteoporotic Compression Fractures.

    PubMed

    Richmond, Bradford J

    2016-01-01

    Vertebral augmentation procedures such as vertebroplasty and kyphoplasty were developed to reduce pain and improve quality of life for patients with osteoporotic vertebral compression fractures. However, the use of vertebral augmentation has been debated and questioned since its inception. This article addresses some of these issues. PMID:26490134

  10. Active DNA demethylation at enhancers during the vertebrate phylotypic period.

    PubMed

    Bogdanović, Ozren; Smits, Arne H; de la Calle Mustienes, Elisa; Tena, Juan J; Ford, Ethan; Williams, Ruth; Senanayake, Upeka; Schultz, Matthew D; Hontelez, Saartje; van Kruijsbergen, Ila; Rayon, Teresa; Gnerlich, Felix; Carell, Thomas; Veenstra, Gert Jan C; Manzanares, Miguel; Sauka-Spengler, Tatjana; Ecker, Joseph R; Vermeulen, Michiel; Gómez-Skarmeta, José Luis; Lister, Ryan

    2016-04-01

    The vertebrate body plan and organs are shaped during a conserved embryonic phase called the phylotypic stage. However, the mechanisms that guide the epigenome through this transition and their evolutionary conservation remain elusive. Here we report widespread DNA demethylation of enhancers during the phylotypic period in zebrafish, Xenopus tropicalis and mouse. These enhancers are linked to developmental genes that display coordinated transcriptional and epigenomic changes in the diverse vertebrates during embryogenesis. Binding of Tet proteins to (hydroxy)methylated DNA and enrichment of 5-hydroxymethylcytosine in these regions implicated active DNA demethylation in this process. Furthermore, loss of function of Tet1, Tet2 and Tet3 in zebrafish reduced chromatin accessibility and increased methylation levels specifically at these enhancers, indicative of DNA methylation being an upstream regulator of phylotypic enhancer function. Overall, our study highlights a regulatory module associated with the most conserved phase of vertebrate embryogenesis and suggests an ancient developmental role for Tet dioxygenases. PMID:26928226

  11. Conserved and Divergent Patterns of DNA Methylation in Higher Vertebrates

    PubMed Central

    Jiang, Ning; Wang, Lin; Chen, Jing; Wang, Luwen; Leach, Lindsey; Luo, Zewei

    2014-01-01

    DNA methylation in the genome plays a fundamental role in the regulation of gene expression and is widespread in the genome of eukaryotic species. For example, in higher vertebrates, there is a “global” methylation pattern involving complete methylation of CpG sites genome-wide, except in promoter regions that are typically enriched for CpG dinucleotides, or so called “CpG islands.” Here, we comprehensively examined and compared the distribution of CpG sites within ten model eukaryotic species and linked the observed patterns to the role of DNA methylation in controlling gene transcription. The analysis revealed two distinct but conserved methylation patterns for gene promoters in human and mouse genomes, involving genes with distinct distributions of promoter CpGs and gene expression patterns. Comparative analysis with four other higher vertebrates revealed that the primary regulatory role of the DNA methylation system is highly conserved in higher vertebrates. PMID:25355807

  12. Neural induction and early patterning in vertebrates.

    PubMed

    Ozair, Mohammad Zeeshan; Kintner, Chris; Brivanlou, Ali H

    2013-07-01

    In vertebrates, the development of the nervous system is triggered by signals from a powerful 'organizing' region of the early embryo during gastrulation. This phenomenon--neural induction--was originally discovered and given conceptual definition by experimental embryologists working with amphibian embryos. Work on the molecular circuitry underlying neural induction, also in the same model system, demonstrated that elimination of ongoing transforming growth factor-β (TGFβ) signaling in the ectoderm is the hallmark of anterior neural-fate acquisition. This observation is the basis of the 'default' model of neural induction. Endogenous neural inducers are secreted proteins that act to inhibit TGFβ ligands in the dorsal ectoderm. In the ventral ectoderm, where the signaling ligands escape the inhibitors, a non-neural fate is induced. Inhibition of the TGFβ pathway has now been demonstrated to be sufficient to directly induce neural fate in mammalian embryos as well as pluripotent mouse and human embryonic stem cells. Hence the molecular process that delineates neural from non-neural ectoderm is conserved across a broad range of organisms in the evolutionary tree. The availability of embryonic stem cells from mouse, primates, and humans will facilitate further understanding of the role of signaling pathways and their downstream mediators in neural induction in vertebrate embryos. PMID:24014419

  13. Extraneural Glioblastoma Multiforme Vertebral Metastasis.

    PubMed

    Goodwin, C Rory; Liang, Lydia; Abu-Bonsrah, Nancy; Hdeib, Alia; Elder, Benjamin D; Kosztowski, Thomas; Bettegowda, Chetan; Laterra, John; Burger, Peter; Sciubba, Daniel M

    2016-05-01

    Glioblastoma multiforme (GBM) is the most common malignant central nervous system tumor; however, extraneural metastasis is uncommon. Of those that metastasize extraneurally, metastases to the vertebral bodies represent a significant proportion. We present a review of 28 cases from the published literature of GBM metastasis to the vertebra. The mean age at presentation was 38.4 years with an average overall survival of 26 months. Patients were either asymptomatic with metastasis discovered at autopsy or presented with varying degrees of pain, weakness of the extremities, or other neurologic deficits. Of the cases that included the time to spinal metastasis, the average time was 26.4 months with a reported survival of 10 months after diagnosis of vertebral metastasis. A significant number of patients had no treatments for their spinal metastasis, although the intracranial lesions were treated extensively with surgery and/or adjuvant therapy. With increasing incremental gains in the survival of patients with GBM, clinicians will encounter patients with extracranial metastasis. As such, this review presents timely information concerning the presentation and outcomes of patients with vertebral metastasis. PMID:26704201

  14. Extraneural Glioblastoma Multiforme Vertebral Metastasis

    PubMed Central

    Goodwin, C. Rory; Liang, Lydia; Abu-Bonsrah, Nancy; Hdeib, Alia; Elder, Benjamin D.; Kosztowski, Thomas; Bettegowda, Chetan; Laterra, John; Burger, Peter; Sciubba, Daniel M.

    2016-01-01

    Glioblastoma multiforme (GBM) is the most common malignant central nervous system tumor; however, extraneural metastasis is uncommon. Of those that metastasize extraneurally, metastases to the vertebral bodies represent a significant proportion. We present a review of 28 cases from the published literature of GBM metastasis to the vertebra. The mean age at presentation was 38.4 years with an average overall survival of 26 months. Patients were either asymptomatic with metastasis discovered at autopsy or presented with varying degrees of pain, weakness of the extremities, or other neurologic deficits. Of the cases that included the time to spinal metastasis, the average time was 26.4 months with a reported survival of 10 months after diagnosis of vertebral metastasis. A significant number of patients had no treatments for their spinal metastasis, although the intracranial lesions were treated extensively with surgery and/or adjuvant therapy. With increasing incremental gains in the survival of patients with GBM, clinicians will encounter patients with extracranial metastasis. As such, this review presents timely information concerning the presentation and outcomes of patients with vertebral metastasis. PMID:26704201

  15. Vertebral development and amphibian evolution.

    PubMed

    Carroll, R L; Kuntz, A; Albright, K

    1999-01-01

    Amphibians provide an unparalleled opportunity to integrate studies of development and evolution through the investigation of the fossil record of larval stages. The pattern of vertebral development in modern frogs strongly resembles that of Paleozoic labyrinthodonts in the great delay in the ossification of the vertebrae, with the centra forming much later than the neural arches. Slow ossification of the trunk vertebrae in frogs and the absence of ossification in the tail facilitate the rapid loss of the tail during metamorphosis, and may reflect retention of the pattern in their specific Paleozoic ancestors. Salamanders and caecilians ossify their centra at a much earlier stage than frogs, which resembles the condition in Paleozoic lepospondyls. The clearly distinct patterns and rates of vertebral development may indicate phylogenetic separation between the ultimate ancestors of frogs and those of salamanders and caecilians within the early radiation of ancestral tetrapods. This divergence may date from the Lower Carboniferous. Comparison with the molecular regulation of vertebral development described in modern mammals and birds suggests that the rapid chondrification of the centra in salamanders relative to that of frogs may result from the earlier migration of sclerotomal cells expressing Pax1 to the area surrounding the notochord. PMID:11324019

  16. Vertebral Fractures: Clinical Importance and Management.

    PubMed

    Kendler, D L; Bauer, D C; Davison, K S; Dian, L; Hanley, D A; Harris, S T; McClung, M R; Miller, P D; Schousboe, J T; Yuen, C K; Lewiecki, E M

    2016-02-01

    Vertebral fractures are common and can result in acute and chronic pain, decreases in quality of life, and diminished lifespan. The identification of vertebral fractures is important because they are robust predictors of future fractures. The majority of vertebral fractures do not come to clinical attention. Numerous modalities exist for visualizing suspected vertebral fracture. Although differing definitions of vertebral fracture may present challenges in comparing data between different investigations, at least 1 in 5 men and women aged >50 years have one or more vertebral fractures. There is clinical guidance to target spine imaging to individuals with a high probability of vertebral fracture. Radiology reports of vertebral fracture need to clearly state that the patient has a "fracture," with further pertinent details such as the number, recency, and severity of vertebral fracture, each of which is associated with risk of future fractures. Patients with vertebral fracture should be considered for antifracture therapy. Physical and pharmacologic modalities of pain control and exercises or physiotherapy to maintain spinal movement and strength are important components in the care of vertebral fracture patients. PMID:26524708

  17. Bilateral mechanical rotational vertebral artery occlusion.

    PubMed

    Dargon, Phong T; Liang, Conrad W; Kohal, Anmol; Dogan, Aclan; Barnwell, Stanley L; Landry, Gregory J

    2013-10-01

    Rotational vertebral artery occlusion, or bow hunter's stroke, is reversible, positional symptomatic vertebrobasilar ischemia. The typical mechanism of action is obstruction of a dominant vertebral artery with contralateral head rotation in the setting of baseline ipsilateral vertebral artery stenosis or occlusion. Here we present a rare case of mechanical occlusion of bilateral patent vertebral arteries manifesting as near syncope with rightward head rotation. Diagnostic cerebral angiography showed dynamic right C5 vertebral occlusion and left C2 vertebral occlusion. The patient underwent right C4/5 transverse process decompression. Postoperative angiogram showed patent flow through the right vertebral artery in neutral position and with head turn with resultant resolution of symptoms. PMID:23465174

  18. Prevalence of osteoporotic vertebral fracture in Spanish women over age 45.

    PubMed

    Herrera, Antonio; Mateo, Jesús; Gil-Albarova, Jorge; Lobo-Escolar, Antonio; Artigas, José M; López-Prats, Fernando; Mesa, Manuel; Ibarz, Elena; Gracia, Luis

    2015-03-01

    The aim of this work is to study the prevalence of osteoporotic vertebral fractures in Spanish women over 45 years of age, based on the selection of a nationwide sample. An observational, cross-sectional, multicenter study was conducted during 2006, in all of Spain's regions. The sample analyzed was of 5000 individuals, representative of the female population over age 45 in Spain. A questionnaire was used to determine which factors are most often associated with vertebral fractures. We also assessed whether the Prevalent Vertebral Fracture Index, proposed by Vogt, is useful in indicating a possible osteoporotic vertebral fracture. Five hundred orthopedic surgeons, from various Spanish regions, were trained in different aspects of the study: inclusion and exclusion criteria, management of the risk factor questionnaire, and implementation of the Vogt questionnaire. The number of fracture cases was 1549 (31.79%). 528 Women (34.08%) had a single vertebral fracture, and 1021 (65.92%) had multiple vertebral fractures. The following factors were statistically significantly associated with vertebral fracture: age, late menarche, early menopause, diabetes mellitus, hyperparathyroidism, rheumatoid arthritis, height loss, daily physical activity, corticosteroid therapy, personal history of osteoporotic fracture and previous diagnosis of osteoporosis. The differences in Vogt score according to age and fracture status were statistically significant. The conclusion of the study is that vertebral osteoporotic fracture in the female Spanish population is frequent. The high prevalence in the Spanish population older than 60 years is probably related to malnutrition in the period from 1936 to 1952. PMID:25577153

  19. Ewing's sarcoma of the vertebral column

    SciTech Connect

    Pilepich, M.V.; Vietti, T.J.; Nesbit, M.E.; Tefft, M.; Kissane, J.; Burgert, O.; Pritchard, D.; Gehan, E.A.

    1981-01-01

    Twenty-two patients with vertebral primaries were registered in the Intergroup Ewing's Sarcoma Study between 1973 and 1977. The radiation doses to the primary tumors ranged between 3800 and 6200 rad. All patients received intensive combination chemotherapy. After a followup ranging between 14 and 62 months, 14 patients remained disease-free. All patients with primary tumor of the cervical and dorsal spine remained disease-free. Of eight patients with lesions in the distal spine, (sacrococcygeal region) six developed recurrence, in three a local recurrence was observed despite doses of 6000 rad or higher. Doses of 5000 rad or less (in addition to combination chemotherapy as used in the Intergroup Ewing's Study) appear adequate in controlling the primary tumors of the proximal segments of the spinal column.

  20. Global patterns in threats to vertebrates by biological invasions.

    PubMed

    Bellard, C; Genovesi, P; Jeschke, J M

    2016-01-27

    Biological invasions as drivers of biodiversity loss have recently been challenged. Fundamentally, we must know where species that are threatened by invasive alien species (IAS) live, and the degree to which they are threatened. We report the first study linking 1372 vertebrates threatened by more than 200 IAS from the completely revised Global Invasive Species Database. New maps of the vulnerability of threatened vertebrates to IAS permit assessments of whether IAS have a major influence on biodiversity, and if so, which taxonomic groups are threatened and where they are threatened. We found that centres of IAS-threatened vertebrates are concentrated in the Americas, India, Indonesia, Australia and New Zealand. The areas in which IAS-threatened species are located do not fully match the current hotspots of invasions, or the current hotspots of threatened species. The relative importance of biological invasions as drivers of biodiversity loss clearly varies across regions and taxa, and changes over time, with mammals from India, Indonesia, Australia and Europe are increasingly being threatened by IAS. The chytrid fungus primarily threatens amphibians, whereas invasive mammals primarily threaten other vertebrates. The differences in IAS threats between regions and taxa can help efficiently target IAS, which is essential for achieving the Strategic Plan 2020 of the Convention on Biological Diversity. PMID:26817767

  1. Asymmetry in the epithalamus of vertebrates

    PubMed Central

    L. CONCHA, MIGUEL; W. WILSON, STEPHEN

    2001-01-01

    The epithalamus is a major subdivision of the diencephalon constituted by the habenular nuclei and pineal complex. Structural asymmetries in this region are widespread amongst vertebrates and involve differences in size, neuronal organisation, neurochemistry and connectivity. In species that possess a photoreceptive parapineal organ, this structure projects asymmetrically to the left habenula, and in teleosts it is also situated on the left side of the brain. Asymmetries in size between the left and right sides of the habenula are often associated with asymmetries in neuronal organisation, although these two types of asymmetry follow different evolutionary courses. While the former is more conspicuous in fishes (with the exception of teleosts), asymmetries in neuronal organisation are more robust in amphibia and reptiles. Connectivity of the parapineal organ with the left habenula is not always coupled with asymmetries in habenular size and/or neuronal organisation suggesting that, at least in some species, assignment of parapineal and habenular asymmetries may be independent events. The evolutionary origins of epithalamic structures are uncertain but asymmetry in this region is likely to have existed at the origin of the vertebrate, perhaps even the chordate, lineage. In at least some extant vertebrate species, epithalamic asymmetries are established early in development, suggesting a genetic regulation of asymmetry. In some cases, epigenetic factors such as hormones also influence the development of sexually dimorphic habenular asymmetries. Although the genetic and developmental mechanisms by which neuroanatomical asymmetries are established remain obscure, some clues regarding the mechanisms underlying laterality decisions have recently come from studies in zebrafish. The Nodal signalling pathway regulates laterality by biasing an otherwise stochastic laterality decision to the left side of the epithalamus. This genetic mechanism ensures a consistency of

  2. Adaptive evolution of Hoxc13 genes in the origin and diversification of the vertebrate integument.

    PubMed

    Wu, Jianghong; Husile; Sun, Hailian; Wang, Feng; Li, Yurong; Zhao, Cunfa; Zhang, Wenguang

    2013-11-01

    The problem of origination and diversification of integument derivatives in vertebrates is still a challenge. The homeobox (Hox) genes Hoxc13 control integument formation in vertebrate. Hoxc13 show strong expression in the integument development, are highly conserved across vertebrates, and show mutations that are associated with skin and appendages. To test whether the evolution of the integument is associated with positive selection or relaxation of Hoxc13, we obtained these genes in a wide range of vertebrates. In Hoxc13, we found evidence of diversifying selection after speciation during the origin of vertebrates. In addition, we found the glycine-rich regions in Hoxc13 protein in mammals, but not among non-mammalian taxa. Our results strongly implicate that Hoxc13 genes could have played an important role in the evolution of integument structure. PMID:25961277

  3. Evolutionary Specialization of Tactile Perception in Vertebrates.

    PubMed

    Schneider, Eve R; Gracheva, Elena O; Bagriantsev, Slav N

    2016-05-01

    Evolution has endowed vertebrates with the remarkable tactile ability to explore the world through the perception of physical force. Yet the sense of touch remains one of the least well understood senses at the cellular and molecular level. Vertebrates specializing in tactile perception can highlight general principles of mechanotransduction. Here, we review cellular and molecular adaptations that underlie the sense of touch in typical and acutely mechanosensitive vertebrates. PMID:27053733

  4. Variance in the treatment of vertebral haemangiomas.

    PubMed

    Rawat, Sheh; Nangia, S; Ezhilalan, R B; Bansal, A K; Ghosh, D

    2007-01-01

    Vertebral haemangiomas constitute an infrequently encounterd entity in clinical practice. Although x-ray, computerised tomography scan and magnetic resonance Imaging scan provide a pathognomic picture confirming the diagnosis of vertebral haemangiomas, angiography constitutes an important tool for diagnosis and helps in deciding and execution of treatment. Various treatment modalities like surgery, radiotherapy, pre-operative embolisation, percutaneous vertebroplasty and intralesional ethanol have been discussed in the setting of asymptomatic vertebral haemangiomas to those presenting with features of cord compression. PMID:17802977

  5. General management of vertebral fractures.

    PubMed

    Rapado, A

    1996-03-01

    Vertebral fractures cause pain and disability. Four concepts should guide their comprehensive management: treat the patient, not the skeleton; use a multidisciplinary approach; engage the patient and his or her family in the treatment; and provide appropriate goals, education, encouragement, and support. The goals include procuring bone mass and preventing injury: back support, physical therapy, occupational therapy, psychosocial support, and prevention of falls. Initial treatment includes bed rest, pain management with local and systemic analgesia, bracing to improve comfort, and patient reassurance. Long-term management includes spinal stretching exercises and continuing ordinary activities within limits permitted by pain. A back school program is an effective addition to conventional concepts using physiotherapy exclusively. In certain selected patients, the indication for operative treatment of vertebral fracture depends on the additional injury, and extent and characteristics of cord compression; stability of the fracture; and the amount of deformity. Vertebroplasty can be effective in the control of pain and in obtaining stability of the spine. PMID:8777087

  6. Centrosome positioning in vertebrate development

    PubMed Central

    Tang, Nan; Marshall, Wallace F.

    2012-01-01

    Summary The centrosome, a major organizer of microtubules, has important functions in regulating cell shape, polarity, cilia formation and intracellular transport as well as the position of cellular structures, including the mitotic spindle. By means of these activities, centrosomes have important roles during animal development by regulating polarized cell behaviors, such as cell migration or neurite outgrowth, as well as mitotic spindle orientation. In recent years, the pace of discovery regarding the structure and composition of centrosomes has continuously accelerated. At the same time, functional studies have revealed the importance of centrosomes in controlling both morphogenesis and cell fate decision during tissue and organ development. Here, we review examples of centrosome and centriole positioning with a particular emphasis on vertebrate developmental systems, and discuss the roles of centrosome positioning, the cues that determine positioning and the mechanisms by which centrosomes respond to these cues. The studies reviewed here suggest that centrosome functions extend to the development of tissues and organs in vertebrates. PMID:23277534

  7. Ghrelin Receptors in Non-Mammalian Vertebrates

    PubMed Central

    Kaiya, Hiroyuki; Kangawa, Kenji; Miyazato, Mikiya

    2012-01-01

    The growth hormone secretagogue-receptor (GHS-R) was discovered in humans and pigs in 1996. The endogenous ligand, ghrelin, was discovered 3 years later, in 1999, and our understanding of the physiological significance of the ghrelin system in vertebrates has grown steadily since then. Although the ghrelin system in non-mammalian vertebrates is a subject of great interest, protein sequence data for the receptor in non-mammalian vertebrates has been limited until recently, and related biological information has not been well organized. In this review, we summarize current information related to the ghrelin receptor in non-mammalian vertebrates. PMID:23882259

  8. A descending dopamine pathway conserved from basal vertebrates to mammals

    PubMed Central

    Ryczko, Dimitri; Cone, Jackson J.; Alpert, Michael H.; Goetz, Laurent; Auclair, François; Dubé, Catherine; Parent, Martin; Roitman, Mitchell F.; Alford, Simon; Dubuc, Réjean

    2016-01-01

    Dopamine neurons are classically known to modulate locomotion indirectly through ascending projections to the basal ganglia that project down to brainstem locomotor networks. Their loss in Parkinson’s disease is devastating. In lampreys, we recently showed that brainstem networks also receive direct descending dopaminergic inputs that potentiate locomotor output. Here, we provide evidence that this descending dopaminergic pathway is conserved to higher vertebrates, including mammals. In salamanders, dopamine neurons projecting to the striatum or brainstem locomotor networks were partly intermingled. Stimulation of the dopaminergic region evoked dopamine release in brainstem locomotor networks and concurrent reticulospinal activity. In rats, some dopamine neurons projecting to the striatum also innervated the pedunculopontine nucleus, a known locomotor center, and stimulation of the dopaminergic region evoked pedunculopontine dopamine release in vivo. Finally, we found dopaminergic fibers in the human pedunculopontine nucleus. The conservation of a descending dopaminergic pathway across vertebrates warrants re-evaluating dopamine’s role in locomotion. PMID:27071118

  9. A descending dopamine pathway conserved from basal vertebrates to mammals.

    PubMed

    Ryczko, Dimitri; Cone, Jackson J; Alpert, Michael H; Goetz, Laurent; Auclair, François; Dubé, Catherine; Parent, Martin; Roitman, Mitchell F; Alford, Simon; Dubuc, Réjean

    2016-04-26

    Dopamine neurons are classically known to modulate locomotion indirectly through ascending projections to the basal ganglia that project down to brainstem locomotor networks. Their loss in Parkinson's disease is devastating. In lampreys, we recently showed that brainstem networks also receive direct descending dopaminergic inputs that potentiate locomotor output. Here, we provide evidence that this descending dopaminergic pathway is conserved to higher vertebrates, including mammals. In salamanders, dopamine neurons projecting to the striatum or brainstem locomotor networks were partly intermingled. Stimulation of the dopaminergic region evoked dopamine release in brainstem locomotor networks and concurrent reticulospinal activity. In rats, some dopamine neurons projecting to the striatum also innervated the pedunculopontine nucleus, a known locomotor center, and stimulation of the dopaminergic region evoked pedunculopontine dopamine release in vivo. Finally, we found dopaminergic fibers in the human pedunculopontine nucleus. The conservation of a descending dopaminergic pathway across vertebrates warrants re-evaluating dopamine's role in locomotion. PMID:27071118

  10. 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. PMID:25968309

  11. Evolution and Functional Classification of Vertebrate Gene Deserts

    SciTech Connect

    Ovcharenko, I; Loots, G; Nobrega, M; Hardison, R; Miller, W; Stubbs, L

    2004-07-14

    Gene deserts, long stretches of DNA sequence devoid of protein coding genes, span approximately one quarter of the human genome. Through human-chicken genome comparisons we were able to characterized one third of human gene deserts as evolutionarily stable - they are highly conserved in vertebrates, resist chromosomal rearrangements, and contain multiple conserved non-coding elements physically linked to their neighboring genes. A linear relationship was observed between human and chicken orthologous stable gene deserts, where the human deserts appear to have expanded homogeneously by a uniform accumulation of repetitive elements. Stable gene deserts are associated with key vertebrate genes that construct the framework of vertebrate development; many of which encode transcription factors. We show that the regulatory machinery governing genes associated with stable gene deserts operates differently from other regions in the human genome and relies heavily on distant regulatory elements. The regulation guided by these elements is independent of the distance between the gene and its distant regulatory element, or the distance between two distant regulatory cassettes. The location of gene deserts and their associated genes in the genome is independent of chromosomal length or content presenting these regions as well-bounded regions evolving separately from the rest of the genome.

  12. Evolutionary Transition of Promoter and Gene Body DNA Methylation across Invertebrate–Vertebrate Boundary

    PubMed Central

    Keller, Thomas E.; Han, Priscilla; Yi, Soojin V.

