1
|
Piot E, Hippauf L, Charlanne L, Picard B, Badaut J, Gilbert C, Guinet C. From land to ocean: One month for southern elephant seal pups to acquire aquatic skills prior to their first departure to sea. Physiol Behav 2024; 279:114525. [PMID: 38531424 DOI: 10.1016/j.physbeh.2024.114525] [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: 12/14/2023] [Revised: 03/18/2024] [Accepted: 03/21/2024] [Indexed: 03/28/2024]
Abstract
Weaned southern elephant seals (SES) quickly transition from terrestrial to aquatic life after a 5- to 6-week post-weaning period. At sea, juveniles and adult elephant seals present extreme, continuous diving behaviour. Previous studies have highlighted the importance of the post-weaning period for weanlings to prepare for the physiological challenges of their future sea life. However, very little is known about how their body condition during this period may influence the development of their behaviour and brain activities. To characterise changes in the behavioural and brain activity of weanlings prior to ocean departure, we implemented a multi-logger approach combining measurements of movements (related to behaviour), pressure (related to diving), and brain electrical activity. As pups age, the amount of time allocated to resting decreases in favour of physical activity. Most resting (9.6 ± 1.2 h/day) takes place during daytime, with periods of slow-wave sleep representing 4.9 ± 0.9 h/day during the first 2 weeks. Furthermore, an increasing proportion of physical activity transitions from land to shore. Additionally, pups in poorer condition (lean group) are more active earlier than those in better condition (corpulent group). Finally, at weaning, clear circadian activity with two peaks at dawn and dusk is observed, and this pattern remains unchanged during the 4 weeks on land. This circadian pattern matches the one observed in adults at sea, with more prey catches at dawn and dusk, raising the question of whether it is endogenous or triggered by the mother during lactation.
Collapse
Affiliation(s)
- Erwan Piot
- Laboratoire MECADEV, UMR 7179 CNRS/MNHN, 1 Avenue du Petit Château, 91800 Brunoy, France; CNRS UMR 5536, Université de Bordeaux, 33076 Bordeaux, France.
| | - Lea Hippauf
- CNRS UMR 5536, Université de Bordeaux, 33076 Bordeaux, France
| | - Laura Charlanne
- Université de Strasbourg, CNRS, IPHC, Département d'Ecologie, Physiologie et Ethologie, 23 rue Becquerel, 67087 Strasbourg, France
| | - Baptiste Picard
- Centre d'Études Biologiques de Chizé-Centre National de la Recherche Scientifique (CEBC-CNRS), UMR 7372 CNRS/Université de La Rochelle, 79360 Villiers-en-Bois, France
| | - Jérôme Badaut
- CNRS UMR 5536, Université de Bordeaux, 33076 Bordeaux, France
| | - Caroline Gilbert
- Laboratoire MECADEV, UMR 7179 CNRS/MNHN, 1 Avenue du Petit Château, 91800 Brunoy, France; École Nationale Vétérinaire d'Alfort, 7 Avenue du Général de Gaulle, 94704 Maisons-Alfort cedex, France
| | - Christophe Guinet
- Centre d'Études Biologiques de Chizé-Centre National de la Recherche Scientifique (CEBC-CNRS), UMR 7372 CNRS/Université de La Rochelle, 79360 Villiers-en-Bois, France
| |
Collapse
|
2
|
Noren SR. Building Cetacean Locomotor Muscles throughout Ontogeny to Support High-Performance Swimming into Adulthood. Integr Comp Biol 2023; 63:785-795. [PMID: 36990644 DOI: 10.1093/icb/icad011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/20/2023] [Accepted: 03/21/2023] [Indexed: 03/31/2023] Open
Abstract
The demands on the locomotor muscles at birth are different for cetaceans than terrestrial mammals. Cetacean muscles do not need to support postural costs as the neonate transitions from the womb because water's buoyant force supports body weight. Rather, neonatal cetacean muscles must sustain locomotion under hypoxic conditions as the neonate accompanies its mother swimming underwater. Despite disparate demands at birth, cetaceans like terrestrial mammals require postnatal development to attain mature musculature. Neonatal cetaceans have a low proportion of muscle mass, and their locomotor muscles have lower mitochondrial density, myoglobin content (Mb), and buffering capacity than those found in the adult locomotor muscle. For example, the locomotor muscle of the neonatal bottlenose dolphin has only 10 and 65% of the Mb and buffering capacity, respectively, found in the adult locomotor muscle. The maturation period required to achieve mature Mb and buffering capacity in the locomotor muscle varies across cetacean species from 0.75 to 4 and 1.17 to 3.4 years, respectively. The truncated nursing interval of harbor porpoises and sub-ice travel of beluga whales may be drivers for faster muscle maturation in these species. Despite these postnatal changes in the locomotor muscle, ontogenetic changes in locomotor muscle fiber type seem to be rare in cetaceans. Regardless, the underdeveloped aerobic and anaerobic capacities of the locomotor muscle of immature dolphins result in diminished thrusting capability and swim performance. Size-specific stroke amplitudes (23-26% of body length) of 0-3-month-old dolphins are significantly smaller than those of >10-month-olds (29-30% of body length), and 0-1-month-olds only achieve 37 and 52% of the mean and maximum swim speed of adults, respectively. Until swim performance improves with muscle maturation, young cetaceans are precluded from achieving their pod's swim speeds, which could have demographic consequences when fleeing anthropogenic disturbances.
Collapse
Affiliation(s)
- S R Noren
- Institute of Marine Sciences, University of California Santa Cruz Center for Ocean Health, 115 McAllister Way, Santa Cruz, CA 95060, USA
| |
Collapse
|
3
|
Graham AM, Jamison JM, Bustos M, Cournoyer C, Michaels A, Presnell JS, Richter R, Crocker DE, Fustukjian A, Hunter ME, Rea LD, Marsillach J, Furlong CE, Meyer WK, Clark NL. Reduction of Paraoxonase Expression Followed by Inactivation across Independent Semiaquatic Mammals Suggests Stepwise Path to Pseudogenization. Mol Biol Evol 2023; 40:msad104. [PMID: 37146172 PMCID: PMC10202596 DOI: 10.1093/molbev/msad104] [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: 11/14/2022] [Revised: 03/27/2023] [Accepted: 04/17/2023] [Indexed: 05/07/2023] Open
Abstract
Convergent adaptation to the same environment by multiple lineages frequently involves rapid evolutionary change at the same genes, implicating these genes as important for environmental adaptation. Such adaptive molecular changes may yield either change or loss of protein function; loss of function can eliminate newly deleterious proteins or reduce energy necessary for protein production. We previously found a striking case of recurrent pseudogenization of the Paraoxonase 1 (Pon1) gene among aquatic mammal lineages-Pon1 became a pseudogene with genetic lesions, such as stop codons and frameshifts, at least four times independently in aquatic and semiaquatic mammals. Here, we assess the landscape and pace of pseudogenization by studying Pon1 sequences, expression levels, and enzymatic activity across four aquatic and semiaquatic mammal lineages: pinnipeds, cetaceans, otters, and beavers. We observe in beavers and pinnipeds an unexpected reduction in expression of Pon3, a paralog with similar expression patterns but different substrate preferences. Ultimately, in all lineages with aquatic/semiaquatic members, we find that preceding any coding-level pseudogenization events in Pon1, there is a drastic decrease in expression, followed by relaxed selection, thus allowing accumulation of disrupting mutations. The recurrent loss of Pon1 function in aquatic/semiaquatic lineages is consistent with a benefit to Pon1 functional loss in aquatic environments. Accordingly, we examine diving and dietary traits across pinniped species as potential driving forces of Pon1 functional loss. We find that loss is best associated with diving activity and likely results from changes in selective pressures associated with hypoxia and hypoxia-induced inflammation.
