Axial Skeleton

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Laura Ab Wilson - One of the best experts on this subject based on the ideXlab platform.

  • Regionalization of the Axial Skeleton in the ‘ambush predator’ guild – are there developmental rules underlying body shape evolution in ray-finned fishes?
    BMC Evolutionary Biology, 2013
    Co-Authors: Erin E Maxwell, Laura Ab Wilson
    Abstract:

    Background A long, slender body plan characterized by an elongate antorbital region and posterior displacement of the unpaired fins has evolved multiple times within ray-finned fishes, and is associated with ambush predation. The Axial Skeleton of ray-finned fishes is divided into abdominal and caudal regions, considered to be evolutionary modules. In this study, we test whether the convergent evolution of the ambush predator body plan is associated with predictable, regional changes in the Axial Skeleton, specifically whether the abdominal region is preferentially lengthened relative to the caudal region through the addition of vertebrae. We test this hypothesis in seven clades showing convergent evolution of this body plan, examining abdominal and caudal vertebral counts in over 300 living and fossil species. In four of these clades, we also examined the relationship between the fineness ratio and vertebral regionalization using phylogenetic independent contrasts. Results We report that in five of the clades surveyed, Lepisosteidae, Esocidae, Belonidae, Sphyraenidae and Fistulariidae, vertebrae are added preferentially to the abdominal region. In Lepisosteidae, Esocidae, and Belonidae, increasing abdominal vertebral count was also significantly related to increasing fineness ratio, a measure of elongation. Two clades did not preferentially add abdominal vertebrae: Saurichthyidae and Aulostomidae. Both of these groups show the development of a novel caudal region anterior to the insertion of the anal fin, morphologically differentiated from more posterior caudal vertebrae. Conclusions The preferential addition of abdominal vertebrae in fishes with an elongate body shape is consistent with the existence of a conservative positioning module formed by the boundary between the abdominal and caudal vertebral regions and the anterior insertion of the anal fin. Dissociation of this module is possible, although less probable than changes in the independently evolving abdominal region. Dissociation of the Axial Skeleton-median fin module leads to increased regionalization within the caudal vertebral column, something that has evolved several times in bony fishes, and may be homologous with the sacral region of tetrapods. These results suggest that modularity of the Axial Skeleton may result in somewhat predictable evolutionary outcomes in bony fishes.

  • regionalization of the Axial Skeleton in the ambush predator guild are there developmental rules underlying body shape evolution in ray finned fishes
    BMC Evolutionary Biology, 2013
    Co-Authors: Erin E Maxwell, Laura Ab Wilson
    Abstract:

    Background A long, slender body plan characterized by an elongate antorbital region and posterior displacement of the unpaired fins has evolved multiple times within ray-finned fishes, and is associated with ambush predation. The Axial Skeleton of ray-finned fishes is divided into abdominal and caudal regions, considered to be evolutionary modules. In this study, we test whether the convergent evolution of the ambush predator body plan is associated with predictable, regional changes in the Axial Skeleton, specifically whether the abdominal region is preferentially lengthened relative to the caudal region through the addition of vertebrae. We test this hypothesis in seven clades showing convergent evolution of this body plan, examining abdominal and caudal vertebral counts in over 300 living and fossil species. In four of these clades, we also examined the relationship between the fineness ratio and vertebral regionalization using phylogenetic independent contrasts.

  • Regionalization of the Axial Skeleton in the ‘ambush predator’ guild – are there developmental rules underlying body shape evolution in ray-finned fishes?
    BMC Evolutionary Biology, 2013
    Co-Authors: Erin E Maxwell, Laura Ab Wilson
    Abstract:

    Background A long, slender body plan characterized by an elongate antorbital region and posterior displacement of the unpaired fins has evolved multiple times within ray-finned fishes, and is associated with ambush predation. The Axial Skeleton of ray-finned fishes is divided into abdominal and caudal regions, considered to be evolutionary modules. In this study, we test whether the convergent evolution of the ambush predator body plan is associated with predictable, regional changes in the Axial Skeleton, specifically whether the abdominal region is preferentially lengthened relative to the caudal region through the addition of vertebrae. We test this hypothesis in seven clades showing convergent evolution of this body plan, examining abdominal and caudal vertebral counts in over 300 living and fossil species. In four of these clades, we also examined the relationship between the fineness ratio and vertebral regionalization using phylogenetic independent contrasts.