    2016-01-01

    Genomes of invertebrates and vertebrates exhibit highly divergent patterns of DNA methylation. Invertebrate genomes tend to be sparsely methylated, and DNA methylation is mostly targeted to a subset of transcription units (gene bodies). In a drastic contrast, vertebrate genomes are generally globally and heavily methylated, punctuated by the limited local hypo-methylation of putative regulatory regions such as promoters. These genomic differences also translate into functional differences in DNA methylation and gene regulation. Although promoter DNA methylation is an important regulatory component of vertebrate gene expression, its role in invertebrate gene regulation has been little explored. Instead, gene body DNA methylation is associated with expression of invertebrate genes. However, the evolutionary steps leading to the differentiation of invertebrate and vertebrate genomic DNA methylation remain unresolved. Here we analyzed experimentally determined DNA methylation maps of several species across the invertebrate–vertebrate boundary, to elucidate how vertebrate gene methylation has evolved. We show that, in contrast to the prevailing idea, a substantial number of promoters in an invertebrate basal chordate Ciona intestinalis are methylated. Moreover, gene expression data indicate significant, epigenomic context-dependent associations between promoter methylation and expression in C. intestinalis. However, there is no evidence that promoter methylation in invertebrate chordate has been evolutionarily maintained across the invertebrate–vertebrate boundary. Rather, body-methylated invertebrate genes preferentially obtain hypo-methylated promoters among vertebrates. Conversely, promoter methylation is preferentially found in lineage- and tissue-specific vertebrate genes. These results provide important insights into the evolutionary origin of epigenetic regulation of vertebrate gene expression. PMID:26715626

  13. Problems with six-point vertebral morphometry

    NASA Astrophysics Data System (ADS)

    Gardner, Jill C.; Yaffe, Laurence G.; Johansen, Jennifer M.; von Ingersleben, Gabriel; Chestnut, Charles H., III

    1998-06-01

    In this study we have examined errors in measurements of vertebral heights and vertebral area resulting from spin rotation and projection effects in x-ray images. Measurement errors were evaluated with phantom images, and simulated rotations of a 3D spine model. An active contour model (snake) was used for measurements of vertebral area. The model contained two pressure parameters which were needed to obtain good fits of the snake to upper and lower edges (endplates) of rotated vertebral bodies. Details of the snake model are included in this report. The results of this study indicate that six point vertebral morphometry can result to significant measurement errors, representing an overestimation of vertebral height and area, in cases showing projection effects and concealed endplate contours. In serial studies, such errors could produce the erroneous appearance of `growing' vertebral bodies. One can improve the accuracy of the morphometric analysis by using additional fiducial points placed on corresponding endplate contours. Additional useful information on fracture and vertebral deformity can be obtained by accurately tracking edge contours, using an active contour model, or comparable techniques.

  14. [Vertebral changes in histiocytosis x (author's transl)].

    PubMed

    Greinacher, I; Gutjahr, P

    1978-06-01

    Manifestations of histiocytosis X in the vertebral column occurred in 3 of 15 children. Pathological alterations showed a marked variability. Especially a vertebra plana should be considered as eosinophilic granuloma, until another cause is proven. Bone scans were positive in all three cases. Even in most severe cases with vertebral destruction neurological abnormalities were absent. PMID:308238

  15. The evolutionary origins of chordate hematopoiesis and vertebrate endothelia.

    PubMed

    Pascual-Anaya, Juan; Albuixech-Crespo, Beatriz; Somorjai, Ildikó Maureen Lara; Carmona, Rita; Oisi, Yasuhiro; Alvarez, Susana; Kuratani, Shigeru; Muñoz-Chápuli, Ramón; Garcia-Fernàndez, Jordi

    2013-03-15

    The vertebrate circulatory system is the most complex vascular system among those of metazoans, with key innovations including a multi-chambered heart and highly specialized blood cells. Invertebrate vessels, on the other hand, consist of hemal spaces between the basal laminae of epithelia. How the evolutionary transition from an invertebrate-type system to the complex vertebrate one occurred is, however, poorly understood. We investigate here the development of the cardiovascular system of the cephalochordate amphioxus Branchiostoma lanceolatum in order to gain insight into the origin of the vertebrate cardiovascular system. The cardiac markers Hand, Csx (Nkx2-5) and Tbx4/5 reveal a broad cardiac-like domain in amphioxus; such a decentralized organization during development parallels that seen in the adult anatomy. Our data therefore support the hypothesis that amphioxus never possessed a proper heart, even transiently during development. We also define a putative hematopoietic domain, supported by the expression of the hematopoietic markers Scl and Pdvegfr. We show that this area is closed to the dorsal aorta anlages, partially linked to excretory tissues, and that its development is regulated by retinoic acid, thus recalling the aorta-gonads-mesonephros (AGM) area of vertebrates. This region probably produces Pdvegfr+ hemal cells, with an important role in amphioxus vessel formation, since treatments with an inhibitor of PDGFR/VEGFR lead to a decrease of Laminin in the basal laminae of developing vessels. Our results point to a chordate origin of hematopoiesis in an AGM-like area from where hemal Pdvegfr+ cells are produced. These Pdvegfr+ cells probably resemble the ancestral chordate blood cells from which the vertebrate endothelium later originated. PMID:23201012

  16. EGR1 and EGR2 involvement in vertebrate tendon differentiation.

    PubMed

    Lejard, Véronique; Blais, Frédéric; Guerquin, Marie-Justine; Bonnet, Aline; Bonnin, Marie-Ange; Havis, Emmanuelle; Malbouyres, Maryline; Bidaud, Christelle Bonod; Maro, Géraldine; Gilardi-Hebenstreit, Pascale; Rossert, Jérome; Ruggiero, Florence; Duprez, Delphine

    2011-02-18

    The molecules involved in vertebrate tendon formation during development remain largely unknown. To date, only two DNA-binding proteins have been identified as being involved in vertebrate tendon formation, the basic helix-loop-helix transcription factor Scleraxis and, recently, the Mohawk homeobox gene. We investigated the involvement of the early growth response transcription factors Egr1 and Egr2 in vertebrate tendon formation. We established that Egr1 and Egr2 expression in tendon cells was correlated with the increase of collagen expression during tendon cell differentiation in embryonic limbs. Vertebrate tendon differentiation relies on a muscle-derived FGF (fibroblast growth factor) signal. FGF4 was able to activate the expression of Egr genes and that of the tendon-associated collagens in chick limbs. Egr gene misexpression experiments using the chick model allowed us to establish that either Egr gene has the ability to induce de novo expression of the reference tendon marker scleraxis, the main tendon collagen Col1a1, and other tendon-associated collagens Col3a1, Col5a1, Col12a1, and Col14a1. Mouse mutants for Egr1 or Egr2 displayed reduced amounts of Col1a1 transcripts and a decrease in the number of collagen fibrils in embryonic tendons. Moreover, EGR1 and EGR2 trans-activated the mouse Col1a1 proximal promoter and were recruited to the tendon regulatory regions of this promoter. These results identify EGRs as novel DNA-binding proteins involved in vertebrate tendon differentiation by regulating type I collagen production. PMID:21173153

  17. Duplication and maintenance of the Myb genes of vertebrate animals

    PubMed Central

    Davidson, Colin J.; Guthrie, Erin E.; Lipsick, Joseph S.

    2013-01-01

    Summary Gene duplication is an important means of generating new genes. The major mechanisms by which duplicated genes are preserved in the face of purifying selection are thought to be neofunctionalization, subfunctionalization, and increased gene dosage. However, very few duplicated gene families in vertebrate species have been analyzed by functional tests in vivo. We have therefore examined the three vertebrate Myb genes (c-Myb, A-Myb, and B-Myb) by cytogenetic map analysis, by sequence analysis, and by ectopic expression in Drosophila. We provide evidence that the vertebrate Myb genes arose by two rounds of regional genomic duplication. We found that ubiquitous expression of c-Myb and A-Myb, but not of B-Myb or Drosophila Myb, was lethal in Drosophila. Expression of any of these genes during early larval eye development was well tolerated. However, expression of c-Myb and A-Myb, but not of B-Myb or Drosophila Myb, during late larval eye development caused drastic alterations in adult eye morphology. Mosaic analysis implied that this eye phenotype was cell-autonomous. Interestingly, some of the eye phenotypes caused by the retroviral v-Myb oncogene and the normal c-Myb proto-oncogene from which v-Myb arose were quite distinct. Finally, we found that post-translational modifications of c-Myb by the GSK-3 protein kinase and by the Ubc9 SUMO-conjugating enzyme that normally occur in vertebrate cells can modify the eye phenotype caused by c-Myb in Drosophila. These results support a model in which the three Myb genes of vertebrates arose by two sequential duplications. The first duplication was followed by a subfunctionalization of gene expression, then neofunctionalization of protein function to yield a c/A-Myb progenitor. The duplication of this progenitor was followed by subfunctionalization of gene expression to give rise to tissue-specific c-Myb and A-Myb genes. PMID:23431116

  18. Variation in vertebral number and its morphological implication in Galaxias platei.

    PubMed

    Barriga, J P; Milano, D; Cussac, V E

    2013-11-01

    Variation in the vertebral number of the puyen grande Galaxias platei was examined for specimens from 22 localities that span the entire distribution range of the species (from 40° to 55° S). The mean vertebral number (NMW ) increases towards high latitudes, i.e. Jordan's rule is applicable to this species. Owing to the wide geographic variation of the species, not only in latitude but also in altitude, the most explicative variable for NMW was mean winter air temperature, showing negative dependence. Morphological data suggest that the increment in vertebral number lies in the pre-pelvic region of the trunk and in the caudal region, but not in the segment between pelvic-fin insertion and the origin of the anal fin. As these alterations in body shape have important consequences for hydrodynamics and swimming performance, vertebral number variation in G. platei also holds implications for both individual and population fitness. PMID:24124792

  19. 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

  20. Nanotechnology for treating osteoporotic vertebral fractures.

    PubMed

    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

  1. Variation in anthropoid vertebral formulae: implications for homology and homoplasy in hominoid evolution.

    PubMed

    Williams, Scott A

    2012-03-01

    Variation in vertebral formulae within and among hominoid species has complicated our understanding of hominoid vertebral evolution. Here, variation is quantified using diversity and similarity indices derived from population genetics. These indices allow for testing models of hominoid vertebral evolution that call for disparate amounts of homoplasy, and by inference, different patterns of evolution. Results are interpreted in light of "short-backed" (J Exp Zool (Mol Dev Evol) 302B:241-267) and "long-backed" (J Exp Zool (Mol Dev Evol) 314B:123-134) ancestries proposed in different models of hominin vertebral evolution. Under the long-back model, we should expect reduced variation in vertebral formulae associated with adaptively driven homoplasy (independently and repeatedly reduced lumbar regions) and the relatively strong directional selection presumably associated with it, especially in closely related taxa that diverged relatively recently (e.g., Pan troglodytes and Pan paniscus). Instead, high amounts of intraspecific variation are observed among all hominoids except humans and eastern gorillas, taxa that have likely experienced strong stabilizing selection on vertebral formulae associated with locomotor and habitat specializations. Furthermore, analyses of interspecific similarity support an evolutionary scenario in which the vertebral formulae observed in western gorillas and chimpanzees represent a reasonable approximation of the ancestral condition for great apes and humans, from which eastern gorillas, humans, and bonobos derived their unique vertebral profiles. Therefore, these results support the short-back model and are compatible with a scenario of homology of reduced lumbar regions in hominoid primates. Fossil hominin vertebral columns are discussed and shown to support, rather than contradict, the short-back model. PMID:22532475

  2. Evolution of oxytocin pathways in the brain of vertebrates

    PubMed Central

    Knobloch, H. Sophie; Grinevich, Valery

    2014-01-01

    The central oxytocin system transformed tremendously during the evolution, thereby adapting to the expanding properties of species. In more basal vertebrates (paraphyletic taxon Anamnia, which includes agnathans, fish and amphibians), magnocellular neurosecretory neurons producing homologs of oxytocin reside in the wall of the third ventricle of the hypothalamus composing a single hypothalamic structure, the preoptic nucleus. This nucleus further diverged in advanced vertebrates (monophyletic taxon Amniota, which includes reptiles, birds, and mammals) into the paraventricular and supraoptic nuclei with accessory nuclei (AN) between them. The individual magnocellular neurons underwent a process of transformation from primitive uni- or bipolar neurons into highly differentiated neurons. Due to these microanatomical and cytological changes, the ancient release modes of oxytocin into the cerebrospinal fluid were largely replaced by vascular release. However, the most fascinating feature of the progressive transformations of the oxytocin system has been the expansion of oxytocin axonal projections to forebrain regions. In the present review we provide a background on these evolutionary advancements. Furthermore, we draw attention to the non-synaptic axonal release in small and defined brain regions with the aim to clearly distinguish this way of oxytocin action from the classical synaptic transmission on one side and from dendritic release followed by a global diffusion on the other side. Finally, we will summarize the effects of oxytocin and its homologs on pro-social reproductive behaviors in representatives of the phylogenetic tree and will propose anatomically plausible pathways of oxytocin release contributing to these behaviors in basal vertebrates and amniots. PMID:24592219

  3. Evolutionary Diversification of the Vertebrate Transferrin Multi-gene Family

    PubMed Central

    Hughes, Austin L.; Friedman, Robert

    2014-01-01

    In a phylogenetic analysis of vertebrate transferrins (TFs), six major clades (subfamilies) were identified: (1) S, the mammalian serotransferrins; (2) ICA, the mammalian inhibitor of carbonic anhydrase (ICA) homologs; (3) L, the mammalian lactoferrins; (4) O, the ovotransferrins of birds and reptiles; (4) M, the melanotransferrins of bony fishes, amphibians, reptiles, birds, and mammals; and (5) M-like, a newly identified TF subfamily found in bony fishes, amphibians, reptiles, and birds. A phylogenetic tree based on the joint alignment of N-lobes and C-lobes supported the hypothesis that three separate events of internal duplication occurred in vertebrate TFs: (1) in the common ancestor of the M subfamily; (2) in the common ancestor of the M-like subfamily; and (3) in the common ancestor of other vertebrate TFs. The S, ICA, and L subfamilies were found only in placental mammals, and the phylogenetic analysis supported the hypothesis that these three subfamilies arose by gene duplication after the divergence of placental mammals from marsupials. The M-like subfamily was unusual in several respects, including the presence of a uniquely high proportion of clade-specific conserved residues, including distinctive but conserved residues in the sites homologous to those functioning in carbonate binding of human serotransferrin. The M-like family also showed a unusually high proportion of cationic residues in the positively charged region corresponding to human lactoferrampin, suggesting a distinctive role of this region in the M-like subfamily, perhaps in antimicrobial defense. PMID:25142446

  4. Increased complexity of gene structure and base composition in vertebrates.

    PubMed

    Wu, Ying; Yuan, Huizhong; Tan, Shengjun; Chen, Jian-Qun; Tian, Dacheng; Yang, Haiwang

    2011-07-20

    How the structure and base composition of genes changed with the evolution of vertebrates remains a puzzling question. Here we analyzed 895 orthologous protein-coding genes in six multicellular animals: human, chicken, zebrafish, sea squirt, fruit fly, and worm. Our analyses reveal that many gene regions, particularly intron and 3' UTR, gradually expanded throughout the evolution of vertebrates from their invertebrate ancestors, and that the number of exons per gene increased. Studies based on all protein-coding genes in each genome provide consistent results. We also find that GC-content increased in many gene regions (especially 5' UTR) in the evolution of endotherms, except in coding-exons. Analysis of individual genomes shows that 3' UTR demonstrated stronger length and GC-content correlation with intron than 5' UTR, and gene with large intron in all six species demonstrated relatively similar GC-content. Our data indicates a great increase in complexity in vertebrate genes and we propose that the requirement for morphological and functional changes is probably the driving force behind the evolution of structure and base composition complexity in multicellular animal genes. PMID:21777854

  5. 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

  6. Contribution of the vertebral artery to cerebral circulation in the rat snake Elaphe obsoleta

    NASA Technical Reports Server (NTRS)

    Zippel, K. C.; Lillywhite, H. B.; Mladinich, C. R.; Hargens, A. (Principal Investigator)

    1998-01-01

    Blood supplying the brain in vertebrates is carried primarily by the carotid vasculature. In most mammals, cerebral blood flow is supplemented by the vertebral arteries, which anastomose with the carotids at the base of the brain. In other tetrapods, cerebral blood is generally believed to be supplied exclusively by the carotid vasculature, and the vertebral arteries are usually described as disappearing into the dorsal musculature between the heart and head. There have been several reports of a vertebral artery connection with the cephalic vasculature in snakes. We measured regional blood flows using fluorescently labeled microspheres and demonstrated that the vertebral artery contributes a small but significant fraction of cerebral blood flow (approximately 13% of total) in the rat snake Elaphe obsoleta. Vascular casts of the anterior vessels revealed that the vertebral artery connection is indirect, through multiple anastomoses with the inferior spinal artery, which connects with the carotid vasculature near the base of the skull. Using digital subtraction angiography, fluoroscopy, and direct observations of flow in isolated vessels, we confirmed that blood in the inferior spinal artery flows craniad from a point anterior to the vertebral artery connections. Such collateral blood supply could potentially contribute to the maintenance of cerebral circulation during circumstances when craniad blood flow is compromised, e.g., during the gravitational stress of climbing.

  7. 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. PMID:25415965

  8. [Venomous and poisonous animals. IV. Envenomations by venomous aquatic vertebrates].

    PubMed

    Bédry, R; De Haro, L

    2007-04-01

    Epidemiological information on marine envenomation is generally less extensive in Europe than in tropical regions where these injuries are more severe and the need for medical advice is more frequent. For these reasons use of regional Poison Control Centers in the area where the injury occurs must be encouraged. The purpose of this review is to describe envenomation by bony fish (lion fish, stone fish, and catfish), cartilaginous fish (stingrays and poisonous sharks), or other venomous aquatic vertebrates (moray-eels and marine snakes). Understanding of these envenomation syndromes is important not only in tropical areas but also in Europe where importation of dangerous species has increased in recent years. PMID:17691425

  9. New insights into the vertebral Hox code of archosaurs.

    PubMed

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

    2015-01-01

    Variation in axial formulae (i.e., number and identity of vertebrae) is an important feature in the evolution of vertebrates. Vertebrae at different axial positions exhibit a region-specific morphology. Key determinants for the establishment of particular vertebral shapes are the highly conserved Hox genes. Here, we analyzed Hox gene expression in the presacral vertebral column in the Nile crocodile in order to complement and extend a previous examination in the alligator and thus establish a Hox code for the axial skeleton of crocodilians in general. The newly determined expression of HoxA-4, C-5, B-7, and B-8 all revealed a crocodilian-specific pattern. HoxA-4 and HoxC-5 characterize cervical morphologies and the latter furthermore is associated with the position of the forelimb relative to the axial skeleton. HoxB-7 and HoxB-8 map exclusively to the dorsal vertebral region. The resulting expression patterns of these two Hox genes is the first description of their exact expression in the archosaurian embryo. Our comparative analyses of the Hox code in several amniote taxa provide new evidence that evolutionary differences in the axial skeleton correspond to changes in Hox gene expression domains. We detect two general processes: (i) expansion of a Hox gene's expression domain as well as (ii) a shift of gene expression. We infer that the ancestral archosaur Hox code may have resembled that of the crocodile. In association with the evolution of morphological traits, it may have been modified to patterns that can be observed in birds. PMID:26372060

  10. Rotations in a Vertebrate Setting

    NASA Astrophysics Data System (ADS)

    McCollum, Gin

    2003-05-01

    Rotational movements of the head are often considered to be measured in a single three dimensional coordinate system implemented by the semicircular canals of the vestibular system of the inner ear. However, the vertebrate body -- including the nervous system -- obeys rectangular symmetries alien to rotation groups. At best, nervous systems mimic the physical rotation group in a fragmented way, only partially reintegrating physical movements in whole organism responses. The vestibular canal reference frame is widely used in nervous systems, for example by eye movements. It is used to some extent even in the cerebrum, as evidenced by the remission of hemineglect -- in which half of space is ignored -- when the vestibular system is stimulated. However, reintegration of space by the organism remains incomplete. For example, compensatory eye movements (which in most cases aid visual fixation) may disagree with conscious self-motion perception. In addition, movement-induced nausea, illusions, and cue-free perceptions demonstrate symmetry breaking or incomplete spatial symmetries. As part of a long-term project to investigate rotation groups in nervous systems, we have analyzed the symmetry group of a primary vestibulo-spinal projection.

  11. Toward understanding the evolution of vertebrate gene regulatory networks: comparative genomics and epigenomic approaches.

    PubMed

    Martinez-Morales, Juan R

    2016-07-01

    Vertebrates, as most animal phyla, originated >500 million years ago during the Cambrian explosion, and progressively radiated into the extant classes. Inferring the evolutionary history of the group requires understanding the architecture of the developmental programs that constrain the vertebrate anatomy. Here, I review recent comparative genomic and epigenomic studies, based on ChIP-seq and chromatin accessibility, which focus on the identification of functionally equivalent cis-regulatory modules among species. This pioneer work, primarily centered in the mammalian lineage, has set the groundwork for further studies in representative vertebrate and chordate species. Mapping of active regulatory regions across lineages will shed new light on the evolutionary forces stabilizing ancestral developmental programs, as well as allowing their variation to sustain morphological adaptations on the inherited vertebrate body plan. PMID:26293604

  12. Cervical vertebral strain measurements under axial and eccentric loading.

    PubMed

    Pintar, F A; Yoganandan, N; Pesigan, M; Reinartz, J; Sances, A; Cusick, J F

    1995-11-01

    The mid to lower cervical spine is a common site for compression related injury. In the present study, we determined the patterns of localized strain distribution in the anterior aspect of the vertebral body and in the lateral masses of lower cervical three-segment units. Miniature strain gages were mounted to human cadaveric vertebrae. Each preparation was line-loaded using a knife-edge oriented in the coronal plane that was moved incrementally from anterior to posterior to induce compression-flexion or compression-extension loading. Uniform compressive loading and failure runs were also conducted. Failure tests indicated strain shifting to "restabilize" the preparation after failure of a component. Under these various compressive loading vectors, the location which resulted in the least amount of deformation for a given force application (i.e., stiffest axis) was quantified to be in the region between 0.5- 1.0 cm anterior to the posterior longitudinal ligament. The location in which line-loading produced no rotation (i.e., balance point) was in this region; it was also close to where the vertebral body strains change from compressive to tensile. Strain values from line loading in this region produced similar strains as recorded under uniform compressive loading, and this was also the region of minimum strain. The region of minimum strain was also more pronounced under higher magnitudes of loading, suggesting that as the maximum load carrying capacity is reached the stiffest axis becomes more well defined. PMID:8748531

  13. Vertebral column anomalies in Indo-Pacific and Atlantic humpback dolphins Sousa spp.

    PubMed

    Weir, Caroline R; Wang, John Y

    2016-08-01

    Conspicuous vertebral column abnormalities in humpback dolphins (genus Sousa) were documented for the first time during 3 photo-identification field studies of small populations in Taiwan, Senegal and Angola. Seven Taiwanese humpback dolphins S. chinensis taiwanensis with vertebral column anomalies (lordosis, kyphosis or scoliosis) were identified, along with 2 possible cases of vertebral osteomyelitis. There was evidence from several individuals photographed over consecutive years that the anomalies became more pronounced with age. Three Atlantic humpback dolphins S. teuszii were observed with axial deviations of the vertebral column (lordosis and kyphosis). Another possible case was identified in a calf, and 2 further animals were photographed with dorsal indents potentially indicative of anomalies. Vertebral column anomalies of humpback dolphins were predominantly evident in the lumbo-caudal region, but one Atlantic humpback dolphin had an anomaly in the cervico-thoracic region. Lordosis and kyphosis occurred simultaneously in several individuals. Apart from the described anomalies, all dolphins appeared in good health and were not obviously underweight or noticeably compromised in swim speed. This study presents the first descriptions of vertebral column anomalies in the genus Sousa. The causative factors for the anomalies were unknown in every case and are potentially diverse. Whether these anomalies result in reduced fitness of individuals or populations merits attention, as both the Taiwanese and Atlantic humpback dolphin are species of high conservation concern. PMID:27503913

  14. Update of vertebral cementoplasty in porotic patients

    PubMed Central

    Masala, Salvatore; Muto, Mario

    2015-01-01

    Vertebroplasty (VP) is a percutaneous mini-invasive technique developed in the late 1980s as antalgic and stabilizing treatment in patients affected by symptomatic vertebral fracture due to porotic disease, traumatic injury and primary or secondary vertebral spine tumors. The technique consists of a simple metameric injection of an inert cement (poly-methyl-methacrylate, PMMA), through a needle by trans-peduncular, parapeduncular or trans-somatic approach obtaining a vertebral augmentation and stabilization effect associated with pain relief. The technique is simple and fast, and should be performed under fluoroscopy or CT guidance in order to obtain a good result with low complication rate. The aim of this paper is to illustrate the utility of VP, the indications-contraindications criteria, how to technically perform the technique using imaging guidance, and the results and complications of this treatment in patients affected by symptomatic vertebral compression fracture. PMID:26015527

  15. Vertebrate eye development as modeled in Drosophila.

    PubMed

    Wawersik, S; Maas, R L

    2000-04-12

    Pax6, a member of the paired-box family of transcription factors, is critical for oculogenesis in both vertebrates and insects. Identification of potential vertebrate Pax6 targets has been guided by studies in Drosophila, where the Pax6 homologs eyeless ( ey ) and twin of eyeless ( toy ) function within a network of genes that synergistically pattern the developing fly eye. These targets, which share homology with the fly genes sine oculis, eyes absent and dachshund, exist in mice and humans as the Six, Eya and Dach gene families. Members of these gene families are present in the developing vertebrate eye, and preliminary studies suggest that they may function in a network analogous to that in the fly. Thus, despite radically different architecture, a similar molecular scaffold underlies both vertebrate and fly eye patterning, suggesting that the considerable power of Drosophila genetics can be harnessed to study mammalian ocular development. PMID:10767315

  16. Evolution of Herbivory in Terrestrial Vertebrates

    NASA Astrophysics Data System (ADS)

    Sues, Hans-Dieter

    2000-08-01

    Although herbivory probably first appeared over 300 million years ago, it only became established as a common feeding strategy during Late Permian times. Subsequently, herbivory evolved in numerous lineages of terrestrial vertebrates, and the acquisition of this mode of feeding was frequently associated with considerable evolutionary diversification in those lineages. This book represents a comprehensive overview of the evolution of herbivory in land-dwelling amniote tetrapods in recent years. In Evolution of Herbivory in Terrestrial Vertebrates, leading experts review the evolutionary history and structural adaptations required for feeding on plants in the major groups of land-dwelling vertebrates, especially dinosaurs and ungulate mammals. As such, this volume will be the definitive reference source on this topic for evolutionary biologists and vertebrate paleontologists.