Collapse
Affiliation(s)
- Allie M Graham
- Department of Human Genetics, University of Utah, Salt Lake City, UT
| | - Jerrica M Jamison
- Department of Biological Sciences, University of Toronto—Scarborough, Scarborough, Ontario, Canada
| | - Marisol Bustos
- Department of Biomedical Engineering, University of Texas—San Antonio, San Antonio, TX
| | | | - Alexa Michaels
- Graduate School of Biomedical Sciences, Tufts University, Boston, MA
- The Jackson Laboratory, Bar Harbor, ME
| | - Jason S Presnell
- Department of Human Genetics, University of Utah, Salt Lake City, UT
| | - Rebecca Richter
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA
| | - Daniel E Crocker
- Department of Biology, Sonoma State University, Rohnert Park, CA
| | | | - Margaret E Hunter
- U.S. Geological Survey, Wetland and Aquatic Research Center, Gainesville, FL
| | - Lorrie D Rea
- Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska—Fairbanks, Fairbanks, AK
| | - Judit Marsillach
- Department of Environmental & Occupational Health Sciences, University of Washington School of Public Health, Seattle, WA
| | - Clement E Furlong
- Department of Medicine, Division of Medical Genetics, University of Washington, Seattle, WA
- Department of Genome Sciences, University of Washington, Seattle, WA
| | - Wynn K Meyer
- Department of Biological Sciences, Lehigh University, Bethlehem, PA
| | - Nathan L Clark
- Department of Human Genetics, University of Utah, Salt Lake City, UT
| |
Collapse
|
4
|
Grecian WJ, Stenson GB, Biuw M, Boehme L, Folkow LP, Goulet PJ, Jonsen ID, Malde A, Nordøy ES, Rosing-Asvid A, Smout S. Environmental drivers of population-level variation in the migratory and diving ontogeny of an Arctic top predator. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211042. [PMID: 35316952 PMCID: PMC8889203 DOI: 10.1098/rsos.211042] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
The development of migratory strategies that enable juveniles to survive to sexual maturity is critical for species that exploit seasonal niches. For animals that forage via breath-hold diving, this requires a combination of both physiological and foraging skill development. Here, we assess how migratory and dive behaviour develop over the first year of life for a migratory Arctic top predator, the harp seal Pagophilus groenlandicus, tracked using animal-borne satellite relay data loggers. We reveal similarities in migratory movements and differences in diving behaviour between 38 juveniles tracked from the Greenland Sea and Northwest Atlantic breeding populations. In both regions, periods of resident and transitory behaviour during migration were associated with proxies for food availability: sea ice concentration and bathymetric depth. However, while ontogenetic development of dive behaviour was similar for both populations of juveniles over the first 25 days, after this time Greenland Sea animals performed shorter and shallower dives and were more closely associated with sea ice than Northwest Atlantic animals. Together, these results highlight the role of both intrinsic and extrinsic factors in shaping early life behaviour. Variation in the environmental conditions experienced during early life may shape how different populations respond to the rapid changes occurring in the Arctic ocean ecosystem.
Collapse
Affiliation(s)
- W. James Grecian
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, UK
| | - Garry B. Stenson
- Fisheries and Oceans Canada, St John's, Newfoundland and Labrador, Canada
| | - Martin Biuw
- Institute of Marine Research, FRAM—High North Research Centre for Climate and the Environment, Tromsø, Norway
| | - Lars Boehme
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, UK
| | - Lars P. Folkow
- Department of Arctic and Marine Biology, University of Tromsø—the Arctic University of Norway, Tromsø, Norway
| | - Pierre J. Goulet
- Fisheries and Oceans Canada, St John's, Newfoundland and Labrador, Canada
| | - Ian D. Jonsen
- Department of Biological Sciences, Macquarie University, Sydney, Australia
| | - Aleksander Malde
- Department of Arctic and Marine Biology, University of Tromsø—the Arctic University of Norway, Tromsø, Norway
| | - Erling S. Nordøy
- Department of Arctic and Marine Biology, University of Tromsø—the Arctic University of Norway, Tromsø, Norway
| | | | - Sophie Smout
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, UK
| |
Collapse
|
5
|
Weitzner EL, Pearson LE, Tomanek L, Liwanag HEM. Early diving behavior in Weddell seal (Leptonychotes weddellii) pups. J Mammal 2021. [DOI: 10.1093/jmammal/gyab058] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
During the dependency period in mammals with parental care, offspring must develop the behavioral skills that allow them to forage independently and thus survive into early adulthood. Deep-diving Weddell seals (Leptonychotes weddellii) are a model species for research on diving physiology, yet previous studies lack a thorough investigation into the diving behavior of dependent pups when they first begin to enter the water. To capture fine-scale dive behavior during the dependency period, we deployed time-depth recorders (TDRs) on Weddell seal pups (n = 18) from the age of 1 week through 7 weeks, during the 2017 and 2019 breeding seasons in McMurdo Sound, Antarctica. Dive parameters were correlated with time of day, age, sex, and weaning status, to characterize diving behavior, and we used raw wet/dry data to determine which times of the day pups were most likely to be in the water. Pups made their deepest and longest dives and had the longest post-dive durations in the morning hours. Pups were in the water more during the late night and morning hours than in the afternoon. Whereas dive depth significantly increased with age, dive duration significantly increased with age and after weaning. Post-dive duration significantly decreased with age and after weaning. We discuss how dependent pups may prioritize the development of swimming and navigational abilities as opposed to building and practicing foraging skills.
Collapse
Affiliation(s)
- Emma L Weitzner
- Department of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA 93401, USA
| | - Linnea E Pearson
- Department of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA 93401, USA
| | - Lars Tomanek
- Department of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA 93401, USA
| | - Heather E M Liwanag
- Department of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA 93401, USA
| |
Collapse
|
6
|
He K, Eastman TG, Czolacz H, Li S, Shinohara A, Kawada SI, Springer MS, Berenbrink M, Campbell KL. Myoglobin primary structure reveals multiple convergent transitions to semi-aquatic life in the world's smallest mammalian divers. eLife 2021; 10:e66797. [PMID: 33949308 PMCID: PMC8205494 DOI: 10.7554/elife.66797] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 05/04/2021] [Indexed: 01/01/2023] Open
Abstract
The speciose mammalian order Eulipotyphla (moles, shrews, hedgehogs, solenodons) combines an unusual diversity of semi-aquatic, semi-fossorial, and fossorial forms that arose from terrestrial forbearers. However, our understanding of the ecomorphological pathways leading to these lifestyles has been confounded by a fragmentary fossil record, unresolved phylogenetic relationships, and potential morphological convergence, calling for novel approaches. The net surface charge of the oxygen-storing muscle protein myoglobin (ZMb), which can be readily determined from its primary structure, provides an objective target to address this question due to mechanistic linkages with myoglobin concentration. Here, we generate a comprehensive 71 species molecular phylogeny that resolves previously intractable intra-family relationships and then ancestrally reconstruct ZMb evolution to identify ancient lifestyle transitions based on protein sequence alone. Our phylogenetically informed analyses confidently resolve fossorial habits having evolved twice in talpid moles and reveal five independent secondary aquatic transitions in the order housing the world's smallest endothermic divers.
Collapse
Affiliation(s)
- Kai He
- Department of Biological Sciences, University of ManitobaWinnipegCanada
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Southern Medical UniversityGuangzhouChina
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of SciencesKunmingChina
- Guangdong Provincial Key Laboratory of Single Cell Technology and Application, Southern Medical UniversityGuangzhouChina
| | - Triston G Eastman
- Department of Biological Sciences, University of ManitobaWinnipegCanada
| | - Hannah Czolacz
- Department of Evolution, Ecology and Behaviour, University of LiverpoolLiverpoolUnited Kingdom
| | - Shuhao Li
- Department of Biological Sciences, University of ManitobaWinnipegCanada
| | - Akio Shinohara
- Department of Bio-resources, Division of Biotechnology, Frontier Science Research Center, University of MiyazakiMiyazakiJapan
| | - Shin-ichiro Kawada
- Department of Zoology, Division of Vertebrates, National Museum of Nature and ScienceTokyoJapan
| | - Mark S Springer
- Department of Evolution, Ecology and Organismal Biology, University of California, RiversideRiversideUnited States
| | - Michael Berenbrink
- Department of Evolution, Ecology and Behaviour, University of LiverpoolLiverpoolUnited Kingdom
| | - Kevin L Campbell
- Department of Biological Sciences, University of ManitobaWinnipegCanada
| |
Collapse
|
7
|
Arregui M, Singleton EM, Saavedra P, Pabst DA, Moore MJ, Sierra E, Rivero MA, Câmara N, Niemeyer M, Fahlman A, McLellan WA, Bernaldo de Quirós Y. Myoglobin Concentration and Oxygen Stores in Different Functional Muscle Groups from Three Small Cetacean Species. Animals (Basel) 2021; 11:ani11020451. [PMID: 33572177 PMCID: PMC7915992 DOI: 10.3390/ani11020451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/30/2021] [Accepted: 02/02/2021] [Indexed: 01/18/2023] Open
Abstract
Simple Summary Marine mammals display several physiological adaptations to their marine environment. Higher myoglobin concentrations in their muscles compared to terrestrial mammals allow them to increase their onboard oxygen stores, enhancing the time available to dive. Most previous studies have calculated cetaceans’ onboard oxygen stores by assuming the myoglobin concentration of a single muscle to be representative of all the muscles in the body. In this study, we analyzed this assumption by comparing it to a more precise method that weighs all body muscles and measures myoglobin concentration in different functional groups. Abstract Compared with terrestrial mammals, marine mammals possess increased muscle myoglobin concentrations (Mb concentration, g Mb · 100g−1 muscle), enhancing their onboard oxygen (O2) stores and their aerobic dive limit. Although myoglobin is not homogeneously distributed, cetacean muscle O2 stores have been often determined by measuring Mb concentration from a single muscle sample (longissimus dorsi) and multiplying that value by the animal’s locomotor muscle or total muscle mass. This study serves to determine the accuracy of previous cetacean muscle O2 stores calculations. For that, body muscles from three delphinid species: Delphinus delphis, Stenella coeruleoalba, and Stenella frontalis, were dissected and weighed. Mb concentration was calculated from six muscles/muscle groups (epaxial, hypaxial and rectus abdominis; mastohumeralis; sternohyoideus; and dorsal scalenus), each representative of different functional groups (locomotion powering swimming, pectoral fin movement, feeding and respiration, respectively). Results demonstrated that the Mb concentration was heterogeneously distributed, being significantly higher in locomotor muscles. Locomotor muscles were the major contributors to total muscle O2 stores (mean 92.8%) due to their high Mb concentration and large muscle masses. Compared to this method, previous studies assuming homogenous Mb concentration distribution likely underestimated total muscle O2 stores by 10% when only considering locomotor muscles and overestimated them by 13% when total muscle mass was considered.
