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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 PMCID: PMC11380952 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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2
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Aalkjær C, Wang T. The cardiovascular challenges in giraffes. J Muscle Res Cell Motil 2023; 44:53-60. [PMID: 35879488 DOI: 10.1007/s10974-022-09626-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 07/10/2022] [Indexed: 11/30/2022]
Abstract
Giraffes are the highest living animals on Earth and therefore are challenged by gravity more than any other species. In particular the cardiovascular system needs to adapt to this challenge. Giraffes have a mean blood pressure around 200 mmHg, which ensures a mean arterial pressure near the head of 100 mmHg when the giraffe is standing with the neck in a near vertical position. This immediately raises several questions. How do giraffes avoid edema in the legs where the arterial pressure is 300 mmHg or higher? How does the heart produce a pressure of 200 mmHg, and what is the energy required for this endeavor? How can the kidney tolerate a pressure of about 200 mmHg and does this mean that giraffes have a high glomerular filtration rate? What is the arterial pressure in the head of giraffes when they drink, and how is perfusion of the brain maintained when they lift their head after drinking? In this short review, we present some answers to these questions.
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Affiliation(s)
- Christian Aalkjær
- Department of Biomedicine, Aarhus University, 8000, Aarhus C, Denmark.
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Tobias Wang
- Zoophysiology, Department of Biological Sciences, Aarhus University, 8000, Aarhus C, Denmark
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3
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A Preliminary Study on the Siphon Mechanism in Giraffe ( Giraffa camelopardalis). Animals (Basel) 2022; 12:ani12233348. [PMID: 36496868 PMCID: PMC9740075 DOI: 10.3390/ani12233348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 11/23/2022] [Accepted: 11/26/2022] [Indexed: 12/04/2022] Open
Abstract
Adult giraffes reach heights of 4.5 m with a heart-to-head distance of over 2 m, making cranial blood supply challenging. Ultrasound confirmed that the giraffe jugular vein collapses during head movement from ground level to fully erect, negating the possibility of a siphon mechanism in the neck. We showed that a short-length siphon structure over a simulated head-to-heart distance for a giraffe significantly influences flow in a collapsible tube. The siphon structure is determined according to brain case measurements. The short-length siphon structure in a shorter-necked ostrich showed no significant increase in flow. The shorter head-to-heart distance might be the reason for the lack of effect in ostriches. A siphon mechanism situated in the cranium is certainly possible, with a significant effect exerted on the amount of pressure the heart must generate to allow adequate cranial blood perfusion in a long-necked giraffe. The study validated that a cranial-bound siphon structure can operate and will be of significant value for adequate cranial blood perfusion in long-necked species such as giraffes and might also have existed in extinct species of long-necked dinosaurs.
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Natterson-Horowitz B, Baccouche BM, Mary J, Shivkumar T, Bertelsen MF, Aalkjær C, Smerup MH, Ajijola OA, Hadaya J, Wang T. Did giraffe cardiovascular evolution solve the problem of heart failure with preserved ejection fraction? EVOLUTION MEDICINE AND PUBLIC HEALTH 2021; 9:248-255. [PMID: 34447575 PMCID: PMC8385250 DOI: 10.1093/emph/eoab016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 06/04/2021] [Indexed: 11/18/2022]
Abstract
The evolved adaptations of other species can be a source of insight for novel biomedical innovation. Limitations of traditional animal models for the study of some pathologies are fueling efforts to find new approaches to biomedical investigation. One emerging approach recognizes the evolved adaptations in other species as possible solutions to human pathology. The giraffe heart, for example, appears resistant to pathology related to heart failure with preserved ejection fraction (HFpEF)—a leading form of hypertension-associated cardiovascular disease in humans. Here, we postulate that the physiological pressure-induced left ventricular thickening in giraffes does not result in the pathological cardiovascular changes observed in humans with hypertension. The mechanisms underlying this cardiovascular adaptation to high blood pressure in the giraffe may be a bioinspired roadmap for preventive and therapeutic strategies for human HFpEF.
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Affiliation(s)
- Barbara Natterson-Horowitz
- Department of Medicine, Harvard Medical School, Boston, MA, USA.,Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA.,Division of Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Basil M Baccouche
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA.,Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
| | - Jennifer Mary
- Zoobiquity Research Initiative at UCLA, Los Angeles, CA 90024, USA
| | | | | | | | - Morten H Smerup
- Department of Cardiothoracic Surgery, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Olujimi A Ajijola
- UCLA Cardiac Arrhythmia Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Joseph Hadaya
- UCLA Cardiac Arrhythmia Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,Molecular, Cellular and Integrative Physiology Program, UCLA, Los Angeles, CA, USA
| | - Tobias Wang
- Zoophysiology, Department of Biology, Aarhus University, Aarhus, Denmark
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5
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Liu C, Gao J, Huang J, Wang W, Heller R, Qiu Q. Giraffa camelopardalis. Trends Genet 2021; 37:860-861. [PMID: 34112506 DOI: 10.1016/j.tig.2021.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 05/17/2021] [Indexed: 10/21/2022]
Affiliation(s)
- Chang Liu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Jianbo Gao
- Department of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China
| | - Jinghui Huang
- Department of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China
| | - Wen Wang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Rasmus Heller
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N 2200, Denmark.
| | - Qiang Qiu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China.
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6
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Liu C, Gao J, Cui X, Li Z, Chen L, Yuan Y, Zhang Y, Mei L, Zhao L, Cai D, Hu M, Zhou B, Li Z, Qin T, Si H, Li G, Lin Z, Xu Y, Zhu C, Yin Y, Zhang C, Xu W, Li Q, Wang K, Gilbert MTP, Heller R, Wang W, Huang J, Qiu Q. A towering genome: Experimentally validated adaptations to high blood pressure and extreme stature in the giraffe. SCIENCE ADVANCES 2021; 7:7/12/eabe9459. [PMID: 33731352 PMCID: PMC7968835 DOI: 10.1126/sciadv.abe9459] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 02/02/2021] [Indexed: 05/02/2023]
Abstract
The suite of adaptations associated with the extreme stature of the giraffe has long interested biologists and physiologists. By generating a high-quality chromosome-level giraffe genome and a comprehensive comparison with other ruminant genomes, we identified a robust catalog of giraffe-specific mutations. These are primarily related to cardiovascular, bone growth, vision, hearing, and circadian functions. Among them, the giraffe FGFRL1 gene is an outlier with seven unique amino acid substitutions not found in any other ruminant. Gene-edited mice with the giraffe-type FGFRL1 show exceptional hypertension resistance and higher bone mineral density, both of which are tightly connected with giraffe adaptations to high stature. Our results facilitate a deeper understanding of the molecular mechanism underpinning distinct giraffe traits, and may provide insights into the study of hypertension in humans.
