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Bärnthaler T, Ramachandra AB, Ebanks S, Guerrera N, Sharma L, Dela Cruz CS, Humphrey JD, Manning EP. Developmental changes in lung function of mice are independent of sex as a biological variable. Am J Physiol Lung Cell Mol Physiol 2024; 326:L627-L637. [PMID: 38375577 DOI: 10.1152/ajplung.00120.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 12/20/2023] [Accepted: 02/08/2024] [Indexed: 02/21/2024] Open
Abstract
Pulmonary function testing (PFT) in mice includes biomechanical assessment of lung function relevant to physiology in health and its alteration in disease, hence, it is frequently used in preclinical modeling of human lung pathologies. Despite numerous reports of PFT in mice of various ages, there is a lack of reference data for developing mice collected using consistent methods. Therefore, we profiled PFTs in male and female C57BL/6J mice from 2 to 23 wk of age, providing reference values for age- and sex-dependent changes in mouse lung biomechanics during development and young adulthood. Although males and females have similar weights at birth, females weigh significantly less than males after 5 wk of age (P < 0.001) with largest weight gain observed between 3 and 8 wk in females and 3 and 13 wk in males, after which weight continued to increase more slowly up to 23 wk of age. Lung function parameters including static compliance and inspiratory capacity also increased rapidly between 3 and 8 wk in female and male mice, with male mice having significantly greater static compliance and inspiratory capacity than female mice (P < 0.001). Although these parameters appear higher in males at a given age, allometric scaling showed that static compliance and inspiratory compliance were comparable between the two sexes. This suggests that differences in measurements of lung function are likely body weight-based rather than sex-based. We expect these data to facilitate future lung disease research by filling a critical knowledge gap in our field.NEW & NOTEWORTHY This study provides reference values for changes in mouse lung biomechanics from 2 to 23 wk of age. There are rapid developmental changes in lung structure and function of male and female mice between the ages of 3 and 8 wk. Male mice become noticeably heavier than female mice at or about 5 wk of age. We identified that differences in normal lung function measurements are likely weight-based, not sex-based.
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Affiliation(s)
- Thomas Bärnthaler
- Division of Pharmacology, Otto Loewi Research Center, Medical University of Graz, Graz, Austria
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University, New Haven, Connecticut, United States
| | - Abhay B Ramachandra
- Department of Biomedical Engineering,Yale University, New Haven, Connecticut, United States
| | - Sadè Ebanks
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University, New Haven, Connecticut, United States
| | - Nicole Guerrera
- Department of Medicine (Cardiovascular Medicine), Yale Translational Research Imaging Center, Yale University, New Haven, Connecticut, United States
| | - Lokesh Sharma
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University, New Haven, Connecticut, United States
| | - Charles S Dela Cruz
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University, New Haven, Connecticut, United States
| | - Jay D Humphrey
- Department of Biomedical Engineering,Yale University, New Haven, Connecticut, United States
| | - Edward P Manning
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University, New Haven, Connecticut, United States
- VA Connecticut Healthcare System, West Haven, Connecticut, United States
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Hinckley A, Sanchez-Donoso I, Comas M, Camacho-Sanchez M, Hawkins MTR, Hasan NH, Leonard JA. Challenging ecogeographical rules: Phenotypic variation in the Mountain Treeshrew (Tupaia montana) along tropical elevational gradients. PLoS One 2022; 17:e0268213. [PMID: 35714073 PMCID: PMC9205479 DOI: 10.1371/journal.pone.0268213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 04/22/2022] [Indexed: 11/19/2022] Open
Abstract
Bergmann’s and Allen’s rules were defined to describe macroecological patterns across latitudinal gradients. Bergmann observed a positive association between body size and latitude for endothermic species while Allen described shorter appendages as latitude increases. Almost two centuries later, there is still ongoing discussion about these patterns. Temperature, the common variable in these two rules, varies predictably across both latitude and elevation. Although these rules have been assessed extensively in mammals across latitude, particularly in regions with strong seasonality, studies on tropical montane mammals are scarce. We here test for these patterns and assess the variation of several other locomotory, diet-associated, body condition, and thermoregulatory traits across elevation in the Mountain Treeshrew (Tupaia montana) on tropical mountains in Borneo. Based on morphological measurements from both the field and scientific collections, we found a complex pattern: Bergmann’s rule was not supported in our tropical mountain system, since skull length, body size, and weight decreased from the lowest elevations (<1000 m) to middle elevations (2000–2500 m), and then increased from middle elevations to highest elevations. Allen’s rule was supported for relative tail length, which decreased with elevation, but not for ear and hindfoot length, with the former remaining constant and the latter increasing with elevation. This evidence together with changes in presumed diet-related traits (rostrum length, zygomatic breadth and upper tooth row length) along elevation suggest that selective pressures other than temperature, are playing a more important role shaping the morphological variation across the distribution of the Mountain Treeshrew. Diet, food acquisition, predation pressure, and/or intra- and inter-specific competition, are some of the potential factors driving the phenotypic variation of this study system. The lack of variation in body condition might suggest local adaptation of this species across its elevational range, perhaps due to generalist foraging strategies. Finally, a highly significant temporal effect was detected in several traits but not in others, representing the first phenotypic variation temporal trends described on treeshrews.