Collapse
Affiliation(s)
- Marina Arregui
- Atlantic Center for Cetacean Research, Institute of Animal Health and Food Safety (IUSA), Veterinary School, University of Las Palmas de Gran Canaria, C/Transmontaña s/n, 35413 Las Palmas, Spain; (M.A.); (M.A.R.); (N.C.); (Y.B.d.Q.)
| | - Emily M. Singleton
- Department of Biology and Marine Biology, University of North Carolina Wilmington, 601 S. College Road, Wilmington, NC 28403, USA; (E.M.S.); (D.A.P.); (W.A.M.)
| | - Pedro Saavedra
- Department of Mathematics, Campus de Tafira s/n, University of Las Palmas de Gran Canaria, 35017 Las Palmas, Spain;
| | - D. Ann Pabst
- Department of Biology and Marine Biology, University of North Carolina Wilmington, 601 S. College Road, Wilmington, NC 28403, USA; (E.M.S.); (D.A.P.); (W.A.M.)
| | - Michael J. Moore
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA;
| | - Eva Sierra
- Atlantic Center for Cetacean Research, Institute of Animal Health and Food Safety (IUSA), Veterinary School, University of Las Palmas de Gran Canaria, C/Transmontaña s/n, 35413 Las Palmas, Spain; (M.A.); (M.A.R.); (N.C.); (Y.B.d.Q.)
- Correspondence: ; Tel.: +34-928-4597-08
| | - Miguel A. Rivero
- Atlantic Center for Cetacean Research, Institute of Animal Health and Food Safety (IUSA), Veterinary School, University of Las Palmas de Gran Canaria, C/Transmontaña s/n, 35413 Las Palmas, Spain; (M.A.); (M.A.R.); (N.C.); (Y.B.d.Q.)
| | - Nakita Câmara
- Atlantic Center for Cetacean Research, Institute of Animal Health and Food Safety (IUSA), Veterinary School, University of Las Palmas de Gran Canaria, C/Transmontaña s/n, 35413 Las Palmas, Spain; (M.A.); (M.A.R.); (N.C.); (Y.B.d.Q.)
| | - Misty Niemeyer
- International Fund for Animal Welfare, Yarmouth Port, MA 02675, USA;
| | - Andreas Fahlman
- Global Diving Research Inc., Ottawa, ON K2J 5E8, Canada;
- Fundación Oceanogràphic, Department of Research, Ciutat de les Arts i de les Ciències, Carrer d’Eduardo Primo Yúfera, 1B, 46013 Valencia, Spain
- Department of Life Sciences, Texas A&M University-Corpus Christi, 6300 Ocean Drive, Unit 5892, Corpus Christi, TX 78412, USA
| | - William A. McLellan
- Department of Biology and Marine Biology, University of North Carolina Wilmington, 601 S. College Road, Wilmington, NC 28403, USA; (E.M.S.); (D.A.P.); (W.A.M.)
| | - Yara Bernaldo de Quirós
- Atlantic Center for Cetacean Research, Institute of Animal Health and Food Safety (IUSA), Veterinary School, University of Las Palmas de Gran Canaria, C/Transmontaña s/n, 35413 Las Palmas, Spain; (M.A.); (M.A.R.); (N.C.); (Y.B.d.Q.)
- Department of Life Sciences, Texas A&M University-Corpus Christi, 6300 Ocean Drive, Unit 5892, Corpus Christi, TX 78412, USA
| |
Collapse
|
8
|
Thometz NM, Hermann-Sorensen H, Russell B, Rosen DAS, Reichmuth C. Molting strategies of Arctic seals drive annual patterns in metabolism. CONSERVATION PHYSIOLOGY 2021; 9:coaa112. [PMID: 33659059 PMCID: PMC7905162 DOI: 10.1093/conphys/coaa112] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/30/2020] [Accepted: 11/09/2020] [Indexed: 06/12/2023]
Abstract
Arctic seals, including spotted (Phoca largha), ringed (Pusa hispida) and bearded (Erignathus barbatus) seals, are directly affected by sea ice loss. These species use sea ice as a haul-out substrate for various critical functions, including their annual molt. Continued environmental warming will inevitably alter the routine behavior and overall energy budgets of Arctic seals, but it is difficult to quantify these impacts as their metabolic requirements are not well known-due in part to the difficulty of studying wild individuals. Thus, data pertaining to species-specific energy demands are urgently needed to better understand the physiological consequences of rapid environmental change. We used open-flow respirometry over a four-year period to track fine-scale, longitudinal changes in the resting metabolic rate (RMR) of four spotted seals, three ringed seals and one bearded seal trained to participate in research. Simultaneously, we collected complementary physiological and environmental data. Species-specific metabolic demands followed expected patterns based on body size, with the largest species, the bearded seal, exhibiting the highest absolute RMR (0.48 ± 0.04 L O2 min-1) and the lowest mass-specific RMR (4.10 ± 0.47 ml O2 min-1 kg-1), followed by spotted (absolute: 0.33 ± 0.07 L O2 min-1; mass-specific: 6.13 ± 0.73 ml O2 min-1 kg-1) and ringed (absolute: 0.20 ± 0.04 L O2 min-1; mass-specific: 7.01 ± 1.38 ml O2 min-1 kg-1) seals. Further, we observed clear and consistent annual patterns in RMR that related to the distinct molting strategies of each species. For species that molted over relatively short intervals-spotted (33 ± 4 days) and ringed (28 ± 6 days) seals-metabolic demands increased markedly in association with molt. In contrast, the bearded seal exhibited a prolonged molting strategy (119 ± 2 days), which appeared to limit the overall cost of molting as indicated by a relatively stable annual RMR. These findings highlight energetic trade-offs associated with different molting strategies and provide quantitative data that can be used to assess species-specific vulnerabilities to changing conditions.
Collapse
Affiliation(s)
- Nicole M Thometz
- Department of Biology, University of San Francisco, 2130 Fulton St, San Francisco, 94117 CA, USA
- Institute of Marine Sciences, University of California Santa Cruz, Long Marine Laboratory, 115 McAllister Way, Santa Cruz, 95060 CA, USA
| | - Holly Hermann-Sorensen
- Institute of Marine Sciences, University of California Santa Cruz, Long Marine Laboratory, 115 McAllister Way, Santa Cruz, 95060 CA, USA
| | - Brandon Russell
- Alaska SeaLife Center, 301 Railway Ave, Seward, 99664 AK, USA
| | - David A S Rosen
- Marine Mammal Research Unit, Institute for the Oceans and Fisheries, The University of British Columbia, 2202 Main Mall, Vancouver, BC V6T 1Z4, Canada
| | - Colleen Reichmuth
- Institute of Marine Sciences, University of California Santa Cruz, Long Marine Laboratory, 115 McAllister Way, Santa Cruz, 95060 CA, USA
- Alaska SeaLife Center, 301 Railway Ave, Seward, 99664 AK, USA
| |
Collapse
|
9
|
Weitzner EL, Fanter CE, Hindle AG. Pinniped Ontogeny as a Window into the Comparative Physiology and Genomics of Hypoxia Tolerance. Integr Comp Biol 2020; 60:1414-1424. [PMID: 32559283 DOI: 10.1093/icb/icaa083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Diving physiology has received considerable scientific attention as it is a central element of the extreme phenotype of marine mammals. Many scientific discoveries have illuminated physiological mechanisms supporting diving, such as massive, internally bound oxygen stores and dramatic cardiovascular regulation. However, the cellular and molecular mechanisms that support the diving phenotype remain mostly unexplored as logistic and legal restrictions limit the extent of scientific manipulation possible. With next-generation sequencing (NGS) tools becoming more widespread and cost-effective, there are new opportunities to explore the diving phenotype. Genomic investigations come with their own challenges, particularly those including cross-species comparisons. Studying the regulatory pathways that underlie diving mammal ontogeny could provide a window into the comparative physiology of hypoxia tolerance. Specifically, in pinnipeds, which shift from terrestrial pups to elite diving adults, there is potential to characterize the transcriptional, epigenetic, and posttranslational differences between contrasting phenotypes while leveraging a common genome. Here we review the current literature detailing the maturation of the diving phenotype in pinnipeds, which has primarily been explored via biomarkers of metabolic capability including antioxidants, muscle fiber typing, and key aerobic and anaerobic metabolic enzymes. We also discuss how NGS tools have been leveraged to study phenotypic shifts within species through ontogeny, and how this approach may be applied to investigate the biochemical and physiological mechanisms that develop as pups become elite diving adults. We conclude with a specific example of the Antarctic Weddell seal by overlapping protein biomarkers with gene regulatory microRNA datasets.