  17. A Case of Aerococcus Urinae Vertebral Osteomyelitis

    PubMed Central

    Jerome, Michael; Slim, Jihad; Sison, Raymund; Marton, Randy

    2015-01-01

    Aerococcus urinae is an aerobic, alpha hemolytic gram positive coccus bacterium that grows in pairs or clusters. We report the first case of vertebral osteomyelitis due to A. urinae. This has not been previously reported in the literature. PMID:26069429

  18. RFamide Peptides in Early Vertebrate Development

    PubMed Central

    Sandvik, Guro Katrine; Hodne, Kjetil; Haug, Trude Marie; Okubo, Kataaki; Weltzien, Finn-Arne

    2014-01-01

    RFamides (RFa) are neuropeptides involved in many different physiological processes in vertebrates, such as reproductive behavior, pubertal activation of the reproductive endocrine axis, control of feeding behavior, and pain modulation. As research has focused mostly on their role in adult vertebrates, the possible roles of these peptides during development are poorly understood. However, the few studies that exist show that RFa are expressed early in development in different vertebrate classes, perhaps mostly associated with the central nervous system. Interestingly, the related peptide family of FMRFa has been shown to be important for brain development in invertebrates. In a teleost, the Japanese medaka, knockdown of genes in the Kiss system indicates that Kiss ligands and receptors are vital for brain development, but few other functional studies exist. Here, we review the literature of RFa in early vertebrate development, including the possible functional roles these peptides may play. PMID:25538682

  19. Sleep and orexins in nonmammalian vertebrates.

    PubMed

    Volkoff, Hélène

    2012-01-01

    Although a precise definition of "sleep" has yet to be established, sleep-like behaviors have been observed in all animals studied to date including mammals and nonmammalian vertebrates. Orexins are hypothalamic neuropeptides that are involved in the regulation of many physiological functions, including feeding, thermoregulation, cardiovascular control, as well as the control of the sleep-wakefulness cycle. To date, the knowledge on the functions of orexins in nonmammalian vertebrates is still limited, but the similarity of the structures of orexins and their receptors among vertebrates suggest that they have similar conserved physiological functions. This review describes our current knowledge on sleep in nonmammalian vertebrates (birds, reptiles, amphibians, and fish) and the possible role of orexins in the regulation of their energy homeostasis and arousal states. PMID:22640621

  20. Innate immunity in vertebrates: an overview.

    PubMed

    Riera Romo, Mario; Pérez-Martínez, Dayana; Castillo Ferrer, Camila

    2016-06-01

    Innate immunity is a semi-specific and widely distributed form of immunity, which represents the first line of defence against pathogens. This type of immunity is critical to maintain homeostasis and prevent microbe invasion, eliminating a great variety of pathogens and contributing with the activation of the adaptive immune response. The components of innate immunity include physical and chemical barriers, humoral and cell-mediated components, which are present in all jawed vertebrates. The understanding of innate defence mechanisms in non-mammalian vertebrates is the key to comprehend the general picture of vertebrate innate immunity and its evolutionary history. This is also essential for the identification of new molecules with applications in immunopharmacology and immunotherapy. In this review, we describe and discuss the main elements of vertebrate innate immunity, presenting core findings in this field and identifying areas that need further investigation. PMID:26878338

  1. [Vertebral osteomyelitis associated with epidural block].

    PubMed

    Carrillo Esper, R; Cruz-Bautista, I

    2001-01-01

    Infectious complications after epidural anesthesia are infrequent and the most common are epidural and subdural abscess. We report one rare case of vertebral osteomyelitus associated with an epidural catheter and review the literature. PMID:11381807

  2. Vertebrate Cells Express Protozoan Antigen after Hybridization

    NASA Astrophysics Data System (ADS)

    Crane, Mark St. J.; Dvorak, James A.

    1980-04-01

    Epimastigotes, the invertebrate host stage of Trypanosoma cruzi, the protozoan parasite causing Chagas' disease in man, were fused with vertebrate cells by using polyethylene glycol. Hybrid cells were selected on the basis of T. cruzi DNA complementation of biochemical deficiencies in the vertebrate cells. Some clones of the hybrid cells expressed T. cruzi-specific antigen. It might be possible to use selected antigens obtained from the hybrids as vaccines for immunodiagnosis or for elucidation of the pathogenesis of Chagas' disease.

  3. Vertebral artery occlusion and oral contraceptives.

    PubMed Central

    Ask-Upmark, E; Bickerstaff, E R

    1976-01-01

    If vertebral artery occlusion occurs in degenerative arterial disease it is almost invariably left-sided, but in vertebral artery deficiency syndromes associated with oral contraceptives a striking preponderance of right-sided involvement has been shown. This observation adds support to the view that causes other than changes in the wall of the vessel at the site of occlusion must be sought as an explanation of the occlusion. PMID:1252812

  4. Cilia in vertebrate development and disease

    PubMed Central

    Oh, Edwin C.; Katsanis, Nicholas

    2012-01-01

    Through the combined study of model organisms, cell biology, cell signaling and medical genetics we have significantly increased our understanding of the structure and functions of the vertebrate cilium. This ancient organelle has now emerged as a crucial component of certain signaling and sensory perception pathways in both developmental and homeostatic contexts. Here, we provide a snapshot of the structure, function and distribution of the vertebrate cilium and of the pathologies that are associated with its dysfunction. PMID:22223675

  5. Cervical vertebral fusion with anterior meningocele

    PubMed Central

    Chavredakis, Emmanuel; Carter, David; Bhojak, Manesh; Jenkinson, Michael D; Clark, Simon R

    2015-01-01

    We present the first described case of cervical vertebral fusion associated with anterior meningocele and syringomyelia. A 45-year-old woman presented with minor trauma, and plain cervical spine radiographs highlighted a congenital deformity of the cervical vertebral bodies. She had a normal neurological examination; however, further imaging revealed a meningocele and syringomyelia. This case highlights the importance of thorough imaging investigation when presented with a congenital deformity in order to detect and prevent development of degenerative spinal cord pathologies. PMID:25923673

  6. Percutaneous Vertebral Body Augmentation: An Updated Review

    PubMed Central

    Omidi-Kashani, Farzad

    2014-01-01

    There are many medical conditions like osteoporosis, tumor, or osteonecrosis that weaken the structural strength of the vertebral body and prone it to fracture. Percutaneous vertebral augmentation that is usually applied by polymethylmethacrylate is a relatively safe, effective, and long lasting procedure commonly performed in these situations. In this paper, we updated a review of biomechanics, indications, contraindications, surgical techniques, complications, and overall prognosis of these minimally invasive spinal procedures. PMID:25379561

  7. Risk factors for vertebral deformities in men: relationship to number of vertebral deformities. European Vertebral Osteoporosis Study Group.

    PubMed

    Ismail, A A; O'Neill, T W; Cooper, C; Silman, A J

    2000-02-01

    Recent epidemiological studies suggest a similar overall prevalence of vertebral deformity in men to that in women, though the influence of increasing age on the prevalence of vertebral deformity is less marked in men. However, most affected men have only a single or two vertebral deformities, which may be unrelated to osteoporosis. The aim of this study was to examine the role of risk factors, previously demonstrated to be associated with vertebral osteoporosis in females, in men with single/dual deformities compared to those with multiple deformities. Age stratified random samples of men aged 50 years and over were recruited from population registers in 30 European centers as part of the European Vertebral Osteoporosis Study (EVOS). Subjects had a lateral spinal radiograph and the presence of vertebral deformity was determined using the McCloskey algorithm. Lifestyle and other risk factor data were obtained from an interviewer-administered questionnaire. In all 6937 men with a mean age of 64.4 (SD = 8.5) years were studied of whom 738 (10.6%) subjects had one or two deformities, and 109 (1.6%) subjects had three or more deformities. There was a marked increase in the prevalence of multiple vertebral deformities with increasing age, but only a modest effect of age on the prevalence of single deformities. Associations between various risk factors for osteoporosis and vertebral deformity were analyzed separately in men with single/dual vertebral deformity from those with three or more deformities using logistic regression. After adjustment for age, there were statistically significant associations between the following risk factors and multiple deformities: previous hip fracture (odds ratio [OR] 10.5), lack of regular physical activity (OR 2.9), low body mass (OR 2.5), and previous steroid use (OR 2.3). By contrast, there were only weak associations with these same variables in males with single/dual deformities and, apart from poor self-reported general health, all

  8. 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

  9. Evolution and development of interhemispheric connections in the vertebrate forebrain

    PubMed Central

    Suárez, Rodrigo; Gobius, Ilan; Richards, Linda J.

    2014-01-01

    Axonal connections between the left and right sides of the brain are crucial for bilateral integration of lateralized sensory, motor, and associative functions. Throughout vertebrate species, forebrain commissures share a conserved developmental plan, a similar position relative to each other within the brain and similar patterns of connectivity. However, major events in the evolution of the vertebrate brain, such as the expansion of the telencephalon in tetrapods and the origin of the six-layered isocortex in mammals, resulted in the emergence and diversification of new commissural routes. These new interhemispheric connections include the pallial commissure, which appeared in the ancestors of tetrapods and connects the left and right sides of the medial pallium (hippocampus in mammals), and the corpus callosum, which is exclusive to eutherian (placental) mammals and connects both isocortical hemispheres. A comparative analysis of commissural systems in vertebrates reveals that the emergence of new commissural routes may have involved co-option of developmental mechanisms and anatomical substrates of preexistent commissural pathways. One of the embryonic regions of interest for studying these processes is the commissural plate, a portion of the early telencephalic midline that provides molecular specification and a cellular scaffold for the development of commissural axons. Further investigations into these embryonic processes in carefully selected species will provide insights not only into the mechanisms driving commissural evolution, but also regarding more general biological problems such as the role of developmental plasticity in evolutionary change. PMID:25071525

  10. Quantitative vertebral compression fracture evaluation using a height compass

    NASA Astrophysics Data System (ADS)

    Yao, Jianhua; Burns, Joseph E.; Wiese, Tatjana; Summers, Ronald M.

    2012-03-01

    Vertebral compression fractures can be caused by even minor trauma in patients with pathological conditions such as osteoporosis, varying greatly in vertebral body location and compression geometry. The location and morphology of the compression injury can guide decision making for treatment modality (vertebroplasty versus surgical fixation), and can be important for pre-surgical planning. We propose a height compass to evaluate the axial plane spatial distribution of compression injury (anterior, posterior, lateral, and central), and distinguish it from physiologic height variations of normal vertebrae. The method includes four steps: spine segmentation and partition, endplate detection, height compass computation and compression fracture evaluation. A height compass is computed for each vertebra, where the vertebral body is partitioned in the axial plane into 17 cells oriented about concentric rings. In the compass structure, a crown-like geometry is produced by three concentric rings which are divided into 8 equal length arcs by rays which are subtended by 8 common central angles. The radius of each ring increases multiplicatively, with resultant structure of a central node and two concentric surrounding bands of cells, each divided into octants. The height value for each octant is calculated and plotted against octants in neighboring vertebrae. The height compass shows intuitive display of the height distribution and can be used to easily identify the fracture regions. Our technique was evaluated on 8 thoraco-abdominal CT scans of patients with reported compression fractures and showed statistically significant differences in height value at the sites of the fractures.

  11. CRDB: database of chemosensory receptor gene families in vertebrate.

    PubMed

    Dong, Dong; Jin, Ke; Wu, Xiaoli; Zhong, Yang

    2012-01-01

    Chemosensory receptors (CR) are crucial for animals to sense the environmental changes and survive on earth. The emergence of whole-genome sequences provides us an opportunity to identify the entire CR gene repertoires. To completely gain more insight into the evolution of CR genes in vertebrates, we identified the nearly all CR genes in 25 vertebrates using homology-based approaches. Among these CR gene repertoires, nearly half of them were identified for the first time in those previously uncharacterized species, such as the guinea pig, giant panda and elephant, etc. Consistent with previous findings, we found that the numbers of CR genes vary extensively among different species, suggesting an extreme form of 'birth-and-death' evolution. For the purpose of facilitating CR gene analysis, we constructed a database with the goals to provide a resource for CR genes annotation and a web tool for exploring their evolutionary patterns. Besides a search engine for the gene extraction from a specific chromosome region, an easy-to-use phylogenetic analysis tool was also provided to facilitate online phylogeny study of CR genes. Our work can provide a rigorous platform for further study on the evolution of CR genes in vertebrates. PMID:22393364

  12. Homeotic effects, somitogenesis and the evolution of vertebral numbers in recent and fossil amniotes

    PubMed Central

    Müller, Johannes; Scheyer, Torsten M.; Head, Jason J.; Barrett, Paul M.; Werneburg, Ingmar; Ericson, Per G. P.; Pol, Diego; Sánchez-Villagra, Marcelo R.

    2010-01-01

    The development of distinct regions in the amniote vertebral column results from somite formation and Hox gene expression, with the adult morphology displaying remarkable variation among lineages. Mammalian regionalization is reportedly very conservative or even constrained, but there has been no study investigating vertebral count variation across Amniota as a whole, undermining attempts to understand the phylogenetic, ecological, and developmental factors affecting vertebral column variation. Here, we show that the mammalian (synapsid) and reptilian lineages show early in their evolutionary histories clear divergences in axial developmental plasticity, in terms of both regionalization and meristic change, with basal synapsids sharing the conserved axial configuration of crown mammals, and basal reptiles demonstrating the plasticity of extant taxa. We conducted a comprehensive survey of presacral vertebral counts across 436 recent and extinct amniote taxa. Vertebral counts were mapped onto a generalized amniote phylogeny as well as individual ingroup trees, and ancestral states were reconstructed by using squared-change parsimony. We also calculated the relationship between presacral and cervical numbers to infer the relative influence of homeotic effects and meristic changes and found no correlation between somitogenesis and Hox-mediated regionalization. Although conservatism in presacral numbers characterized early synapsid lineages, in some cases reptiles and synapsids exhibit the same developmental innovations in response to similar selective pressures. Conversely, increases in body mass are not coupled with meristic or homeotic changes, but mostly occur in concert with postembryonic somatic growth. Our study highlights the importance of fossils in large-scale investigations of evolutionary developmental processes. PMID:20080660

  13. Complete sequence of a sea lamprey (Petromyzon marinus) mitochondrial genome: Early establishment of the vertebrate genome organization

    SciTech Connect

    Lee, W.J.; Kocher, T.D.

    1995-02-01

    The complete nucleotide sequence of a sea lamprey (Petromyzon marinus) mitochondrial genome has been determined. The lamprey genome is 16,201 bp in length and contains genes for 13 proteins, two rRNAs, 22 tRNAs and two major noncoding regions. The order and transcriptional polarities of protein-coding genes are basically identical to those of other chordate mtDNAs, demonstrating that the common mitochondrial gene organization of vertebrates was established at early stage of vertebrate evolution. The two major noncoding regions are separated by two tRNA genes. The first region probably functions as the control region because it contains distinctive conserved sequence blocks (CSB-II and III) common to other vertebrate control regions. The central conserved domain observed in other vertebrate control regions is not found in the lamprey, suggesting that it is a recently evolved functional domain in vertebrates. Noncoding segments are not found in the expected position of the origin of replication for the second strand, suggesting either that one of the tRNA genes has a dual function or that the second noncoding region may function as the second-strand origin. The base composition at the wobble positions of fourfold degenerate codon families is highly biased toward thymine (32.7%). Values of GC- and AT-skew are typical of vertebrate mitochondrial genomes. 38 refs., 11 figs., 5 tabs.

  14. Global patterns of terrestrial vertebrate diversity and conservation.

    PubMed

    Jenkins, Clinton N; Pimm, Stuart L; Joppa, Lucas N

    2013-07-01

    Identifying priority areas for biodiversity is essential for directing conservation resources. Fundamentally, we must know where individual species live, which ones are vulnerable, where human actions threaten them, and their levels of protection. As conservation knowledge and threats change, we must reevaluate priorities. We mapped priority areas for vertebrates using newly updated data on >21,000 species of mammals, amphibians, and birds. For each taxon, we identified centers of richness for all species, small-ranged species, and threatened species listed with the International Union for the Conservation of Nature. Importantly, all analyses were at a spatial grain of 10 × 10 km, 100 times finer than previous assessments. This fine scale is a significant methodological improvement, because it brings mapping to scales comparable with regional decisions on where to place protected areas. We also mapped recent species discoveries, because they suggest where as-yet-unknown species might be living. To assess the protection of the priority areas, we calculated the percentage of priority areas within protected areas using the latest data from the World Database of Protected Areas, providing a snapshot of how well the planet's protected area system encompasses vertebrate biodiversity. Although the priority areas do have more protection than the global average, the level of protection still is insufficient given the importance of these areas for preventing vertebrate extinctions. We also found substantial differences between our identified vertebrate priorities and the leading map of global conservation priorities, the biodiversity hotspots. Our findings suggest a need to reassess the global allocation of conservation resources to reflect today's improved knowledge of biodiversity and conservation. PMID:23803854

  15. Vascular Plant and Vertebrate Inventory of Tuzigoot National Monument

    USGS Publications Warehouse

    Powell, Brian F.; Albrecht, E.W.; Halvorson, William Lee; Schmidt, Cecilia A.; Anning, P.; Docherty, K.

    2005-01-01

    Executive Summary From 2002 to 2004, we surveyed for plants and vertebrates (amphibians, reptiles, birds, and mammals) at Tuzigoot National Monument (NM) and adjacent areas in Arizona. This was the first effort of its kind in the area and was part of a larger effort to inventory vascular plants and vertebrates in eight National Park Service units in Arizona and New Mexico. In addition to our own surveys, we also compiled a complete list of species that have been found by previous studies. We found 330 species, including 142 that had not previously been recorded at the monument (Table 1). We found 39 species of non-native plants, 11 non-native fishes, three non-native birds, and one non-native species each of amphibian and mammal. Based on our work and that of others, there have been 597 species of plants and vertebrates found at the monument. The bird community at the monument had the highest species richness of any national park unit in central and southern Arizona. We found all other taxa to have intermediate species richness compared to other park units in the region. This extraordinary species richness observed for birds, as well as for some other taxa, is due primarily to Tavasci Marsh and the Verde River, two critical sources of perennial water, which provide habitat for many regionally rare or uncommon species. The location of the monument at the northern edge of the Sonoran Desert and at the southern edge of the Mogollon Rim also plays an important role in determining the distribution and community composition of the plant and vertebrate communities. Based on our findings, we believe the high number of non-native species, especially fish and plants, should be of particular management concern. We detail other management challenges, most notably the rapid increase in housing and associated commercial development near the monument, which will continue to impact the plant and vertebrate communities. Based on our data and a review of past studies, we believe the

  16. Development and evolution of the vertebrate primary mouth.

    PubMed

    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

  17. Evidence for Natural Selection in Nucleotide Content Relationships Based on Complete Mitochondrial Genomes: Strong Effect of Guanine Content on Separation between Terrestrial and Aquatic Vertebrates

    PubMed Central

    Sorimachi, Kenji; Okayasu, Teiji

    2015-01-01

    The complete vertebrate mitochondrial genome consists of 13 coding genes. We used this genome to investigate the existence of natural selection in vertebrate evolution. From the complete mitochondrial genomes, we predicted nucleotide contents and then separated these values into coding and non-coding regions. When nucleotide contents of a coding or non-coding region were plotted against the nucleotide content of the complete mitochondrial genomes, we obtained linear regression lines only between homonucleotides and their analogs. On every plot using G or A content purine, G content in aquatic vertebrates was higher than that in terrestrial vertebrates, while A content in aquatic vertebrates was lower than that in terrestrial vertebrates. Based on these relationships, vertebrates were separated into two groups, terrestrial and aquatic. However, using C or T content pyrimidine, clear separation between these two groups was not obtained. The hagfish (Eptatretus burgeri) was further separated from both terrestrial and aquatic vertebrates. Based on these results, nucleotide content relationships predicted from the complete vertebrate mitochondrial genomes reveal the existence of natural selection based on evolutionary separation between terrestrial and aquatic vertebrate groups. In addition, we propose that separation of the two groups might be linked to ammonia detoxification based on high G and low A contents, which encode Glu rich and Lys poor proteins. PMID:25853054

  18. Dysplasia of the caudal vertebral articular facets in four dogs: results of radiographic, myelographic and magnetic resonance imaging investigations.

    PubMed

    Penderis, J; Schwarz, T; McConnell, J F; Garosi, L S; Thomson, C E; Dennis, R

    2005-05-01

    Congenital anomalies of the vertebral column associated with aberrations of one of the primary vertebral ossification centres have been frequently described in the veterinary literature, but clinically significant abnormalities of secondary vertebral ossification centres, particularly involving the caudal articular processes, are much less frequently reported. This paper describes three dogs with aplasia and one dog with hypoplasia of the caudal vertebral articular processes. Thoracolumbar spinal cord compression and ataxia was evident in the three dogs with aplasia but no clinical signs were evident in the dog with hypoplasia. The radiographic appearance was similar in all four cases, with aplasia or hypoplasia of the caudal articular facets at one or more intervertebral joints in the thoracolumbar region. Bone proliferation was evident secondary to an associated degenerative joint disease. Compensatory hyperplasia of the adjacent cranial articular facets and ligamentum flavum protruded into the vertebral canal, resulting in a compressive myelopathy observed by myelography and magnetic resonance imaging. PMID:15879540

  19. Spatially Explicit Trends in the Global Conservation Status of Vertebrates

    PubMed Central

    Rodrigues, Ana S. L.; Brooks, Thomas M.; Butchart, Stuart H. M.; Chanson, Janice; Cox, Neil; Hoffmann, Michael; Stuart, Simon N.

    2014-01-01

    The world's governments have committed to preventing the extinction of threatened species and improving their conservation status by 2020. However, biodiversity is not evenly distributed across space, and neither are the drivers of its decline, and so different regions face very different challenges. Here, we quantify the contribution of regions and countries towards recent global trends in vertebrate conservation status (as measured by the Red List Index), to guide action towards the 2020 target. We found that>50% of the global deterioration in the conservation status of birds, mammals and amphibians is concentrated in <1% of the surface area, 39/1098 ecoregions (4%) and eight/195 countries (4%) – Australia, China, Colombia, Ecuador, Indonesia, Malaysia, Mexico, and the United States. These countries hold a third of global diversity in these vertebrate groups, partially explaining why they concentrate most of the losses. Yet, other megadiverse countries – most notably Brazil (responsible for 10% of species but just 1% of deterioration), plus India and Madagascar – performed better in conserving their share of global vertebrate diversity. Very few countries, mostly island nations (e.g. Cook Islands, Fiji, Mauritius, Seychelles, and Tonga), have achieved net improvements. Per capita wealth does not explain these patterns, with two of the richest countries – United States and Australia – fairing conspicuously poorly. Different countries were affected by different combinations of threats. Reducing global rates of biodiversity loss will require investment in the regions and countries with the highest responsibility for the world's biodiversity, focusing on conserving those species and areas most in peril and on reducing the drivers with the highest impacts. PMID:25426636

  20. Spatially explicit trends in the global conservation status of vertebrates.

    PubMed

    Rodrigues, Ana S L; Brooks, Thomas M; Butchart, Stuart H M; Chanson, Janice; Cox, Neil; Hoffmann, Michael; Stuart, Simon N

    2014-01-01

    The world's governments have committed to preventing the extinction of threatened species and improving their conservation status by 2020. However, biodiversity is not evenly distributed across space, and neither are the drivers of its decline, and so different regions face very different challenges. Here, we quantify the contribution of regions and countries towards recent global trends in vertebrate conservation status (as measured by the Red List Index), to guide action towards the 2020 target. We found that>50% of the global deterioration in the conservation status of birds, mammals and amphibians is concentrated in <1% of the surface area, 39/1098 ecoregions (4%) and eight/195 countries (4%) - Australia, China, Colombia, Ecuador, Indonesia, Malaysia, Mexico, and the United States. These countries hold a third of global diversity in these vertebrate groups, partially explaining why they concentrate most of the losses. Yet, other megadiverse countries - most notably Brazil (responsible for 10% of species but just 1% of deterioration), plus India and Madagascar - performed better in conserving their share of global vertebrate diversity. Very few countries, mostly island nations (e.g. Cook Islands, Fiji, Mauritius, Seychelles, and Tonga), have achieved net improvements. Per capita wealth does not explain these patterns, with two of the richest countries - United States and Australia - fairing conspicuously poorly. Different countries were affected by different combinations of threats. Reducing global rates of biodiversity loss will require investment in the regions and countries with the highest responsibility for the world's biodiversity, focusing on conserving those species and areas most in peril and on reducing the drivers with the highest impacts. PMID:25426636

  1. Comparative studies of vertebrate lipoprotein lipase: a key enzyme of very low density lipoprotein metabolism.

    PubMed

    Holmes, Roger S; Vandeberg, John L; Cox, Laura A

    2011-06-01

    Lipoprotein lipase (LIPL or LPL; E.C.3.1.1.34) serves a dual function as a triglyceride lipase of circulating chylomicrons and very-low-density lipoproteins (VLDL) and facilitates receptor-mediated lipoprotein uptake into heart, muscle and adipose tissue. Comparative LPL amino acid sequences and protein structures and LPL gene locations were examined using data from several vertebrate genome projects. Mammalian LPL genes usually contained 9 coding exons on the positive strand. Vertebrate LPL sequences shared 58-99% identity as compared with 33-49% sequence identities with other vascular triglyceride lipases, hepatic lipase (HL) and endothelial lipase (EL). Two human LPL N-glycosylation sites were conserved among seven predicted sites for the vertebrate LPL sequences examined. Sequence alignments, key amino acid residues and conserved predicted secondary and tertiary structures were also studied. A CpG island was identified within the 5'-untranslated region of the human LPL gene which may contribute to the higher than average (×4.5 times) level of expression reported. Phylogenetic analyses examined the relationships and potential evolutionary origins of vertebrate lipase genes, LPL, LIPG (encoding EL) and LIPC (encoding HL) which suggested that these have been derived from gene duplication events of an ancestral neutral lipase gene, prior to the appearance of fish during vertebrate evolution. Comparative divergence rates for these vertebrate sequences indicated that LPL is evolving more slowly (2-3 times) than for LIPC and LIPG genes and proteins. PMID:21561822

  2. Conserved or lost: molecular evolution of the key gene GULO in vertebrate vitamin C biosynthesis.

    PubMed

    Yang, Hongwen

    2013-06-01

    L-gulono-gamma-lactone oxidase (GULO) catalyzes the final step in vertebrate vitamin C biosynthesis. Vitamin C-incapable vertebrates lack the GULO gene. Gene structure and phylogenetic analyses showed that vertebrate GULO genes are 64-95% identical at the amino acid level and consist of 11 conserved exons. GULO pseudogenes have multiple indel mutations and premature stop codons in higher primates, guinea pigs, and some bats. No GULO-like sequences were identified in teleost fishes. During animal GULO evolution, exon F was subdivided into F1 and F2. Additional GULO retropseudogenes were identified in dogs, cats, and giant pandas. GULO-flanking genome regions acquired frequent segment translocations and inversions during vertebrate evolution. Purifying selection was detected across vertebrate GULO genes (d(N)/d(S) = 0.069), except for some positively selected sites identified in sharks and frogs. These positive sites demonstrated little functional significance when mapped onto the three-dimensional GULO protein structure. Vertebrate GULO genes are conserved except for those that are lost. PMID:23404229

  3. Epigenetic conservation at gene regulatory elements revealed by non-methylated DNA profiling in seven vertebrates.

    PubMed

    Long, Hannah K; Sims, David; Heger, Andreas; Blackledge, Neil P; Kutter, Claudia; Wright, Megan L; Grützner, Frank; Odom, Duncan T; Patient, Roger; Ponting, Chris P; Klose, Robert J

    2013-01-01

    Two-thirds of gene promoters in mammals are associated with regions of non-methylated DNA, called CpG islands (CGIs), which counteract the repressive effects of DNA methylation on chromatin. In cold-blooded vertebrates, computational CGI predictions often reside away from gene promoters, suggesting a major divergence in gene promoter architecture across vertebrates. By experimentally identifying non-methylated DNA in the genomes of seven diverse vertebrates, we instead reveal that non-methylated islands (NMIs) of DNA are a central feature of vertebrate gene promoters. Furthermore, NMIs are present at orthologous genes across vast evolutionary distances, revealing a surprising level of conservation in this epigenetic feature. By profiling NMIs in different tissues and developmental stages we uncover a unifying set of features that are central to the function of NMIs in vertebrates. Together these findings demonstrate an ancient logic for NMI usage at gene promoters and reveal an unprecedented level of epigenetic conservation across vertebrate evolution. DOI:http://dx.doi.org/10.7554/eLife.00348.001. PMID:23467541

  4. Branch management: mechanisms of axon branching in the developing vertebrate CNS

    PubMed Central

    Kalil, Katherine; Dent, Erik W.