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Affiliation(s)
- Chang Liu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Jianbo Gao
- Department of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China
| | - Xinxin Cui
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Zhipeng Li
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Lei Chen
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Yuan Yuan
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Yaolei Zhang
- BGI-Qingdao, BGI-Shenzhen, Qingdao 266555, China
| | - Liangwei Mei
- Department of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China
| | - Lan Zhao
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Xi'an 710069, China
| | - Dan Cai
- BGI-Qingdao, BGI-Shenzhen, Qingdao 266555, China
| | - Mingliang Hu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Botong Zhou
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Zihe Li
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Tao Qin
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Huazhe Si
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Guangyu Li
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Zeshan Lin
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Yicheng Xu
- Jiaxing SynBioLab. Co. Ltd., Jiaxing 314000, China
| | - Chenglong Zhu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Yuan Yin
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Chenzhou Zhang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Wenjie Xu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - Qingjie Li
- Research Center of Traditional Chinese Medicine, The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun 130021, China
| | - Kun Wang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China
| | - M Thomas P Gilbert
- Center for Evolutionary Hologenomics, GLOBE Institute, University of Copenhagen, Øster Voldgade 5-7, Copenhagen 1350, Denmark
- Norwegian University of Science and Technology, University Museum, 7491 Trondheim, Norway
| | - Rasmus Heller
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N 2200, Denmark.
| | - Wen Wang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China.
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China
| | - Jinghui Huang
- Department of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, China.
| | - Qiang Qiu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710072, China.
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Abstract
Gravity affects the physiology of many animals, and the effect is, for good reason, most pronounced in tall species. The physiology-in particular, cardiovascular function-of giraffes has therefore captivated the interest of physiologists for centuries. Several studies document high mean arterial blood pressure of giraffes of about 200 mm Hg. This appears necessary to establish a cerebral perfusion pressure on the order of 100 mm Hg at the cranial end of the carotid arteries. Here, we discuss the unique characteristics of blood vessels, the heart, and the kidney of giraffes and how these functional and structural adaptations are related to very high blood pressure. We also discuss how the cerebral circulation of giraffes is established and what we know about how the blood flow and arterial and venous pressures in giraffes change when they stop to drink and subsequently lift their heads 5-6 m in one sweeping movement.
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Affiliation(s)
- Christian Aalkjær
- Department of Biomedicine, Aarhus University, Aarhus C 8000, Denmark; .,Department of Biomedical Sciences, University of Copenhagen, Copenhagen 2200, Denmark
| | - Tobias Wang
- Department of Biology, Aarhus University, Aarhus C 8000, Denmark;
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8
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Michel JB. William Harvey réinterprété à la lumière de l’évolution des espèces (I). Med Sci (Paris) 2020; 36:997-1003. [DOI: 10.1051/medsci/2020170] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Au commencement est la pompe cardiaque qui produit un flux sanguin cyclique (énergie cinétique, Ek). En 1619, William Harvey (1578-1657) décrit expérimentalement, en utilisant des garrots veineux ou artériels, l’anatomie fonctionnelle de la circulation sanguine chez l’homme, à l’exception de la circulation capillaire. Pour la première fois est décrite la circulation sanguine en deux circuits fermés parallèles, l’un à haute pression, l’autre à basse pression. Marcello Malpighi (1628-1694) la complète par l’observation en microscopie du réseau capillaire. Un siècle plus tard, apparaissent les premières hypothèses sur l’évolution des espèces. Jean-Baptiste Lamarck (1744-1829) propose en 1809 une théorie de transmission évolutive des caractères phénotypiques par adaptation aux contraintes environnementales. En 1859, Charles Darwin (1809-1882) élabore une théorie de la sélection naturelle. L’interprétation qui prévaut actuellement intègre à la fois la génétique et l’épigénétique dans la transmission intergénérationnelle, et dans la dynamique de développement des caractères phénotypiques individuels, en particulier chez l’homme.
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9
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Muller Z, Lee DE, Scheijen CPJ, Strauss MKL, Carter KD, Deacon F. Giraffe translocations: A review and discussion of considerations. Afr J Ecol 2020. [DOI: 10.1111/aje.12727] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Zoe Muller
- School of Biological Sciences Life Sciences Building University of Bristol Bristol UK
- Giraffe Research & Conservation Trust Nairobi Kenya
| | - Derek E. Lee
- Wild Nature Institute Concord NH USA
- Mueller Laboratory Department of Biology Pennsylvania State University State College PA USA
| | - Ciska P. J. Scheijen
- Wildlife and Grassland Sciences University of the Free State Bloemfontein South Africa
- Rockwood Conservation Griekwastad South Africa
| | | | - Kerryn D. Carter
- Elephant Connection Kavango Zambezi Transfrontier Conservation Area Mwandi Zambia
| | - Francois Deacon
- Wildlife and Grassland Sciences University of the Free State Bloemfontein South Africa
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10
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Vitali F, Kariuki EK, Mijele D, Kaitho T, Faustini M, Preziosi R, Gakuya F, Ravasio G. Etorphine-Azaperone Immobilisation for Translocation of Free-Ranging Masai Giraffes ( Giraffa Camelopardalis Tippelskirchi): A Pilot Study. Animals (Basel) 2020; 10:ani10020322. [PMID: 32085568 PMCID: PMC7070639 DOI: 10.3390/ani10020322] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 02/12/2020] [Accepted: 02/14/2020] [Indexed: 12/18/2022] Open