Erin E Maxwell - One of the best experts on this subject based on the ideXlab platform.

  • Regionalization of the Axial Skeleton in the ‘ambush predator’ guild – are there developmental rules underlying body shape evolution in ray-finned fishes?
    BMC Evolutionary Biology, 2013
    Co-Authors: Erin E Maxwell, Laura Ab Wilson
    Abstract:

    Background A long, slender body plan characterized by an elongate antorbital region and posterior displacement of the unpaired fins has evolved multiple times within ray-finned fishes, and is associated with ambush predation. The Axial Skeleton of ray-finned fishes is divided into abdominal and caudal regions, considered to be evolutionary modules. In this study, we test whether the convergent evolution of the ambush predator body plan is associated with predictable, regional changes in the Axial Skeleton, specifically whether the abdominal region is preferentially lengthened relative to the caudal region through the addition of vertebrae. We test this hypothesis in seven clades showing convergent evolution of this body plan, examining abdominal and caudal vertebral counts in over 300 living and fossil species. In four of these clades, we also examined the relationship between the fineness ratio and vertebral regionalization using phylogenetic independent contrasts. Results We report that in five of the clades surveyed, Lepisosteidae, Esocidae, Belonidae, Sphyraenidae and Fistulariidae, vertebrae are added preferentially to the abdominal region. In Lepisosteidae, Esocidae, and Belonidae, increasing abdominal vertebral count was also significantly related to increasing fineness ratio, a measure of elongation. Two clades did not preferentially add abdominal vertebrae: Saurichthyidae and Aulostomidae. Both of these groups show the development of a novel caudal region anterior to the insertion of the anal fin, morphologically differentiated from more posterior caudal vertebrae. Conclusions The preferential addition of abdominal vertebrae in fishes with an elongate body shape is consistent with the existence of a conservative positioning module formed by the boundary between the abdominal and caudal vertebral regions and the anterior insertion of the anal fin. Dissociation of this module is possible, although less probable than changes in the independently evolving abdominal region. Dissociation of the Axial Skeleton-median fin module leads to increased regionalization within the caudal vertebral column, something that has evolved several times in bony fishes, and may be homologous with the sacral region of tetrapods. These results suggest that modularity of the Axial Skeleton may result in somewhat predictable evolutionary outcomes in bony fishes.

  • regionalization of the Axial Skeleton in the ambush predator guild are there developmental rules underlying body shape evolution in ray finned fishes
    BMC Evolutionary Biology, 2013
    Co-Authors: Erin E Maxwell, Laura Ab Wilson
    Abstract:

    Background A long, slender body plan characterized by an elongate antorbital region and posterior displacement of the unpaired fins has evolved multiple times within ray-finned fishes, and is associated with ambush predation. The Axial Skeleton of ray-finned fishes is divided into abdominal and caudal regions, considered to be evolutionary modules. In this study, we test whether the convergent evolution of the ambush predator body plan is associated with predictable, regional changes in the Axial Skeleton, specifically whether the abdominal region is preferentially lengthened relative to the caudal region through the addition of vertebrae. We test this hypothesis in seven clades showing convergent evolution of this body plan, examining abdominal and caudal vertebral counts in over 300 living and fossil species. In four of these clades, we also examined the relationship between the fineness ratio and vertebral regionalization using phylogenetic independent contrasts.

  • Regionalization of the Axial Skeleton in the ‘ambush predator’ guild – are there developmental rules underlying body shape evolution in ray-finned fishes?
    BMC Evolutionary Biology, 2013
    Co-Authors: Erin E Maxwell, Laura Ab Wilson
    Abstract:

    Background A long, slender body plan characterized by an elongate antorbital region and posterior displacement of the unpaired fins has evolved multiple times within ray-finned fishes, and is associated with ambush predation. The Axial Skeleton of ray-finned fishes is divided into abdominal and caudal regions, considered to be evolutionary modules. In this study, we test whether the convergent evolution of the ambush predator body plan is associated with predictable, regional changes in the Axial Skeleton, specifically whether the abdominal region is preferentially lengthened relative to the caudal region through the addition of vertebrae. We test this hypothesis in seven clades showing convergent evolution of this body plan, examining abdominal and caudal vertebral counts in over 300 living and fossil species. In four of these clades, we also examined the relationship between the fineness ratio and vertebral regionalization using phylogenetic independent contrasts.

