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Panaino W, Parrini F, Kamerman PR, Hetem RS, Meyer LCR, Smith D, van Dyk G, Fuller A. Temminck pangolins relax the precision of body temperature regulation when resources are scarce in a semi-arid environment. CONSERVATION PHYSIOLOGY 2023; 11:coad068. [PMID: 37649641 PMCID: PMC10465008 DOI: 10.1093/conphys/coad068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 07/25/2023] [Accepted: 08/15/2023] [Indexed: 09/01/2023]
Abstract
Climate change is impacting mammals both directly (for example, through increased heat) and indirectly (for example, through altered food resources). Understanding the physiological and behavioural responses of mammals in already hot and dry environments to fluctuations in the climate and food availability allows for a better understanding of how they will cope with a rapidly changing climate. We measured the body temperature of seven Temminck's pangolins (Smutsia temminckii) in the semi-arid Kalahari for periods of between 4 months and 2 years. Pangolins regulated body temperature within a narrow range (34-36°C) over the 24-h cycle when food (and hence water, obtained from their prey) was abundant. When food resources were scarce, body temperature was regulated less precisely, 24-h minimum body temperatures were lower and the pangolins became more diurnally active, particularly during winter when prey was least available. The shift toward diurnal activity exposed pangolins to higher environmental heat loads, resulting in higher 24-h maximum body temperatures. Biologging of body temperature to detect heterothermy, or estimating food abundance (using pitfall trapping to monitor ant and termite availability), therefore provide tools to assess the welfare of this elusive but threatened mammal. Although the physiological and behavioural responses of pangolins buffered them against food scarcity during our study, whether this flexibility will be sufficient to allow them to cope with further reductions in food availability likely with climate change is unknown.
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Affiliation(s)
- Wendy Panaino
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, 2000, South Africa
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, 2193, South Africa
| | - Francesca Parrini
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, 2000, South Africa
| | - Peter R Kamerman
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, 2193, South Africa
| | - Robyn S Hetem
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, 2000, South Africa
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, 2193, South Africa
| | - Leith C R Meyer
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, 2193, South Africa
- Department of Paraclinical Sciences, and Centre for Veterinary Wildlife Research, University of Pretoria, Pretoria, 0110, South Africa
| | - Dylan Smith
- Tswalu Kalahari Reserve, van Zylsrus, 8467, Northern Cape, South Africa
| | - Gus van Dyk
- Tswalu Kalahari Reserve, van Zylsrus, 8467, Northern Cape, South Africa
| | - Andrea Fuller
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, 2193, South Africa
- Department of Paraclinical Sciences, and Centre for Veterinary Wildlife Research, University of Pretoria, Pretoria, 0110, South Africa
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Zheng Z, Hua R, Xu G, Yang H, Shi P. Gene losses may contribute to subterranean adaptations in naked mole-rat and blind mole-rat. BMC Biol 2022; 20:44. [PMID: 35172813 PMCID: PMC8851862 DOI: 10.1186/s12915-022-01243-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 01/28/2022] [Indexed: 01/18/2023] Open
Abstract
Background Naked mole-rats (Heterocephalus glaber, NMRs) and blind mole-rats (Spalax galili, BMRs) are representative subterranean rodents that have evolved many extraordinary traits, including hypoxia tolerance, longevity, and cancer resistance. Although multiple candidate loci responsible for these traits have been uncovered by genomic studies, many of them are limited to functional changes to amino acid sequence and little is known about the contributions of other genetic events. To address this issue, we focused on gene losses (unitary pseudogenes) and systematically analyzed gene losses in NMRs and BMRs, aiming to elucidate the potential roles of pseudogenes in their adaptation to subterranean lifestyle. Results We obtained the pseudogene repertoires in NMRs and BMRs, as well as their respective aboveground relatives, guinea pigs and rats, on a genome-wide scale. As a result, 167, 139, 341, and 112 pseudogenes were identified in NMRs, BMRs, guinea pigs, and rats, respectively. Functional enrichment analysis identified 4 shared and 2 species-specific enriched functional groups (EFGs) in subterranean lineages. Notably, the pseudogenes in these EFGs might be associated with either regressive (e.g., visual system) or adaptive (e.g., altered DNA damage response) traits. In addition, several pseudogenes including TNNI3K and PDE5A might be associated with specific cardiac features observed in subterranean lineages. Interestingly, we observed 20 convergent gene losses in NMRs and BMRs. Given that the functional investigations of these genes are generally scarce, we provided functional evidence that independent loss of TRIM17 in NMRs and BMRs might be beneficial for neuronal survival under hypoxia, supporting the positive role of eliminating TRIM17 function in hypoxia adaptation. Our results also suggested that pseudogenes, together with positively selected genes, reinforced subterranean adaptations cooperatively. Conclusions Our study provides new insights into the molecular underpinnings of subterranean adaptations and highlights the importance of gene losses in mammalian evolution. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01243-0.