Abstract
Simple Summary Due to their peculiar anatomy and sensitivity to drugs, giraffes are among the most challenging mammals to immobilise. Masai giraffes have recently been listed as endangered. Hence, their conservation needs actions that require veterinary capture such as translocations. In this study, we evaluated a new protocol of immobilisation for translocation of free-ranging Masai giraffes. The hypothesis is that, by combining a potent opioid with a tranquiliser, it is possible to mitigate the capture stress, which is a major cause of disastrous homeostatic consequences, including capture myopathy and death. The combination produced, in all individuals, smooth and quick inductions and reliable immobilisations. Although hypoxaemia in a few individuals and acidosis were seen, the overall cardiorespiratory function was adequate. Whereas the initial stress to the capture was limited in the individuals, likely due to tourism-related habituation, the opioid-related excitement and resulting increased exertion was responsible for worse immobilisation and physiological derangement. A low dose of an antagonist was used and evaluated and, in the two-week boma follow-up, it proved to be efficient in providing safe recoveries and transport. At the investigated doses, the combination provided partially reversed immobilisation that allowed uneventful translocation in free-ranging Masai giraffes. Abstract Etorphine-azaperone immobilisation was evaluated for translocation of Masai giraffes. Nine giraffes were darted with 0.012 ± 0.001 mg/kg etorphine and 0.07 ± 0.01 mg/kg azaperone. Once ataxic, giraffes were roped for recumbency and restrained manually. Naltrexone (3 mg/mg etorphine) was immediately given intravenously to reverse etorphine-related side effects. Protocol evaluation included physiological monitoring, blood-gas analyses, anaesthetic times, and quality scores (1 = excellent, 4 = poor). Sedation onset and recumbency were achieved in 2.6 ± 0.8 and 5.6 ± 1.4 min. Cardio-respiratory function (HR = 70 ± 16, RR = 32 ± 8, MAP = 132 ± 16) and temperature (37.8 ± 0.5) were stable. Arterial gas analysis showed hypoxaemia in some individuals (PaO2 = 67 ± 8 mmHg) and metabolic acidosis (pH = 7.23 ± 0.05, PaCO2 = 34 ± 4 mmHg, HCO3− = 12.9 ± 1.2 mmol/l). Minor startle response occurred, while higher induction-induced excitement correlated to longer inductions, worse restraint, and decreased HCO3−. After 19 ± 3.5 min of restraint, giraffes were allowed to stand and were loaded onto a chariot. Immobilisations were good and scored 2 (1–3). Inductions and recoveries were smooth and scored 1 (1–2). Translocations were uneventful and no complications occurred in 14-days boma follow-up.
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Affiliation(s)
- Francesca Vitali
- Dipartimento di Medicina Veterinaria, Università degli Studi di Milano, Via dell’Università 6, 26900 Lodi, Italy; (M.F.); (G.R.)
- Correspondence: ; Tel.: +39-348-714-6920
| | - Edward K. Kariuki
- Department of Veterinary Services, Kenya Wildlife Service, P.O. Box 40241-00100 Nairobi, Kenya; (E.K.K.); (D.M.); (T.K.); (F.G.)
| | - Domnic Mijele
- Department of Veterinary Services, Kenya Wildlife Service, P.O. Box 40241-00100 Nairobi, Kenya; (E.K.K.); (D.M.); (T.K.); (F.G.)
| | - Titus Kaitho
- Department of Veterinary Services, Kenya Wildlife Service, P.O. Box 40241-00100 Nairobi, Kenya; (E.K.K.); (D.M.); (T.K.); (F.G.)
| | - Massimo Faustini
- Dipartimento di Medicina Veterinaria, Università degli Studi di Milano, Via dell’Università 6, 26900 Lodi, Italy; (M.F.); (G.R.)
| | - Richard Preziosi
- Ecology and Environment Research Centre, Department of Natural Sciences, Faculty of Science and Engineering, Manchester Metropolitan University, Manchester M1 5GD, UK;
| | - Francis Gakuya
- Department of Veterinary Services, Kenya Wildlife Service, P.O. Box 40241-00100 Nairobi, Kenya; (E.K.K.); (D.M.); (T.K.); (F.G.)
| | - Giuliano Ravasio
- Dipartimento di Medicina Veterinaria, Università degli Studi di Milano, Via dell’Università 6, 26900 Lodi, Italy; (M.F.); (G.R.)
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11
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Snelling EP, Seymour RS, Giussani DA, Fuller A, Maloney SK, Farrell AP, Mitchell D, George KP, Dzialowski EM, Jonker SS, Wube T. Scaling of cardiac morphology is interrupted by birth in the developing sheep Ovis aries. J Anat 2019; 235:96-105. [PMID: 30993709 DOI: 10.1111/joa.12990] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2019] [Indexed: 11/28/2022] Open
Abstract
Scaling of the heart across development can reveal the degree to which variation in cardiac morphology depends on body mass. In this study, we assessed the scaling of heart mass, left and right ventricular masses, and ventricular mass ratio, as a function of eviscerated body mass across fetal and postnatal development in Horro sheep Ovis aries (~50-fold body mass range; N = 21). Whole hearts were extracted from carcasses, cleaned, dissected into chambers and weighed. We found a biphasic relationship when heart mass was scaled against body mass, with a conspicuous 'breakpoint' around the time of birth, manifest not by a change in the scaling exponent (slope), but rather a jump in the elevation. Fetal heart mass (g) increased with eviscerated body mass (Mb , kg) according to the power equation 4.90 Mb 0.88 ± 0.26 (± 95% CI ) , whereas postnatal heart mass increased according to 10.0 Mb 0.88 ± 0.10 . While the fetal and postnatal scaling exponents are identical (0.88) and reveal a clear dependence of heart mass on body mass, only the postnatal exponent is significantly less than 1.0, indicating the postnatal heart becomes a smaller component of body mass as the body grows, which is a pattern found frequently with postnatal cardiac development among mammals. The rapid doubling in heart mass around the time of birth is independent of any increase in body mass and is consistent with the normalization of wall stress in response to abrupt changes in volume loading and pressure loading at parturition. We discuss variation in scaling patterns of heart mass across development among mammals, and suggest that the variation results from a complex interplay between hard-wired genetics and epigenetic influences.