Collapse
Affiliation(s)
- Emma L Weitzner
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA
| | - Cornelia E Fanter
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA
| | - Allyson G Hindle
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA
| |
Collapse
|
10
|
Hill RW, Sleboda DA, Millar JJ. Youth in the study of comparative physiology: insights from demography in the wild. J Comp Physiol B 2020; 191:1-16. [PMID: 33090252 PMCID: PMC7819908 DOI: 10.1007/s00360-020-01315-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 09/07/2020] [Accepted: 09/20/2020] [Indexed: 12/03/2022]
Abstract
Of all the properties of individual animals of interest to comparative physiologists, age and stage of development are among the most consequential. In a natural population of any species, the survivorship curve is an important determinant of the relative abundances of ages and stages of development. Demography, thus, has significant implications for the study of comparative physiology. When Edward Deevey published his influential summary of survivorship in animal populations in the wild seven decades ago, he emphasized “serious deficiencies” because survivorship curves for natural populations at the time did not include data on the earliest life stages. Such data have accumulated over intervening years. We survey, for the first time, empirical knowledge of early-age survivorship in populations of most major animal groups in a state of nature. Despite wide variation, it is almost universally true that > 50% of newly born or hatched individuals die before the onset of sexual maturity, even in species commonly assumed to exhibit high early-age survivorship. These demographic facts are important considerations for studies in comparative and environmental physiology whether physiologists (i) aim to elucidate function throughout the life cycle, including both early stages and adults, or (ii) focus on adults (in which case early-age survivorship can potentially affect adult characteristics through selection or epigenesis). We establish that Deevey’s Type I curve (which applies to species with relatively limited early mortality) has few or no actual analogs in the real, natural world.
Collapse
Affiliation(s)
- Richard W Hill
- Department of Integrative Biology, Michigan State University, East Lansing, MI, 48824, USA.
| | - David A Sleboda
- Department of Physiology, McGill University, Montreal, QC, H3G 0B1, Canada
| | - Justin J Millar
- Big Data Institute, University of Oxford, Old Road Campus, Oxford, OX3 7LF, UK
| |
Collapse
|
11
|
Noren SR. Postnatal development of diving physiology: implications of anthropogenic disturbance for immature marine mammals. ACTA ACUST UNITED AC 2020; 223:223/17/jeb227736. [PMID: 32917778 DOI: 10.1242/jeb.227736] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Marine mammals endure extended breath-holds while performing active behaviors, which has fascinated scientists for over a century. It is now known that these animals have large onboard oxygen stores and utilize oxygen-conserving mechanisms to prolong aerobically supported dives to great depths, while typically avoiding (or tolerating) hypoxia, hypercarbia, acidosis and decompression sickness (DCS). Over the last few decades, research has revealed that diving physiology is underdeveloped at birth. Here, I review the postnatal development of the body's oxygen stores, cardiorespiratory system and other attributes of diving physiology for pinnipeds and cetaceans to assess how physiological immaturity makes young marine mammals vulnerable to disturbance. Generally, the duration required for body oxygen stores to mature varies across species in accordance with the maternal dependency period, which can be over 2 years long in some species. However, some Arctic and deep-diving species achieve mature oxygen stores comparatively early in life (prior to weaning). Accelerated development in these species supports survival during prolonged hypoxic periods when calves accompany their mothers under sea ice and to the bathypelagic zone, respectively. Studies on oxygen utilization patterns and heart rates while diving are limited, but the data indicate that immature marine mammals have a limited capacity to regulate heart rate (and hence oxygen utilization) during breath-hold. Underdeveloped diving physiology, in combination with small body size, limits diving and swimming performance. This makes immature marine mammals particularly vulnerable to mortality during periods of food limitation, habitat alterations associated with global climate change, fishery interactions and other anthropogenic disturbances, such as exposure to sonar.
Collapse
Affiliation(s)
- Shawn R Noren
- Institute of Marine Science, University of California, Santa Cruz, CA 95060, USA
| |
Collapse
|
12
|
Hindle AG. Diving deep: understanding the genetic components of hypoxia tolerance in marine mammals. J Appl Physiol (1985) 2020; 128:1439-1446. [PMID: 32324472 DOI: 10.1152/japplphysiol.00846.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Marine mammals have highly specialized physiology, exhibited in many species by extreme breath-holding capabilities that allow deep dives and extended submergence. Cardiovascular control and cell-level hypoxia tolerance are key features of this phenotype. Identifying genomic signatures tied to physiology will be valuable in understanding these natural model species, which may generate translational opportunities to human diseases arising from hypoxic stress or tissue injury. Genomic analyses have now been conducted in dolphins, river dolphins, minke whales, bowhead whales, and polar bears, with multispecies studies exploring evolutionary signals across marine mammal lineages, encompassing extinct and extant divers. Single-species genome studies for sirenians do not yet exist. Extant marine mammals arose in three lineages from separate aquatic recolonizations. Their physiological specializations, along with these independent origins create an interesting case to examine convergent evolution. Although molecular mechanisms of hypoxia tolerance are not universally apparent across marine mammal genomic studies, altered evolutionary rates have been identified for genes linked to oxygen binding and transport (e.g., MB, HBA, and HBB), blood pressure control (e.g., endothelin pathway genes), and cell protection in multiple species. Despite convergent phenotypes across clades, instances of identical molecular convergence have been uncommon. Given the inherent logistical and regulatory difficulties associated with functional genetic experiments in marine mammals, several avenues of further investigation are suggested to enable validation of candidate genes for hypoxia tolerance: leveraging phylogeny to better understand convergent phenotypes; ontogenic studies to identify regulation of key genes underlying the elite, adult, hypoxia-tolerant physiology; and cell culture manipulations to understand gene function.
Collapse
Affiliation(s)
- Allyson G Hindle
- School of Life Sciences, University of Nevada, Las Vegas, Nevada
| |
Collapse
|
13
|
Clarac F, Scheyer TM, Desojo JB, Cerda IA, Sanchez S. The evolution of dermal shield vascularization in Testudinata and Pseudosuchia: phylogenetic constraints versus ecophysiological adaptations. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190132. [PMID: 31928197 PMCID: PMC7017437 DOI: 10.1098/rstb.2019.0132] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2019] [Indexed: 01/18/2023] Open
Abstract
Studies on living turtles have demonstrated that shells are involved in the resistance to hypoxia during apnea via bone acidosis buffering; a process which is complemented with cutaneous respiration, transpharyngeal and cloacal gas exchanges in the soft-shell turtles. Bone acidosis buffering during apnea has also been identified in crocodylian osteoderms, which are also known to employ heat transfer when basking. Although diverse, many of these functions rely on one common trait: the vascularization of the dermal shield. Here, we test whether the above ecophysiological functions played an adaptive role in the evolutionary transitions between land and aquatic environments in both Pseudosuchia and Testudinata. To do so, we measured the bone porosity as a proxy for vascular density in a set of dermal plates before performing phylogenetic comparative analyses. For both lineages, the dermal plate porosity obviously varies depending on the animal lifestyle, but these variations prove to be highly driven by phylogenetic relationships. We argue that the complexity of multi-functional roles of the post-cranial dermal skeleton in both Pseudosuchia and Testudinata probably is the reason for a lack of obvious physiological signal, and we discuss the role of the dermal shield vascularization in the evolution of these groups. This article is part of the theme issue 'Vertebrate palaeophysiology'.