Yuji Makino - One of the best experts on this subject based on the ideXlab platform.

  • Developmental biology and etiology of Axial Skeleton: Lessons from a mouse model of spondylocostal dysostosis and spondylothoracic dysostosis
    Journal of Oral Biosciences, 2013
    Co-Authors: Yuji Makino, Kazuo Kaneko, Akira Yamaguchi, Tadahiro Iimura
    Abstract:

    Abstract Skeletal patterning is tightly linked to embryonic morphogenesis. Accumulated evidence on genotype–phenotype analyses in model animals and human has uncovered molecular signals that participate in skeletal size, shape, and spatial organization. Embryonic morphogenesis endows morphological information to groups of skeletal precursors. Accordingly, some of the congenital skeletal disorders are manifested as defects in embryogenesis prior to skeletal tissue differentiation and pathologically categorized as dysostosis. Spondylocostal dysostosis (SCDO) and spondylothoracic dysostosis (STDO) are skeletal disorders that are highly specific to the Axial Skeleton, vertebrae, and ribs, whose embryonic origin is the segmented mesodermal structure called somite. The genes responsible for these diseases have recently been identified and are operated during somite formation. Current investigations on organogenesis of mouse models of SCDO and STDO uncovered the existence of more complicated regulatory steps for the spatiotemporal organization of the Axial Skeleton than the original view of direct link between morphogenesis and skeletal patterning. Molecular and cellular findings in Axial Skeleton development are expected to contribute to develop more efficient therapeutic strategies against common medical problems.

  • spatiotemporal disorder in the Axial Skeleton development of the mesp2 null mouse a model of spondylocostal dysostosis and spondylothoracic dysostosis
    Bone, 2013
    Co-Authors: Yuji Makino, Yu Takahashi, Rieko Tanabe, Yoshihiro Tamamura, Takashi Watanabe, Mayu Haraikawa, Miwako Hamagaki, Kenji Hata, Jun Kanno
    Abstract:

    Abstract Spondylocostal dysostosis (SCDO) is a genetic disorder characterized by severe malformation of the Axial Skeleton. Mesp2 encodes a basic helix–loop–helix type transcription factor that is required for somite formation. Its human homologue, Mesp2, is a gene affected in patients with SCDO and a related vertebral disorder, spondylothoracic dysostosis (STDO). This work investigated how the loss of Mesp2 affects Axial Skeleton development and causes the clinical features of SCDO and STDO. We first confirmed, by three-dimensional computed tomography scanning, that Mesp2-null mice exhibited mineralized tissue patterning resembling the radiological features of SCDO and STDO. Histological observations and in situ hybridization probing for extracellular matrix molecules demonstrated that the developing vertebral bodies in Mesp2-null mice were extensively fused with rare insertions of intervertebral tissue. Unexpectedly, the intervertebral tissues were mostly fused longitudinally in the vertebral column, instead of exhibiting extended formation, as was expected based on the caudalized properties of Mesp2-null somite derivatives. Furthermore, the differentiation of vertebral body chondrocytes in Mesp2-null mice was spatially disordered and largely delayed, with an increased cell proliferation rate. The quantitative three-dimensional immunofluorescence image analyses of phospho-Smad2 and -Smad1/5/8 revealed that these chondrogenic phenotypes were associated with spatially disordered inputs of TGF-β and BMP signaling in the Mesp2-null chondrocytes, and also demonstrated an amorphous arrangement of cells with distinct properties. Furthermore, a significant delay in ossification in Mesp2-null vertebrae was observed by peripheral quantitative computed tomography. The current observations of the spatiotemporal disorder of vertebral organogenesis in the Mesp2-null mice provide further insight into the pathogenesis of SCDO and STDO, and the physiological development of the Axial Skeleton.

Birgit Fischer Hansen - One of the best experts on this subject based on the ideXlab platform.