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Affiliation(s)
- Edward P Snelling
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, Gauteng, South Africa
| | - Roger S Seymour
- School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Dino A Giussani
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Andrea Fuller
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, Gauteng, South Africa
| | - Shane K Maloney
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, Gauteng, South Africa.,School of Human Sciences, University of Western Australia, Crawley, WA, Australia
| | - Anthony P Farrell
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada.,Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada
| | - Duncan Mitchell
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, Gauteng, South Africa.,School of Human Sciences, University of Western Australia, Crawley, WA, Australia
| | - Keith P George
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Edward M Dzialowski
- Developmental Integrative Biology Research Group, Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Sonnet S Jonker
- Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
| | - Tilaye Wube
- Department of Zoological Sciences, College of Natural and Computational Sciences, Addis Ababa University, Addis Ababa, Ethiopia
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12
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Hu Q, Nelson TJ, Snelling EP, Seymour RS. Femoral bone perfusion through the nutrient foramen during growth and locomotor development of western grey kangaroos ( Macropus fuliginosus). ACTA ACUST UNITED AC 2018; 221:jeb.168625. [PMID: 29361586 DOI: 10.1242/jeb.168625] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Accepted: 12/14/2017] [Indexed: 11/20/2022]
Abstract
The nutrient artery passes through the nutrient foramen on the shaft of the femur and supplies more than half of the total blood flow to the bone. Assuming that the size of the nutrient foramen correlates with the size of the nutrient artery, an index of blood flow rate (Qi) can be calculated from nutrient foramen dimensions. Interspecific Qi is proportional to locomotor activity levels in adult mammals, birds and reptiles. However, no studies have yet estimated intraspecific Qi to test for the effects of growth and locomotor development on bone blood flow requirements. In this study, we used micro-CT and medical CT scanning to measure femoral dimensions and foramen radius to calculate femoral Qi during the in-pouch and post-pouch life stages of western grey kangaroos (Macropus fuliginosus) weighing 5.7 g to 70.5 kg and representing a 12,350-fold range in body mass. A biphasic scaling relationship between Qi and body mass was observed (breakpoint at ca. 1-5 kg body mass right before permanent pouch exit), with a steep exponent of 0.96±0.09 (95% CI) during the in-pouch life stage and a statistically independent exponent of -0.59±0.90 during the post-pouch life stage. In-pouch joeys showed Qi values that were 50-100 times higher than those of adult diprotodont marsupials of the same body mass, but gradually converged with them as post-pouch adults. Bone modelling during growth appears to be the main determinant of femoral bone blood flow during in-pouch development, whereas bone remodelling for micro-fracture repair due to locomotion gradually becomes the main determinant when kangaroos leave the pouch and become more active.
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Affiliation(s)
- Qiaohui Hu
- Department of Ecology and Environmental Science, School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Thomas J Nelson
- Department of Ecology and Environmental Science, School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Edward P Snelling
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, Gauteng 2193, South Africa
| | - Roger S Seymour
- Department of Ecology and Environmental Science, School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
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13
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Bourgeois B, Watts K, Thomas DM, Carmichael O, Hu FB, Heo M, Hall JE, Heymsfield SB. Associations between height and blood pressure in the United States population. Medicine (Baltimore) 2017; 96:e9233. [PMID: 29390353 PMCID: PMC5815765 DOI: 10.1097/md.0000000000009233] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 11/17/2017] [Accepted: 11/20/2017] [Indexed: 01/10/2023] Open
Abstract
The mechanisms linking short stature with an increase in cardiovascular and cerebrovascular disease risk remain elusive. This study tested the hypothesis that significant associations are present between height and blood pressure in a representative sample of the US adult population.Participants were 12,988 men and women from a multiethnic sample (age ≥ 18 years) evaluated in the 1999 to 2006 National Health and Nutrition Examination Survey who were not taking antihypertensive medications and who had complete height, weight, % body fat, and systolic and diastolic arterial blood pressure (SBP and DBP) measurements; mean arterial blood pressure and pulse pressure (MBP and PP) were calculated. Multiple regression models for men and women were developed with each blood pressure as dependent variable and height, age, race/ethnicity, body mass index, % body fat, socioeconomic status, activity level, and smoking history as potential independent variables.Greater height was associated with significantly lower SBP and PP, and higher DBP (all P < .001) in combined race/ethnic-sex group models beginning in the 4th decade. Predicted blood pressure differences between people who are short and tall increased thereafter with greater age except for MBP. Socioeconomic status, activity level, and smoking history did not consistently contribute to blood pressure prediction models.Height-associated blood pressure effects were present in US adults who appeared in the 4th decade and increased in magnitude with greater age thereafter. These observations, in the largest and most diverse population sample evaluated to date, provide support for postulated mechanisms linking adult stature with cardiovascular and cerebrovascular disease risk.
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Affiliation(s)
| | - Krista Watts
- Department of mathematical sciences, United States Military Academy, West Point, NY
| | - Diana M. Thomas
- Department of mathematical sciences, United States Military Academy, West Point, NY
| | - Owen Carmichael
- Pennington Biomedical Research Center, LSU System, Baton Rouge, LA
| | - Frank B. Hu
- Department of Nutrition and Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA
| | | | - John E. Hall
- Departments of Physiology and Biophysics and Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MS
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14
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PAUL GREGORYS. Restoring Maximum Vertical Browsing Reach in Sauropod Dinosaurs. Anat Rec (Hoboken) 2017; 300:1802-1825. [DOI: 10.1002/ar.23617] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2008] [Revised: 04/16/2015] [Accepted: 12/10/2016] [Indexed: 12/24/2022]
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15
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Crossley DA, Burggren WW, Reiber CL, Altimiras J, Rodnick KJ. Mass Transport: Circulatory System with Emphasis on Nonendothermic Species. Compr Physiol 2016; 7:17-66. [PMID: 28134997 DOI: 10.1002/cphy.c150010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mass transport can be generally defined as movement of material matter. The circulatory system then is a biological example given its role in the movement in transporting gases, nutrients, wastes, and chemical signals. Comparative physiology has a long history of providing new insights and advancing our understanding of circulatory mass transport across a wide array of circulatory systems. Here we focus on circulatory function of nonmodel species. Invertebrates possess diverse convection systems; that at the most complex generate pressures and perform at a level comparable to vertebrates. Many invertebrates actively modulate cardiovascular function using neuronal, neurohormonal, and skeletal muscle activity. In vertebrates, our understanding of cardiac morphology, cardiomyocyte function, and contractile protein regulation by Ca2+ highlights a high degree of conservation, but differences between species exist and are coupled to variable environments and body temperatures. Key regulators of vertebrate cardiac function and systemic blood pressure include the autonomic nervous system, hormones, and ventricular filling. Further chemical factors regulating cardiovascular function include adenosine, natriuretic peptides, arginine vasotocin, endothelin 1, bradykinin, histamine, nitric oxide, and hydrogen sulfide, to name but a few. Diverse vascular morphologies and the regulation of blood flow in the coronary and cerebral circulations are also apparent in nonmammalian species. Dynamic adjustments of cardiovascular function are associated with exercise on land, flying at high altitude, prolonged dives by marine mammals, and unique morphology, such as the giraffe. Future studies should address limits of gas exchange and convective transport, the evolution of high arterial pressure across diverse taxa, and the importance of the cardiovascular system adaptations to extreme environments. © 2017 American Physiological Society. Compr Physiol 7:17-66, 2017.