Collapse
Affiliation(s)
- François Clarac
- Department of Organismal Biology, Subdepartment of Evolution and Development, Uppsala University, Norbyvägen 18A, 752 36 Uppsala, Sweden
| | - Torsten M. Scheyer
- Paleontological Institute and Museum, University of Zurich, Karl Schmid-Strasse 4, 8006 Zurich, Switzerland
| | - Julia B. Desojo
- CONICET, División Paleontología Vertebrados, Museo de La Plata, Paseo del Bosque s/n°, B1900FWA La Plata, Argentina
| | - Ignacio A. Cerda
- CONICET, Argentina y Instituto de Investigacion en Paleobiología y Geología, Universidad Nacional de Río Negro, Museo Carlos Ameghino, Belgrano 1700, Paraje Pichi Ruca (predio Marabunta), 8300 Cipolletti, Río Negro, Argentina
| | - Sophie Sanchez
- Department of Organismal Biology, Subdepartment of Evolution and Development, Uppsala University, Norbyvägen 18A, 752 36 Uppsala, Sweden
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, CS-40220, 38043 Grenoble Cedex, France
| |
Collapse
|
14
|
Shero MR, Reiser PJ, Simonitis L, Burns JM. Links between muscle phenotype and life history: differentiation of myosin heavy chain composition and muscle biochemistry in precocial and altricial pinniped pups. J Comp Physiol B 2019; 189:717-734. [DOI: 10.1007/s00360-019-01240-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 09/15/2019] [Accepted: 09/30/2019] [Indexed: 11/29/2022]
|
15
|
Burggren W, Bautista N. Invited review: Development of acid-base regulation in vertebrates. Comp Biochem Physiol A Mol Integr Physiol 2019; 236:110518. [DOI: 10.1016/j.cbpa.2019.06.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 06/24/2019] [Accepted: 06/25/2019] [Indexed: 12/26/2022]
|
16
|
Hindle AG, Allen KN, Batten AJ, Hückstädt LA, Turner-Maier J, Schulberg SA, Johnson J, Karlsson E, Lindblad-Toh K, Costa DP, Bloch DB, Zapol WM, Buys ES. Low guanylyl cyclase activity in Weddell seals: implications for peripheral vasoconstriction and perfusion of the brain during diving. Am J Physiol Regul Integr Comp Physiol 2019; 316:R704-R715. [PMID: 30892912 PMCID: PMC6620652 DOI: 10.1152/ajpregu.00283.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 03/15/2019] [Accepted: 03/15/2019] [Indexed: 01/06/2023]
Abstract
Nitric oxide (NO) is a potent vasodilator, which improves perfusion and oxygen delivery during tissue hypoxia in terrestrial animals. The vertebrate dive response involves vasoconstriction in select tissues, which persists despite profound hypoxia. Using tissues collected from Weddell seals at necropsy, we investigated whether vasoconstriction is aided by downregulation of local hypoxia signaling mechanisms. We focused on NO-soluble guanylyl cyclase (GC)-cGMP signaling, a well-known vasodilatory transduction pathway. Seals have a lower GC protein abundance, activity, and capacity to respond to NO stimulation than do terrestrial mammals. In seal lung homogenates, GC produced less cGMP (20.1 ± 3.7 pmol·mg protein-1·min-1) than the lungs of dogs (-80 ± 144 pmol·mg protein-1·min-1 less than seals), sheep (-472 ± 96), rats (-664 ± 104) or mice (-1,160 ± 104, P < 0.0001). Amino acid sequences of the GC enzyme α-subunits differed between seals and terrestrial mammals, potentially affecting their structure and function. Vasoconstriction in diving Weddell seals is not consistent across tissues; perfusion is maintained in the brain and heart but decreased in other organs such as the kidney. A NO donor increased median GC activity 49.5-fold in the seal brain but only 27.4-fold in the kidney, consistent with the priority of cerebral perfusion during diving. Nos3 expression was high in the seal brain, which could improve NO production and vasodilatory potential. Conversely, Pde5a expression was high in the seal renal artery, which may increase cGMP breakdown and vasoconstriction in the kidney. Taken together, the results of this study suggest that alterations in the NO-cGMP pathway facilitate the diving response.
Collapse
Affiliation(s)
- Allyson G Hindle
- Anesthesia Center for Critical Care Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts
| | - Kaitlin N Allen
- Anesthesia Center for Critical Care Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts
| | - Annabelle J Batten
- Anesthesia Center for Critical Care Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts
| | - Luis A Hückstädt
- Department of Ecology and Evolutionary Biology, University of California , Santa Cruz, California
| | - Jason Turner-Maier
- Vertebrate Genome Biology, Broad Institute of Massachusetts Institute of Technology and Harvard University , Cambridge, Massachusetts
| | - S Anne Schulberg
- Anesthesia Center for Critical Care Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts
| | - Jeremy Johnson
- Vertebrate Genome Biology, Broad Institute of Massachusetts Institute of Technology and Harvard University , Cambridge, Massachusetts
| | - Elinor Karlsson
- Vertebrate Genome Biology, Broad Institute of Massachusetts Institute of Technology and Harvard University , Cambridge, Massachusetts
| | - Kerstin Lindblad-Toh
- Vertebrate Genome Biology, Broad Institute of Massachusetts Institute of Technology and Harvard University , Cambridge, Massachusetts
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University , Uppsala , Sweden
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California , Santa Cruz, California
| | - Donald B Bloch
- Anesthesia Center for Critical Care Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts
- Division of Rheumatology, Allergy and Immunology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts
| | - Warren M Zapol
- Anesthesia Center for Critical Care Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts
| | - Emmanuel S Buys
- Anesthesia Center for Critical Care Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts
| |
Collapse
|
17
|
Pearson LE, Weitzner EL, Burns JM, Hammill MO, Liwanag HEM. From ice to ocean: changes in the thermal function of harp seal pelt with ontogeny. J Comp Physiol B 2019; 189:501-511. [PMID: 30923894 DOI: 10.1007/s00360-019-01214-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 02/28/2019] [Accepted: 03/19/2019] [Indexed: 11/26/2022]
Abstract
Many animals exhibit ontogenetic changes associated with adaptations for survival. Harp seals (Pagophilus groenlandicus) live in the Arctic and rely on thick insulation to maintain thermal homeostasis. Adult harp seals primarily use blubber for insulation, but newborn harp seals rely on a lanugo pelt while nursing, as their blubber layer develops and their first-year pelage grows. This study compared ontogenetic changes in the thermal properties of harp seal pelts in water and in air. Thermal conductivity, pelt thickness, and thermal resistance were measured in water for pelts of harp seal neonates (1 day old), thin whitecoats (4 day old), fat whitecoats (9 day old), ragged jackets (2 week old), beaters (3 week old), and adults and compared to previously published measurements made on the same pelts in air. Pelt conductivity was significantly higher in water than air for pre-molt and molting pups (P ≤ 0.031). Unlike adult pelage, which flattened underwater, lanugo hairs lifted underwater, a phenomenon that has not been reported previously. Thermal resistance of the pelt was significantly reduced in water compared to air for neonates and thin whitecoats (P ≤ 0.0001). A mathematical model of conductive heat transfer for an ellipsoid body showed volume-specific heat loss in water decreased and then stabilized as harp seals aged (P = 0.0321) and was significantly higher for neonates, thin whitecoats, and ragged jackets in water than in air (P ≤ 0.0089). Overall, pelt function is reduced in water for harp seal pups with lanugo, and this renders neonates and thin whitecoats particularly vulnerable to heat loss if submerged.
Collapse
Affiliation(s)
- Linnea E Pearson
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 2150 Koyukuk Dr., Fairbanks, AK, 99775, USA.
| | - Emma L Weitzner
- Department of Biological Sciences, California Polytechnic State University, 1 Grand Ave., San Luis Obispo, CA, 93407, USA
| | - Jennifer M Burns
- Department of Biology, University of Alaska Anchorage, 3101 Science Cir., Anchorage, AK, 99508, USA
| | - Mike O Hammill
- Department of Fisheries and Oceans, Maurice Lamontagne Institute, 850 Route de la Mer, Mont-Joli, QC, H5H 3Z4, Canada
| | - Heather E M Liwanag
- Department of Biological Sciences, California Polytechnic State University, 1 Grand Ave., San Luis Obispo, CA, 93407, USA
| |
Collapse
|
18
|
Abstract
This Review focuses on the original papers that have made a difference to our thinking and were first in describing an adaptation to diving, and less on those that later repeated the findings with better equipment. It describes some important anatomical peculiarities of phocid seals, as well as their many physiological responses to diving. In so doing, it is argued that the persistent discussions on the relevance and differences between responses seen in forced dives in the laboratory and those during free diving in the wild are futile. In fact, both are two sides of the same coin, aimed at protecting the body against asphyxic insult and extending diving performance.
Collapse
Affiliation(s)
- Arnoldus Schytte Blix
- Department of Arctic and Marine Biology, UiT - The Arctic University of Norway, 9037 Tromsø, Norway .,St Catharine's College, Cambridge CB2 1RL, UK
| |
Collapse
|
19
|
Vacquie-Garcia J, Lydersen C, Biuw M, Haug T, Fedak MA, Kovacs KM. Hooded seal Cystophora cristata foraging areas in the Northeast Atlantic Ocean-Investigated using three complementary methods. PLoS One 2017; 12:e0187889. [PMID: 29211797 PMCID: PMC5718402 DOI: 10.1371/journal.pone.0187889] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 10/27/2017] [Indexed: 11/30/2022] Open
Abstract
Identifying environmental characteristics that define the ecological niche of a species is essential to understanding how changes in physical conditions might affect its distribution and other aspects of its ecology. The present study used satellite relay data loggers (SRDLs) to study habitat use by Northeast Atlantic hooded seals (N = 20; 9 adult females, 3 adult males, and 8 juveniles). Three different methods were used in combination to achieve maximum insight regarding key foraging areas for hooded seals in this region, which have decline by 85% in recent decades: 1) first passage time (FPT); 2) vertical transit rate and; 3) change in dive drift rate. Generalized additive mixed models (GAMM) were applied to each method to determine whether specific habitat characteristics were associated with foraging. Separate models were run for the post-molting and the post-breeding seasons; sex and age classes were included in the GAMMs. All three methods highlighted a few common geographic areas as being important foraging zones; however, there were also some different areas identified by the different methods, which highlights the importance of using multiple indexes when analyzing tracking and diving data to study foraging behavior. Foraging occurred most commonly in relatively shallow areas with high Sea Surface Temperatures (SST), corresponding to continental shelf areas with Atlantic Water masses. All age and sex classes overlapped spatially to some extent, but the different age and sex groups showed differences in the bathymetry of their foraging areas as well as in their vertical use of the water column. When foraging, pups dove in the upper part of the water column in relatively deep areas. Adult females foraged relatively shallowly in deep water areas too, though in shallower areas than pups. Adult males foraged close to the bottom in shallower areas.