    2014-01-01

    The remarkable ability of a single axon to extend multiple branches and form terminal arbors allows vertebrate neurons to integrate information from divergent regions of the nervous system. Axons select appropriate pathways during development, but it is the branches that extend interstitially from the axon shaft and arborize at specific targets that are responsible for virtually all of the synaptic connectivity in the vertebrate CNS. How do axons form branches at specific target regions? Recent studies have identified molecular cues that activate intracellular signalling pathways in axons and mediate dynamic reorganization of the cytoskeleton to promote the formation of axon branches. PMID:24356070

  5. Developmental mechanisms of vertebrate limb evolution.

    PubMed

    Cohn, M J

    2001-01-01

    Over the past few years, our understanding of the evolution of limbs has been improved by important new discoveries in the fossil record. Additionally, rapid progress has been made in identifying the molecular basis of vertebrate limb development. It is now possible to integrate these two areas of research in order to identify the molecular developmental mechanisms underlying the evolution of paired appendages in vertebrates. After the origin of paired appendages, several vertebrate lineages reduced or eliminated fins and limbs and returned to the limbless condition. Examples include eels, caecilians, snakes, slow worms and several marine mammals. Analyses of fossil and extant vertebrates show that evolution of limblessness frequently occurred together with elongation of the trunk and loss of clear morphological boundaries in the vertebral column. This may be suggestive of a common developmental mechanism linking these two processes. We have addressed this question by analysing python embryonic development at tissue, cellular and molecular levels, and we have identified a developmental mechanism which may account for evolution of limb loss in these animals. PMID:11277086

  6. Enhancer turnover and conserved regulatory function in vertebrate evolution

    PubMed Central

    Domené, Sabina; Bumaschny, Viviana F.; de Souza, Flávio S. J.; Franchini, Lucía F.; Nasif, Sofía; Low, Malcolm J.; Rubinstein, Marcelo

    2013-01-01

    Mutations in regulatory regions including enhancers are an important source of variation and innovation during evolution. Enhancers can evolve by changes in the sequence, arrangement and repertoire of transcription factor binding sites, but whole enhancers can also be lost or gained in certain lineages in a process of turnover. The proopiomelanocortin gene (Pomc), which encodes a prohormone, is expressed in the pituitary and hypothalamus of all jawed vertebrates. We have previously described that hypothalamic Pomc expression in mammals is controlled by two enhancers—nPE1 and nPE2—that are derived from transposable elements and that presumably replaced the ancestral neuronal Pomc regulatory regions. Here, we show that nPE1 and nPE2, even though they are mammalian novelties with no homologous counterpart in other vertebrates, nevertheless can drive gene expression specifically to POMC neurons in the hypothalamus of larval and adult transgenic zebrafish. This indicates that when neuronal Pomc enhancers originated de novo during early mammalian evolution, the newly created cis- and trans-codes were similar to the ancestral ones. We also identify the neuronal regulatory region of zebrafish pomca and confirm that it is not homologous to the mammalian enhancers. Our work sheds light on the process of gene regulatory evolution by showing how a locus can undergo enhancer turnover and nevertheless maintain the ancestral transcriptional output. PMID:24218639

  7. 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

  8. The origin of the vertebrate skeleton

    NASA Astrophysics Data System (ADS)

    Pivar, Stuart

    2011-01-01

    The anatomy of the human and other vertebrates has been well described since the days of Leonardo da Vinci and Vesalius. The causative origin of the configuration of the bones and of their shapes and forms has been addressed over the ensuing centuries by such outstanding investigators as Goethe, Von Baer, Gegenbauer, Wilhelm His and D'Arcy Thompson, who sought to apply mechanical principles to morphogenesis. However, no coherent causative model of morphogenesis has ever been presented. This paper presents a causative model for the origin of the vertebrate skeleton, based on the premise that the body is a mosaic enlargement of self-organized patterns engrained in the membrane of the egg cell. Drawings illustrate the proposed hypothetical origin of membrane patterning and the changes in the hydrostatic equilibrium of the cytoplasm that cause topographical deformations resulting in the vertebrate body form.

  9. Chitin is endogenously produced in vertebrates

    PubMed Central

    Sohn, Joel J.; Amemiya, Chris T.

    2015-01-01

    Chitin, a biopolymer of N-acetylglucosamine, is abundant in invertebrates and fungi, and is an important structural molecule. There has been a longstanding belief that vertebrates do not produce chitin, however, we have obtained compelling evidence to the contrary. Chitin synthase genes are present in numerous fishes and amphibians, and chitin is localized in situ to the lumen of the developing zebrafish gut, in epithelial cells of fish scales, and in at least three different cell types in larval salamander appendages. Chitin synthase gene knockdowns and various histochemical experiments in zebrafish further authenticated our results. Finally, a polysaccharide was extracted from scales of salmon that exhibited all the chemical hallmarks of chitin. Our data and analyses demonstrate the existence of endogenous chitin in vertebrates and suggest that it serves multiple roles in vertebrate biology. PMID:25772447

  10. Three Distinct Glutamate Decarboxylase Genes in Vertebrates

    PubMed Central

    Grone, Brian P.; Maruska, Karen P.

    2016-01-01

    Gamma-aminobutyric acid (GABA) is a widely conserved signaling molecule that in animals has been adapted as a neurotransmitter. GABA is synthesized from the amino acid glutamate by the action of glutamate decarboxylases (GADs). Two vertebrate genes, GAD1 and GAD2, encode distinct GAD proteins: GAD67 and GAD65, respectively. We have identified a third vertebrate GAD gene, GAD3. This gene is conserved in fishes as well as tetrapods. We analyzed protein sequence, gene structure, synteny, and phylogenetics to identify GAD3 as a homolog of GAD1 and GAD2. Interestingly, we found that GAD3 was lost in the hominid lineage. Because of the importance of GABA as a neurotransmitter, GAD3 may play important roles in vertebrate nervous systems. PMID:27461130

  11. [Amphioxus: how to become a vertebrate].

    PubMed

    Bertrand, Stéphanie; Camasses, Alain; Escriva, Hector

    2007-01-01

    Evo-devo is a young disciplin, which aims to explain the morphological evolution of organisms through developmental mechanisms and genes networks. A major question within this discipline is the origin of vertebrates. It seems now admitted that vertebrates derive from an invertebrate chordate ancestor. Several models among living chordate representatives are used today to answer this question. The small world of evo-evo interested in the emergence of vertebrates is ebullient about the advent of several totally sequenced genomes allowing comparative analyses to become evermore reliable. Furthermore "non classical" models are developed which can be submitted to refined developmental analysis. One of these is amphioxus (genus Branchyostoma), "a peaceful anchory fillet to illuminate chordate evolution" (Garcia-Fernandez, 2006a, b). The features of this model are described in this review. PMID:17762824

  12. The evolution of early vertebrate photoreceptors

    PubMed Central

    Collin, Shaun P.; Davies, Wayne L.; Hart, Nathan S.; Hunt, David M.

    2009-01-01

    Meeting the challenge of sampling an ancient aquatic landscape by the early vertebrates was crucial to their survival and would establish a retinal bauplan to be used by all subsequent vertebrate descendents. Image-forming eyes were under tremendous selection pressure and the ability to identify suitable prey and detect potential predators was thought to be one of the major drivers of speciation in the Early Cambrian. Based on the fossil record, we know that hagfishes, lampreys, holocephalans, elasmobranchs and lungfishes occupy critical stages in vertebrate evolution, having remained relatively unchanged over hundreds of millions of years. Now using extant representatives of these ‘living fossils’, we are able to piece together the evolution of vertebrate photoreception. While photoreception in hagfishes appears to be based on light detection and controlling circadian rhythms, rather than image formation, the photoreceptors of lampreys fall into five distinct classes and represent a critical stage in the dichotomy of rods and cones. At least four types of retinal cones sample the visual environment in lampreys mediating photopic (and potentially colour) vision, a sampling strategy retained by lungfishes, some modern teleosts, reptiles and birds. Trichromacy is retained in cartilaginous fishes (at least in batoids and holocephalans), where it is predicted that true scotopic (dim light) vision evolved in the common ancestor of all living gnathostomes. The capacity to discriminate colour and balance the tradeoff between resolution and sensitivity in the early vertebrates was an important driver of eye evolution, where many of the ocular features evolved were retained as vertebrates progressed on to land. PMID:19720654

  13. Effort required to finish shotgun-generated genome sequences differs significantly among vertebrates

    PubMed Central

    2010-01-01

    Background The approaches for shotgun-based sequencing of vertebrate genomes are now well-established, and have resulted in the generation of numerous draft whole-genome sequence assemblies. In contrast, the process of refining those assemblies to improve contiguity and increase accuracy (known as 'sequence finishing') remains tedious, labor-intensive, and expensive. As a result, the vast majority of vertebrate genome sequences generated to date remain at a draft stage. Results To date, our genome sequencing efforts have focused on comparative studies of targeted genomic regions, requiring sequence finishing of large blocks of orthologous sequence (average size 0.5-2 Mb) from various subsets of 75 vertebrates. This experience has provided a unique opportunity to compare the relative effort required to finish shotgun-generated genome sequence assemblies from different species, which we report here. Importantly, we found that the sequence assemblies generated for the same orthologous regions from various vertebrates show substantial variation with respect to misassemblies and, in particular, the frequency and characteristics of sequence gaps. As a consequence, the work required to finish different species' sequences varied greatly. Application of the same standardized methods for finishing provided a novel opportunity to "assay" characteristics of genome sequences among many vertebrate species. It is important to note that many of the problems we have encountered during sequence finishing reflect unique architectural features of a particular vertebrate's genome, which in some cases may have important functional and/or evolutionary implications. Finally, based on our analyses, we have been able to improve our procedures to overcome some of these problems and to increase the overall efficiency of the sequence-finishing process, although significant challenges still remain. Conclusion Our findings have important implications for the eventual finishing of the draft whole

  14. Pediatric congenital vertebral artery arteriovenous malformation.

    PubMed

    Shownkeen, Harish; Bova, Davide; Chenelle, Andrew G; Origitano, Thomas C

    2003-05-01

    Vertebral arteriovenous fistulas are rare in children and the congenital form has been seldom reported in the literature. Prior to using endovascular therapy techniques, only surgery was the main treatment. The most common endovascular treatment is through the use of detachable balloons. This report describes the clinical and radiological findings of a congenital vertebral artery fistula in a 20-month-old child. Balloons could not be safely employed; therefore, embolization was performed with Guglielmi detachable microcoils. We review the history and treatment of these lesions, their clinical presentation, and imaging features, including their outcome, with particular attention to the pediatric population. PMID:12695869

  15. Percutaneous vertebral augmentation for painful osteolytic vertebral metastasis: a case report

    PubMed Central

    Anselmetti, Giovanni C; Tutton, Sean M; Facchini, Francis R; Miller, Larry E; Block, Jon E

    2012-01-01

    Introduction Vertebral metastases are associated with significant pain, disability, and morbidity. Open surgery for fracture stabilization is often inappropriate in this population due to a poor risk-benefit profile, particularly if life expectancy is short. Percutaneous vertebroplasty and kyphoplasty are appealing adjunctive procedures in patients with malignancy for alleviation of intractable pain. However, these patients have higher risk of serious complications, notably cement extravasation. Described in this report is a case of a painful osteolytic vertebral metastasis that was successfully treated by a novel percutaneous vertebral augmentation system. Case presentation A 42-year-old Caucasian female presented with a history of metastatic lung cancer unresponsive to radiation and chemotherapy with symptoms inadequately controlled by opiates over the previous 6 months. Magnetic resonance imaging and spiral computed tomography with two-dimensional reconstruction showed an osteolytic vertebral metastasis with complete involvement of the T10 vertebral body, extending to the cortical vertebral wall anteriorly and posteriorly. The patient was treated with percutaneous vertebral augmentation (Kiva® VCF Treatment System, Benvenue Medical, Inc, Santa Clara, CA) utilizing a novel coil-shaped polyetheretherketone implant designed to minimize the risk of cement extravasation. After the minimally invasive procedure, bone cement distribution within the vertebral body was ideal, with no observed cement extravasation. No complications were reported, pain completely resolved within 24 hours, and use of intravenous narcotics was progressively diminished within 1 week. Complete pain relief was maintained throughout 4 months of follow-up. Conclusion The Kiva System represents a novel and effective minimally invasive treatment option for patients suffering from severe pain due to osteolytic vertebral metastasis. PMID:23754917

  16. Vertebral Osteomyelitis Caused by Helicobacter cinaedi

    PubMed Central

    Yoshizaki, Aisa; Takegawa, Hiroshi; Doi, Asako; Mizuno, Yasushi

    2015-01-01

    Helicobacter cinaedi causes bacteremia, cellulitis, and gastroenteritis. We report the first case of vertebral osteomyelitis caused by H. cinaedi in an elderly man with low back pain and fever. The pathogen was detected in blood and lumbar disc, and the infection was successfully treated with oral doxycycline for 11 weeks. PMID:26109448

  17. A Cambrian origin for vertebrate rods

    PubMed Central

    Asteriti, Sabrina; Grillner, Sten; Cangiano, Lorenzo

    2015-01-01

    Vertebrates acquired dim-light vision when an ancestral cone evolved into the rod photoreceptor at an unknown stage preceding the last common ancestor of extant jawed vertebrates (∼420 million years ago Ma). The jawless lampreys provide a unique opportunity to constrain the timing of this advance, as their line diverged ∼505 Ma and later displayed high-morphological stability. We recorded with patch electrodes the inner segment photovoltages and with suction electrodes the outer segment photocurrents of Lampetra fluviatilis retinal photoreceptors. Several key functional features of jawed vertebrate rods are present in their phylogenetically homologous photoreceptors in lamprey: crucially, the efficient amplification of the effect of single photons, measured by multiple parameters, and the flow of rod signals into cones. These results make convergent evolution in the jawless and jawed vertebrate lines unlikely and indicate an early origin of rods, implying strong selective pressure toward dim-light vision in Cambrian ecosystems. DOI: http://dx.doi.org/10.7554/eLife.07166.001 PMID:26095697

  18. 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. PMID:27386723

  19. Transposon-mediated Genome Manipulations in Vertebrates

    PubMed Central

    Ivics, Zoltán; Li, Meng Amy; Mátés, Lajos; Boeke, Jef D.; Bradley, Allan; Izsvák, Zsuzsanna

    2010-01-01

    Transposable elements are segments of DNA with the unique ability to move about in the genome. This inherent feature can be exploited to harness these elements as gene vectors for diverse genome manipulations. Transposon-based genetic strategies have been established in vertebrate species over the last decade, and current progress in this field indicates that transposable elements will serve as indispensable tools in the genetic toolkit of vertebrate models. In particular, transposons can be applied as vectors for somatic and germline transgenesis, and as insertional mutagens in both loss-of-function and gain-of-function forward mutagenesis screens. The major advantage of using transposons as genetic tools is that they facilitate analysis of gene function in an easy, controlled and scalable manner. Transposon-based technologies are beginning to be exploited to link sequence information to gene functions in vertebrate models. In this article, we provide an overview of transposon-based methods used in vertebrate model organisms, and highlight the most important considerations concerning genetic applications of the transposon systems. PMID:19478801

  20. Pleistocene vertebrates of the Yukon Territory

    NASA Astrophysics Data System (ADS)

    Harington, C. R.

    2011-08-01

    Unglaciated parts of the Yukon constitute one of the most important areas in North America for yielding Pleistocene vertebrate fossils. Nearly 30 vertebrate faunal localities are reviewed spanning a period of about 1.6 Ma (million years ago) to the close of the Pleistocene some 10 000 BP (radiocarbon years before present, taken as 1950). The vertebrate fossils represent at least 8 species of fishes, 1 amphibian, 41 species of birds and 83 species of mammals. Dominant among the large mammals are: steppe bison ( Bison priscus), horse ( Equus sp.), woolly mammoth ( Mammuthus primigenius), and caribou ( Rangifer tarandus) - signature species of the Mammoth Steppe fauna ( Fig. 1), which was widespread from the British Isles, through northern Europe, and Siberia to Alaska, Yukon and adjacent Northwest Territories. The Yukon faunas extend from Herschel Island in the north to Revenue Creek in the south and from the Alaskan border in the west to Ketza River in the east. The Yukon holds evidence of the earliest-known people in North America. Artifacts made from bison, mammoth and caribou bones from Bluefish Caves, Old Crow Basin and Dawson City areas show that people had a substantial knowledge of making and using bone tools at least by 25 000 BP, and possibly as early as 40 000 BP. A suggested chronological sequence of Yukon Pleistocene vertebrates ( Table 1) facilitates comparison of selected faunas and indicates the known duration of various taxa.

  1. Vertebral osteomyelitis combined streptococcal viridans endocarditis.

    PubMed

    Lee, Kuo-Chen; Tsai, Yi-Ting; Lin, Chih-Yuan; Tsai, Chien-Sung

    2003-01-01

    Endocarditis may be difficult to diagnose in patients with osteomyelitis in an early stage because they usually are treated for fever, bone pain and stiffness in the outpatient department. Herein we report an uncommon patient who developed severe lower back pain sustained for 2 months, and streptococcal viridans infected vertebral osteomyelitis combined endocarditis were diagnosed and cured. PMID:12493523

  2. Did Language Evolve Like the Vertebrate Eye?

    ERIC Educational Resources Information Center

    Botha, Rudolf P.

    2002-01-01

    Offers a critical appraisal of the way in which the idea that human language or some of its features evolved like the vertebrate eye by natural selection is articulated in Pinker and Bloom's (1990) selectionist account of language evolution. Argues that this account is less than insightful because it fails to draw some of the conceptual…

  3. A differential staining technique for vertebrate histology.

    PubMed

    Bhattacharyya, T K

    1979-03-01

    A staining method is described for studying micro-anatomy of different vertebrate tissues in the light microscope. A staining sequence of celestin blue--erythrosin--orange G--fast green with mordanting in phosphomolybdic acid yields a satisfactory differentiation and fine colour contrast in various tissues. The efficacy of the method was tested on different avian and mammalian tissues. PMID:86938

  4. Vertebrate Pest Control. Sale Publication 4077.

    ERIC Educational Resources Information Center

    Stimmann, M. W.; Clark, Dell O.

    This guide gives descriptions of common vertebrate pests and guidelines for using some common pesticides. The pests discussed are rats, mice, bats, moles, muskrats, ground squirrels, and gophers. Information is given for each pest on the type of damage the pest can do, the habitat and biology of the pest, and the most effective control methods.…

  5. Control of Vertebrate Pests of Agricultural Crops.

    ERIC Educational Resources Information Center

    Wingard, Robert G.; Studholme, Clinton R.

    This agriculture extension service publication of Pennsylvania State University discusses the damage from and control of vertebrate pests. Specific discussions describe the habits, habitat, and various control measures for blackbirds and crows, deer, meadow and pine mice, European starlings, and woodchucks. Where confusion with non-harmful species…

  6. Search for conserved amino acid residues of the [Formula: see text]-crystallin proteins of vertebrates.

    PubMed

    Shiliaev, Nikita G; Selivanova, Olga M; Galzitskaya, Oxana V

    2016-04-01

    [Formula: see text]-crystallin is the major eye lens protein and a member of the small heat-shock protein (sHsp) family. [Formula: see text]-crystallins have been shown to support lens clarity by preventing the aggregation of lens proteins. We performed the bioinformatics analysis of [Formula: see text]-crystallin sequences from vertebrates to find conserved amino acid residues as the three-dimensional (3D) structure of [Formula: see text]-crystallin is not identified yet. We are the first who demonstrated that the N-terminal region is conservative along with the central domain for vertebrate organisms. We have found that there is correlation between the conserved and structured regions. Moreover, amyloidogenic regions also correspond to the structured regions. We analyzed the amino acid composition of [Formula: see text]-crystallin A and B chains. Analyzing the occurrence of each individual amino acid residue, we have found that such amino acid residues as leucine, serine, lysine, proline, phenylalanine, histidine, isoleucine, glutamic acid, and valine change their content simultaneously in A and B chains in different classes of vertebrates. Aromatic amino acids occur more often in [Formula: see text]-crystallins from vertebrates than on the average in proteins among 17 animal proteomes. We obtained that the identity between A and B chains in the mammalian group is 0.35, which is lower than the published 0.60. PMID:26972563

  7. Diversity and Community Composition of Vertebrates in Desert River Habitats.

    PubMed

    Free, C L; Baxter, G S; Dickman, C R; Lisle, A; Leung, L K-P

    2015-01-01

    Animal species are seldom distributed evenly at either local or larger spatial scales, and instead tend to aggregate in sites that meet their resource requirements and maximise fitness. This tendency is likely to be especially marked in arid regions where species could be expected to concentrate at resource-rich oases. In this study, we first test the hypothesis that productive riparian sites in arid Australia support higher vertebrate diversity than other desert habitats, and then elucidate the habitats selected by different species. We addressed the first aim by examining the diversity and composition of vertebrate assemblages inhabiting the Field River and adjacent sand dunes in the Simpson Desert, western Queensland, over a period of two and a half years. The second aim was addressed by examining species composition in riparian and sand dune habitats in dry and wet years. Vertebrate species richness was estimated to be highest (54 species) in the riverine habitats and lowest on the surrounding dune habitats (45 species). The riverine habitats had different species pools compared to the dune habitats. Several species, including the agamid Gowidon longirostris and tree frog Litoria rubella, inhabited the riverine habitats exclusively, while others such as the skinks Ctenotus ariadnae and C. dux were captured only in the dune habitats. The results suggest that, on a local scale, diversity is higher along riparian corridors and that riparian woodland is important for tree-dependent species. Further, the distribution of some species, such as Mus musculus, may be governed by environmental variables (e.g. soil moisture) associated with riparian corridors that are not available in the surrounding desert environment. We conclude that inland river systems may be often of high conservation value, and that management should be initiated where possible to alleviate threats to their continued functioning. PMID:26637127

  8. Diversity and Community Composition of Vertebrates in Desert River Habitats

    PubMed Central

    Free, C. L.; Baxter, G. S.; Dickman, C. R.; Lisle, A.; Leung, L. K.-P.

    2015-01-01

    Animal species are seldom distributed evenly at either local or larger spatial scales, and instead tend to aggregate in sites that meet their resource requirements and maximise fitness. This tendency is likely to be especially marked in arid regions where species could be expected to concentrate at resource-rich oases. In this study, we first test the hypothesis that productive riparian sites in arid Australia support higher vertebrate diversity than other desert habitats, and then elucidate the habitats selected by different species. We addressed the first aim by examining the diversity and composition of vertebrate assemblages inhabiting the Field River and adjacent sand dunes in the Simpson Desert, western Queensland, over a period of two and a half years. The second aim was addressed by examining species composition in riparian and sand dune habitats in dry and wet years. Vertebrate species richness was estimated to be highest (54 species) in the riverine habitats and lowest on the surrounding dune habitats (45 species). The riverine habitats had different species pools compared to the dune habitats. Several species, including the agamid Gowidon longirostris and tree frog Litoria rubella, inhabited the riverine habitats exclusively, while others such as the skinks Ctenotus ariadnae and C. dux were captured only in the dune habitats. The results suggest that, on a local scale, diversity is higher along riparian corridors and that riparian woodland is important for tree-dependent species. Further, the distribution of some species, such as Mus musculus, may be governed by environmental variables (e.g. soil moisture) associated with riparian corridors that are not available in the surrounding desert environment. We conclude that inland river systems may be often of high conservation value, and that management should be initiated where possible to alleviate threats to their continued functioning. PMID:26637127

  9. Whole Genome Duplications Shaped the Receptor Tyrosine Kinase Repertoire of Jawed Vertebrates

    PubMed Central

    Brunet, Frédéric G.; Volff, Jean-Nicolas; Schartl, Manfred

    2016-01-01

    The receptor tyrosine kinase (RTK) gene family, involved primarily in cell growth and differentiation, comprises proteins with a common enzymatic tyrosine kinase intracellular domain adjacent to a transmembrane region. The amino-terminal portion of RTKs is extracellular and made of different domains, the combination of which characterizes each of the 20 RTK subfamilies among mammals. We analyzed a total of 7,376 RTK sequences among 143 vertebrate species to provide here the first comprehensive census of the jawed vertebrate repertoire. We ascertained the 58 genes previously described in the human and mouse genomes and established their phylogenetic relationships. We also identified five additional RTKs amounting to a total of 63 genes in jawed vertebrates. We found that the vertebrate RTK gene family has been shaped by the two successive rounds of whole genome duplications (WGD) called 1R and 2R (1R/2R) that occurred at the base of the vertebrates. In addition, the Vegfr and Ephrin receptor subfamilies were expanded by single gene duplications. In teleost fish, 23 additional RTK genes have been retained after another expansion through the fish-specific third round (3R) of WGD. Several lineage-specific gene losses were observed. For instance, birds have lost three RTKs, and different genes are missing in several fish sublineages. The RTK gene family presents an unusual high gene retention rate from the vertebrate WGDs (58.75% after 1R/2R, 64.4% after 3R), resulting in an expansion that might be correlated with the evolution of complexity of vertebrate cellular communication and intracellular signaling. PMID:27260203

  10. Whole Genome Duplications Shaped the Receptor Tyrosine Kinase Repertoire of Jawed Vertebrates.

    PubMed

    Brunet, Frédéric G; Volff, Jean-Nicolas; Schartl, Manfred

    2016-01-01

    The receptor tyrosine kinase (RTK) gene family, involved primarily in cell growth and differentiation, comprises proteins with a common enzymatic tyrosine kinase intracellular domain adjacent to a transmembrane region. The amino-terminal portion of RTKs is extracellular and made of different domains, the combination of which characterizes each of the 20 RTK subfamilies among mammals. We analyzed a total of 7,376 RTK sequences among 143 vertebrate species to provide here the first comprehensive census of the jawed vertebrate repertoire. We ascertained the 58 genes previously described in the human and mouse genomes and established their phylogenetic relationships. We also identified five additional RTKs amounting to a total of 63 genes in jawed vertebrates. We found that the vertebrate RTK gene family has been shaped by the two successive rounds of whole genome duplications (WGD) called 1R and 2R (1R/2R) that occurred at the base of the vertebrates. In addition, the Vegfr and Ephrin receptor subfamilies were expanded by single gene duplications. In teleost fish, 23 additional RTK genes have been retained after another expansion through the fish-specific third round (3R) of WGD. Several lineage-specific gene losses were observed. For instance, birds have lost three RTKs, and different genes are missing in several fish sublineages. The RTK gene family presents an unusual high gene retention rate from the vertebrate WGDs (58.75% after 1R/2R, 64.4% after 3R), resulting in an expansion that might be correlated with the evolution of complexity of vertebrate cellular communication and intracellular signaling. PMID:27260203

  11. Prevalent Vertebral Fractures among Children Initiating Glucocorticoid Therapy for the Treatment of Rheumatic Disorders

    PubMed Central

    Huber, A.M.; Gaboury, I.; Cabral, D.A.; Lang, B.; Ni, A.; Stephure, D.; Taback, S.; Dent, P.; Ellsworth, J.; LeBlanc, C.; Saint-Cyr, C.; Scuccimarri, R.; Hay, J.; Lentle, B.; Matzinger, M.; Shenouda, N.; Moher, D.; Rauch, F.; Siminoski, K.; Ward, L.M.