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Affiliation(s)
- Dane A Crossley
- Department of Biological Sciences, University of North Texas, Denton, Texas, USA
| | - Warren W Burggren
- Department of Biological Sciences, University of North Texas, Denton, Texas, USA
| | - Carl L Reiber
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, Nevada, USA
| | - Jordi Altimiras
- AVIAN Behavioral Genomics and Physiology, IFM Biology, Linköping University, Linköping, Sweden
| | - Kenneth J Rodnick
- Department of Biological Sciences, Idaho State University, Pocatello, Idaho, USA
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16
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Abstract
Cardiovascular function in dinosaurs can be inferred from fossil evidence with knowledge of how metabolic rate, blood flow rate, blood pressure, and heart size are related to body size in living animals. Skeletal stature and nutrient foramen size in fossil femora provide direct evidence of a high arterial blood pressure, a large four-chambered heart, a high aerobic metabolic rate, and intense locomotion. But was the heart of a huge, long-necked sauropod dinosaur able to pump blood up 9 m to its head?
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Affiliation(s)
- Roger S. Seymour
- School of Biological Sciences, University of Adelaide, Adelaide, Australia
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17
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Agaba M, Ishengoma E, Miller WC, McGrath BC, Hudson CN, Bedoya Reina OC, Ratan A, Burhans R, Chikhi R, Medvedev P, Praul CA, Wu-Cavener L, Wood B, Robertson H, Penfold L, Cavener DR. Giraffe genome sequence reveals clues to its unique morphology and physiology. Nat Commun 2016; 7:11519. [PMID: 27187213 PMCID: PMC4873664 DOI: 10.1038/ncomms11519] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 04/01/2016] [Indexed: 11/12/2022] Open
Abstract
The origins of giraffe's imposing stature and associated cardiovascular adaptations are unknown. Okapi, which lacks these unique features, is giraffe's closest relative and provides a useful comparison, to identify genetic variation underlying giraffe's long neck and cardiovascular system. The genomes of giraffe and okapi were sequenced, and through comparative analyses genes and pathways were identified that exhibit unique genetic changes and likely contribute to giraffe's unique features. Some of these genes are in the HOX, NOTCH and FGF signalling pathways, which regulate both skeletal and cardiovascular development, suggesting that giraffe's stature and cardiovascular adaptations evolved in parallel through changes in a small number of genes. Mitochondrial metabolism and volatile fatty acids transport genes are also evolutionarily diverged in giraffe and may be related to its unusual diet that includes toxic plants. Unexpectedly, substantial evolutionary changes have occurred in giraffe and okapi in double-strand break repair and centrosome functions. Giraffe's unique anatomy and physiology include its stature and associated cardiovascular adaptation. Here, Douglas Cavener and colleagues provide de novo genome assemblies of giraffe and its closest relative okapi and provide comparative analyses to infer insights into evolution and adaptation.
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Affiliation(s)
- Morris Agaba
- School of Life Sciences and Bioengineering, African Institute of Science and Technology, Arusha 4222, Tanzania.,Biosciences Eastern and Central Africa, International Livestock Research Institute, Nairobi GPO00100, Kenya.,Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Edson Ishengoma
- School of Life Sciences and Bioengineering, African Institute of Science and Technology, Arusha 4222, Tanzania
| | - Webb C Miller
- Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Barbara C McGrath
- Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Chelsea N Hudson
- Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Oscar C Bedoya Reina
- Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA.,MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK
| | - Aakrosh Ratan
- Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA.,Center for Public Health Genomics, Department of Computer Science, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Rico Burhans
- Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Rayan Chikhi
- Center for Genomics and Bioinformatics, Department of Computer Science and Engineering, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA.,Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Paul Medvedev
- Center for Genomics and Bioinformatics, Department of Computer Science and Engineering, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA.,Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Craig A Praul
- Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Lan Wu-Cavener
- Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Brendan Wood
- Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | | | | | - Douglas R Cavener
- School of Life Sciences and Bioengineering, African Institute of Science and Technology, Arusha 4222, Tanzania.,Center for Genomics and Bioinformatics, Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA
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18
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O'Brien HD, Gignac PM, Hieronymus TL, Witmer LM. A comparison of postnatal arterial patterns in a growth series of giraffe (Artiodactyla: Giraffa camelopardalis). PeerJ 2016; 4:e1696. [PMID: 26925324 PMCID: PMC4768699 DOI: 10.7717/peerj.1696] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 01/26/2016] [Indexed: 11/20/2022] Open
Abstract
Nearly all living artiodactyls (even-toed ungulates) possess a derived cranial arterial pattern that is highly distinctive from most other mammals. Foremost among a suite of atypical arterial configurations is the functional and anatomical replacement of the internal carotid artery with an extensive, subdural arterial meshwork called the carotid rete. This interdigitating network branches from the maxillary artery and is housed within the cavernous venous sinus. As the cavernous sinus receives cooled blood draining from the nasal mucosa, heat rapidly dissipates across the high surface area of the rete to be carried away from the brain by the venous system. This combination yields one of the most effective mechanisms of selective brain cooling. Although arterial development begins from the same embryonic scaffolding typical of mammals, possession of a rete is typically accompanied by obliteration of the internal carotid artery. Among taxa with available ontogenetic data, the point at which the internal carotid obliterates is variable throughout development. In small-bodied artiodactyls, the internal carotid typically obliterates prior to parturition, but in larger species, the vessel may remain patent for several years. In this study, we use digital anatomical data collection methods to describe the cranial arterial patterns for a growth series of giraffe (Giraffa camelopardalis), from parturition to senescence. Giraffes, in particular, have unique cardiovascular demands and adaptations owing to their exceptional body form and may not adhere to previously documented stages of cranial arterial development. We find the carotid arterial system to be conserved between developmental stages and that obliteration of the giraffe internal carotid artery occurs prior to parturition.