Collapse
Affiliation(s)
| | | | - Martin Biuw
- Norwegian Polar Institute, Fram Centre, Tromsø, Norway
- Institute of Marine Research, Tromsø, Norway
| | - Tore Haug
- Institute of Marine Research, Tromsø, Norway
| | - Mike A. Fedak
- Scottish Oceans Institute, University of St Andrews, St Andrews, Scotland, United Kingdom
| | - Kit M. Kovacs
- Norwegian Polar Institute, Fram Centre, Tromsø, Norway
| |
Collapse
|
20
|
Noren SR, West K. Muscle biochemistry of a pelagic delphinid (Stenella longirostris longirostris): insight into fishery-induced separation of mothers and calves. J Exp Biol 2017; 220:1490-1496. [DOI: 10.1242/jeb.153668] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 02/01/2017] [Indexed: 11/20/2022]
Abstract
ABSTRACT
The length of time required for postnatal maturation of the locomotor muscle (longissimus dorsi) biochemistry [myoglobin (Mb) content and buffering capacity] in marine mammals typically varies with nursing duration, but it can be accelerated by species-specific behavioral demands, such as deep-diving and sub-ice transit. We examined how the swimming demands of a pelagic lifestyle influence postnatal maturation of Mb and buffering capacity in spinner dolphins (Stenella longirostris longirostris). Mb content of newborn (1.16±0.07 g Mb per 100 g wet muscle mass, n=6) and juvenile (2.77±0.22 g per 100 g, n=4) spinner dolphins were only 19% and 46% of adult levels (6.00±0.74 g per 100 g, n=6), respectively. At birth, buffering capacity was 52.70±4.48 slykes (n=6) and increased to 78.53±1.91 slykes (n=6) once a body length of 141 cm was achieved, representing 1.6- to 2.0-year-old dolphins. Based on the age of weaning (1.3–1.6 years post-partum), muscle maturation occurred just after weaning as described for coastal bottlenose dolphins (Tursiops truncatus). Thus, a pelagic lifestyle does not promote rapid maturation of muscle biochemistry. Rather, it promotes enhanced muscle biochemistry: newborn and adult spinner dolphins had four- and two-times greater Mb contents than newborn and adult bottlenose dolphins, respectively. Indeed, adult levels rivaled those of deep-diving cetaceans. Nonetheless, the relatively underdeveloped muscle biochemistry of calves likely contributes to documented mother–calf separations for spinner dolphins chased by the tuna purse-seine fishery.
Collapse
Affiliation(s)
- Shawn R. Noren
- Institute of Marine Science, University of California, Santa Cruz, Center for Ocean Health, 100 Shaffer Road, Santa Cruz, CA 95060, USA
| | - Kristi West
- College of Natural and Computational Sciences, Hawaii Pacific University, 45-045 Kamehameha Hwy., Kaneohe, HI 96744, USA
| |
Collapse
|
21
|
Cartwright R, Newton C, West KM, Rice J, Niemeyer M, Burek K, Wilson A, Wall AN, Remonida-Bennett J, Tejeda A, Messi S, Marcial-Hernandez L. Tracking the Development of Muscular Myoglobin Stores in Mysticete Calves. PLoS One 2016; 11:e0145893. [PMID: 26788728 PMCID: PMC4720374 DOI: 10.1371/journal.pone.0145893] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 12/09/2015] [Indexed: 11/30/2022] Open
Abstract
For marine mammals, the ability to tolerate apnea and make extended dives is a defining adaptive trait, facilitating the exploitation of marine food resources. Elevated levels of myoglobin within the muscles are a consistent hallmark of this trait, allowing oxygen collected at the surface to be stored in the muscles and subsequently used to support extended dives. In mysticetes, the largest of marine predators, details on muscular myoglobin levels are limited. The developmental trajectory of muscular myoglobin stores has yet to be documented and any physiological links between early behavior and the development of muscular myoglobin stores remain unknown. In this study, we used muscle tissue samples from stranded mysticetes to investigate these issues. Samples from three different age cohorts and three species of mysticetes were included (total sample size = 18). Results indicate that in mysticete calves, muscle myoglobin stores comprise only a small percentage (17–23%) of conspecific adult myoglobin complements. Development of elevated myoglobin levels is protracted over the course of extended maturation in mysticetes. Additionally, comparisons of myoglobin levels between and within muscles, along with details of interspecific differences in rates of accumulation of myoglobin in very young mysticetes, suggest that levels of exercise may influence the rate of development of myoglobin stores in young mysticetes. This new information infers a close interplay between the physiology, ontogeny and early life history of young mysticetes and provides new insight into the pressures that may shape adaptive strategies in migratory mysticetes. Furthermore, the study highlights the vulnerability of specific age cohorts to impending changes in the availability of foraging habitat and marine resources.
Collapse
Affiliation(s)
- Rachel Cartwright
- California State University Channel Islands, Camarillo, California, United States of America
- The Keiki Kohola Project, Lahaina, Hawaii, United States of America
- * E-mail:
| | - Cori Newton
- California State University Channel Islands, Camarillo, California, United States of America
| | - Kristi M. West
- Hawaii Pacific University Stranding Program, College of Natural and Computational Sciences, Hawaii Pacific University, Kaneohe, Hawaii, United States of America
| | - Jim Rice
- Oregon Marine Mammal Stranding Network, Marine Mammal Institute, Oregon State University, Newport, Oregon, United States of America
| | - Misty Niemeyer
- International Fund for Animal Welfare, Yarmouth Port, Massachusetts, United States of America
| | - Kathryn Burek
- Alaska Veterinary Pathology Services, Eagle River, Alaska, United States of America
| | - Andrew Wilson
- California State University Channel Islands, Camarillo, California, United States of America
| | - Alison N. Wall
- California State University Channel Islands, Camarillo, California, United States of America
| | - Jean Remonida-Bennett
- California State University Channel Islands, Camarillo, California, United States of America
| | - Areli Tejeda
- California State University Channel Islands, Camarillo, California, United States of America
| | - Sarah Messi
- California State University Channel Islands, Camarillo, California, United States of America
| | - Lila Marcial-Hernandez
- California State University Channel Islands, Camarillo, California, United States of America
| |
Collapse
|
22
|
Shero MR, Costa DP, Burns JM. Scaling matters: incorporating body composition into Weddell seal seasonal oxygen store comparisons reveals maintenance of aerobic capacities. J Comp Physiol B 2015; 185:811-24. [PMID: 26164426 DOI: 10.1007/s00360-015-0922-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 06/24/2015] [Accepted: 07/02/2015] [Indexed: 12/24/2022]
Abstract
Adult Weddell seals (Leptonychotes weddellii) haul-out on the ice in October/November (austral spring) for the breeding season and reduce foraging activities for ~4 months until their molt in the austral fall (January/February). After these periods, animals are at their leanest and resume actively foraging for the austral winter. In mammals, decreased exercise and hypoxia exposure typically lead to decreased production of O2-carrying proteins and muscle wasting, while endurance training increases aerobic potential. To test whether similar effects were present in marine mammals, this study compared the physiology of 53 post-molt female Weddell seals in the austral fall to 47 pre-breeding females during the spring in McMurdo Sound, Antarctica. Once body mass and condition (lipid) were controlled for, there were no seasonal changes in total body oxygen (TBO2) stores. Within each season, hematocrit and hemoglobin values were negatively correlated with animal size, and larger animals had lower mass-specific TBO2 stores. But because larger seals had lower mass-specific metabolic rates, their calculated aerobic dive limit was similar to smaller seals. Indicators of muscular efficiency, myosin heavy chain composition, myoglobin concentrations, and aerobic enzyme activities (citrate synthase and β-hydroxyacyl CoA dehydrogenase) were likewise maintained across the year. The preservation of aerobic capacity is likely critical to foraging capabilities, so that following the molt Weddell seals can rapidly regain body mass at the start of winter foraging. In contrast, muscle lactate dehydrogenase activity, a marker of anaerobic metabolism, exhibited seasonal plasticity in this diving top predator and was lowest after the summer period of reduced activity.