    2014-01-01

    Objectives Vertebral fractures are an under-recognized problem in children with inflammatory disorders. We studied spine health among 134 children (87 girls) with rheumatic conditions (median age 10 years) within 30 days of initiating glucocorticoid (GC) therapy. Methods Children were categorized as follows: juvenile dermatomyositis (juvenile DM, N=30), juvenile idiopathic arthritis (JIA; N=28), systemic lupus erythematosus (SLE) and related conditions (N=26), systemic arthritis (N=22), systemic vasculitis (N=16), and other conditions (N=12). Thoracolumbar spine radiograph and dual energy x-ray absorptiometry for lumbar spine areal bone mineral density (LS BMD) were performed within 30 days of GC initiation. Genant semi-quantitative grading was used for vertebral morphometry. Second metacarpal morphometry was carried out on a hand radiograph. Clinical factors including disease and physical activity, calcium and vitamin D intake, cumulative GC dose, underlying diagnosis, LS BMD Z-score and back pain were analyzed for association with vertebral fracture. Results Thirteen vertebral fractures were noted in 9 children (7%). Six patients had a single vertebral fracture and three patients had two to three fractures. Fractures were clustered in the mid-thoracic region (69%). Three vertebral fractures (23%) were moderate (Grade 2); the others were mild (Grade 1). For the entire cohort, mean (±SD) LS BMD Z-score was significantly different from zero (−0.55±1.2, p<0.001) despite a mean height Z-score that was similar to the healthy average (0.02±1.0, p=0.825). Back pain was highly associated with increased odds for fracture (OR 10.6, 95% CI 2.1 to 53.8, p=0.004). Conclusions In pediatric rheumatic conditions, vertebral fractures can be present prior to prolonged GC exposure. PMID:20391507

  12. Determination of vertebral pose in 3D by minimization of vertebral asymmetry

    NASA Astrophysics Data System (ADS)

    Vrtovec, Tomaž; Pernuš, Franjo; Likar, Boštjan

    2011-03-01

    The vertebral pose in three dimensions (3D) may provide valuable information for quantitative clinical measurements or aid the initialization of image analysis techniques. We propose a method for automated determination of the vertebral pose in 3D that, in an iterative registration scheme, estimates the position and rotation of the vertebral coordinate system in 3D images. By searching for the hypothetical points, which are located where the boundaries of anatomical structures would have maximal symmetrical correspondences when mirrored over the vertebral planes, the asymmetry of vertebral anatomical structures is minimized. The method was evaluated on 14 normal and 14 scoliotic vertebrae in images acquired by computed tomography (CT). For each vertebra, 1000 randomly initialized experiments were performed. The results show that the vertebral pose can be successfully determined in 3D with mean accuracy of 0.5mm and 0.6° and mean precision of 0.17mm and 0.17. according to the 3D position and 3D rotation, respectively.

  13. Pneumococcal Vertebral Osteomyelitis after Epidural Injection: A Rare Event

    PubMed Central

    Johnson, Tamara M; Chitturi, Chandrika; Lange, Michael; Suh, Jin S; Slim, Jihad

    2016-01-01

    Streptococcus pneumoniae vertebral infections have rarely been reported. Herein, we report a case of pneumococcal vertebral osteomyelitis with paraspinal and epidural abscesses as well as concomitant bacteremia following epidural injection. This will be the second case in the literature reporting pneumococcal vertebral osteomyelitis related to epidural manipulation. PMID:27621563

  14. Intra-arterial Onyx Embolization of Vertebral Body Lesions

    PubMed Central

    Sedora-Roman, Neda I.; Reddy, Arra Suresh; Ogilvy, Christopher S.; Thomas, Ajith J.

    2013-01-01

    While Onyx embolization of cerebrospinal arteriovenous shunts is well-established, clinical researchers continue to broaden applications to other vascular lesions of the neuraxis. This report illustrates the application of Onyx (eV3, Plymouth, MN) embolization to vertebral body lesions, specifically, a vertebral hemangioma and renal cell carcinoma vertebral body metastatic lesion. PMID:24729960

  15. Pneumococcal Vertebral Osteomyelitis after Epidural Injection: A Rare Event.

    PubMed

    Johnson, Tamara M; Chitturi, Chandrika; Lange, Michael; Suh, Jin S; Slim, Jihad

    2016-01-01

    Streptococcus pneumoniae vertebral infections have rarely been reported. Herein, we report a case of pneumococcal vertebral osteomyelitis with paraspinal and epidural abscesses as well as concomitant bacteremia following epidural injection. This will be the second case in the literature reporting pneumococcal vertebral osteomyelitis related to epidural manipulation. PMID:27621563

  16. The variety of vertebrate mechanisms of sex determination.

    PubMed

    Trukhina, Antonina V; Lukina, Natalia A; Wackerow-Kouzova, Natalia D; Smirnov, Alexander F

    2013-01-01

    The review deals with features of sex determination in vertebrates. The mechanisms of sex determination are compared between fishes, amphibians, reptilians, birds, and mammals. We focus on structural and functional differences in the role of sex-determining genes in different vertebrates. Special attention is paid to the role of estrogens in sex determination in nonmammalian vertebrates. PMID:24369014

  17. 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

  18. New Findings Concerning Vertebrate Porin

    NASA Astrophysics Data System (ADS)

    Thinnes, Friedrich P.; Reymann, Susanne

    Eukaryotic porin can be considered to be a good candidate for forming the channel component of the protein complex which, depending on the approach used, may realize its expression either as the outwardly-rectifying depolarization-induced chloride channel or as the volume-sensitive organic osmolyte-anion channel. As a basis for this proposition, we point to a series of correspondences in properties between mammalian porin and the ORDIC channel complex. Specifically, mammalian porin is expressed in the plasmalemma of different cells and chloride channels can be blocked by anti-human porin antibodies in astrocytes and endothelial cells. There is an indication of colocalisation of human porin and the cystic fibrosis (CF) gene product, CFTR, in the apical region of epithelial cells. The primary structure of porin from a CF patient was found to be normal. Cytosol and amniotic fluid fractions influence the channel characteristics of mammalian porin. Channel-active mammalian porin binds ATP and the stilbene disulphonate grouping of the chloride channel inhibitor DIDS. Human porin in black membranes is a pathway for taurine, and biogenic polyamines reduce the voltage dependence of human porin. Assuming the relationship between human porin and the ORDIC channel/VSOAC complex, studies on plasmalemma-integrated human porin have a relevance for CF research. In addition, we refer to a case study on a child with encephalomyopathy in which porin could not be detected using monoclonal anti-human porin antibodies. Our studies were based on purified and sequenced human porin from different cells and from different cell compartments. In addition, we raised antibodies against mature human porin or synthetic parts of the molecule. This provided a firm foundation for our topochemical work with which we were able to establish the multi-topological expression of eukaryotic porin channels. The data are summarized and discussed.

  19. The ancestral role of nodal signalling in breaking L/R symmetry in the vertebrate forebrain.

    PubMed

    Lagadec, Ronan; Laguerre, Laurent; Menuet, Arnaud; Amara, Anis; Rocancourt, Claire; Péricard, Pierre; Godard, Benoît G; Rodicio, Maria Celina; Rodriguez-Moldes, Isabel; Mayeur, Hélène; Rougemont, Quentin; Mazan, Sylvie; Boutet, Agnès

    2015-01-01

    Left-right asymmetries in the epithalamic region of the brain are widespread across vertebrates, but their magnitude and laterality varies among species. Whether these differences reflect independent origins of forebrain asymmetries or taxa-specific diversifications of an ancient vertebrate feature remains unknown. Here we show that the catshark Scyliorhinus canicula and the lampreys Petromyzon marinus and Lampetra planeri exhibit conserved molecular asymmetries between the left and right developing habenulae. Long-term pharmacological treatments in these species show that nodal signalling is essential to their generation, rather than their directionality as in teleosts. Moreover, in contrast to zebrafish, habenular left-right differences are observed in the absence of overt asymmetry of the adjacent pineal field. These data support an ancient origin of epithalamic asymmetry, and suggest that a nodal-dependent asymmetry programme operated in the forebrain of ancestral vertebrates before evolving into a variable trait in bony fish. PMID:25819227

  20. Mid-Wisconsinan vertebrates and their environment from January Cave, Alberta, Canada

    NASA Astrophysics Data System (ADS)

    Burns, James A.

    1991-01-01

    January Cave, in the Rocky Mountains of southwestern Alberta, has yielded vertebrate remains from a coprocenosis of mid-Wisconsinan-age. Taphonomic analysis indicates accumulation by raptors, mostly owls, and mammalian carnivores. The vertebrate record, together with pollen analysis, indicates that cool, dry conditions prevailed in an extensive tundra-like environment, with prairie elements in the valleys below. Thirty-four mammalian taxa have been recovered from January Cave. Today, some of these species (e.g., Lemmus sibiricus and Dicrostonyx torquatus) do not coexist with others (e.g., Cynomys sp., Mustela nigripes, Vulpes velox, and Lagurus curtatus). Therefore, the January Cave local fauna represents a "nonanalog" mammalian community characteristic of the late Pleistocene. It suggests that the region enjoyed an equable climate, with reduced climatic extremes but still cool, further supporting a mid-Wisconsinan age estimate for the fauna. It is the first major, small vertebrate fauna of its age to be reported from Alberta.

  1. 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. PMID:24333517

  2. Cellular automata segmentation of the boundary between the compacta of vertebral bodies and surrounding structures

    NASA Astrophysics Data System (ADS)

    Egger, Jan; Nimsky, Christopher

    2016-03-01

    Due to the aging population, spinal diseases get more and more common nowadays; e.g., lifetime risk of osteoporotic fracture is 40% for white women and 13% for white men in the United States. Thus the numbers of surgical spinal procedures are also increasing with the aging population and precise diagnosis plays a vital role in reducing complication and recurrence of symptoms. Spinal imaging of vertebral column is a tedious process subjected to interpretation errors. In this contribution, we aim to reduce time and error for vertebral interpretation by applying and studying the GrowCut - algorithm for boundary segmentation between vertebral body compacta and surrounding structures. GrowCut is a competitive region growing algorithm using cellular automata. For our study, vertebral T2-weighted Magnetic Resonance Imaging (MRI) scans were first manually outlined by neurosurgeons. Then, the vertebral bodies were segmented in the medical images by a GrowCut-trained physician using the semi-automated GrowCut-algorithm. Afterwards, results of both segmentation processes were compared using the Dice Similarity Coefficient (DSC) and the Hausdorff Distance (HD) which yielded to a DSC of 82.99+/-5.03% and a HD of 18.91+/-7.2 voxel, respectively. In addition, the times have been measured during the manual and the GrowCut segmentations, showing that a GrowCutsegmentation - with an average time of less than six minutes (5.77+/-0.73) - is significantly shorter than a pure manual outlining.

  3. Vertebral Augmentation Involving Vertebroplasty or Kyphoplasty for Cancer-Related Vertebral Compression Fractures: An Economic Analysis

    PubMed Central

    2016-01-01

    Background Untreated vertebral compression fractures can have serious clinical consequences and impose a considerable impact on patients' quality of life and on caregivers. Since non-surgical management of these fractures has limited effectiveness, vertebral augmentation procedures are gaining acceptance in clinical practice for pain control and fracture stabilization. The objective of this analysis was to determine the cost-effectiveness and budgetary impact of kyphoplasty or vertebroplasty compared with non-surgical management for the treatment of vertebral compression fractures in patients with cancer. Methods We performed a systematic review of health economic studies to identify relevant studies that compare the cost-effectiveness of kyphoplasty or vertebroplasty with non-surgical management for the treatment of vertebral compression fractures in adults with cancer. We also performed a primary cost-effectiveness analysis to assess the clinical benefits and costs of kyphoplasty or vertebroplasty compared with non-surgical management in the same population. We developed a Markov model to forecast benefits and harms of treatments, and corresponding quality-adjusted life years and costs. Clinical data and utility data were derived from published sources, while costing data were derived using Ontario administrative sources. We performed sensitivity analyses to examine the robustness of the results. In addition, a 1-year budget impact analysis was performed using data from Ontario administrative sources. Two scenarios were explored: (a) an increase in the total number of vertebral augmentation procedures performed among patients with cancer in Ontario, maintaining the current proportion of kyphoplasty versus vertebroplasty; and (b) no increase in the total number of vertebral augmentation procedures performed among patients with cancer in Ontario but an increase in the proportion of kyphoplasties versus vertebroplasties. Results The base case considered each of

  4. Vertebral Augmentation Involving Vertebroplasty or Kyphoplasty for Cancer-Related Vertebral Compression Fractures: A Systematic Review

    PubMed Central

    2016-01-01

    Background Cancers that metastasize to the spine and primary cancers such as multiple myeloma can result in vertebral compression fractures or instability. Conservative strategies, including bed rest, bracing, and analgesic use, can be ineffective, resulting in continued pain and progressive functional disability limiting mobility and self-care. Surgery is not usually an option for cancer patients in advanced disease states because of their poor medical health or functional status and limited life expectancy. The objectives of this review were to evaluate the effectiveness and safety of percutaneous image-guided vertebral augmentation techniques, vertebroplasty and kyphoplasty, for palliation of cancer-related vertebral compression fractures. Methods We performed a systematic literature search for studies on vertebral augmentation of cancer-related vertebral compression fractures published from January 1, 2000, to October 2014; abstracts were screened by a single reviewer. For those studies meeting the eligibility criteria, full-text articles were obtained. Owing to the heterogeneity of the clinical reports, we performed a narrative synthesis based on an analytical framework constructed for the type of cancer-related vertebral fractures and the diversity of the vertebral augmentation interventions. Results The evidence review identified 3,391 citations, of which 111 clinical reports (4,235 patients) evaluated the effectiveness of vertebroplasty (78 reports, 2,545 patients) or kyphoplasty (33 reports, 1,690 patients) for patients with mixed primary spinal metastatic cancers, multiple myeloma, or hemangiomas. Overall the mean pain intensity scores often reported within 48 hours of vertebral augmentation (kyphoplasty or vertebroplasty), were significantly reduced. Analgesic use, although variably reported, usually involved parallel decreases, particularly in opioids, and mean pain-related disability scores were also significantly improved. In a randomized controlled

  5. Major African contributions to Palaeozoic and Mesozoic vertebrate palaeontology

    NASA Astrophysics Data System (ADS)

    Durand, J. F.

    2005-10-01

    Over more than two centuries, Africa has been an important source of knowledge with regard to the origins, evolution and distribution of important animal taxa. Not only did Africa south of the Sahara contain a second zoogeographical region virtually unknown four centuries ago, but also gave the world the first insight into the palaeontological wealth and the existence of Gondwana. The section on Agnatha includes a discussion on conodonts from South Africa, considered to be the some of the oldest and best-preserved vertebrate fossils in the world. The section on the Gnathostomata includes a very brief overview of the most important fish taxa from the Palaeozoic to Mesozoic of Africa. The section on the Tetrapoda includes an overview of the major taxa found in the fossil record of the Palaeozoic and Mesozoic of Africa. The Permian and Triassic tetrapod fossils that indicate the evolution and radiation of the parareptiles, eureptiles and synapsids are highlighted. The most important vertebrate fossils from Africa that contributed to our understanding of the radiation of evolutionary important groups such as the fish, tetrapods, tortoises, snakes, crocodiles, dinosaurs and mammals are discussed. The Jurassic and Cretaceous assemblages containing dinosaur and mammal remains, deposited after the break up of Gondwana, are discussed. Finally a perspective on the importance of Africa as fossil repository and the limitations of palaeontological endeavour in Africa is given.

  6. Anterior-posterior patterning and segmentation of the vertebrate head

    PubMed Central

    Schilling, Thomas F.

    2008-01-01

    Segmentation of the vertebrate head emerges out of earlier processes that establish the anterior-posterior (A-P) axis. Recent genetic studies and comparisons across species have led to a better understanding of the links between A-P patterning and segmentation. These point to similar signals acting on both head and trunk, such as retinoic acid and fibroblast growth factors. These form interacting networks of diffusible morphogen gradients that pattern both hindbrain rhombomeres and mesodermal somites. New computational models, particularly for retinoic acid, have revealed how morphogen gradients are established and made robust to changes in signaling levels. However, the orientations of these gradients, as well as how they interact to generate segments, differ remarkably between germ layers and body regions. Thus, the vertebrate head is, in part, built through modifications of the same processes that link A-P patterning and segmentation in the trunk, but fundamental differences in how these processes are deployed lend further doubt to the notion that head and trunk segments are homologous. PMID:21669823

  7. Thoracic and Lumbar Vertebral Bone Mineral Density Changes in a Natural Occurring Dog Model of Diffuse Idiopathic Skeletal Hyperostosis

    PubMed Central

    De Decker, Steven; Lam, Richard; Packer, Rowena M. A.; Gielen, Ingrid M. V. L.; Volk, Holger A.

    2015-01-01

    Ankylosing spinal disorders can be associated with alterations in vertebral bone mineral density (BMD). There is however controversy about vertebral BMD in patients wuse idiopathic skeletal hyperostosis (DISH). DISH in Boxer dogs has been considered a natural occurring disease model for DISH in people. The purpose of this study was to compare vertebral BMD between Boxers with and without DISH. Fifty-nine Boxers with (n=30) or without (n=29) DISH that underwent computed tomography were included. Vertebral BMD was calculated for each thoracic and lumbar vertebra by using an earlier reported and validated protocol. For each vertebral body, a region of interest was drawn on the axial computed tomographic images at three separate locations: immediately inferior to the superior end plate, in the middle of the vertebral body, and superior to the inferior end plate. Values from the three axial slices were averaged to give a mean Hounsfield Unit value for each vertebral body. Univariate statistical analysis was performed to identify factors to be included in a multivariate model. The multivariate model including all dogs demonstrated that vertebral DISH status (Coefficient 24.63; 95% CI 16.07 to 33.19; p <0.001), lumbar vertebrae (Coefficient -17.25; 95% CI -23.42 to -11.09; p < 0.01), and to a lesser extent higher age (Coefficient -0.56; 95% CI -1.07 to -0.05; p = 0.03) were significant predictors for vertebral BMD. When the multivariate model was repeated using only dogs with DISH, vertebral DISH status (Coefficient 20.67; 95% CI, 10.98 to 30.37; p < 0.001) and lumbar anatomical region (Coefficient -38.24; 95% CI, -47.75 to -28.73; p < 0.001) were again predictors for vertebral BMD but age was not. The results of this study indicate that DISH can be associated with decreased vertebral BMD. Further studies are necessary to evaluate the clinical importance and pathophysiology of this finding. PMID:25898128

  8. Thoracic and lumbar vertebral bone mineral density changes in a natural occurring dog model of diffuse idiopathic skeletal hyperostosis.

    PubMed

    De Decker, Steven; Lam, Richard; Packer, Rowena M A; Gielen, Ingrid M V L; Volk, Holger A

    2015-01-01

    Ankylosing spinal disorders can be associated with alterations in vertebral bone mineral density (BMD). There is however controversy about vertebral BMD in patients wuse idiopathic skeletal hyperostosis (DISH). DISH in Boxer dogs has been considered a natural occurring disease model for DISH in people. The purpose of this study was to compare vertebral BMD between Boxers with and without DISH. Fifty-nine Boxers with (n=30) or without (n=29) DISH that underwent computed tomography were included. Vertebral BMD was calculated for each thoracic and lumbar vertebra by using an earlier reported and validated protocol. For each vertebral body, a region of interest was drawn on the axial computed tomographic images at three separate locations: immediately inferior to the superior end plate, in the middle of the vertebral body, and superior to the inferior end plate. Values from the three axial slices were averaged to give a mean Hounsfield Unit value for each vertebral body. Univariate statistical analysis was performed to identify factors to be included in a multivariate model. The multivariate model including all dogs demonstrated that vertebral DISH status (Coefficient 24.63; 95% CI 16.07 to 33.19; p <0.001), lumbar vertebrae (Coefficient -17.25; 95% CI -23.42 to -11.09; p < 0.01), and to a lesser extent higher age (Coefficient -0.56; 95% CI -1.07 to -0.05; p = 0.03) were significant predictors for vertebral BMD. When the multivariate model was repeated using only dogs with DISH, vertebral DISH status (Coefficient 20.67; 95% CI, 10.98 to 30.37; p < 0.001) and lumbar anatomical region (Coefficient -38.24; 95% CI, -47.75 to -28.73; p < 0.001) were again predictors for vertebral BMD but age was not. The results of this study indicate that DISH can be associated with decreased vertebral BMD. Further studies are necessary to evaluate the clinical importance and pathophysiology of this finding. PMID:25898128

  9. Mineralization and collagen orientation throughout aging at the vertebral endplate in the human lumbar spine.

    PubMed

    Paietta, Rachel C; Burger, Evalina L; Ferguson, Virginia L

    2013-11-01

    The human vertebral body and intervertebral disc interface forms the region where the cartilaginous endplate, annulus fibrosis and bone of the vertebral body are connected through an intermediate calcified cartilage layer. While properties of both the vertebral body and components of the disc have been extensively studied, limited quantitative data exists describing the microstructure of the vertebral body-intervertebral disc interface in the spine throughout development and degeneration. Quantitative backscattered scanning electron and second harmonic generation confocal imaging were used to collect quantitative data describing the mineral content and collagen fiber orientation across the interface, respectively. Specimens spanned ages 56 days to 84 years and measurements were taken across the vertebral endplate at the outer annulus, inner annulus and nucleus pulposis. In mature and healthy endplates, collagen fibers span the calcified cartilage layer in all regions, including the endplate adjacent to the central nucleus pulposis. We also observed an abrupt transition from high mineral volume fractions (35-50%) to 0% over short distances measuring 3-15 microns in width across the transition from calcified cartilage to unmineralized cartilage. The alignment of collagen fibers at the outer annulus and thickness of the CC layer indicated that collagen fiber mineralization adjacent to the bone may serve to anchor the soft tissue without a gradual change in material properties. Combining backscattered scanning electron microscopy and second harmonic generation imaging on the same sections thus enable a novel assessment of morphology and properties in both mineralized and soft tissues at the vertebral body-intervertebral disc throughout development and aging. PMID:23999190

  10. Vertebral destruction due to abdominal aortic aneurysm

    PubMed Central

    Jiménez Viseu Pinheiro, J.F.; Blanco Blanco, J.F.; Pescador Hernández, D.; García García, F.J.

    2014-01-01

    Introduction Low back pain is a common cause of medical consultation, and usually supposes a non-malignant prognostic. Presentation of case We report an atypical appearance of low back pain associated to shock and pulsatile abdominal mass that made us diagnose an abdominal aortic aneurysm as reason of vertebral lysis and pain. Discusion Surgical repair of contained AAA should be directed to secondary re-rupture prevention, with an approximate survival near to 100% at selected patients for elective surgery. Consequently, orthopedic surgery for back spine stabilization has to be elective in those cases when vertebral destruction is above 30% and clinic is directly related to spine instability. Conclusion We should consider AAA as other cause of low back pain and routinely examine the abdomen and seek complementary imaging proves when risk factors for AAA are present. PMID:25569196

  11. Patterns and Processes of Vertebrate Evolution

    NASA Astrophysics Data System (ADS)

    Carroll, Robert Lynn

    1997-04-01

    This new text provides an integrated view of the forces that influence the patterns and rates of vertebrate evolution from the level of living populations and species to those that resulted in the origin of the major vertebrate groups. The evolutionary roles of behavior, development, continental drift, and mass extinctions are compared with the importance of variation and natural selection that were emphasized by Darwin. It is extensively illustrated, showing major transitions between fish and amphibians, dinosaurs and birds, and land mammals to whales. No book since Simpson's Major Features of Evolution has attempted such a broad study of the patterns and forces of evolutionary change. Undergraduate students taking a general or advanced course on evolution, and graduate students and professionals in evolutionary biology and paleontology will find the book of great interest.