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Affiliation(s)
- Arlo Hinckley
- Conservation & Evolutionary Genetics Group, Estación Biológica de Doñana-CSIC, Seville, Spain
- Division of Mammals, Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, United States of America
- Departamento de Zoología, Universidad de Sevilla, Seville, Spain
- * E-mail: (AH); (JAL)
| | - Ines Sanchez-Donoso
- Conservation & Evolutionary Genetics Group, Estación Biológica de Doñana-CSIC, Seville, Spain
| | - Mar Comas
- Conservation & Evolutionary Genetics Group, Estación Biológica de Doñana-CSIC, Seville, Spain
- Departamento de Zoología, Universidad de Granada, Granada, Spain
- Department of Biological Sciences, Dartmouth College, Hanover, NH, United States of America
| | - Miguel Camacho-Sanchez
- Conservation & Evolutionary Genetics Group, Estación Biológica de Doñana-CSIC, Seville, Spain
- Instituto Andaluz de Investigación y Formación Agraria, Pesquera, Alimentaria y de la Producción Ecológica (IFAPA), Alcalá del Río, Seville, Spain
| | - Melissa T. R. Hawkins
- Division of Mammals, Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, United States of America
| | - Noor Haliza Hasan
- Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | - Jennifer A. Leonard
- Conservation & Evolutionary Genetics Group, Estación Biológica de Doñana-CSIC, Seville, Spain
- * E-mail: (AH); (JAL)
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Theriot MK, Lanier HC, Olson LE. Harnessing natural history collections to detect trends in body‐size change as a response to warming: a critique and review of best practices. Methods Ecol Evol 2022. [DOI: 10.1111/2041-210x.13861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Miranda K. Theriot
- Sam Noble Oklahoma Museum of Natural History, 2401 Chautauqua Ave Norman,, Oklahoma, 73072 USA
- Department of Biology University of Oklahoma 730 Van Vleet Oval, Room 314, Norman, Oklahoma 73019 USA
- University of Alaska Museum 1962 Yukon Dr, Fairbanks, AK 99775 USA
- Department of Biology and Wildlife University of Alaska Fairbanks 101 Murie 2090 Koyukuk Drive, Fairbanks, AK 99709 USA
| | - Hayley C. Lanier
- Sam Noble Oklahoma Museum of Natural History, 2401 Chautauqua Ave Norman,, Oklahoma, 73072 USA
- Department of Biology University of Oklahoma 730 Van Vleet Oval, Room 314, Norman, Oklahoma 73019 USA
| | - Link E. Olson
- University of Alaska Museum 1962 Yukon Dr, Fairbanks, AK 99775 USA
- Department of Biology and Wildlife University of Alaska Fairbanks 101 Murie 2090 Koyukuk Drive, Fairbanks, AK 99709 USA
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Pilatti P, Moratelli R, Aguiar LMS, Astúa D. Distribution and Morphological Variation of Xeronycteris vieirai Gregorin and Ditchfield, 2005 (Chiroptera, Phyllostomidae). ACTA CHIROPTEROLOGICA 2022. [DOI: 10.3161/15081109acc2021.23.2.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Patricia Pilatti
- Laboratório de Mastozoologia, Departamento de Zoologia, Universidade Federal de Pernambuco. Avenida Professor Moraes Rêgo, s/n, Cidade Universitária, Recife, PE, 50670-901, Brazil
| | - Ricardo Moratelli
- Fiocruz Mata Atlântica, Fundação Oswaldo Cruz. Rua Sampaio Corrêa s/n, Colônia Juliano Moreira, Taquara, Rio de Janeiro, RJ, 22713-375, Brazil
| | - Ludmilla M. S. Aguiar
- Laboratório de Biologia e Conservação de Morcegos, Departamento de Zoologia, Instituto de Biologia, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Asa Norte, Brasília, DF, 70910-900, Brazil
| | - Diego Astúa
- Laboratório de Mastozoologia, Departamento de Zoologia, Universidade Federal de Pernambuco. Avenida Professor Moraes Rêgo, s/n, Cidade Universitária, Recife, PE, 50670-901, Brazil
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Woodman N, Miller-Murthy A, Olson LE, Sargis EJ. The limitations of external measurements for aging small mammals: the cautionary example of the Lesser Treeshrew (Scandentia: Tupaiidae: Tupaia minor Günther, 1876). J Mammal 2021. [DOI: 10.1093/jmammal/gyab055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Age is a basic demographic characteristic vital to studies of mammalian social organization, population dynamics, and behavior. To eliminate potentially confounding ontogenetic variation, morphological comparisons among populations of mammals typically are limited to mature individuals (i.e., those assumed to have ceased most somatic growth). In our morphometric studies of treeshrews (Scandentia), adult individuals are defined by the presence of fully erupted permanent dentition, a common criterion in specimen-based mammalogy. In a number of cases, however, we have had poorly sampled populations of interest in which there were potentially useful specimens that could not be included in samples because they lacked associated skulls. Such specimens typically are associated with external body and weight measurements recorded by the original collectors, and we sought to determine whether these data could be used successfully as a proxy for age or at least to establish maturity. We analyzed four traditional external dimensions (head-and-body length, tail length, hind foot length, and ear length) and weight associated with 103 specimens from two allopatric populations of the Lesser Treeshrew (Tupaia minor Günther, 1876) from Peninsular Malaysia and from Borneo, which we treated as separate samples (populations). Individuals were assigned to one of eight age categories based on dental eruption stage, and measurements were compared among groups. In general, mean sizes of infants and subadults were smaller than those of adults, but the majority of subadults fell within the range of variation of adults. The large overlap among infants, subadults, and adults in external measurements and weight indicates that such measures are poor proxies for age in this species, probably for treeshrews in general, and possibly for other small mammals. This has significant implications for any investigation wherein relative age of individuals in a given population is an important consideration.
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Affiliation(s)
- Neal Woodman
- U.S. Geological Survey, Eastern Ecological Science Center, Laurel, MD, USA
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | - Ananth Miller-Murthy
- Division of Vertebrate Zoology, Yale Peabody Museum of Natural History, New Haven, CT, USA
| | - Link E Olson
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
- University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Eric J Sargis
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
- Division of Vertebrate Zoology, Yale Peabody Museum of Natural History, New Haven, CT, USA
- Department of Anthropology, Yale University, New Haven, CT, USA
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LaFlèche LJ, Waterman JM. Not playing by the rules: mixed support of ecogeographic rules in an arid‐adapted African ground squirrel. J Zool (1987) 2020. [DOI: 10.1111/jzo.12810] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- L. J. LaFlèche
- Department of Biological Sciences University of Manitoba Winnipeg MB Canada
| | - J. M. Waterman
- Department of Biological Sciences University of Manitoba Winnipeg MB Canada
- Mammal Research Institute Department of Zoology and Entomology University of Pretoria South Africa
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Woodman N, Miller-Murthy A, Olson LE, Sargis EJ. Coming of age: morphometric variation in the hand skeletons of juvenile and adult Lesser Treeshrews (Scandentia: Tupaiidae: Tupaia minor Günther, 1876). J Mammal 2020. [DOI: 10.1093/jmammal/gyaa056] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Morphometric analyses of the manus skeleton have proven useful in understanding species limits and morphological divergence among tupaiid treeshrews (Scandentia: Tupaiidae). Specimens in these studies are typically limited to mature individuals with fully erupted permanent dentition, which eliminates potentially confounding variation attributable to age, but also can exclude rare taxa and small island populations that are poorly represented in systematic collections. To determine the real limits associated with including immature animals in such studies, we used multivariate analyses to study sexual and age variation of the manus skeleton in two allopatric populations of the Lesser Treeshrew (Tupaia minor Günther, 1876) from the Malay Peninsula and from Borneo that we treated as separate samples. Individuals were aged using dental eruption of the permanent dentition. We also recorded the degree of epiphyseal fusion of the bones of the manus based on x-rays of study skins. We then tested our ability to distinguish the two populations using a series of discriminant function analyses of hand measurements from samples that included varying proportions of immature individuals and adults. We found no evidence of sexual dimorphism in hand proportions, permitting us to combine females and males in our samples. Epiphyseal fusion of the metacarpals and phalanges typically occurs by the time the third molars have completely erupted, and fusion of the distal epiphyses of the radius and ulna typically occurs by the time the permanent fourth premolars are in place. There is occasional asynchrony between dental age and epiphyseal fusion. In both populations, the hands of most infants and subadults provide morphometric values within the range of variation of adults, although they are typically distributed in the lower part of the adult range and have the potential to bias the sample toward lower mean size. The inclusion of infants and subadults when attempting to discriminate between two taxa generally results in lower rates of correct classifications, although the rates increase as the sample of immature individuals is limited to older subadults. As a general rule, we recommend that specimens of infants and subadults continue to be excluded from analyses when exploring taxonomic boundaries among treeshrews. In cases of extremely small sample sizes of adults, however, older subadults—in which the permanent third premolars are erupting or in place—can be used with appropriate caution.