  • pattern of malformations in the Axial Skeleton in human trisomy 18 fetuses
    American Journal of Medical Genetics, 1997
    Co-Authors: Inger Kjær, Jean W. Keeling, Birgit Fischer Hansen
    Abstract:

    We examined and described the development and abnormalities of the Axial Skeleton in 10 human trisomy 18 fetuses. Whole-body radiographs and radiographs of midsagittal tissue blocks of the cranial base and the spine were studied. In 3 fetuses no spinal radiographs were available. Seven osseous regions or fields along the body axis were analyzed, four in the spine, and three in the cranial base and nasal bones. Malformations occurred in the occipital field in all fetuses. This was a characteristic notching, either unilateral or bilateral, of the basilar part of the occipital bone. Nasal bones were abnormal in 8 cases, either absent or hypoplastic. Malformations were found in the thoracic and/or lumbosacral field in 7 fetuses. A single abnormality was found in the cervical spine in one fetus. The pattern of Axial skeletal malformation in trisomy 18 fetuses recorded in the present study has not been described previously. Axial skeletal radiography should be included in autopsies of fetuses when chromosome disorders are present or suspected. The methods applied here are unaffected by autolysis. 26 refs., 5 figs.

  • Axial Skeleton and pituitary gland in human fetuses with spina bifida and cranial encephalocele.
    Pediatric Pathology & Laboratory Medicine, 1996
    Co-Authors: Inger Kjær, Birgit Fischer Hansen, Jean W. Keeling
    Abstract:

    The purpose of this study was to investigate the Axial Skeleton and the pituitary gland in fetuses with spina bifida or cranial encephalocele in order to elucidate the pathogenesis of the conditions. The findings were related to former investigations performed on normal fetuses and on fetuses with anencephaly and rachischisis. Eight human fetuses from spontaneous or therapeutic abortions, 11-28 weeks of gestational age, were investigated. Radiographs were taken of the Axial Skeleton and histological investigation, including immunohistochemical marking for thyroid-stimulating hormone was performed on tissue blocks of the cranial base, including the sella turcica and the pituitary gland. Radiography revealed only minor malformations in the Axial Skeleton and not in all cases. The types of malformations resembled those seen in anencephaly and rachischisis. Histological investigations revealed severe malformations in the sella turcica region in spina bifida and minor ones in cranial encephalocele. Pharyngeall...

R.a. Dickson - One of the best experts on this subject based on the ideXlab platform.

  • PRIMARY BONE TUMOURS OF THE Axial Skeleton: A 42-YEAR SURVEY FROM THE LEEDS REGIONAL BONE TUMOUR REGISTRY
    2008
    Co-Authors: S.p. Kelley, Robert U. Ashford, R.a. Dickson
    Abstract:

    Purpose: We conducted a review of the Leeds Regional Bone Tumour Registry for primary bone tumours of the Axial Skeleton since establishment in 1958 until year 2000 to analyze the incidence of primary tumours of the Axial Skeleton and to record their site of occurrence, sex distribution, survival and pathology. Method: Primary tumours of the Axial Skeleton are particularly rare, accounting for between 4% and 13% of published series of primary bone tumours. The Leeds Bone Tumour Registry was reviewed and a total of 2750 cases of bone tumours and tumour-like cases were analyzed. Consultants in orthopaedic surgery, neurosurgery, oncology and pathology in North and West Yorkshire and Humberside contribute to the Registry. Results: Primary bone tumours of the Axial Skeleton constitute only 126 of the 2,750 cases (4.6%). Chordoma was the most frequent tumour in the cervical and sacral regions, while the most common diagnosis overall was myeloma. Osteosarcoma ranked third. Mean age of presentation was 42 years. Pain was the most common presenting symptom, occurring in 95% of malignant and 76% of benign tumours. Neurological involvement occurred in 52% of malignant tumours and usually meant a poor prognosis, Conclusions: The establishment of Bone Tumour Registries is the only way that sufficient data on large numbers of these rare tumours can be accumulated to provide a valuable and otherwise unavailable source of information for research, education and clinical follow-up.

  • primary tumors of the Axial Skeleton experience of the leeds regional bone tumor registry
    Spine, 1990
    Co-Authors: Clark R Dreghorn, Raymond J Newman, Graham J Hardy, R.a. Dickson
    Abstract:

    : Primary tumors of the Axial Skeleton are rare and a survey of the Leeds Regional Bone Tumor Registry found them to constitute only 55 of the 1950 cases (2.8%). Chordoma was the most frequent tumor in the cervical and sacral regions as well as the most common diagnosis overall and osteosarcoma ranked second. Pain was the most frequent presenting symptom but over half the patients developed some neurological abnormality. In spite of treatment survival was poor in patients with malignant lesions or neurological involvement. The establishment of Bone Tumor Registries is the only way that sufficient data on large numbers of these rare tumours can be amassed to provide a valuable and otherwise unavailable source of information for research, education and service.