  12. Acute compressive myelopathy due to vertebral haemangioma

    PubMed Central

    Macki, Mohamed; Bydon, Mohamad; Kaloostian, Paul; Bydon, Ali

    2014-01-01

    A 47-year-old woman with a history of anaemia presented to the emergency room with an acute onset of leg weakness. Physical examination of the bilateral lower extremities was significant for 0/5 muscle strength in all muscle groups with decreased pinprick and temperature sensation. A sensory level at the umbilicus was appreciated. Fine touch and proprioception were preserved. Bowel and bladder function were intact. CT revealed several thoracic, vertebral haemangiomatas. An MRI was suggestive of an epidural clot at the T8–T10-weighted posterior epidural space. At the level of the lesion, the cerebrospinal fluid space was completely effaced, and the flattened spinal cord exhibited signs of oedema and compressive myelopathy. The patient immediately underwent surgical decompression of the spinal cord. An epidural clot and vessel conglomeration were identified. A postoperative spinal angiogram confirmed the diagnosis of vertebral haemangioma. At 1-month follow-up, the patient regained strength and sensation. PMID:24777075

  13. Dynamic epithelia of the developing vertebrate face

    PubMed Central

    Choe, Chong Pyo; Crump, J. Gage

    2015-01-01

    A segmental series of endoderm-derived pouch and ectoderm-derived cleft epithelia act as signaling centers in the developing face. Their precise morphogenesis is therefore essential for proper patterning of the vertebrate head. Intercellular adhesion and polarity are highly dynamic within developing facial epithelial cells, with signaling from the adjacent mesenchyme controlling both epithelial character and directional migration. Endodermal and ectodermal epithelia fuse to form the primary mouth and gill slits, which involves basement membrane dissolution, cell intercalations, and apoptosis, as well as undergo further morphogenesis to generate the middle ear cavity and glands of the neck. Recent studies of facial epithelia are revealing both core programs of epithelial morphogenesis and insights into the coordinated assembly of the vertebrate head. PMID:25748249

  14. Clinical Management of Vertebral Compression Fractures.

    PubMed

    Miller, Paul D

    2016-01-01

    Vertebral compression fractures (VCF's) are the most common form of osteoporotic fractures. Whether symptomatic or asymptomatic, they both represent a high risk for not only vertebral but also nonvertebral fractures in untreated populations. This high risk of future fracture after a VCF is independent of the T-score because bone strength is a combination of bone mineral density and bone quality. VCFs are the single greatest risk for future fractures at all other skeletal sites in untreated populations, including hip fractures. They are often unrecognized despite their exceptionally high prevalence in all genders and most ethnic groups as age increases. This article highlights some of the key messages about VCF's, and how assessment for their presence and then management will reduce the risk of all osteoporotic fractures. PMID:26439186

  15. Turning Heads: Development of Vertebrate Branchiomotor Neurons

    PubMed Central

    Chandrasekhar, Anand

    2007-01-01

    The cranial motor neurons innervate muscles that control eye, jaw, and facial movements of the vertebrate head and parasympathetic neurons that innervate certain glands and organs. These efferent neurons develop at characteristic locations in the brainstem, and their axons exit the neural tube in well-defined trajectories to innervate target tissues. This review is focused on a subset of cranial motor neurons called the branchiomotor neurons, which innervate muscles derived from the branchial (pharyngeal) arches. First, the organization of the branchiomotor pathways in zebrafish, chick, and mouse embryos will be compared, and the underlying axon guidance mechanisms will be addressed. Next, the molecular mechanisms that generate branchiomotor neurons and specify their identities will be discussed. Finally, the caudally directed or tangential migration of facial branchiomotor neurons will be examined. Given the advances in the characterization and analysis of vertebrate genomes, we can expect rapid progress in elucidating the cellular and molecular mechanisms underlying the development of these vital neuronal networks. PMID:14699587

  16. Population momentum across vertebrate life histories

    USGS Publications Warehouse

    Koons, D.N.; Grand, J.B.; Arnold, J.M.

    2006-01-01

    Population abundance is critically important in conservation, management, and demographic theory. Thus, to better understand how perturbations to the life history affect long-term population size, we examined population momentum for four vertebrate classes with different life history strategies. In a series of demographic experiments we show that population momentum generally has a larger effect on long-term population size for organisms with long generation times than for organisms with short generation times. However, patterns between population momentum and generation time varied across taxonomic groups and according to the life history parameter that was changed. Our findings indicate that momentum may be an especially important aspect of population dynamics for long-lived vertebrates, and deserves greater attention in life history studies. Further, we discuss the importance of population momentum in natural resource management, pest control, and conservation arenas. ?? 2006 Elsevier B.V. All rights reserved.

  17. Pyogenic Vertebral Osteomyelitis in Heroin Addicts

    PubMed Central

    Fishbach, Ronald S.; Rosenblatt, Jon E.; Dahlgren, James G.

    1973-01-01

    The diagnosis of pyogenic vertebral osteomyelitis was made in seven narcotic addicts between 1967 and 1972. Vertebrae involved were either cervical or lumbar. Bacteriologic diagnosis was made in each case by percutaneous needle biopsy and aspiration. Staphylococcus aureus was cultured in two patients. Five patients had infections due to Gram-negative bacteria, including Klebsiella pneumoniae, Pseudomonas aeruginosa and Enterobacter. All patients were cured by treatment with antibiotics and immobilization. PMID:4199351

  18. The Timing of Timezyme Diversification in Vertebrates

    PubMed Central

    Cazaméa-Catalan, Damien; Besseau, Laurence; Falcón, Jack; Magnanou, Elodie

    2014-01-01

    All biological functions in vertebrates are synchronized with daily and seasonal changes in the environment by the time keeping hormone melatonin. Its nocturnal surge is primarily due to the rhythmic activity of the arylalkylamine N-acetyl transferase AANAT, which thus became the focus of many investigations regarding its evolution and function. Various vertebrate isoforms have been reported from cartilaginous fish to mammals but their origin has not been clearly established. Using phylogeny and synteny, we took advantage of the increasing number of available genomes in order to test whether the various rounds of vertebrate whole genome duplications were responsible for the diversification of AANAT. We highlight a gene secondary loss of the AANAT2 in the Sarcopterygii, revealing for the first time that the AAANAT1/2 duplication occurred before the divergence between Actinopterygii (bony fish) and Sarcopterygii (tetrapods, lobe-finned fish, and lungfish). We hypothesize the teleost-specific whole genome duplication (WDG) generated the appearance of the AANAT1a/1b and the AANAT2/2′paralogs, the 2′ isoform being rapidly lost in the teleost common ancestor (ray-finned fish). We also demonstrate the secondary loss of the AANAT1a in a Paracantopterygii (Atlantic cod) and of the 1b in some Ostariophysi (zebrafish and cave fish). Salmonids present an even more diverse set of AANATs that may be due to their specific WGD followed by secondary losses. We propose that vertebrate AANAT diversity resulted from 3 rounds of WGD followed by previously uncharacterized secondary losses. Extant isoforms show subfunctionalized localizations, enzyme activities and affinities that have increased with time since their emergence. PMID:25486407

  19. Light sensitivity in a vertebrate mechanoreceptor?

    PubMed Central

    Baker, Gary E.; de Grip, Willem J.; Turton, Michael; Wagner, Hans-Joachim; Foster, Russell G.; Douglas, Ron H.

    2015-01-01

    ABSTRACT Using immunohistochemistry and western blot analysis, we demonstrate that melanopsin is localised in cells around the central pore of lateral line neuromasts in the African clawed frog, Xenopus laevis. Since melanopsin is a known photoreceptor pigment with diverse functions in vertebrates, we suggest that the lateral line of Xenopus laevis, which is primarily a mechanoreceptor, might also be light sensitive. Potential functions of such photosensitivity are discussed, including its role in mediating locomotor responses following dermal illumination. PMID:26206352

  20. Transmission of Ranavirus between Ectothermic Vertebrate Hosts

    PubMed Central

    Brenes, Roberto; Gray, Matthew J.; Waltzek, Thomas B.; Wilkes, Rebecca P.; Miller, Debra L.

    2014-01-01

    Transmission is an essential process that contributes to the survival of pathogens. Ranaviruses are known to infect different classes of lower vertebrates including amphibians, fishes and reptiles. Differences in the likelihood of infection among ectothermic vertebrate hosts could explain the successful yearlong persistence of ranaviruses in aquatic environments. The goal of this study was to determine if transmission of a Frog Virus 3 (FV3)-like ranavirus was possible among three species from different ectothermic vertebrate classes: Cope’s gray treefrog (Hyla chrysoscelis) larvae, mosquito fish (Gambusia affinis), and red-eared slider (Trachemys scripta elegans). We housed individuals previously exposed to the FV3-like ranavirus with naïve (unexposed) individuals in containers divided by plastic mesh screen to permit water flow between subjects. Our results showed that infected gray treefrog larvae were capable of transmitting ranavirus to naïve larval conspecifics and turtles (60% and 30% infection, respectively), but not to fish. Also, infected turtles and fish transmitted ranavirus to 50% and 10% of the naïve gray treefrog larvae, respectively. Nearly all infected amphibians experienced mortality, whereas infected turtles and fish did not die. Our results demonstrate that ranavirus can be transmitted through water among ectothermic vertebrate classes, which has not been reported previously. Moreover, fish and reptiles might serve as reservoirs for ranavirus given their ability to live with subclinical infections. Subclinical infections of ranavirus in fish and aquatic turtles could contribute to the pathogen’s persistence, especially when highly susceptible hosts like amphibians are absent as a result of seasonal fluctuations in relative abundance. PMID:24667325

  1. The timing of Timezyme diversification in vertebrates.

    PubMed

    Cazaméa-Catalan, Damien; Besseau, Laurence; Falcón, Jack; Magnanou, Elodie

    2014-01-01

    All biological functions in vertebrates are synchronized with daily and seasonal changes in the environment by the time keeping hormone melatonin. Its nocturnal surge is primarily due to the rhythmic activity of the arylalkylamine N-acetyl transferase AANAT, which thus became the focus of many investigations regarding its evolution and function. Various vertebrate isoforms have been reported from cartilaginous fish to mammals but their origin has not been clearly established. Using phylogeny and synteny, we took advantage of the increasing number of available genomes in order to test whether the various rounds of vertebrate whole genome duplications were responsible for the diversification of AANAT. We highlight a gene secondary loss of the AANAT2 in the Sarcopterygii, revealing for the first time that the AAANAT1/2 duplication occurred before the divergence between Actinopterygii (bony fish) and Sarcopterygii (tetrapods, lobe-finned fish, and lungfish). We hypothesize the teleost-specific whole genome duplication (WDG) generated the appearance of the AANAT1a/1b and the AANAT2/2'paralogs, the 2' isoform being rapidly lost in the teleost common ancestor (ray-finned fish). We also demonstrate the secondary loss of the AANAT1a in a Paracantopterygii (Atlantic cod) and of the 1b in some Ostariophysi (zebrafish and cave fish). Salmonids present an even more diverse set of AANATs that may be due to their specific WGD followed by secondary losses. We propose that vertebrate AANAT diversity resulted from 3 rounds of WGD followed by previously uncharacterized secondary losses. Extant isoforms show subfunctionalized localizations, enzyme activities and affinities that have increased with time since their emergence. PMID:25486407

  2. Common normal variants of pediatric vertebral development that mimic fractures: a pictorial review from a national longitudinal bone health study

    PubMed Central

    Jaremko, Jacob Lester; Siminoski, Kerry; Firth, Gregory; Matzinger, Mary Ann; Shenouda, Nazih; Konji, Victor N.; Roth, Johannes; Sbrocchi, Anne Marie; Reed, Martin; O’Brien, Kathleen; Nadel, Helen; McKillop, Scott; Kloiber, Reinhard; Dubois, Josée; Coblentz, Craig; Charron, Martin; Ward, Leanne M.

    2015-01-01

    Children with glucocorticoid-treated illnesses are at risk for osteoporotic vertebral fractures and growing awareness has led to increased monitoring for these fractures. However scant literature describes developmental changes in vertebral morphology that can mimic fractures. The goal of this paper is to aid in distinguishing between normal variants and fractures. We illustrate differences using lateral spine radiographs obtained annually from children recruited to the Canada-wide STeroid-Associated Osteoporosis in the Pediatric Population (STOPP) observational study, in which 400 children with glucocorticoid-treated leukemia, rheumatic disorders, and nephrotic syndrome were enrolled near glucocorticoid initiation and followed prospectively for 6 years. Normal variants mimicking fractures exist in all regions of the spine and fall into two groups. The first group comprises variants mimicking pathological vertebral height loss, including not-yet-ossified vertebral apophyses superiorly and inferiorly which can lead to a vertebral shape easily over-interpreted as anterior wedge fracture, physiologic beaking, and spondylolisthesis associated with shortened posterior vertebral height. The second group includes variants mimicking other radiologic signs of fractures: anterior vertebral artery groove resembling an anterior buckle fracture, Cupid’s bow balloon disk morphology, Schmorl nodes mimicking concave endplate fractures, and parallax artifact resembling endplate interruption or biconcavity. If an unexpected vertebral body contour is detected, careful attention to its location, detailed morphology, and (if available) serial changes over time may clarify whether it is a fracture requiring change in management or simply a normal variant. Awareness of the variants described in this paper can improve accuracy in the diagnosis of pediatric vertebral fractures. PMID:25828359

  3. Common normal variants of pediatric vertebral development that mimic fractures: a pictorial review from a national longitudinal bone health study.

    PubMed

    Jaremko, Jacob L; Siminoski, Kerry; Firth, Gregory B; Matzinger, Mary Ann; Shenouda, Nazih; Konji, Victor N; Roth, Johannes; Sbrocchi, Anne Marie; Reed, Martin H; O'Brien, Mary Kathleen; Nadel, Helen; McKillop, Scott; Kloiber, Reinhard; Dubois, Josée; Coblentz, Craig; Charron, Martin; Ward, Leanne M

    2015-04-01

    Children with glucocorticoid-treated illnesses are at risk for osteoporotic vertebral fractures, and growing awareness of this has led to increased monitoring for these fractures. However scant literature describes developmental changes in vertebral morphology that can mimic fractures. The goal of this paper is to aid in distinguishing between normal variants and fractures. We illustrate differences using lateral spine radiographs obtained annually from children recruited to the Canada-wide STeroid-Associated Osteoporosis in the Pediatric Population (STOPP) observational study, in which 400 children with glucocorticoid-treated leukemia, rheumatic disorders, and nephrotic syndrome were enrolled near glucocorticoid initiation and followed prospectively for 6 years. Normal variants mimicking fractures exist in all regions of the spine and fall into two groups. The first group comprises variants mimicking pathological vertebral height loss, including not-yet-ossified vertebral apophyses superiorly and inferiorly, which can lead to a vertebral shape easily over-interpreted as anterior wedge fracture, physiological beaking, or spondylolisthesis associated with shortened posterior vertebral height. The second group includes variants mimicking other radiologic signs of fractures: anterior vertebral artery groove resembling an anterior buckle fracture, Cupid's bow balloon disk morphology, Schmorl nodes mimicking concave endplate fractures, and parallax artifact resembling endplate interruption or biconcavity. If an unexpected vertebral body contour is detected, careful attention to its location, detailed morphology, and (if available) serial changes over time may clarify whether it is a fracture requiring change in management or simply a normal variant. Awareness of the variants described in this paper can improve accuracy in the diagnosis of pediatric vertebral fractures. PMID:25828359

  4. T-cell receptors in ectothermic vertebrates.

    PubMed

    Charlemagne, J; Fellah, J S; De Guerra, A; Kerfourn, F; Partula, S

    1998-12-01

    The structure and expression of genes encoding molecules homologous to mammalian T-cell receptors (TCR) have been recently studied in ectothermic vertebrate species representative of chondrychthians, teleosts, and amphibians. The overall TCR chain structure is well conserved in phylogeny: TCR beta- and TCR alpha-like chains were detected in all the species analyzed; TCR gamma- and TCR delta-like chains were also present in a chondrychthian species. The diversity potential of the variable (V) and joining (J) segments is rather large and, as in mammals, conserved diversity (D) segments are associated to the TCR beta and TCR delta chains. An important level of junctional diversity occurred at the V-(D)-J junctions, with the potential addition of N- and P-nucleotides. Thus, the conservation of the structure and of the potential of diversity of TCR molecules have been under a permanent selective pressure during vertebrate evolution. The structure of MHC class I and class II molecules was also well conserved in jawed vertebrates. TCR and MHC molecules are strongly functionally linked and play a determinant role in the initiation and the regulation of the specific immune responses; thus, it is not surprising that their structures have been reciprocally frozen during evolution. PMID:9914905

  5. The immunoglobulins of cold-blooded vertebrates.

    PubMed

    Pettinello, Rita; Dooley, Helen

    2014-01-01

    Although lymphocyte-like cells secreting somatically-recombining receptors have been identified in the jawless fishes (hagfish and lamprey), the cartilaginous fishes (sharks, skates, rays and chimaera) are the most phylogenetically distant group relative to mammals in which bona fide immunoglobulins (Igs) have been found. Studies of the antibodies and humoral immune responses of cartilaginous fishes and other cold-blooded vertebrates (bony fishes, amphibians and reptiles) are not only revealing information about the emergence and roles of the different Ig heavy and light chain isotypes, but also the evolution of specialised adaptive features such as isotype switching, somatic hypermutation and affinity maturation. It is becoming increasingly apparent that while the adaptive immune response in these vertebrate lineages arose a long time ago, it is most definitely not primitive and has evolved to become complex and sophisticated. This review will summarise what is currently known about the immunoglobulins of cold-blooded vertebrates and highlight the differences, and commonalities, between these and more "conventional" mammalian species. PMID:25427250

  6. Effects of hypoxia on vertebrate blood vessels.

    PubMed

    Russell, Michael J; Dombkowski, Ryan A; Olson, Kenneth R

    2008-03-01

    Hypoxia contracts mammalian respiratory vessels and increases vascular resistance in respiratory tissues of many vertebrates. In systemic vessels these responses vary, hypoxia relaxes mammalian vessels and contracts systemic arteries from cyclostomes. It has been proposed that hypoxic vasoconstriction in cyclostome systemic arteries is the antecedent to mammalian hypoxic pulmonary vasoconstriction, however, phylogenetic characterization of hypoxic responses is lacking. In this study, we characterized the hypoxic response of isolated systemic and respiratory vessels from a variety of vertebrates using standard myography. Pre-gill/respiratory (ventral aorta, afferent branchial artery, pulmonary artery) and post-gill/systemic (dorsal and thoracic aortas, efferent branchial artery) from lamprey (Petromyzon marinus), sandbar shark (Carcharhinus plumbeus), yellowfin tuna (Thunnus albacares), American bullfrog (Rana catesbeiana), American alligator (Alligator mississippiensis), Pekin duck (Anas platyrhynchos domesticus), chicken (Gallus domesticus) and rat (Rattus norvegicus) were exposed to hypoxia at rest or during pre-stimulation (elevated extracellular potassium, epinephrine or norepinephrine). Hypoxia produced a relaxation or transient contraction followed by relaxation in all pre-gill vessels, except for contraction in lamprey, and vasoconstriction or tri-phasic constriction-dilation-constriction in all pulmonary vessels. Hypoxia contracted systemic vessels from all animals except shark and rat and in pre-contracted rat aortas it produced a transient contraction followed by relaxation. These results show that while the classic "systemic hypoxic vasodilation and pulmonary hypoxic vasoconstriction" may occur in the microcirculation, the hypoxic response of the vertebrate macrocirculation is quite variable. These findings also suggest that hypoxic vasoconstriction is a phylogenetically ancient response. PMID:18214862

  7. Fungal osteomyelitis with vertebral re-ossification

    PubMed Central

    O′Guinn, Devon J.; Serletis, Demitre; Kazemi, Noojan

    2015-01-01

    Introduction We present a rare case of thoracic vertebral osteomyelitis secondary to pulmonary Blastomyces dermatitides. Presentation of case A 27-year-old male presented with three months of chest pains and non-productive cough. Examination revealed diminished breath sounds on the right. CT/MR imaging confirmed a right-sided pre-/paravertebral soft tissue mass and destructive lytic lesions from T2 to T6. CT-guided needle biopsy confirmed granulomatous pulmonary Blastomycosis. Conservative management with antifungal therapy was initiated. Neurosurgical review confirmed no clinical or profound radiographic instability, and the patient was stabilized with TLSO bracing. Serial imaging 3 months later revealed near-resolution of the thoracic soft tissue mass, with vertebral re-ossification from T2 to T6. Discussion Fungal osteomyelitis presents a rare entity in the spectrum of spinal infections. In such cases, lytic spinal lesions are classically seen in association with a large paraspinous mass. Fungal infections of the spinal column may be treated conservatively, with surgical intervention reserved for progressive cases manifesting with neurological compromise and/or spinal column instability. Here, we found unexpected evidence for vertebral re-ossification across the affected thoracic levels (T2-6) in response to IV antibiotic therapy and conservative bracing, nearly 3 months later. PMID:26692163

  8. Flapping wing aerodynamics: from insects to vertebrates.

    PubMed

    Chin, Diana D; Lentink, David

    2016-04-01

    More than a million insects and approximately 11,000 vertebrates utilize flapping wings to fly. However, flapping flight has only been studied in a few of these species, so many challenges remain in understanding this form of locomotion. Five key aerodynamic mechanisms have been identified for insect flight. Among these is the leading edge vortex, which is a convergent solution to avoid stall for insects, bats and birds. The roles of the other mechanisms - added mass, clap and fling, rotational circulation and wing-wake interactions - have not yet been thoroughly studied in the context of vertebrate flight. Further challenges to understanding bat and bird flight are posed by the complex, dynamic wing morphologies of these species and the more turbulent airflow generated by their wings compared with that observed during insect flight. Nevertheless, three dimensionless numbers that combine key flow, morphological and kinematic parameters - the Reynolds number, Rossby number and advance ratio - govern flapping wing aerodynamics for both insects and vertebrates. These numbers can thus be used to organize an integrative framework for studying and comparing animal flapping flight. Here, we provide a roadmap for developing such a framework, highlighting the aerodynamic mechanisms that remain to be quantified and compared across species. Ultimately, incorporating complex flight maneuvers, environmental effects and developmental stages into this framework will also be essential to advancing our understanding of the biomechanics, movement ecology and evolution of animal flight. PMID:27030773

  9. The Immunoglobulins of Cold-Blooded Vertebrates

    PubMed Central

    Pettinello, Rita; Dooley, Helen

    2014-01-01

    Although lymphocyte-like cells secreting somatically-recombining receptors have been identified in the jawless fishes (hagfish and lamprey), the cartilaginous fishes (sharks, skates, rays and chimaera) are the most phylogenetically distant group relative to mammals in which bona fide immunoglobulins (Igs) have been found. Studies of the antibodies and humoral immune responses of cartilaginous fishes and other cold-blooded vertebrates (bony fishes, amphibians and reptiles) are not only revealing information about the emergence and roles of the different Ig heavy and light chain isotypes, but also the evolution of specialised adaptive features such as isotype switching, somatic hypermutation and affinity maturation. It is becoming increasingly apparent that while the adaptive immune response in these vertebrate lineages arose a long time ago, it is most definitely not primitive and has evolved to become complex and sophisticated. This review will summarise what is currently known about the immunoglobulins of cold-blooded vertebrates and highlight the differences, and commonalities, between these and more “conventional” mammalian species. PMID:25427250

  10. Group II Intron-Mediated Trans-Splicing in the Gene-Rich Mitochondrial Genome of an Enigmatic Eukaryote, Diphylleia rotans.

    PubMed

    Kamikawa, Ryoma; Shiratori, Takashi; Ishida, Ken-Ichiro; Miyashita, Hideaki; Roger, Andrew J

    2016-02-01

    Although mitochondria have evolved from a single endosymbiotic event, present day mitochondria of diverse eukaryotes display a great range of genome structures, content and features. Group I and group II introns are two features that are distributed broadly but patchily in mitochondrial genomes across branches of the tree of eukaryotes. While group I intron-mediated trans-splicing has been reported from some lineages distantly related to each other, findings of group II intron-mediated trans-splicing has been restricted to members of the Chloroplastida. In this study, we found the mitochondrial genome of the unicellular eukaryote Diphylleia rotans possesses currently the second largest gene repertoire. On the basis of a probable phylogenetic position of Diphylleia, which is located within Amorphea, current mosaic gene distribution in Amorphea must invoke parallel gene losses from mitochondrial genomes during evolution. Most notably, although the cytochrome c oxidase subunit (cox) 1 gene was split into four pieces which located at a distance to each other, we confirmed that a single mature mRNA that covered the entire coding region could be generated by group II intron-mediated trans-splicing. This is the first example of group II intron-mediated trans-splicing outside Chloroplastida. Similar trans-splicing mechanisms likely work for bipartitely split cox2 and nad3 genes to generate single mature mRNAs. We finally discuss origin and evolution of this type of trans-splicing in D. rotans as well as in eukaryotes. PMID:26833505

  11. Group II Intron-Mediated Trans-Splicing in the Gene-Rich Mitochondrial Genome of an Enigmatic Eukaryote, Diphylleia rotans

    PubMed Central

    Kamikawa, Ryoma; Shiratori, Takashi; Ishida, Ken-Ichiro; Miyashita, Hideaki; Roger, Andrew J.