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Affiliation(s)
- Neal Woodman
- U.S. Geological Survey, Patuxent Wildlife Research Center, Laurel, MD, USA
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | - Ananth Miller-Murthy
- Division of Vertebrate Zoology, Yale Peabody Museum of Natural History, New Haven, CT, USA
| | - Link E Olson
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
- University of Alaska Museum, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Eric J Sargis
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
- Division of Vertebrate Zoology, Yale Peabody Museum of Natural History, New Haven, CT, USA
- Department of Anthropology, Yale University, New Haven, CT, USA
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Hope AG, Stephens RB, Mueller SD, Tkach VV, Demboski JR. Speciation of North American pygmy shrews (Eulipotyphla: Soricidae) supports spatial but not temporal congruence of diversification among boreal species. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
AbstractSpeciation among many animals was rapid through the Pleistocene, impacted by climate and periodic isolation and reconnection. As such, species limits among often morphologically cryptic lineages may remain unresolved despite clear mitogenomic partitioning. Accumulating evidence from phylogeographical studies is revealing congruent regional differentiation of lineages across taxonomic groups that share ecological and evolutionary traits. Here, we analyse multiple DNA loci and morphology to resolve the geography and timeframe associated with evolutionary history of North American pygmy shrews (genus Sorex). We then assess lineage diversification among three co-distributed shrew complexes using phylogenetic and approximate Bayesian computation approaches to test a hypothesis of spatial congruence but temporal incongruence of species formation on a continental scale. Our results indicate consistency in regional lineage distributions, partial congruence of the sequence of divergence, and strong but not definitive support for temporal incongruence, suggesting that successive glacial cycles initiated the process of diversification repeatedly through the Pleistocene. Our results emphasize a continuing need for greater genomic coverage in comparative phylogeography, with persistent challenges. We recognize distinct eastern (Sorex hoyi Baird, 1857) and western (Sorex eximius Osgood, 1901) species of pygmy shrew based on available evidence, but discuss issues with taxonomic designations considering the continuum of speciation throughout the boreal biome.
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Affiliation(s)
- Andrew G Hope
- Division of Biology, 116 Ackert Hall, Kansas State University, Manhattan, KS, USA
| | - Ryan B Stephens
- Natural Resources and the Environment, 114 James Hall, University of New Hampshire, Durham, NH, USA
| | | | - Vasyl V Tkach
- Department of Biology, Starcher Hall, University of North Dakota Grand Forks, Grand Forks, ND, USA
| | - John R Demboski
- Denver Museum of Nature & Science, 2001 Colorado Boulevard, Denver, CO, USA
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Korneva A, Zilberberg L, Rifkin DB, Humphrey JD, Bellini C. Absence of LTBP-3 attenuates the aneurysmal phenotype but not spinal effects on the aorta in Marfan syndrome. Biomech Model Mechanobiol 2018; 18:261-273. [PMID: 30306291 DOI: 10.1007/s10237-018-1080-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 09/18/2018] [Indexed: 02/07/2023]
Abstract
Fibrillin-1 is an elastin-associated glycoprotein that contributes to the long-term fatigue resistance of elastic fibers as well as to the bioavailability of transforming growth factor-beta (TGFβ) in arteries. Altered TGFβ bioavailability and/or signaling have been implicated in aneurysm development in Marfan syndrome (MFS), a multi-system condition resulting from mutations to the gene that encodes fibrillin-1. We recently showed that the absence of the latent transforming growth factor-beta binding protein-3 (LTBP-3) in fibrillin-1-deficient mice attenuates the fragmentation of elastic fibers and focal dilatations that are characteristic of aortic root aneurysms in MFS mice, at least to 12 weeks of age. Here, we show further that the absence of LTBP-3 in this MFS mouse model improves the circumferential mechanical properties of the thoracic aorta, which appears to be fundamental in preventing or significantly delaying aneurysm development. Yet, a spinal deformity either remains or is exacerbated in the absence of LTBP-3 and seems to adversely affect the axial mechanical properties of the thoracic aorta, thus decreasing overall vascular function despite the absence of aneurysmal dilatation. Importantly, because of the smaller size of mice lacking LTBP-3, allometric scaling facilitates proper interpretation of aortic dimensions and thus the clinical phenotype. While this study demonstrates that LTBP-3/TGFβ directly affects the biomechanical function of the thoracic aorta, it highlights that spinal deformities in MFS might indirectly and adversely affect the overall aortic phenotype. There is a need, therefore, to consider together the vascular and skeletal effects in this syndromic disease.