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Affiliation(s)
- Haley D O'Brien
- Biological Sciences, Ohio University, Athens, OH, United States; Current affiliation: Department of Anatomy and Cell Biology, Oklahoma State University Center for Health Sciences, Tulsa, OK, United States
| | - Paul M Gignac
- Department of Anatomy and Cell Biology, Oklahoma State University Center for Health Sciences , Tulsa, OK , United States
| | - Tobin L Hieronymus
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University , Rootstown, OH , United States
| | - Lawrence M Witmer
- Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine , Athens, OH , United States
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19
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Danowitz M, Domalski R, Solounias N. The cervical anatomy of Samotherium, an intermediate-necked giraffid. ROYAL SOCIETY OPEN SCIENCE 2015; 2:150521. [PMID: 26716010 PMCID: PMC4680625 DOI: 10.1098/rsos.150521] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 10/27/2015] [Indexed: 06/05/2023]
Abstract
Giraffidae are represented by many extinct species. The only two extant taxa possess diametrically contrasting cervical morphology, as the okapi is short-necked and the giraffe is exceptionally long-necked. Samotherium major, known from the Late Miocene of Samos in Greece and other Eurasian localities, is a key extinct giraffid; it possesses cervical vertebrae that are intermediate in the evolutionary elongation of the neck. We describe detailed anatomical features of the cervicals of S. major, and compare these characteristics with the vertebrae of the two extant giraffid taxa. Based on qualitative morphological characters and a quantitative analysis of cervical dimensions, we find that the S. major neck is intermediate between that of the okapi and the giraffe. Specifically, the more cranial (C2-C3) vertebrae of S. major represent a mosaic of features shared either with the giraffe or with the okapi. The more caudal (C5-C7) S. major vertebrae, however, appear transitional between the two extant taxa, and hence are more unique. Notably, the C6 of S. major exhibits a partially excavated ventral lamina that is strong cranially but completely absent on the caudal half of the ventral vertebral body, features between those seen in the giraffe and the okapi. Comprehensive anatomical descriptions and measurements of the almost-complete cervical column reveal that S. major is a truly intermediate-necked giraffid. Reconstructions of the neck display our findings.
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Affiliation(s)
- Melinda Danowitz
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, 8000 Northern Boulevard, Old Westbury, NY 11568, USA
| | - Rebecca Domalski
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, 8000 Northern Boulevard, Old Westbury, NY 11568, USA
| | - Nikos Solounias
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, 8000 Northern Boulevard, Old Westbury, NY 11568, USA
- Department of Paleontology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA
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20
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Danowitz M, Vasilyev A, Kortlandt V, Solounias N. Fossil evidence and stages of elongation of the Giraffa camelopardalis neck. ROYAL SOCIETY OPEN SCIENCE 2015; 2:150393. [PMID: 26587249 PMCID: PMC4632521 DOI: 10.1098/rsos.150393] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 09/16/2015] [Indexed: 06/05/2023]
Abstract
Several evolutionary theories have been proposed to explain the adaptation of the long giraffe neck; however, few studies examine the fossil cervical vertebrae. We incorporate extinct giraffids, and the okapi and giraffe cervical vertebral specimens in a comprehensive analysis of the anatomy and elongation of the neck. We establish and evaluate 20 character states that relate to general, cranial and caudal vertebral lengthening, and calculate a length-to-width ratio to measure the relative slenderness of the vertebrae. Our sample includes cervical vertebrae (n=71) of 11 taxa representing all seven subfamilies. We also perform a computational comparison of the C3 of Samotherium and Giraffa camelopardalis, which demonstrates that cervical elongation occurs disproportionately along the cranial-caudal vertebral axis. Using the morphological characters and calculated ratios, we propose stages in cervical lengthening, which are supported by the mathematical transformations using fossil and extant specimens. We find that cervical elongation is anisometric and unexpectedly precedes Giraffidae. Within the family, cranial vertebral elongation is the first lengthening stage observed followed by caudal vertebral elongation, which accounts for the extremely long neck of the giraffe.
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Affiliation(s)
- Melinda Danowitz
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568-8000, USA
| | - Aleksandr Vasilyev
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568-8000, USA
| | - Victoria Kortlandt
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568-8000, USA
| | - Nikos Solounias
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568-8000, USA
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21
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Snelling EP, Taggart DA, Maloney SK, Farrell AP, Leigh CM, Waterhouse L, Williams R, Seymour RS. Scaling of left ventricle cardiomyocyte ultrastructure across development in the kangaroo Macropus fuliginosus. ACTA ACUST UNITED AC 2015; 218:1767-76. [PMID: 25908057 DOI: 10.1242/jeb.119453] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 04/14/2015] [Indexed: 11/20/2022]
Abstract
The heart and left ventricle of the marsupial western grey kangaroo Macropus fuliginosus exhibit biphasic allometric growth, whereby a negative shift in the trajectory of cardiac growth occurs at pouch exit. In this study, we used transmission electron microscopy to examine the scaling of left ventricle cardiomyocyte ultrastructure across development in the western grey kangaroo over a 190-fold body mass range (0.355-67.5 kg). The volume-density (%) of myofibrils, mitochondria, sarcoplasmic reticuli and T-tubules increase significantly during in-pouch growth, such that the absolute volume (ml) of these organelles scales with body mass (Mb; kg) with steep hyperallometry: 1.41Mb (1.38), 0.64Mb (1.29), 0.066Mb (1.45) and 0.035Mb (1.87), respectively. Maturation of the left ventricle ultrastructure coincides with pouch vacation, as organelle volume-densities scale independent of body mass across post-pouch development, such that absolute organelle volumes scale in parallel and with relatively shallow hypoallometry: 4.65Mb (0.79), 1.75Mb (0.77), 0.21Mb (0.79) and 0.35Mb (0.79), respectively. The steep hyperallometry of organelle volumes and volume-densities across in-pouch growth is consistent with the improved contractile performance of isolated cardiac muscle during fetal development in placental mammals, and is probably critical in augmenting cardiac output to levels necessary for endothermy and independent locomotion in the young kangaroo as it prepares for pouch exit. The shallow hypoallometry of organelle volumes during post-pouch growth suggests a decrease in relative cardiac requirements as body mass increases in free-roaming kangaroos, which is possibly because the energy required for hopping is independent of speed, and the capacity for energy storage during hopping could increase as the kangaroo grows.