Collapse
Affiliation(s)
- Michelle R Shero
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, 99508, USA. .,School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA.
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, 95060, USA
| | - Jennifer M Burns
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, 99508, USA
| |
Collapse
|
23
|
Moore CD, Fahlman A, Crocker DE, Robbins KA, Trumble SJ. The degradation of proteins in pinniped skeletal muscle: viability of post-mortem tissue in physiological research. CONSERVATION PHYSIOLOGY 2015; 3:cov019. [PMID: 27293704 PMCID: PMC4778441 DOI: 10.1093/conphys/cov019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 03/21/2015] [Accepted: 04/11/2015] [Indexed: 06/06/2023]
Abstract
As marine divers, pinnipeds have a high capacity for exercise at depth while holding their breath. With finite access to oxygen, these species need to be capable of extended aerobic exercise and conservation of energy. Pinnipeds must deal with common physiological hurdles, such as hypoxia, exhaustion and acidosis, that are common to all exercising mammals. The physiological mechanisms in marine mammals used for managing oxygen and carbon dioxide have sparked much research, but access to animals and tissues is difficult and requires permits. Deceased animals that are either bycaught or stranded provide one potential source for tissues, but the validity of biochemical data from post-mortem samples has not been rigorously assessed. Tissues collected from stranded diving mammals may be a crucial source to add to our limited knowledge on the physiology of some of these animals and important to the conservation and management of these species. We aim to determine the reliability of biochemical assays derived from post-mortem tissue and to promote the immediate sampling of stranded animals for the purpose of physiological research. In this study, we mapped the temporal degradation of muscle enzymes from biopsied Northern elephant seals (Mirounga angustirostris) and highlight recommendations for storage protocols for the best preservation of tissue. We also compared the enzymatic activity of different muscle groups (pectoral and latissimus dorsi) in relation to locomotion and measured the effects of four freeze-thaw cycles on muscle tissue enzyme function. Results indicate that enzymatic activity fluctuates greatly, especially with varying storage temperature, storage time, species and muscle group being assayed. In contrast, proteins, such as myoglobin, remain relatively continuous in their increase at 4°C for 48 h. Stranded animals can be a valuable source of biochemical data, but enzyme assays should be used only with great caution in post-mortem tissues.
Collapse
Affiliation(s)
- Colby D. Moore
- Department of Biology, Baylor University, One Bear Place, Waco, TX 76706, USA
| | - Andreas Fahlman
- Department of Life Sciences, Texas A&M University Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, USA
| | - Daniel E. Crocker
- Department of Biology, Sonoma State University, 1801 East Cotati Avenue, Rohnert Park, CA 94928, USA
| | - Kathleen A. Robbins
- Department of Biology, Baylor University, One Bear Place, Waco, TX 76706, USA
| | - Stephen J. Trumble
- Department of Biology, Baylor University, One Bear Place, Waco, TX 76706, USA
| |
Collapse
|
24
|
Burns JM, Lestyk K, Freistroffer D, Hammill MO. Preparing Muscles for Diving: Age-Related Changes in Muscle Metabolic Profiles in Harp (Pagophilus groenlandicus) and Hooded (Cystophora cristata) Seals. Physiol Biochem Zool 2015; 88:167-82. [PMID: 25730272 DOI: 10.1086/680015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In adult marine mammals, muscles can sustain aerobic metabolism during dives in part because they contain large oxygen (O2) stores and metabolic rates are low. However, young pups have significantly lower tissue O2 stores and much higher mass-specific metabolic rates. To investigate how these differences may influence muscle function during dives, we measured the activities of enzymes involved in aerobic and anaerobic metabolic pathways (citrate synthase [CS], β-hydroxyacyl-coenzyme A dehydrogenase [HOAD], lactate dehydrogenase [LDH]) and the LDH isoform profile in six muscles from 41 harp (Pagophilus groenlandicus) and 30 hooded (Cystophora cristata) seals ranging in age from fetal to adult. All neonatal muscles had significantly higher absolute but lower metabolically scaled CS and HOAD activities than adults (∼ 70% and ∼ 85% lower, respectively). Developmental increases in LDH activity lagged that of aerobic enzymes and were not accompanied by changes in isozyme profile, suggesting that changes in enzyme concentration rather than structure determine activity levels. Biochemical maturation proceeded faster in the major locomotory muscles. In combination, findings suggest that pup muscles are unable to support strenuous aerobic exercise or rely heavily on anaerobic metabolism during early diving activities and that pups' high mass-specific metabolic rates may play a key role in limiting the ability of their muscles to support underwater foraging.
Collapse
Affiliation(s)
- J M Burns
- Department of Biological Sciences, University of Alaska, Anchorage, Alaska 99508; 2Department of Life Sciences, Great Basin College, Elko, Nevada 89801; 3Maurice Lamontagne Institute, Department of Fisheries and Oceans, Mont-Joli, Québec, Canada
| | | | | | | |
Collapse
|
25
|
Gmuca NV, Pearson LE, Burns JM, Liwanag HEM. The Fat and the Furriest: Morphological Changes in Harp Seal Fur with Ontogeny. Physiol Biochem Zool 2015; 88:158-66. [DOI: 10.1086/680080] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
26
|
Noren SR, Jay CV, Burns JM, Fischbach AS. Rapid maturation of the muscle biochemistry that supports diving in pacific walruses (Odobenus rosmarus divergens). J Exp Biol 2015; 218:3319-29. [PMID: 26347559 DOI: 10.1242/jeb.125757] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 08/24/2015] [Indexed: 11/20/2022]
Abstract
Physiological constraints dictate animals' abilities to exploit habitats. For marine mammals, it is important to quantify physiological limits that influence diving and their ability to alter foraging behaviors. We characterized age-specific dive limits of walruses by measuring anaerobic (acid buffering capacity) and aerobic (myoglobin content) capacities of the muscles that power hind (longissimus dorsi) and fore (supraspinatus) flipper propulsion. Mean buffering capacities were similar across muscles and age classes (a fetus, 5 neonatal calves, a 3-month old, and 20 adults), ranging from 41.31 – 54.14 slykes and 42.00 – 46.93 slykes in the longissimus and supraspinatus, respectively. Mean myoglobin in the fetus and neonatal calves fell within a narrow range (longissimus: 0.92 – 1.68 g 100 g wet muscle mass−1; supraspinatus: 0.88 – 1.64 g wet muscle mass−1). By 3 months postpartum, myoglobin in the longissimus increased by 79%, but levels in the supraspinatus remained unaltered. From 3-months postpartum to adulthood, myoglobin increased by an additional 26% in the longissimus and increased by 126% in the supraspinatus; myoglobin remained greater in the longissimus compared to the supraspinatus. Walruses are unique among marine mammals because they are born with mature muscle acid buffering capacity and attain mature myoglobin content early in life. Despite rapid physiological development, small body size limits the diving capacity of immature walruses and extreme sexual dimorphism reduces the diving capacity of adult females compared to adult males. Thus, free-ranging immature walruses likely exhibit the shortest foraging dives while adult males are capable of the longest foraging dives.
Collapse
Affiliation(s)
- Shawn R. Noren
- Institute of Marine Science, University of California, Santa Cruz, Center for Ocean Health, 100 Shaffer Road, Santa Cruz, CA 95060, USA
| | - Chadwick V. Jay
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK 99508, USA
| | - Jennifer M. Burns
- University of Alaska, Anchorage, Department of Biological Sciences, CPSB 202C, 3101 Science Circle, University of Alaska, Anchorage, AK 99508, USA
| | - Anthony S. Fischbach
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK 99508, USA
| |
Collapse
|
27
|
Living in the fast lane: rapid development of the locomotor muscle in immature harbor porpoises (Phocoena phocoena). J Comp Physiol B 2014; 184:1065-76. [DOI: 10.1007/s00360-014-0854-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 07/29/2014] [Accepted: 08/05/2014] [Indexed: 10/24/2022]
|
28
|
Moore CD, Crocker DE, Fahlman A, Moore MJ, Willoughby DS, Robbins KA, Kanatous SB, Trumble SJ. Ontogenetic changes in skeletal muscle fiber type, fiber diameter and myoglobin concentration in the Northern elephant seal (Mirounga angustirostris). Front Physiol 2014; 5:217. [PMID: 24959151 PMCID: PMC4050301 DOI: 10.3389/fphys.2014.00217] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Accepted: 05/20/2014] [Indexed: 11/13/2022] Open
Abstract
Northern elephant seals (Mirounga angustirostris) (NES) are known to be deep, long-duration divers and to sustain long-repeated patterns of breath-hold, or apnea. Some phocid dives remain within the bounds of aerobic metabolism, accompanied by physiological responses inducing lung compression, bradycardia, and peripheral vasoconstriction. Current data suggest an absence of type IIb fibers in pinniped locomotory musculature. To date, no fiber type data exist for NES, a consummate deep diver. In this study, NES were biopsied in the wild. Ontogenetic changes in skeletal muscle were revealed through succinate dehydrogenase (SDH) based fiber typing. Results indicated a predominance of uniformly shaped, large type I fibers and elevated myoglobin (Mb) concentrations in the longissimus dorsi (LD) muscle of adults. No type II muscle fibers were detected in any adult sampled. This was in contrast to the juvenile animals that demonstrated type II myosin in Western Blot analysis, indicative of an ontogenetic change in skeletal muscle with maturation. These data support previous hypotheses that the absence of type II fibers indicates reliance on aerobic metabolism during dives, as well as a depressed metabolic rate and low energy locomotion. We also suggest that the lack of type IIb fibers (adults) may provide a protection against ischemia reperfusion (IR) injury in vasoconstricted peripheral skeletal muscle.