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Affiliation(s)
- A Korneva
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - L Zilberberg
- Departments of Cell Biology and Medicine, New York University, New York, NY, USA
| | - D B Rifkin
- Departments of Cell Biology and Medicine, New York University, New York, NY, USA
| | - J D Humphrey
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
- Vascular Biology and Therapeutics Program, Yale School of Medicine, New Haven, CT, USA
| | - C Bellini
- Department of Bioengineering, Northeastern University, Boston, MA, USA.
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Woodman N. Taxonomic evaluation of the three “type” specimens of the fringe-footed shrew,Sorex fimbripes(Mammalia: Soricidae) and recommended nomenclatural status of the name. P BIOL SOC WASH 2018. [DOI: 10.2988/18-00007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Neal Woodman
- USGS Patuxent Wildlife Research Center, MRC-108, National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, Washington, D.C. 20013-7012 USA
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Woodman N. Rediscovery of the type series of the Acadian Masked Shrew,Sorex acadicus(Mammalia: Soricidae), with the designation of a neotype and a reevaluation of its taxonomic status. P BIOL SOC WASH 2018. [DOI: 10.2988/17-00022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Neal Woodman
- Biological Survey Unit, U.S.G.S. Patuxent Wildlife Research Center, MRC-111, National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, Washington, D.C. 20013-7012, U.S.A.,
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Li B, Urban JP, Yu J. Development of spinal deformities in the tight-skin mouse. Bone Res 2017; 5:16053. [PMID: 28944086 PMCID: PMC5605766 DOI: 10.1038/boneres.2016.53] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 09/26/2016] [Accepted: 11/03/2016] [Indexed: 01/23/2023] Open
Abstract
Tight-skin (TSK) mice are commonly used as an animal model to study the pathogenesis of Marfan syndrome (MFS), but little is known of their skeletal phenotype and in particular of the development of the spinal deformities, common in MFS. Here we examined growth of the axial skeletons of TSK and wild-type(B6) mice during their period of rapid growth. The whole bodies of mice, 4–12 weeks of age, were scanned after sacrifice, by micro-computed tomography (microCT). We reconstructed three-dimensional models of the spine and ribs, and measured vertebral body heights and rib lengths using the Mac-based image-processing software “OsiriX”. Although the TSK mice were smaller than the B6 mice at 4 weeks, they experienced an early growth spurt and by 8 weeks the height, but not the width, of the vertebral body was significantly greater in the TSK mice than the B6 mice. Measurement of the angles of scoliotic and kyphotic curves post-mortem in the mice was problematic, hence we measured changes that develop in skeletal elements in these disorders. As a marker of kyphosis, we measured anterior wedging of the vertebral bodies; as a marker for scoliosis we measured asymmetries in rib length. We found, unlike in the B6 mice where the pattern was diffuse, wedging in TSK mice was directly related to spinal level and peaked steeply at the thoracolumbar junction. There was also significant asymmetry in length of the ribs in the TSK mice, but not in the B6 mice. The TSK mice thus appear to exhibit spinal deformities seen in MFS and could be a useful model for gaining understanding of the mechanisms of development of scoliosis and kyphosis in this disorder.
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Affiliation(s)
- Bing Li
- Department of Orthopedics, Tianjin Hospital, Tianjin, China.,Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Jill Pg Urban
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Jing Yu
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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