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Affiliation(s)
- Edward P Snelling
- Department of Ecology and Environmental Science, School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - David A Taggart
- Department of Ecology and Environmental Science, School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Shane K Maloney
- School of Anatomy, Physiology and Human Biology, University of Western Australia, Crawley, WA 6009, Australia
| | - Anthony P Farrell
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada V6T 1Z4 Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
| | - Christopher M Leigh
- School of Medical Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Lyn Waterhouse
- Adelaide Microscopy, University of Adelaide, Adelaide, SA 5005, Australia
| | - Ruth Williams
- Adelaide Microscopy, University of Adelaide, Adelaide, SA 5005, Australia
| | - Roger S Seymour
- Department of Ecology and Environmental Science, School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
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22
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Snelling EP, Taggart DA, Maloney SK, Farrell AP, Seymour RS. Biphasic Allometry of Cardiac Growth in the Developing KangarooMacropus fuliginosus. Physiol Biochem Zool 2015; 88:216-25. [DOI: 10.1086/679718] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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23
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Bertelsen MF. Giraffidae. FOWLER'S ZOO AND WILD ANIMAL MEDICINE, VOLUME 8 2015. [PMCID: PMC7151920 DOI: 10.1016/b978-1-4557-7397-8.00061-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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24
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Smerup M, Damkjær M, Brøndum E, Baandrup UT, Kristiansen SB, Nygaard H, Aalkjær C, Sauer C, Buchanan R, Bertelsen MF, Østergaard K, Grøndahl C, Candy G, Hasenkam JM, Secher NH, Bie P, Wang T. The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output. J Exp Biol 2015; 219:457-63. [DOI: 10.1242/jeb.132753] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 11/06/2015] [Indexed: 11/20/2022]
Abstract
Giraffes – the tallest extant animals on Earth – are renowned for their high central arterial blood pressure, which is necessary to secure brain perfusion. The pressure which may exceed 300 mmHg has historically been attributed to an exceptionally large heart. Recently, this has been refuted by several studies demonstrating that the mass of giraffe heart is similar to that of other mammals when expressed relative to body mass. It remains enigmatic, however, how the normal-sized giraffe heart generates such massive arterial pressures.
We hypothesized that giraffe hearts have a small intraventricular cavity and a relatively thick ventricular wall, allowing for generation of high arterial pressures at normal left ventricular wall tension. In nine anaesthetized giraffes (495±38 kg), we determined in vivo ventricular dimensions using echocardiography along with intraventricular and aortic pressures to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min−1, respectively. End-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, yielding an ejection fraction of 56±4%, and a stroke volume of 0.59 ml kg−1. Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke volume characterizes the giraffe heart. The adaptations result in typical mammalian left ventricular wall tensions, but results in lowered cardiac output.
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Affiliation(s)
- Morten Smerup
- Department of Cardiothoracic Surgery, Rigshospitalet, Copenhagen, Denmark and Clinical Institute, Aarhus University, Aarhus, Denmark
| | - Mads Damkjær
- Hans Christian Andersen Children's Hospital, Odense, Denmark
- Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Emil Brøndum
- Department of Biomedicine, Aarhus University, Aarhus, and Department of Biomedicine, Copenhagen University, Copenhagen, Denmark
| | - Ulrik T. Baandrup
- Department of Pathology, Center for Clinical Research, Vendsyssel Hospital, Aalborg University, Aalborg, Denmark
| | | | - Hans Nygaard
- Department of Thoracic and Cardiovascular Surgery and Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Christian Aalkjær
- Department of Biomedicine, Aarhus University, Aarhus, and Department of Biomedicine, Copenhagen University, Copenhagen, Denmark
| | - Cathrine Sauer
- Centre for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg C, Denmark
| | - Rasmus Buchanan
- Zoophysiology, Department of Biological Sciences, Aarhus University, Aarhus C, Denmark
| | | | - Kristine Østergaard
- Department of Pathology, Center for Clinical Research, Vendsyssel Hospital, Aalborg University, Aalborg, Denmark
| | - Carsten Grøndahl
- Centre for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg C, Denmark
| | - Geoffrey Candy
- Department of Physiology and Medicine, University of the Witwatersrand, Johannesburg, South Africa
| | - J. Michael Hasenkam
- Department of Thoracic and Cardiovascular Surgery and Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Niels H. Secher
- Department of Anesthesiology, Rigshospitalet, Copenhagen, Denmark
| | - Peter Bie
- Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Tobias Wang
- Zoophysiology, Department of Biological Sciences, Aarhus University, Aarhus C, Denmark
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25
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White CR, Seymour RS. The role of gravity in the evolution of mammalian blood pressure. Evolution 2014; 68:901-8. [PMID: 24152198 DOI: 10.1111/evo.12298] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Accepted: 04/19/2013] [Indexed: 11/30/2022]
Abstract
Understanding of the factors involved in determining the level of central arterial blood pressure in mammals has been clouded by inappropriate allometric analyses that fail to account for phylogenetic relationships among species, and require pressure to approach 0 as body size decreases. The present study analyses systolic, mean arterial, and diastolic blood pressure in 47 species of mammal with phylogenetically informed techniques applied to two-parameter equations. It also sets nonlinear, three-parameter equations to the data to remove the assumption of the two-parameter power equation that the smallest animals must have negligible blood pressure. These analyses show that blood pressure increases with body size. Nonlinear analyses show that mean blood pressure increases from 93 mmHg in a 10 g mouse to 156 mmHg in a 4 tonne elephant. The scaling exponent of blood pressure is generally lower than, though not significantly different from, the exponent predicted on the basis of the expected scaling of the vertical distance between the head and the heart. This indicates that compensation for the vertical distance above the heart is not perfect and suggests that the pressure required to perfuse the capillaries at the top of the body may decrease in larger species.
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Affiliation(s)
- Craig R White
- School of Biological Sciences, The University of Queensland, St. Lucia, QLD, 4072, Australia.