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Affiliation(s)
- Zhizhong Zheng
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, 650223, Kunming, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, China
| | - Rong Hua
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, 650223, Kunming, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, 650204, China.,Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, China
| | - Guoqiang Xu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, China.,Joint Laboratory of Animal Models for Human Diseases and Drug Development, Soochow University and Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China
| | - Hui Yang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, 650223, Kunming, China.
| | - Peng Shi
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, 650223, Kunming, China. .,Joint Laboratory of Animal Models for Human Diseases and Drug Development, Soochow University and Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223, China. .,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, 650223, China. .,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 101408, China.
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Valente R, Alves F, Sousa-Pinto I, Ruivo R, Castro LFC. Functional or Vestigial? The Genomics of the Pineal Gland in Xenarthra. J Mol Evol 2021; 89:565-575. [PMID: 34342686 DOI: 10.1007/s00239-021-10025-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 07/27/2021] [Indexed: 11/28/2022]
Abstract
Vestigial organs are historical echoes of past phenotypes. Determining whether a specific organ constitutes a functional or vestigial structure can be a challenging task, given that distinct levels of atrophy may arise between and within lineages. The mammalian pineal gland, an endocrine organ involved in melatonin biorhythmicity, represents a classic example, often yielding contradicting anatomical observations. In Xenarthra (sloths, anteaters, and armadillos), a peculiar mammalian order, the presence of a distinct pineal organ was clearly observed in some species (i.e., Linnaeus's two-toed sloth), but undetected in other closely related species (i.e., brown-throated sloth). In the nine-banded armadillo, contradicting evidence supports either functional or vestigial scenarios. Thus, to untangle the physiological status of the pineal gland in Xenarthra, we used a genomic approach to investigate the evolution of the gene hub responsible for melatonin synthesis and signaling. We show that both synthesis and signaling compartments are eroded and were probably lost independently among Xenarthra orders. Additionally, by expanding our analysis to 157 mammal genomes, we offer a comprehensive view showing that species with very distinctive habitats and lifestyles have convergently evolved a similar phenotype: Cetacea, Pholidota, Dermoptera, Sirenia, and Xenarthra. Our findings suggest that the recurrent inactivation of melatonin genes correlates with pineal atrophy and endorses the use of genomic analyses to ascertain the physiological status of suspected vestigial structures.
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Affiliation(s)
- Raul Valente
- CIMAR/CIIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Avenida General Norton de Matos, S/N, 4450-208, Matosinhos, Portugal.,FCUP-Department of Biology, Faculty of Sciences, University of Porto (U. Porto), Rua Do Campo Alegre, Porto, Portugal
| | - Filipe Alves
- MARE-Marine and Environmental Sciences Centre, ARDITI, Madeira, Portugal.,OOM-Oceanic Observatory of Madeira, Funchal, Portugal
| | - Isabel Sousa-Pinto
- CIMAR/CIIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Avenida General Norton de Matos, S/N, 4450-208, Matosinhos, Portugal.,FCUP-Department of Biology, Faculty of Sciences, University of Porto (U. Porto), Rua Do Campo Alegre, Porto, Portugal
| | - Raquel Ruivo
- CIMAR/CIIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Avenida General Norton de Matos, S/N, 4450-208, Matosinhos, Portugal
| | - L Filipe C Castro
- CIMAR/CIIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Avenida General Norton de Matos, S/N, 4450-208, Matosinhos, Portugal. .,FCUP-Department of Biology, Faculty of Sciences, University of Porto (U. Porto), Rua Do Campo Alegre, Porto, Portugal.