    2016-01-01

    Although mitochondria have evolved from a single endosymbiotic event, present day mitochondria of diverse eukaryotes display a great range of genome structures, content and features. Group I and group II introns are two features that are distributed broadly but patchily in mitochondrial genomes across branches of the tree of eukaryotes. While group I intron-mediated trans-splicing has been reported from some lineages distantly related to each other, findings of group II intron-mediated trans-splicing has been restricted to members of the Chloroplastida. In this study, we found the mitochondrial genome of the unicellular eukaryote Diphylleia rotans possesses currently the second largest gene repertoire. On the basis of a probable phylogenetic position of Diphylleia, which is located within Amorphea, current mosaic gene distribution in Amorphea must invoke parallel gene losses from mitochondrial genomes during evolution. Most notably, although the cytochrome c oxidase subunit (cox) 1 gene was split into four pieces which located at a distance to each other, we confirmed that a single mature mRNA that covered the entire coding region could be generated by group II intron-mediated trans-splicing. This is the first example of group II intron-mediated trans-splicing outside Chloroplastida. Similar trans-splicing mechanisms likely work for bipartitely split cox2 and nad3 genes to generate single mature mRNAs. We finally discuss origin and evolution of this type of trans-splicing in D. rotans as well as in eukaryotes. PMID:26833505

  12. Vertebrate paralogous conserved noncoding sequences may be related to gene expressions in brain.

    PubMed

    Matsunami, Masatoshi; Saitou, Naruya

    2013-01-01

    Vertebrate genomes include gene regulatory elements in protein-noncoding regions. A part of gene regulatory elements are expected to be conserved according to their functional importance, so that evolutionarily conserved noncoding sequences (CNSs) might be good candidates for those elements. In addition, paralogous CNSs, which are highly conserved among both orthologous loci and paralogous loci, have the possibility of controlling overlapping expression patterns of their adjacent paralogous protein-coding genes. The two-round whole-genome duplications (2R WGDs), which most probably occurred in the vertebrate common ancestors, generated large numbers of paralogous protein-coding genes and their regulatory elements. These events could contribute to the emergence of vertebrate features. However, the evolutionary history and influences of the 2R WGDs are still unclear, especially in noncoding regions. To address this issue, we identified paralogous CNSs. Region-focused Basic Local Alignment Search Tool (BLAST) search of each synteny block revealed 7,924 orthologous CNSs and 309 paralogous CNSs conserved among eight high-quality vertebrate genomes. Paralogous CNSs we found contained 115 previously reported ones and newly detected 194 ones. Through comparisons with VISTA Enhancer Browser and available ChIP-seq data, one-third (103) of paralogous CNSs detected in this study showed gene regulatory activity in the brain at several developmental stages. Their genomic locations are highly enriched near the transcription factor-coding regions, which are expressed in brain and neural systems. These results suggest that paralogous CNSs are conserved mainly because of maintaining gene expression in the vertebrate brain. PMID:23267051

  13. FRAX and the effect of teriparatide on vertebral and non-vertebral fracture

    PubMed Central

    Harvey, Nicholas C; Kanis, John A; Odén, Anders; Burge, Russel T; Mitlak, Bruce H; Johansson, Helena; McCloskey, Eugene V

    2016-01-01

    Summary Daily teriparatide injections have been shown to reduce vertebral and non-vertebral fractures. Here we demonstrate that the magnitude of fracture risk reduction is independent of baseline fracture probability assessed by FRAX. Background Daily administration of 20μg or 40μg teriparatide has been shown to significantly decrease the risk of vertebral and non-vertebral fracture compared with placebo. The aim of the present study was to evaluate fracture risk assessed at baseline using the FRAX® tool and to determine the efficacy of teriparatide as a function of baseline fracture risk. Methods 1637 postmenopausal women in the pivotal phase 3 trial, randomly assigned to receive placebo (n=544), teriparatide 20 μg per day (n=541) or teriparatide 40 μg per day (n=552), were studied. Baseline clinical risk factors were entered into country-specific FRAX models to compute the 10-year probability of major osteoporotic fractures with or without input of femoral neck BMD. Because there was no difference in effect of 20 and 40μg teriparatide daily on fracture occurrence, the two active groups were merged. The interaction between probability of a major fracture and treatment efficacy was examined by Poisson regression. Results The 10-year probability of major osteoporotic fractures (with BMD) ranged from 2.2-67.2%. Treatment with teriparatide was associated with a 37% decrease in all non-vertebral fractures (95% CI:10-56 %) and a 56% decrease in low energy non-vertebral fractures (95% CI:24-75%) compared with placebo. The risk of morphometric vertebral fractures decreased significantly by 66% (95% CI:50-77%). Hazard ratios for the effect of teriparatide on the fracture outcome did not change significantly with increasing fracture probability (p>0.30). Similar findings were noted for the interaction when BMD was excluded from the FRAX model, or when probability of hip fracture was used as the marker of baseline risk. Conclusion We conclude that teriparatide

  14. Prospective Single-Site Experience with Radiofrequency-Targeted Vertebral Augmentation for Osteoporotic Vertebral Compression Fracture

    PubMed Central

    Moser, Franklin G.; Maya, Marcel M.; Blaszkiewicz, Laura; Scicli, Andrea; Miller, Larry E.; Block, Jon E.

    2013-01-01

    Vertebral augmentation procedures are widely used to treat osteoporotic vertebral compression fractures (VCFs). We report our initial experience with radiofrequency-targeted vertebral augmentation (RF-TVA) in 20 patients aged 50 to 90 years with single-level, symptomatic osteoporotic VCF between T10 and L5, back pain severity > 4 on a 0 to 10 scale, Oswestry Disability Index ≥ 21%, 20% to 90% vertebral height loss compared to adjacent vertebral body, and fracture age < 6 months. After treatment, patients were followed through hospital discharge and returned for visits after 1 week, 1 month, and 3 months. Back pain severity improved 66% (P < 0.001), from 7.9 (95% CI: 7.1 to 8.6) at pretreatment to 2.7 (95% CI: 1.5 to 4.0) at 3 months. Back function improved 46% (P < 0.001), from 74 (95% CI: 69% to 79%) at pretreatment to 40 (95% CI: 33% to 47%) at 3 months. The percentage of patients regularly consuming pain medication was 70% at pretreatment and only 21% at 3 months. No adverse events related to the device or procedure were reported. RF-TVA reduces back pain severity, improves back function, and reduces pain medication requirements with no observed complications in patients with osteoporotic VCF. PMID:24228187

  15. Surgical treatment of aggressive vertebral hemangiomas.

    PubMed

    Vasudeva, Viren S; Chi, John H; Groff, Michael W

    2016-08-01

    OBJECTIVE Vertebral hemangiomas are common tumors that are benign and generally asymptomatic. Occasionally these lesions can exhibit aggressive features such as bony expansion and erosion into the epidural space resulting in neurological symptoms. Surgery is often recommended in these cases, especially if symptoms are severe or rapidly progressive. Some surgeons perform decompression alone, others perform gross-total resection, while others perform en bloc resection. Radiation, embolization, vertebroplasty, and ethanol injection have also been used in combination with surgery. Despite the variety of available treatment options, the optimal management strategy is unclear because aggressive vertebral hemangiomas are uncommon lesions, making it difficult to perform large trials. For this reason, the authors chose instead to report their institutional experience along with a comprehensive review of the literature. METHODS A departmental database was searched for patients with a pathological diagnosis of "hemangioma" between 2008 and 2015. Medical records were reviewed to identify patients with aggressive vertebral hemangiomas, and these cases were reviewed in detail. RESULTS Five patients were identified who underwent surgery for treatment of aggressive vertebral hemangiomas during the specified time period. There were 2 lumbar and 3 thoracic lesions. One patient underwent en bloc spondylectomy, 2 patients had piecemeal gross-total resection, and the remaining 2 had subtotal tumor resection. Intraoperative vertebroplasty was used in 3 cases to augment the anterior column or to obliterate residual tumor. Adjuvant radiation was used in 1 case where there was residual tumor as well. The patient who underwent en bloc spondylectomy experienced several postoperative complications requiring additional medical care and reoperation. At an average follow-up of 31 months (range 3-65 months), no patient had any recurrence of disease and all were clinically asymptomatic, except the

  16. Reliability of vertebral fracture assessment using multidetector CT lateral scout views: the Framingham Osteoporosis Study

    PubMed Central

    Samelson, E. J.; Christiansen, B. A.; Demissie, S.; Broe, K. E.; Zhou, Y.; Meng, C. A.; Yu, W.; Cheng, X.; O’Donnell, C. J.; Hoffmann, U.; Genant, H. K.; Kiel, D. P.; Bouxsein, M. L.

    2010-01-01

    Summary Two radiologists evaluated images of the spine from computed tomography (CT) scans on two occasions to diagnose vertebral fracture in 100 individuals. Agreement was fair to good for mild fractures, and agreement was good to excellent for more severe fractures. CT scout views are useful to assess vertebral fracture. Introduction We investigated inter-reader agreement between two radiologists and intra-reader agreement between duplicate readings for each radiologist, in assessment of vertebral fracture using a semi-quantitative method from lateral scout views obtained by CT. Methods Participants included 50 women and 50 men (age 50-87 years, mean 70 years) in the Framingham Study. T4-L4 vertebrae were assessed independently by two radiologists on two occasions using a semi-quantitative scale as normal, mild, moderate, or severe fracture. Results Vertebra-specific prevalence of grade ≥1 (mild) fracture ranged from 3% to 5%. We found fair (κ=56-59%) inter-reader agreement for grade ≥1 vertebral fractures and good (κ=68-72%) inter-reader agreement for grade ≥2 fractures. Intra-reader agreement for grade ≥1 vertebral fracture was fair (κ=55%) for one reader and excellent for another reader (κ=77%), whereas intra-reader agreement for grade ≥2 vertebral fracture was excellent for both readers (κ=76% and 98%). Thoracic vertebrae were more difficult to evaluate than the lumbar region, and agreement was lowest (inter-reader κ=43%) for fracture at the upper (T4-T9) thoracic levels and highest (inter-reader κ=76-78%) for the lumbar spine (L1-L4). Conclusions Based on a semi-quantitative method to classify vertebral fractures using CT scout views, agreement within and between readers was fair to good, with the greatest source of variation occurring for fractures of mild severity and for the upper thoracic region. Agreement was good to excellent for fractures of at least moderate severity. Lateral CT scout views can be useful in clinical research settings

  17. Proliferation, neurogenesis and regeneration in the non-mammalian vertebrate brain.

    PubMed

    Kaslin, Jan; Ganz, Julia; Brand, Michael

    2008-01-12

    Post-embryonic neurogenesis is a fundamental feature of the vertebrate brain. However, the level of adult neurogenesis decreases significantly with phylogeny. In the first part of this review, a comparative analysis of adult neurogenesis and its putative roles in vertebrates are discussed. Adult neurogenesis in mammals is restricted to two telencephalic constitutively active zones. On the contrary, non-mammalian vertebrates display a considerable amount of adult neurogenesis in many brain regions. The phylogenetic differences in adult neurogenesis are poorly understood. However, a common feature of vertebrates (fish, amphibians and reptiles) that display a widespread adult neurogenesis is the substantial post-embryonic brain growth in contrast to birds and mammals. It is probable that the adult neurogenesis in fish, frogs and reptiles is related to the coordinated growth of sensory systems and corresponding sensory brain regions. Likewise, neurons are substantially added to the olfactory bulb in smell-oriented mammals in contrast to more visually oriented primates and songbirds, where much fewer neurons are added to the olfactory bulb. The second part of this review focuses on the differences in brain plasticity and regeneration in vertebrates. Interestingly, several recent studies show that neurogenesis is suppressed in the adult mammalian brain. In mammals, neurogenesis can be induced in the constitutively neurogenic brain regions as well as ectopically in response to injury, disease or experimental manipulations. Furthermore, multipotent progenitor cells can be isolated and differentiated in vitro from several otherwise silent regions of the mammalian brain. This indicates that the potential to recruit or generate neurons in non-neurogenic brain areas is not completely lost in mammals. The level of adult neurogenesis in vertebrates correlates with the capacity to regenerate injury, for example fish and amphibians exhibit the most widespread adult neurogenesis

  18. Insect Tc-six4 marks a unit with similarity to vertebrate placodes.

    PubMed

    Posnien, Nico; Koniszewski, Nikolaus; Bucher, Gregor

    2011-02-01

    Cranial placodes are specialized ectodermal regions in the developing vertebrate head that give rise to both neural and non-neural cell types of the neuroendocrine system and the sense organs of the visual, olfactory and acoustic systems. The cranial placodes develop from a panplacodal region which is specifically marked by genes of the eyes absent/eya and two "six homeobox" family members (sine oculis/six1 and six4). It had been believed that cranial placodes are evolutionary novelties of vertebrates. However, data from non-vertebrate chordates suggest that placode-like structures evolved in the chordate ancestor already. Here, we identify a morphological structure in the embryonic head of the beetle Tribolium castaneum with placode-like features. It is marked by the orthologs of the panplacodal markers Tc-six4, Tc-eya and Tc-sine oculis/six1 (Tc-six1) and expresses several genes known to be involved in adenohypophyseal placode development in vertebrates. Moreover, it contributes to both epidermal and neural tissues. We identify Tc-six4 as a specific marker for this structure that we term the insect head placode. Finally, we reveal the regulatory gene network of the panplacodal genes Tc-six4, Tc-eya and Tc-six1 and identify them as head epidermis patterning genes. Our finding of a placode-like structure in an insect suggests that a placode precursor was already present in the last common ancestor of bilaterian animals. PMID:21034730

  19. 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. PMID:9270407

  20. Early Bone Marrow Edema Pattern of the Osteoporotic Vertebral Compression Fracture : Can Be Predictor of Vertebral Deformity Types and Prognosis?

    PubMed Central

    Ahn, Sung Eun; Park, Ji Seon; Jin, Wook; Park, So Young; Kim, Sung Bum

    2016-01-01

    Objective To evaluate whether an early bone marrow edema pattern predicts vertebral deformity types and prognosis in osteoporotic vertebral compression fracture (OVCF). Methods This retrospective study enrolled 64 patients with 75 acute OVCFs who underwent early MRI and followed up MRI. On early MRI, the low SI pattern of OVCF on T1WI were assessed and classified into 3 types (diffuse, globular or patchy, band-like). On followed up MRI, the vertebral deformity types (anterior wedge, biconcave, crush), degree of vertebral body height loss, incidence of vertebral osteonecrosis and spinal stenosis were assessed for each vertebral fracture types. Results According to the early bone marrow edema pattern on T1WI, 26 vertebrae were type 1, 14 vertebrae were type 2 and 35 vertebrae were type 3. On followed up MRI, the crush-type vertebral deformity was most frequent among the type 1 OVCFs, the biconcave-type vertebral deformity was most frequent among the type 2 OVCFs and the anterior wedge-type vertebral deformity was most frequent among the type 3 OVCFs (p<0.001). In addition, type 1 early bone marrow edema pattern of OVCF on T1WI were associated with higher incidence of severe degree vertebral body height loss, vertebral osteonecrosis and spinal stenosis on the follow up MRI. Conclusion Early bone marrow edema pattern of OVCF on T1WI, significant correlated with vertebral deformity types on the follow up MRI. The severe degree of vertebral height loss, vertebral osteonecrosis, and spinal stenosis were more frequent in patients with diffuse low SI pattern. PMID:26962419

  1. A Hox regulatory network of hindbrain segmentation is conserved to the base of vertebrates.

    PubMed

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

    2014-10-23

    A defining feature governing head patterning of jawed vertebrates is a highly conserved gene regulatory network that integrates hindbrain segmentation with segmentally restricted domains of Hox gene expression. Although non-vertebrate chordates display nested domains of axial Hox expression, they lack hindbrain segmentation. The sea lamprey, a jawless fish, can provide unique insights into vertebrate origins owing to its phylogenetic position at the base of the vertebrate tree. It has been suggested that lamprey may represent an intermediate state where nested Hox expression has not been coupled to the process of hindbrain segmentation. However, little is known about the regulatory network underlying Hox expression in lamprey or its relationship to hindbrain segmentation. Here, using a novel tool that allows cross-species comparisons of regulatory elements between jawed and jawless vertebrates, we report deep conservation of both upstream regulators and segmental activity of enhancer elements across these distant species. Regulatory regions from diverse gnathostomes drive segmental reporter expression in the lamprey hindbrain and require the same transcriptional inputs (for example, Kreisler (also known as Mafba), Krox20 (also known as Egr2a)) in both lamprey and zebrafish. We find that lamprey hox genes display dynamic segmentally restricted domains of expression; we also isolated a conserved exonic hox2 enhancer from lamprey that drives segmental expression in rhombomeres 2 and 4. Our results show that coupling of Hox gene expression to segmentation of the hindbrain is an ancient trait with origin at the base of vertebrates that probably led to the formation of rhombomeric compartments with an underlying Hox code. PMID:25219855

  2. Comparative morphometric study of the australopithecine vertebral series Stw-H8/H41.

    PubMed

    Sanders, W J

    1998-03-01

    Lower spinal structure correlates well with positional behavior among mammals. Nonetheless, the functional morphology of the axial post-crania of australopithecines has received less attention than their appendicular skeletons. This paper presents a detailed description and comparative morphometric analysis of the australopithecine thoracolumbar vertebral series Stw-H8/H41, and examines spinal mechanics in early hominids. Stw-H8/H41 is an important specimen, as the australopithecine vertebral sample is small, and vertebral series are more useful than isolated elements for the interpretation of spinal function. Results of the study support the interpretation that australopithecine species are highly sexually dimorphic. The study also reveals a considerable amount of morphometric variation other than size among australopithecine vertebrae, though the sample is too small and incomplete to ascertain whether this indicates significant interspecific differences in spinal function. Most importantly, structural and metric observations confirm that the morphology of the lower spine in australopithecines has no modern analogue in its entirety. Aspects of zygapophyseal structure, numerical composition of the lumbar region, and centrum wedging suggest that the australopithecine vertebral column was adapted to human-like intrinsic lumbar lordosis and stable balance of the trunk over the pelvis in sustained bipedal locomotion. However, relative centrum size in australopithecines indicates that either they had a different mechanism for channeling vertical forces through the vertebral column than humans, or differed behaviorally from humans in ways that produced smaller increments of compression across their centra. These findings have important implications for hypotheses of australopithecine positional behavior, and demonstrate that larger samples and more complete vertebral series are needed to improve our understanding of australopithecine spinal function. PMID:9547457

  3. Number and type of vertebral deformities: epidemiological characteristics and relation to back pain and height loss. European Vertebral Osteoporosis Study Group.

    PubMed

    Ismail, A A; Cooper, C; Felsenberg, D; Varlow, J; Kanis, J A; Silman, A J; O'Neill, T W

    1999-01-01

    Vertebral deformity is the classical hallmark of osteoporosis. Three types of vertebral deformity are usually described: crush, wedge and biconcave deformities. However, there are few data concerning the descriptive epidemiology of the individual deformity types, and differences in their underlying pathogenesis and clinical impact remain uncertain. The aim of this study was to compare the epidemiological characteristics of the three types of vertebral deformity and to explore the relationships of the number and type of deformity with back pain and height loss. Age-stratified random samples of men and women aged 50 years and over were recruited from population registers in 30 European centers (EVOS study). Subjects were invited to attend for an interviewer-administered questionnaire and lateral spinal radiographs. The presence, type and number of vertebral deformities was determined using the McCloskey-Kanis algorithm. A total of 13,562 men and women were studied; mean age in men was 64.4 years (SD 8.5), and in women 63.8 years (SD 8.5 years). There was evidence of variation in the occurrence of wedge, crush and biconcave deformity by age, sex and vertebral level. Wedge deformities were the most frequent deformity and tended to cluster at the mid-thoracic and thoraco-lumbar regions of the spine in both men and women. Similar predilection for these sites was observed for crush and to a lesser extent biconcave deformities though this was much less marked than for wedge deformities. In both sexes the frequency of biconcave deformities was higher in the lumbar than the thoracic spine and unlike the other deformity types it did not decline in frequency at lower lumbar vertebral levels. The prevalence of all three types of vertebral deformity increased with age and was more marked in women. There were no important differences in the effect of age on the different deformity types. All types of deformity were associated with height loss, which was greatest for individuals

  4. Evolution of Vertebrate Phototransduction: Cascade Activation

    PubMed Central

    Lamb, Trevor D.; Patel, Hardip; Chuah, Aaron; Natoli, Riccardo C.; Davies, Wayne I. L.; Hart, Nathan S.; Collin, Shaun P.; Hunt, David M.

    2016-01-01

    We applied high-throughput sequencing to eye tissue from several species of basal vertebrates (a hagfish, two species of lamprey, and five species of gnathostome fish), and we analyzed the mRNA sequences for the proteins underlying activation of the phototransduction cascade. The molecular phylogenies that we constructed from these sequences are consistent with the 2R WGD model of two rounds of whole genome duplication. Our analysis suggests that agnathans retain an additional representative (that has been lost in gnathostomes) in each of the gene families we studied; the evidence is strong for the G-protein α subunit (GNAT) and the cGMP phosphodiesterase (PDE6), and indicative for the cyclic nucleotide-gated channels (CNGA and CNGB). Two of the species (the hagfish Eptatretus cirrhatus and the lamprey Mordacia mordax) possess only a single class of photoreceptor, simplifying deductions about the composition of cascade protein isoforms utilized in their photoreceptors. For the other lamprey, Geotria australis, analysis of the ratios of transcript levels in downstream and upstream migrant animals permits tentative conclusions to be drawn about the isoforms used in four of the five spectral classes of photoreceptor. Overall, our results suggest that agnathan rod-like photoreceptors utilize the same GNAT1 as gnathostomes, together with a homodimeric PDE6 that may be agnathan-specific, whereas agnathan cone-like photoreceptors utilize a GNAT that may be agnathan-specific, together with the same PDE6C as gnathostomes. These findings help elucidate the evolution of the vertebrate phototransduction cascade from an ancestral chordate phototransduction cascade that existed prior to the vertebrate radiation. PMID:27189541

  5. Evolution of Vertebrate Phototransduction: Cascade Activation.

    PubMed

    Lamb, Trevor D; Patel, Hardip; Chuah, Aaron; Natoli, Riccardo C; Davies, Wayne I L; Hart, Nathan S; Collin, Shaun P; Hunt, David M

    2016-08-01

    We applied high-throughput sequencing to eye tissue from several species of basal vertebrates (a hagfish, two species of lamprey, and five species of gnathostome fish), and we analyzed the mRNA sequences for the proteins underlying activation of the phototransduction cascade. The molecular phylogenies that we constructed from these sequences are consistent with the 2R WGD model of two rounds of whole genome duplication. Our analysis suggests that agnathans retain an additional representative (that has been lost in gnathostomes) in each of the gene families we studied; the evidence is strong for the G-protein α subunit (GNAT) and the cGMP phosphodiesterase (PDE6), and indicative for the cyclic nucleotide-gated channels (CNGA and CNGB). Two of the species (the hagfish Eptatretus cirrhatus and the lamprey Mordacia mordax) possess only a single class of photoreceptor, simplifying deductions about the composition of cascade protein isoforms utilized in their photoreceptors. For the other lamprey, Geotria australis, analysis of the ratios of transcript levels in downstream and upstream migrant animals permits tentative conclusions to be drawn about the isoforms used in four of the five spectral classes of photoreceptor. Overall, our results suggest that agnathan rod-like photoreceptors utilize the same GNAT1 as gnathostomes, together with a homodimeric PDE6 that may be agnathan-specific, whereas agnathan cone-like photoreceptors utilize a GNAT that may be agnathan-specific, together with the same PDE6C as gnathostomes. These findings help elucidate the evolution of the vertebrate phototransduction cascade from an ancestral chordate phototransduction cascade that existed prior to the vertebrate radiation. PMID:27189541

  6. Vertebral Body Growth After Craniospinal Irradiation

    SciTech Connect

    Hartley, Katherine A.; Li Chenghong; Laningham, Fred H.; Krasin, Matthew J.; Xiong Xiaoping; Merchant, Thomas E.

    2008-04-01

    Purpose: To estimate the effects of radiotherapy and clinical factors on vertebral growth in patients with medulloblastoma and supratentorial primitive neuroectodermal tumors treated with craniospinal irradiation (CSI) and chemotherapy. Methods and Materials: The height of eight individual or grouped vertebral bodies (C3, C3-C4, T4, T4-T5, C6-T3, T4-T7, L3, L1-L5) was measured before and after CSI (23.4 or 36-39.6 Gy) in 61 patients. Of the 61 patients, 40 were boys and 21 were girls (median age, 7 years; range, 3-13 years), treated between October 1996 and October 2003. Sagittal T{sub 1}-weighted magnetic resonance images were used for the craniocaudal measurements. The measurements numbered 275 (median, 5/patient; range, 3-7). The median follow-up after CSI was 44.1 months (range, 13.8-74.9 months). Results: Significant growth was observed in all measured vertebrae. Excluding C3-C4, the growth rate of the grouped vertebrae was affected by age, gender, and CSI dose (risk classification). The risk classification alone affected the growth rates of C3 (p = 0.002) and L3 (p = 0.02). Before CSI, the length of all vertebral bodies was an increasing function of age (p <0.0001). The C3 length before CSI was affected by gender and risk classification: C3 was longer for female (p = 0.07) and high-risk (p = 0.07) patients. Conclusion: All vertebrae grew significantly after CSI, with the vertebrae of the boys and younger patients growing at a rate greater than that of their counterparts. The effect of age was similar across all vertebrae, and gender had the greatest effect on the growth of the lower cervical and upper thoracic vertebrae. The effect of the risk classification was greatest in the lumbar spine by a factor of {<=}10.

  7. DEVELOPMENTAL PALEOBIOLOGY OF THE VERTEBRATE SKELETON

    PubMed Central

    RÜCKLIN, MARTIN; DONOGHUE, PHILIP C. J.; CUNNINGHAM, JOHN A.; MARONE, FEDERICA; STAMPANONI, MARCO

    2015-01-01

    Studies of the development of organisms can reveal crucial information on homology of structures. Developmental data are not peculiar to living organisms, and they are routinely preserved in the mineralized tissues that comprise the vertebrate skeleton, allowing us to obtain direct insight into the developmental evolution of this most formative of vertebrate innovations. The pattern of developmental processes is recorded in fossils as successive stages inferred from the gross morphology of multiple specimens and, more reliably and routinely, through the ontogenetic stages of development seen in the skeletal histology of individuals. Traditional techniques are destructive and restricted to a 2-D plane with the third dimension inferred. Effective non-invasive methods of visualizing paleohistology to reconstruct developmental stages of the skeleton are necessary. In a brief survey of paleohistological techniques we discuss the pros and cons of these methods. The use of tomographic methods to reconstruct development of organs is exemplified by the study of the placoderm dentition. Testing evidence for the presence of teeth in placoderms, the first jawed vertebrates, we compare the methods that have been used. These include inferring the development from morphology, and using serial sectioning, microCT or synchrotron X-ray tomographic microscopy (SRXTM) to reconstruct growth stages and directions of growth. The ensuing developmental interpretations are biased by the methods and degree of inference. The most direct and reliable method is using SRXTM data to trace sclerochronology. The resulting developmental data can be used to resolve homology and test hypotheses on the origin of evolutionary novelties. PMID:26306050

  8. Quaternary vertebrates from Greenland: A review

    NASA Astrophysics Data System (ADS)

    Bennike, Ole

    Remains of fishes, birds and mammals are rarely reported from Quaternary deposits in Greenland. The oldest remains come from Late Pliocene and Early Pleistocene deposits and comprise Atlantic cod, hare, rabbit and ringed seal. Interglacial and interstadial deposits have yielded remains of cod, little auk, collared lemming, ringed seal, reindeer and bowhead whale. Early and Mid-Holocene finds include capelin, polar cod, red fish, sculpin, three-spined stickleback, Lapland longspur, Arctic hare, collared lemming, wolf, walrus, ringed seal, reindeer and bowhead whale. It is considered unlikely that vertebrates could survive in Greenland during the peak of the last glaciation, but many species had probably already immigrated in the Early Holocene.