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Østergaard KH, Baandrup UT, Wang T, Bertelsen MF, Andersen JB, Smerup M, Nyengaard JR. Left ventricular morphology of the giraffe heart examined by stereological methods. Anat Rec (Hoboken) 2013; 296:611-21. [PMID: 23420662 DOI: 10.1002/ar.22672] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 01/07/2013] [Indexed: 11/10/2022]
Abstract
The giraffe heart has a relative mass similar to other mammals, but generates twice the blood pressure to overcome the gravitational challenge of perfusing the cerebral circulation. To provide insight as to how the giraffe left ventricle (LV) is structurally adapted to tackle such a high afterload, we performed a quantitative structural study of the LV myocardium in young and adult giraffe hearts. Tissue samples were collected from young and adult giraffe LV. Design-based stereology was used to obtain unbiased estimates of numbers and sizes of cardiomyocytes, nuclei and capillaries. The numerical density of myocyte nuclei was 120 × 10(3) mm(-3) in the adult and 504 × 10(3) mm(-3) in the young LV. The total number (N) of myocyte nuclei was 1.3 × 10(11) in the adult LV and 4.9 × 10(10) in the young LV. In the adult LV the volume per myocyte was 39.5 × 10(3) µm(3) and the number of nuclei per myocyte was 4.2. The numerical density of myocytes was 24.1 × 10(6) cm(-3) and the capillary volume fraction of the adult giraffe ventricle was 0.054. The significantly higher total number of myocyte nuclei in the adult LV, the high density of myocyte nuclei in the LV, and the number of nuclei per myocyte (which was unusually high compared to other mammalian, including human data), all suggest the presence of myocyte proliferation during growth of the animal to increase wall thickness and normalize LV wall tension as the neck lengthens and the need for higher blood pressure ensues.
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Affiliation(s)
- Kristine H Østergaard
- Center for Clinical Research, Vendsyssel Hospital and Aalborg University, Aalborg, Denmark.
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Sander PM, Christian A, Clauss M, Fechner R, Gee CT, Griebeler EM, Gunga HC, Hummel J, Mallison H, Perry SF, Preuschoft H, Rauhut OWM, Remes K, Tütken T, Wings O, Witzel U. Biology of the sauropod dinosaurs: the evolution of gigantism. Biol Rev Camb Philos Soc 2011; 86:117-55. [PMID: 21251189 PMCID: PMC3045712 DOI: 10.1111/j.1469-185x.2010.00137.x] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 03/13/2010] [Accepted: 03/16/2010] [Indexed: 11/28/2022]
Abstract
The herbivorous sauropod dinosaurs of the Jurassic and Cretaceous periods were the largest terrestrial animals ever, surpassing the largest herbivorous mammals by an order of magnitude in body mass. Several evolutionary lineages among Sauropoda produced giants with body masses in excess of 50 metric tonnes by conservative estimates. With body mass increase driven by the selective advantages of large body size, animal lineages will increase in body size until they reach the limit determined by the interplay of bauplan, biology, and resource availability. There is no evidence, however, that resource availability and global physicochemical parameters were different enough in the Mesozoic to have led to sauropod gigantism. We review the biology of sauropod dinosaurs in detail and posit that sauropod gigantism was made possible by a specific combination of plesiomorphic characters (phylogenetic heritage) and evolutionary innovations at different levels which triggered a remarkable evolutionary cascade. Of these key innovations, the most important probably was the very long neck, the most conspicuous feature of the sauropod bauplan. Compared to other herbivores, the long neck allowed more efficient food uptake than in other large herbivores by covering a much larger feeding envelope and making food accessible that was out of the reach of other herbivores. Sauropods thus must have been able to take up more energy from their environment than other herbivores. The long neck, in turn, could only evolve because of the small head and the extensive pneumatization of the sauropod axial skeleton, lightening the neck. The small head was possible because food was ingested without mastication. Both mastication and a gastric mill would have limited food uptake rate. Scaling relationships between gastrointestinal tract size and basal metabolic rate (BMR) suggest that sauropods compensated for the lack of particle reduction with long retention times, even at high uptake rates. The extensive pneumatization of the axial skeleton resulted from the evolution of an avian-style respiratory system, presumably at the base of Saurischia. An avian-style respiratory system would also have lowered the cost of breathing, reduced specific gravity, and may have been important in removing excess body heat. Another crucial innovation inherited from basal dinosaurs was a high BMR. This is required for fueling the high growth rate necessary for a multi-tonne animal to survive to reproductive maturity. The retention of the plesiomorphic oviparous mode of reproduction appears to have been critical as well, allowing much faster population recovery than in megaherbivore mammals. Sauropods produced numerous but small offspring each season while land mammals show a negative correlation of reproductive output to body size. This permitted lower population densities in sauropods than in megaherbivore mammals but larger individuals. Our work on sauropod dinosaurs thus informs us about evolutionary limits to body size in other groups of herbivorous terrestrial tetrapods. Ectothermic reptiles are strongly limited by their low BMR, remaining small. Mammals are limited by their extensive mastication and their vivipary, while ornithsichian dinosaurs were only limited by their extensive mastication, having greater average body sizes than mammals.
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Mitchell G, Skinner J. Lung volumes in giraffes, Giraffa camelopardalis. Comp Biochem Physiol A Mol Integr Physiol 2011; 158:72-8. [DOI: 10.1016/j.cbpa.2010.09.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2010] [Revised: 09/05/2010] [Accepted: 09/07/2010] [Indexed: 11/24/2022]
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van Sittert SJ, Skinner JD, Mitchell G. From fetus to adult--an allometric analysis of the giraffe vertebral column. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2010; 314:469-79. [PMID: 20700891 DOI: 10.1002/jez.b.21353] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
As mammalian cervical vertebral count is almost always limited to seven, the vertebral column of the giraffe (Giraffa camelopardalis) provides an interesting study on scaling and adaptation to shape in light of these constraints. We have defined and described the growth rates of the lengths, widths, and heights of the vertebrae from fetal through neonatal life to maturity. We found that the disproportionate elongation of the cervical vertebrae is not a fetal process but occurs after birth, and that each cervical (C2-C7) vertebrae elongates at the same rate. C7 is able to specialize toward elongation as its function has been shifted to T1. We concluded that T1 is a transitional vertebra whose scaling exponent and length is between that of the cervical and thoracic series. Despite its transitional nature, T1 is still regarded as thoracic, as it possesses an articulating rib that attaches to the sternum. The other dimensions taken (width, height, and spinous process length) show that giraffe vertebral morphology exhibit adaptations to biomechanical strain, and we have underlined the importance of the thoracic spinous processes in supporting the head and neck.
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Affiliation(s)
- Sybrand J van Sittert
- Centre for Veterinary Wildlife Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
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