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Boyles JG, Swart JM, Bennett NC, Ferguson W, Speakman JR, Scantlebury DM. Energetics suggest cause for even further conservation concern for Temminck’s ground pangolin. Anim Conserv 2019. [DOI: 10.1111/acv.12536] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- J. G. Boyles
- Cooperative Wildlife Research Laboratory Center for Ecology, and School of Biological Sciences Southern Illinois University Carbondale IL USA
| | - J. M. Swart
- Welgevonden Game Reserve Vaalwater South Africa
- Department of Zoology and Entomology University of Pretoria Pretoria South Africa
| | - N. C. Bennett
- Department of Zoology and Entomology University of Pretoria Pretoria South Africa
- Mammal Research Institute University of Pretoria Pretoria South Africa
| | - W. Ferguson
- Mammal Research Institute University of Pretoria Pretoria South Africa
- Department of Geography, Geoinformatics and Meteorology University of Pretoria Pretoria South Africa
| | - J. R. Speakman
- Institute of Biological and Environmental Sciences University of Aberdeen Aberdeen UK
- State Key Laboratory of Molecular Developmental Biology Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing China
- CAS Centre of Excellence in Animal Evolution and Genetics Chinese Academy of Sciences Kunming China
| | - D. M. Scantlebury
- School of Biological Sciences Institute for Global Food Security Queen’s University Belfast Belfast UK
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Signore AV, Paijmans JLA, Hofreiter M, Fago A, Weber RE, Springer MS, Campbell KL. Emergence of a Chimeric Globin Pseudogene and Increased Hemoglobin Oxygen Affinity Underlie the Evolution of Aquatic Specializations in Sirenia. Mol Biol Evol 2019; 36:1134-1147. [PMID: 30828717 PMCID: PMC6526914 DOI: 10.1093/molbev/msz044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 02/13/2019] [Accepted: 02/27/2019] [Indexed: 12/13/2022] Open
Abstract
As limits on O2 availability during submergence impose severe constraints on aerobic respiration, the oxygen binding globin proteins of marine mammals are expected to have evolved under strong evolutionary pressures during their land-to-sea transition. Here, we address this question for the order Sirenia by retrieving, annotating, and performing detailed selection analyses on the globin repertoire of the extinct Steller’s sea cow (Hydrodamalis gigas), dugong (Dugong dugon), and Florida manatee (Trichechus manatus latirostris) in relation to their closest living terrestrial relatives (elephants and hyraxes). These analyses indicate most loci experienced elevated nucleotide substitution rates during their transition to a fully aquatic lifestyle. While most of these genes evolved under neutrality or strong purifying selection, the rate of nonsynonymous/synonymous replacements increased in two genes (Hbz-T1 and Hba-T1) that encode the α-type chains of hemoglobin (Hb) during each stage of life. Notably, the relaxed evolution of Hba-T1 is temporally coupled with the emergence of a chimeric pseudogene (Hba-T2/Hbq-ps) that contributed to the tandemly linked Hba-T1 of stem sirenians via interparalog gene conversion. Functional tests on recombinant Hb proteins from extant and ancestral sirenians further revealed that the molecular remodeling of Hba-T1 coincided with increased Hb–O2 affinity in early sirenians. Available evidence suggests that this trait evolved to maximize O2 extraction from finite lung stores and suppress tissue O2 offloading, thereby facilitating the low metabolic intensities of extant sirenians. In contrast, the derived reduction in Hb–O2 affinity in (sub)Arctic Steller’s sea cows is consistent with fueling increased thermogenesis by these once colossal marine herbivores.