  9. Vertebrate gravity sensors as dynamic systems

    NASA Technical Reports Server (NTRS)

    Ross, M. D.

    1985-01-01

    This paper considers verterbrate gravity receptors as dynamic sensors. That is, it is hypothesized that gravity is a constant force to which an acceleration-sensing system would readily adapt. Premises are considered in light of the presence of kinocilia on hair cells of vertebrate gravity sensors; differences in loading of the sensors among species; and of possible reduction in loading by inclusion of much organic material in otoconia. Moreover, organic-inorganic interfaces may confer a piezoelectric property upon otoconia, which increase the sensitivity of the sensory system to small accelerations. Comparisons with man-made accelerometers are briefly taken up.

  10. Evaluation and Management of Vertebral Compression Fractures

    PubMed Central

    Alexandru, Daniela; So, William

    2012-01-01

    Compression fractures affect many individuals worldwide. An estimated 1.5 million vertebral compression fractures occur every year in the US. They are common in elderly populations, and 25% of postmenopausal women are affected by a compression fracture during their lifetime. Although these fractures rarely require hospital admission, they have the potential to cause significant disability and morbidity, often causing incapacitating back pain for many months. This review provides information on the pathogenesis and pathophysiology of compression fractures, as well as clinical manifestations and treatment options. Among the available treatment options, kyphoplasty and percutaneous vertebroplasty are two minimally invasive techniques to alleviate pain and correct the sagittal imbalance of the spine. PMID:23251117

  11. Life-long accumulation of 137Cs and 40K in the vertebral column of a cow.

    PubMed

    Pichl, Elke; Rabitsch, Herbert

    2013-01-01

    We have investigated the accumulation of (137)Cs and (40)K in all the tissues and organs of an adult slaughtered Austrian "mountain pasture cow". In this paper we present measured (137)Cs- and (40)K-activity concentrations in different tissues of the vertebral bodies, in their other bony components and in all the vertebrae forming the vertebral column. Data are also given for activity concentrations of adherent tissues, and for activities of both the components and the whole vertebral column. The dairy cow was born in a highly contaminated region of Styria, Austria, at the time of the radioactive fallout following the Chernobyl accident. Both radionuclides were incorporated during life-long ingestion and their accumulation in all the vertebrae up to the day of slaughtering was determined by high-purity germanium detectors. Our results show considerable variations of (137)Cs- and (40)K-activity concentrations in the components of a certain vertebra, within vertebrae of a particular region, and between vertebrae of different regions of the vertebral column. Particularly, the courses of (137)Cs- and (40)K-activity concentrations in trabecular bone, cortical bone and intervertebral discs of thoracic vertebral bodies are subdivided by a strong drop into two sections. Mean values of (137)Cs-concentration in vertebral bodies of these subsections vary by a factor 4. Compared with corresponding quantities for the skeleton, total mass, as well as total (137)Cs- and (40)K-activities of the whole vertebral column came to 14%, and approximately 38% for each (137)Cs and (40)K, respectively. PMID:22943884

  12. Evolution of vertebrate forebrain development: how many different mechanisms?

    PubMed Central

    FOLEY, ANN C.; STERN, CLAUDIO D.

    2001-01-01

    Over the past 50 years and more, many models have been proposed to explain how the nervous system is initially induced and how it becomes subdivided into gross regions such as forebrain, midbrain, hindbrain and spinal cord. Among these models is the 2-signal model of Nieuwkoop & Nigtevecht (1954), who suggested that an initial signal (‘activation’) from the organiser both neuralises and specifies the forebrain, while later signals (‘transformation’) from the same region progressively caudalise portions of this initial territory. An opposing idea emerged from the work of Otto Mangold (1933) and other members of the Spemann laboratory: 2 or more distinct organisers, emitting different signals, were proposed to be responsible for inducing the head, trunk and tail regions. Since then, evidence has accumulated that supports one or the other model, but it has been very difficult to distinguish between them. Recently, a considerable body of work from mouse embryos has been interpreted as favouring the latter model, and as suggesting that a ‘head organiser’, required for the induction of the forebrain, is spatially separate from the classic organiser (Hensen's node). An extraembryonic tissue, the ‘anterior visceral endoderm’ (AVE), was proposed to be the source of forebrain-inducing signals. It is difficult to find tissues that are directly equivalent embryologically or functionally to the AVE in other vertebrates, which led some (e.g. Kessel, 1998) to propose that mammals have evolved a new way of patterning the head. We will present evidence from the chick embryo showing that the hypoblast is embryologically and functionally equivalent to the mouse AVE. Like the latter, the hypoblast also plays a role in head development. However, it does not act like a true organiser. It induces pre-neural and pre-forebrain markers, but only transiently. Further development of neural and forebrain phenotypes requires additional signals not provided by the hypoblast. In

  13. Axial allometry in a neutrally buoyant environment: effects of the terrestrial-aquatic transition on vertebral scaling.

    PubMed

    Jones, K E; Pierce, S E

    2016-03-01

    Ecological diversification into new environments presents new mechanical challenges for locomotion. An extreme example of this is the transition from a terrestrial to an aquatic lifestyle. Here, we examine the implications of life in a neutrally buoyant environment on adaptations of the axial skeleton to evolutionary increases in body size. On land, mammals must use their thoracolumbar vertebral column for body support against gravity and thus exhibit increasing stabilization of the trunk as body size increases. Conversely, in water, the role of the axial skeleton in body support is reduced, and, in aquatic mammals, the vertebral column functions primarily in locomotion. Therefore, we hypothesize that the allometric stabilization associated with increasing body size in terrestrial mammals will be minimized in secondarily aquatic mammals. We test this by comparing the scaling exponent (slope) of vertebral measures from 57 terrestrial species (23 felids, 34 bovids) to 23 semi-aquatic species (pinnipeds), using phylogenetically corrected regressions. Terrestrial taxa meet predictions of allometric stabilization, with posterior vertebral column (lumbar region) shortening, increased vertebral height compared to width, and shorter, more disc-shaped centra. In contrast, pinniped vertebral proportions (e.g. length, width, height) scale with isometry, and in some cases, centra even become more spool-shaped with increasing size, suggesting increased flexibility. Our results demonstrate that evolution of a secondarily aquatic lifestyle has modified the mechanical constraints associated with evolutionary increases in body size, relative to terrestrial taxa. PMID:26679743

  14. 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. PMID:18946872

  15. A kind of specific osteolytic destruction of the vertebral bodies

    PubMed Central

    Peng, Baogan; Chen, Jinhong; Pang, Xiaodong; Hei, Yan

    2012-01-01

    This report describes two young patients with osteolytic destruction in two adjacent vertebral bodies along with the intervertebral disc, and reveals its possible mechanism. A lateral radiograph and CT scan displayed a giant osteolytic cavity in the L4 vertebral body. An MRI or CT scan with a two-dimensional reconstruction displayed the same changes in the L4 vertebral body and lower endplate erosion in the L3 vertebral body. A comprehensive preoperative evaluation did not identify a specific cause of vertebral destruction. Both patients underwent anterior lumbar fusion surgery. The lesions were removed for histological and immunohistochemical examination. Histopathological study of the destructed vertebral bodies in the two patients revealed the disruption or atrophy of bone trabeculae with infiltration of a large amount of B-lymphocytes and macrophages into the marrow cavities. Studies of its pathogenesis reveal that it is likely to be a B-lymphocyte-mediated local immune inflammatory reaction in the lumbar spine. PMID:22675148

  16. Crossveinless-2 is required for the relocalization of Chordin protein within the vertebral field in mouse embryos

    PubMed Central

    Zakin, Lise; Chang, Ellen Y.; Plouhinec, Jean-Louis; De Robertis, E. M.

    2010-01-01

    Bone morphogenetic proteins (BMPs), as well as the BMP-binding molecules Chordin (Chd), Crossveinless-2 (CV2) and Twisted Gastrulation (Tsg), are essential for axial skeletal development in the mouse embryo. We previously reported a strong genetic interaction between CV2 and Tsg and proposed a role for this interaction in the shaping of the BMP morphogenetic field during vertebral development. In the present study we investigated the roles of CV2 and Chd in the formation of the vertebral morphogenetic field. We performed immunostainings for CV2 and Chd protein on wild-type, CV2−/− or Chd−/− mouse embryo sections at the stage of onset of the vertebral phenotypes. By comparing mRNA and protein localizations we found that CV2 does not diffuse away from its place of synthesis, the vertebral body. The most interesting finding of this study was that Chd synthesized in the intervertebral disc accumulates in the vertebral body. This relocalization does not take place in CV2−/− mutants. Instead, Chd was found to accumulate at its site of synthesis in CV2−/− embryos. These results indicate a CV2-dependent flow of Chd protein from the intervertebral disc to the vertebral body. Smad1/5/8 phosphorylation was decreased in CV2−/−vertebral bodies. This impaired BMP signaling may result from the decreased levels of Chd/BMP complexes diffusing from the intervertebral region. The data indicate a role for CV2 and Chd in the establishment of the vertebral morphogenetic field through the long-range relocalization of Chd/BMP complexes. The results may have general implications for the formation of embryonic organ-forming morphogenetic fields. PMID:20807528

  17. The Vertebrate Primary Cilium in Development, Homeostasis, and Disease

    PubMed Central

    Gerdes, Jantje M.; Davis, Erica E.; Katsanis, Nicholas

    2010-01-01

    Cilia are complex structures that have garnered interest because of their roles in vertebrate development and their involvement in human genetic disorders. In contrast to multicellular invertebrates in which cilia are restricted to specific cell types, these organelles are found almost ubiquitously in vertebrate cells, where they serve a diverse set of signaling functions. Here, we highlight properties of vertebrate cilia, with particular emphasis on their relationship with other subcellular structures, and explore the physiological consequences of ciliary dysfunction. PMID:19345185

  18. Sensing and surviving hypoxia in vertebrates.

    PubMed

    Jonz, Michael G; Buck, Leslie T; Perry, Steve F; Schwerte, Thorsten; Zaccone, Giacomo

    2016-02-01

    Surviving hypoxia is one of the most critical challenges faced by vertebrates. Most species have adapted to changing levels of oxygen in their environment with specialized organs that sense hypoxia, while only few have been uniquely adapted to survive prolonged periods of anoxia. The goal of this review is to present the most recent research on oxygen sensing, adaptation to hypoxia, and mechanisms of anoxia tolerance in nonmammalian vertebrates. We discuss the respiratory structures in fish, including the skin, gills, and air-breathing organs, and recent evidence for chemosensory neuroepithelial cells (NECs) in these tissues that initiate reflex responses to hypoxia. The use of the zebrafish as a genetic and developmental model has allowed observation of the ontogenesis of respiratory and chemosensory systems, demonstration of a putative intracellular O2 sensor in chemoreceptors that may initiate transduction of the hypoxia signal, and investigation into the effects of extreme hypoxia on cardiorespiratory development. Other organisms, such as goldfish and freshwater turtles, display a high degree of anoxia tolerance, and these models are revealing important adaptations at the cellular level, such as the regulation of glutamatergic and GABAergic neurotransmission in defense of homeostasis in central neurons. PMID:25959851

  19. TRPM7 regulates gastrulation during vertebrate embryogenesis

    PubMed Central

    Liu, Wei; Su, Li-Ting; Khadka, Deepak K.; Mezzacappa, Courtney; Komiya, Yuko; Sato, Akira; Habas, Raymond; Runnels, Loren W.

    2010-01-01

    During gastrulation, cells in the dorsal marginal zone polarize, elongate, align and intercalate to establish the physical body axis of the developing embryo. Here we demonstrate that the bifunctional channel-kinase TRPM7 is specifically required for vertebrate gastrulation. TRPM7 is temporally expressed maternally and throughout development, and is spatially enriched in tissues undergoing convergent extension during gastrulation. Functional studies reveal that TRPM7’s ion channel, but not its kinase, specifically affects cell polarity and convergent extension movements during gastrulation, independent of mesodermal specification. During gastrulation, the non-canonical Wnt pathway via Dishevelled (Dvl) orchestrates the activities of the GTPases Rho and Rac to control convergent extension movements. We find that TRPM7 functions synergistically with non-canonical Wnt signaling to regulate Rac activity. The phenotype caused by depletion of the Ca2+- and Mg2+-permeant TRPM7 is suppressed by expression of a dominant negative form of Rac, as well as by Mg2+ supplementation or by expression of the Mg2+ transporter SLC41A2. Together, these studies demonstrate an essential role for the ion channel TRPM7 and Mg2+ in Rac-dependent polarized cell movements during vertebrate gastrulation. PMID:21145885

  20. Recursive splicing in long vertebrate genes

    PubMed Central

    Blazquez, Lorea; Faro, Ana; Haberman, Nejc; Briese, Michael; Trabzuni, Daniah; Ryten, Mina; Weale, Michael E; Hardy, John; Modic, Miha; Curk, Tomaž; Wilson, Stephen W; Plagnol, Vincent; Ule, Jernej

    2015-01-01

    It is generally believed that splicing removes introns as single units from pre-mRNA transcripts. However, some long D. melanogaster introns contain a cryptic site, called a recursive splice site (RS-site), that enables a multi-step process of intron removal termed recursive splicing1,2. The extent to which recursive splicing occurs in other species and its mechanistic basis remain unclear. Here we identify highly conserved RS-sites in genes expressed in the mammalian brain that encode proteins functioning in neuronal development. Moreover, the RS-sites are found in some of the longest introns across vertebrates. We find that vertebrate recursive splicing requires initial definition of a “RS-exon” that follows the RS-site. The RS-exon is then excluded from the dominant mRNA isoform due to competition with a reconstituted 5′ splice site formed at the RS-site after the first splicing step. Conversely, the RS-exon is included when preceded by cryptic exons or promoters that are prevalent in long introns, but which fail to reconstitute an efficient 5′ splice site. Most RS-exons contain a premature stop codon such that their inclusion may decrease mRNA stability. Thus, by establishing a binary splicing switch, RS-sites demarcate different mRNA isoforms emerging from long genes by coupling inclusion of cryptic elements with RS-exons. PMID:25970246

  1. Gene expression throughout a vertebrate's embryogenesis

    PubMed Central

    2011-01-01

    Background Describing the patterns of gene expression during embryonic development has broadened our understanding of the processes and patterns that define morphogenesis. Yet gene expression patterns have not been described throughout vertebrate embryogenesis. This study presents statistical analyses of gene expression during all 40 developmental stages in the teleost Fundulus heteroclitus using four biological replicates per stage. Results Patterns of gene expression for 7,000 genes appear to be important as they recapitulate developmental timing. Among the 45% of genes with significant expression differences between pairs of temporally adjacent stages, significant differences in gene expression vary from as few as five to more than 660. Five adjacent stages have disproportionately more significant changes in gene expression (> 200 genes) relative to other stages: four to eight and eight to sixteen cell stages, onset of circulation, pre and post-hatch, and during complete yolk absorption. The fewest differences among adjacent stages occur during gastrulation. Yet, at stage 16, (pre-mid-gastrulation) the largest number of genes has peak expression. This stage has an over representation of genes in oxidative respiration and protein expression (ribosomes, translational genes and proteases). Unexpectedly, among all ribosomal genes, both strong positive and negative correlations occur. Similar correlated patterns of expression occur among all significant genes. Conclusions These data provide statistical support for the temporal dynamics of developmental gene expression during all stages of vertebrate development. PMID:21356103

  2. Recursive splicing in long vertebrate genes.

    PubMed

    Sibley, Christopher R; Emmett, Warren; Blazquez, Lorea; Faro, Ana; Haberman, Nejc; Briese, Michael; Trabzuni, Daniah; Ryten, Mina; Weale, Michael E; Hardy, John; Modic, Miha; Curk, Tomaž; Wilson, Stephen W; Plagnol, Vincent; Ule, Jernej

    2015-05-21

    It is generally believed that splicing removes introns as single units from precursor messenger RNA transcripts. However, some long Drosophila melanogaster introns contain a cryptic site, known as a recursive splice site (RS-site), that enables a multi-step process of intron removal termed recursive splicing. The extent to which recursive splicing occurs in other species and its mechanistic basis have not been examined. Here we identify highly conserved RS-sites in genes expressed in the mammalian brain that encode proteins functioning in neuronal development. Moreover, the RS-sites are found in some of the longest introns across vertebrates. We find that vertebrate recursive splicing requires initial definition of an 'RS-exon' that follows the RS-site. The RS-exon is then excluded from the dominant mRNA isoform owing to competition with a reconstituted 5' splice site formed at the RS-site after the first splicing step. Conversely, the RS-exon is included when preceded by cryptic promoters or exons that fail to reconstitute an efficient 5' splice site. Most RS-exons contain a premature stop codon such that their inclusion can decrease mRNA stability. Thus, by establishing a binary splicing switch, RS-sites demarcate different mRNA isoforms emerging from long genes by coupling cryptic elements with inclusion of RS-exons. PMID:25970246

  3. Generation of Viable Plant-Vertebrate Chimeras.

    PubMed

    Alvarez, Marjorie; Reynaert, Nicole; Chávez, Myra N; Aedo, Geraldine; Araya, Francisco; Hopfner, Ursula; Fernández, Juan; Allende, Miguel L; Egaña, José T

    2015-01-01

    The extreme dependence on external oxygen supply observed in animals causes major clinical problems and several diseases are related to low oxygen tension in tissues. The vast majority of the animals do not produce oxygen but a few exceptions have shown that photosynthetic capacity is physiologically compatible with animal life. Such symbiotic photosynthetic relationships are restricted to a few aquatic invertebrates. In this work we aimed to explore if we could create a chimerical organism by incorporating photosynthetic eukaryotic cells into a vertebrate animal model. Here, the microalgae Chlamydomonas reinhardtii was injected into zebrafish eggs and the interaction and viability of both organisms were studied. Results show that microalgae were distributed into different tissues, forming a fish-alga chimera organism for a prolonged period of time. In addition, microscopic observation of injected algae, in vivo expression of their mRNA and re-growth of the algae ex vivo suggests that they survived to the developmental process, living for several days after injection. Moreover microalgae did not trigger a significant inflammatory response in the fish. This work provides additional evidence to support the possibility that photosynthetic vertebrates can be engineered. PMID:26126202

  4. Vertebrate helentrons and other novel Helitrons.

    PubMed

    Poulter, Russell T M; Goodwin, Timothy J D; Butler, Margaret I

    2003-08-14

    Helitrons, a novel class of eukaryote mobile genetic elements, are distinguished from other transposable elements by encoding a 'rolling circle' replication (RCR) protein (Rep) and a helicase. Helitrons have recently been described from Arabidopsis, rice and the nematode Caenorhabditis. We now report the discovery of Helitron-like elements in vertebrates, specifically in the genomes of the fish Danio rerio and Sphoeroides nephelus. We also describe Helitrons from the white rot fungus Phanerochaete chrysosporium and from the Anopheles genome. Many of the fish Helitrons have an uncorrupted open reading frame encoding both the RCR Rep protein and a helicase. These fish elements are of particular interest because they also encode, within the single open reading frame, an apurinic-apyrimidinic (AP) endonuclease most closely related to those of certain non-long terminal repeat retrotransposons. As they invariably carry an endonuclease and also form a very distinct clade, we have named these vertebrate elements 'helentrons'. It is likely that these helentrons are still active. PMID:12957391

  5. Degenerative diseases of the vertebral column.

    PubMed

    Resnick, D

    1985-07-01

    Several distinct degenerative processes affect the articulations of the vertebral column; each is associated with characteristic radiographic and pathologic abnormalities, and many are accompanied by significant clinical manifestations. A discussion of these processes is best accomplished according to the type of joint that is involved. With regard to cartilaginous articulations, of which the intervertebral disk is most important, intervertebral (osteo)chondrosis, spondylosis deformans, and, in the cervical spine, uncovertebral arthrosis are the major degenerative disorders. Osteoarthritis (osteoarthrosis) affects any of the synovium-lined joints of the vertebral column, including the apophyseal, costovertebral, transitional lumbosacral, median atlantoaxial, and sacroiliac articulations. Fibrous articulations, ligaments, or entheses (sites of tendon or ligament attachment to bone) are involved in diffuse idiopathic skeletal hyperostosis, ossification of the posterior spinal ligaments, and Baastrup disease. Of the many complications of these degenerative processes, alignment abnormalities (including segmental instability, degenerative spondylolisthesis, senile kyphosis, and degenerative scoliosis), intervertebral disk displacement, calcification or ossification, and spinal stenosis are the most important. PMID:3923556

  6. What can vertebrates tell us about segmentation?

    PubMed Central

    2014-01-01

    Segmentation is a feature of the body plans of a number of diverse animal groupings, including the annelids, arthropods and chordates. However, it has been unclear whether or not these different manifestations of segmentation are independently derived or have a common origin. Central to this issue is whether or not there are common developmental mechanisms that establish segmentation and the evolutionary origins of these processes. A fruitful way to address this issue is to consider how segmentation in vertebrates is directed. During vertebrate development three different segmental systems are established: the somites, the rhombomeres and the pharyngeal arches. In each an iteration of parts along the long axis is established. However, it is clear that the formation of the somites, rhombomeres or pharyngeal arches have little in common, and as such there is no single segmentation process. These different segmental systems also have distinct evolutionary histories, thus highlighting the fact that segmentation can and does evolve independently at multiple points. We conclude that the term segmentation indicates nothing more than a morphological description and that it implies no mechanistic similarity. Thus it is probable that segmentation has arisen repeatedly during animal evolution. PMID:25009737

  7. The evolution of vertebrate opioid receptors

    PubMed Central

    Stevens, Craig W.

    2011-01-01

    The proteins that mediate the analgesic and other effects of opioid drugs and endogenous opioid peptides are known as opioid receptors. Opioid receptors consist of a family of four closely-related proteins belonging to the large superfamily of G-protein coupled receptors. The three types of opioid receptors shown unequivocally to mediate analgesia in animal models are the mu (MOR), delta (DOR), and kappa (KOR) opioid receptor proteins. The role of the fourth member of the opioid receptor family, the nociceptin or orphanin FQ receptor (ORL), is not as clear as hyperalgesia, analgesia, and no effect was reported after administration of ORL agonists. There are now cDNA sequences for all four types of opioid receptors that are expressed in the brain of six species from three different classes of vertebrates. This review presents a comparative analysis of vertebrate opioid receptors using bioinformatics and data from recent human genome studies. Results indicate that opioid receptors arose by gene duplication, that there is a vector of opioid receptor divergence, and that MOR shows evidence of rapid evolution. PMID:19273128

  8. Identifying Synonymous Regulatory Elements in Vertebrate Genomes

    SciTech Connect

    Ovcharenko, I; Nobrega, M A

    2005-02-07

    Synonymous gene regulation, defined as driving shared temporal and/or spatial expression of groups of genes, is likely predicated on genomic elements that contain similar modules of certain transcription factor binding sites (TFBS). We have developed a method to scan vertebrate genomes for evolutionary conserved modules of TFBS in a predefined configuration, and created a tool, named SynoR that identify synonymous regulatory elements (SREs) in vertebrate genomes. SynoR performs de novo identification of SREs utilizing known patterns of TFBS in active regulatory elements (REs) as seeds for genome scans. Layers of multiple-species conservation allow the use of differential phylogenetic sequence conservation filters in the search of SREs and the results are displayed as to provide an extensive annotation of genes containing detected REs. Gene Ontology categories are utilized to further functionally classify the identified genes, and integrated GNF Expression Atlas 2 data allow the cataloging of tissue-specificities of the predicted SREs. We illustrate how this new tool can be used to establish a linkage between human diseases and noncoding genomic content. SynoR is publicly available at http://synor.dcode.org.

  9. The origins and evolution of vertebrate metamorphosis.

    PubMed

    Laudet, Vincent

    2011-09-27

    Metamorphosis, classically defined as a spectacular post-embryonic transition, is well exemplified by the transformation of a tadpole into a frog. It implies the appearance of new body parts (such as the limbs), the resorption of larval features (such as the tail) and the remodelling of many organs (such as the skin or the intestine). In vertebrates, metamorphosis has been well characterized in anuran amphibians, where thyroid hormones orchestrate the intricate and seemingly contradictory changes observed at the cellular and tissue levels. Thyroid hormones control a complex hierarchical cascade of target genes via binding to specific receptors, TRα and TRβ, ligand-activated transcription factors belonging to the nuclear receptor superfamily. Metamorphosis is actually widespread in the vertebrates, though quite diverse in the way it manifests in a particular species. Furthermore, evolutionary and ecological variations of this key event, from paedomorphosis to direct development, provide an excellent illustration of how tinkering with a control pathway can lead to divergent life histories. The study of invertebrate chordates has also shed light on the origin of metamorphosis. The available data suggest that post-embryonic remodelling governed by thyroid hormones is an ancestral feature of chordates. According to this view, metamorphosis of the anurans is an extreme example of a widespread life history transition. PMID:21959163

  10. Permo-Triassic vertebrate extinctions: A program

    NASA Technical Reports Server (NTRS)

    Olson, E. C.

    1988-01-01

    Since the time of the Authors' study on this subject, a great deal of new information has become available. Concepts of the nature of extinctions have changed materially. The Authors' conclusion that a catastrophic event was not responsible for the extinction of vertebrates has modified to the extent that hypotheses involving either the impact of a massive extra-terrestrial body or volcanism provide plausible but not currently fully testable hypotheses. Stated changes resulted in a rapid decrease in organic diversity, as the ratio of origins of taxa to extinctions shifted from strongly positive to negative, with momentary equilibrium being reached at about the Permo-Triassic boundary. The proximate causes of the changes in the terrestrial biota appear to lie in two primary factors: (1) strong climatic changes (global mean temperatures, temperature ranges, humidity) and (2) susceptibility of the dominant vertebrates (large dicynodonts) and the glossopteris flora to disruption of the equlibrium of the world ecosystem. The following proximate causes have been proposed: (1) rhythmic fluctuations in solar radiation, (2) tectonic events as Pangea assembled, altering land-ocean relationships, patterns of wind and water circulation and continental physiography, (3) volcanism, and (4) changes subsequent to impacts of one or more massive extra terrestrial objects, bodies or comets. These hypotheses are discussed.