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Affiliation(s)
- Anthony V Signore
- Department of Biological Sciences, University of Manitoba, Winnipeg, Canada.,School of Biological Sciences, University of Nebraska, Lincoln, NE
| | | | - Michael Hofreiter
- Institute of Biochemistry and Biology, University of Potsdam, Germany
| | - Angela Fago
- Department of Bioscience, Zoophysiology, Aarhus University, Denmark
| | - Roy E Weber
- Department of Bioscience, Zoophysiology, Aarhus University, Denmark
| | - Mark S Springer
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA
| | - Kevin L Campbell
- Department of Biological Sciences, University of Manitoba, Winnipeg, Canada
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HEMATOLOGIC AND SERUM BIOCHEMICAL PARAMETERS OF APPARENTLY HEALTHY RESCUED FORMOSAN PANGOLINS (MANIS PENTADACTYLA PENTADACTYLA). J Zoo Wildl Med 2015; 46:68-76. [DOI: 10.1638/2013-0104r4.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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7
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Pietersen DW, McKechnie AE, Jansen R. Home Range, Habitat Selection and Activity Patterns of an Arid-Zone Population of Temminck's Ground Pangolins,Smutsia temminckii. AFRICAN ZOOLOGY 2014. [DOI: 10.3377/004.049.0215] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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8
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Bao F, Wu S, Su C, Yang L, Zhang F, Ma G. Air temperature changes in a burrow of Chinese pangolin,Manis pentadactyla, in winter. FOLIA ZOOLOGICA 2013. [DOI: 10.25225/fozo.v62.i1.a6.2013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Fangyin Bao
- School of Life Science, Anhui Science and Technology University, Fengyang 233100, Anhui Province, P. R. China
| | - Shibao Wu
- School of Life Science, South China Normal University, Guangzhou 510631, P. R. China
| | - Chao Su
- School of Life Science, South China Normal University, Guangzhou 510631, P. R. China
| | - Li Yang
- School of Life Science, South China Normal University, Guangzhou 510631, P. R. China
| | - Fuhua Zhang
- School of Life Science, South China Normal University, Guangzhou 510631, P. R. China
| | - Guangzhi Ma
- School of Life Science, South China Normal University, Guangzhou 510631, P. R. China
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9
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Hsieh HM, Lee JCI, Wu JH, Chen CA, Chen YJ, Wang GB, Chin SC, Wang LC, Linacre A, Tsai LC. Establishing the pangolin mitochondrial D-loop sequences from the confiscated scales. Forensic Sci Int Genet 2010; 5:303-7. [PMID: 20638354 DOI: 10.1016/j.fsigen.2010.06.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Accepted: 06/07/2010] [Indexed: 11/27/2022]
Abstract
Pangolin scales are encountered in traditional East Asian medicines (TEAM) and the ever increasing demand for these scales has escalated the decline in the numbers of these mammals. The identification of protected pangolin species is necessary to enforce international and national legislation as well as assist with conservation measures. There is limited morphological feature on a pangolin scale thus requiring DNA analysis as a means of identification. We report on the isolation of DNA from pangolin scales and a strategy for obtaining the full length of the mitochondrial D-loop, being 1159 bp. Primer sets creating five overlapping amplicons were designed to amplify sections of this mitochondrial DNA locus. DNA from the blood stain of nineteen Formosan pangolins (Manis pentadactyla pentadactyla) along with 145 scale samples that were suspected to have come from pangolins, was amplified and sequenced; leading to a total of 91 D-loop sequences being obtained. The 19 Formosan pangolin sequences produced 5 haplotypes and 72 of the 145 seized scales provided useable sequence classified as a further 38 haplotypes. The D-loop sequences from those scales suspected to be from a pangolin had a higher similarity to any of the 19 samples taken from M. p. pentadactyla compared to a D-loop sequence from Manis tetradactyla (the only pangolin D-loop sequence in GenBank, NC_004027). These 43 haplotypes were used to establish a local database for the D-loop sequence of pangolins and add to the data of Manis sp. held on GenBank. The PCR amplification strategy development in this study could be used in forensic DNA identification of scales suspected to be from protected pangolin species.
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Affiliation(s)
- Hsing-Mei Hsieh
- Department of Forensic Science, Central Police University, 56 Shu-Jen Road, Kwei-San, Taoyuan 33334, Taiwan, ROC
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van Aardt WJ, Bronner G, Buffenstein R. Hemoglobin–oxygen-affinity and acid-base properties of blood from the fossorial mole-rat, Cryptomys hottentotus pretoriae. Comp Biochem Physiol A Mol Integr Physiol 2007; 147:50-6. [PMID: 17276113 DOI: 10.1016/j.cbpa.2006.11.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2006] [Revised: 11/07/2006] [Accepted: 11/10/2006] [Indexed: 11/26/2022]
Abstract
Oxygen affinity and other hematological parameters in strictly subterranean mole-rats, Cryptomys hottentotus (subspecies pretoriae) were measured immediately upon capture and after 14-21 days in captivity. The pH, hematocrit, hemoglobin (Hb) concentration, blood oxygen content, 2,3 bisphosphoglycerate (2,3 BPG) concentration and oxygen dissociation curves (ODC), as well as tonometric measurements, were determined using whole blood. Additionally ODCs were also determined for stripped hemolysates of individual animals. Compared to other mammals, blood of freshly caught animals had low pH (7.32+/-0.22), elevated hematocrits (48.4+/-3.8 %) and significantly lower P50 values for whole blood (21.1+/-1.6 mm Hg at pH 7.4) than those reported for other similar-sized fossorial and terrestrial mammals. Blood carbon dioxide content (22.4+/-3.9 mMol L(-1)), hemoglobin concentration (1.9+/-0.15 mMol L(-1)), oxygen content (164.8+/-26 mL L(-1)), bicarbonate concentrations (22.5+/-3.5 mMol L(-1)) were within the range of values reported for similar-sized mammals. We conclude that high blood-oxygen affinity, low body temperature and possibly also high hematocrit enable C. h. pretoriae to maintain an adequate oxygen supply to the tissues in a potentially hypoxic burrow atmospheres, but that the blood of this species shows no exceptional CO2 sensitivity or buffering capacity.
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Affiliation(s)
- W J van Aardt
- School of Environmental Sciences and Development, North-West University, Potchefstroom Campus, Potchefstroom, 2520, South Africa
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11
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Nikinmaa M. Haemoglobin function in vertebrates: evolutionary changes in cellular regulation in hypoxia. RESPIRATION PHYSIOLOGY 2001; 128:317-29. [PMID: 11718761 DOI: 10.1016/s0034-5687(01)00309-7] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The evolution of erythrocytic hypoxia responses is reviewed by comparing the cellular control of haemoglobin-oxygen affinity in agnathans, teleost fish and terrestrial vertebrates. The most ancient response to hypoxic conditions appears to be an increase in cell volume, which increases the haemoglobin-oxygen affinity in lampreys. In teleost fish, an increase of cell volume in hypoxic conditions is also evident. The volume increase is coupled to an increase in erythrocyte pH. These changes are caused by an adrenergic activation of sodium/proton exchange across the erythrocyte membrane. The mechanism is important in acute hypoxia and is followed by a decrease in cellular adenosine triphosphate (ATP) and guanosine triphosphate (GTP) concentrations in continued hypoxia. In hypoxic bird embryos, the ATP levels are also reduced. The mechanisms by which hypoxia decreases cellular ATP and GTP concentrations remains unknown, although at least in bird embryos cAMP-dependent mechanisms have been implicated. In mammals, hypoxia responses appear to occur mainly via modulation of cellular organic phosphate concentrations. In moderate hypoxia, 2,3-diphosphoglycerate levels are increased as a result of alkalosis caused by increased ventilation.
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Affiliation(s)
- M Nikinmaa
- Department of Biology, University of Turku, FIN-20014, Turku, Finland.
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12
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Lutz PL, Storey KB. Adaptations to Variations in Oxygen Tension by Vertebrates and Invertebrates. Compr Physiol 1997. [DOI: 10.1002/cphy.cp130221] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Weber RE, Kleinschmidt T, Braunitzer G. Embryonic pig hemoglobins Gower I (zeta 2 epsilon 2), Gower II (alpha 2 epsilon 2), Heide I (zeta 2 theta 2) and Heide II (alpha 2 theta 2): oxygen-binding functions related to structure and embryonic oxygen supply. RESPIRATION PHYSIOLOGY 1987; 69:347-57. [PMID: 2443953 DOI: 10.1016/0034-5687(87)90088-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The common pig lacks a fetal hemoglobin but has four embryonic hemoglobins: Gower I (zeta 2 epsilon 2), Gower II (alpha 2 epsilon 2), Heide I (zeta 2 theta 2) and Heide II (alpha 2 theta 2) as well as adult Hb A (alpha 2 beta 2) and the amino acid sequence for each of the five constituent polypeptide chains has been established. The oxygenation characteristics of the five components, measured in relation to pH, temperature and the erythrocytic ligand 2,3-diphosphoglycerate (DPG), together with the changes in their relative concentrations during early embryonic life, are given. The findings indicate a progressive decrease in maternal-fetal oxygen affinity difference and thus in oxygen transfer efficacy at a given diffusion gradient that correlates with the development of the gas exchange structures. The functional properties of the individual hemoglobins are additionally discussed in relation to molecular structure.
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Affiliation(s)
- R E Weber
- Biologisk Institut, Odense Universitet, Denmark
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