Collapse
Affiliation(s)
- Colby D Moore
- Department of Biology, Baylor University Waco, TX, USA
| | - Daniel E Crocker
- Department of Biology, Sonoma State University Rohnert Park, CA, USA
| | - Andreas Fahlman
- Department of Life Sciences, Texas A&M University Corpus Christi, TX, USA
| | - Michael J Moore
- Department of Biology, Woods Hole Oceanographic Institution Woods Hole, MA, USA
| | - Darryn S Willoughby
- Department of Health, Human Performance and Recreation, Baylor University Waco, TX, USA
| | | | - Shane B Kanatous
- Department of Biology, College of Natural Sciences, Colorado State University Fort Collins, CO, USA
| | | |
Collapse
|
29
|
Pearson LE, Liwanag HEM, Hammill MO, Burns JM. Shifts in thermoregulatory strategy during ontogeny in harp seals (Pagophilus groenlandicus). J Therm Biol 2014; 44:93-102. [PMID: 25086979 DOI: 10.1016/j.jtherbio.2014.02.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 01/20/2014] [Accepted: 02/01/2014] [Indexed: 11/18/2022]
Abstract
Heat balance can be difficult for young and/or small animals in polar regions because environmental conditions in combination with small body size or physiological immaturity can increase heat loss. We investigated how thermoregulatory patterns change with ontogeny in 5 age classes of harp seal (Pagophilus groenlandicus) from birth to post-molt to further understand the timing of thermoregulatory development in relation to their potential vulnerability to ongoing fluctuations in the extent and stability of Arctic pack ice. We measured changes in the amount, conductivity, and resistance of the seal pups׳ insulative layers (blubber and fur), the potential for endogenous heat-generation by shivering (muscle enzyme activity), and nonshivering thermogenesis (NST; brown adipose tissue (BAT) uncoupling protein 1 (UCP1) expression and mitochondrial density). There was no significant difference in blubber conductivity among age classes, though the amount of blubber insulation significantly increased from birth to weaning. Pelage conductivity was low (0.12±0.01Wm(-1)°C(-1)) except in 9-day old pups (0.40±0.08Wm(-1)°C(-1)); the significantly higher conductivity may signal the beginning of the molt, and this age group may be the most vulnerable to early water entry. Citrate synthase activity significantly increased (49.68±3.26 to 75.08±3.52μmolmin(-1)gwetweight(-1)) in the muscle; however it is unlikely that increasing a single enzyme greatly impacts heat generation. BAT of younger pups contained UCP1, though expression and mitochondrial density quickly declined, and the ability of pups to produce heat via NST was lost by weaning. While total thermal resistance did not differ, neonatal and early nursing animals gained the majority of their thermal resistance from lanugo (82.5±0.03%); however, lanugo is not insulative when wet, and NST may be important to maintain euthermia and dry the coat if early immersion in water occurs. By late nursing, blubber seems sufficient as insulation (75.87±0.01% of resistance after 4 weeks), but high conductivity of fur may be responsible for retention of UCP1 expression. Weaned animals rely on blubber insulation, and no longer need NST, as wetted fur is no longer a threat to euthermia.
Collapse
Affiliation(s)
- Linnea E Pearson
- School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 905 North Koyukuk Drive, Fairbanks, AK 99775-7220, USA; Department of Biology, University of Alaska Anchorage, 3101 Science Circle, Anchorage, AK 99508, USA.
| | - Heather E M Liwanag
- Department of Biology, Adelphi University, 1 South Avenue, Garden City, NY 11530, USA.
| | - Mike O Hammill
- Department of Fisheries and Oceans Canada, Maurice Lamontagne Institute, 850 route de la Mer, Mont-Joli, Quebec, Canada H5H 3Z4.
| | - Jennifer M Burns
- Department of Biology, University of Alaska Anchorage, 3101 Science Circle, Anchorage, AK 99508, USA.
| |
Collapse
|
30
|
Panneton WM. The mammalian diving response: an enigmatic reflex to preserve life? Physiology (Bethesda) 2014; 28:284-97. [PMID: 23997188 DOI: 10.1152/physiol.00020.2013] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mammalian diving response is a remarkable behavior that overrides basic homeostatic reflexes. It is most studied in large aquatic mammals but is seen in all vertebrates. Pelagic mammals have developed several physiological adaptations to conserve intrinsic oxygen stores, but the apnea, bradycardia, and vasoconstriction is shared with those terrestrial and is neurally mediated. The adaptations of aquatic mammals are reviewed here as well as the neural control of cardiorespiratory physiology during diving in rodents.
Collapse
Affiliation(s)
- W Michael Panneton
- Department of Pharmacological and Physiological Science, St. Louis University School of Medicine, St. Louis, MO, USA.
| |
Collapse
|
31
|
A review of the multi-level adaptations for maximizing aerobic dive duration in marine mammals: from biochemistry to behavior. J Comp Physiol B 2013; 184:23-53. [DOI: 10.1007/s00360-013-0782-z] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 08/27/2013] [Accepted: 08/30/2013] [Indexed: 11/26/2022]
|
32
|
Mirceta S, Signore AV, Burns JM, Cossins AR, Campbell KL, Berenbrink M. Evolution of mammalian diving capacity traced by myoglobin net surface charge. Science 2013; 340:1234192. [PMID: 23766330 DOI: 10.1126/science.1234192] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Extended breath-hold endurance enables the exploitation of the aquatic niche by numerous mammalian lineages and is accomplished by elevated body oxygen stores and adaptations that promote their economical use. However, little is known regarding the molecular and evolutionary underpinnings of the high muscle myoglobin concentration phenotype of divers. We used ancestral sequence reconstruction to trace the evolution of this oxygen-storing protein across a 130-species mammalian phylogeny and reveal an adaptive molecular signature of elevated myoglobin net surface charge in diving species that is mechanistically linked with maximal myoglobin concentration. This observation provides insights into the tempo and routes to enhanced dive capacity evolution within the ancestors of each major mammalian aquatic lineage and infers amphibious ancestries of echidnas, moles, hyraxes, and elephants, offering a fresh perspective on the evolution of this iconic respiratory pigment.
Collapse
Affiliation(s)
- Scott Mirceta
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | | | | | | | | | | |
Collapse
|
33
|
Geiseler SJ, Blix AS, Burns JM, Folkow LP. Rapid postnatal development of myoglobin from large liver iron stores in hooded seals. ACTA ACUST UNITED AC 2013; 216:1793-8. [PMID: 23348948 DOI: 10.1242/jeb.082099] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Hooded seals (Cystophora cristata) rely on large stores of oxygen, either bound to hemoglobin or myoglobin (Mb), to support prolonged diving activity. Pups are born with fully developed hemoglobin stores, but their Mb levels are only 25-30% of adult levels. We measured changes in muscle [Mb] from birth to 1 year of age in two groups of captive hooded seal pups, one being maintained in a seawater pool and one on land during the first 2 months. All pups fasted during the first month, but were fed from then on. The [Mb] of the swimming muscle musculus longissimus dorsi (LD) doubled during the month of fasting in the pool group. These animals had significantly higher levels and a more rapid rise in LD [Mb] than those kept on land. The [Mb] of the shoulder muscle, m. supraspinatus, which is less active in both swimming and hauled-out animals, was consistently lower than in the LD and did not differ between groups. This suggests that a major part of the postnatal rise in LD [Mb] is triggered by (swimming) activity, and this coincides with the previously reported rapid early development of diving capacity in wild hooded seal pups. Liver iron concentration, as determined from another 25 hooded seals of various ages, was almost 10 times higher in young pups (1-34 days) than in yearling animals and adults, and liver iron content of pups dropped during the first month, implying that liver iron stores support the rapid initial rise in [Mb].
Collapse
Affiliation(s)
- Samuel J Geiseler
- Department of Arctic and Marine Biology, University of Tromsø, NO-9037 Tromsø, Norway.
| | | | | | | |
Collapse
|
34
|
Velten BP, Dillaman RM, Kinsey ST, McLellan WA, Pabst DA. Novel locomotor muscle design in extreme deep-diving whales. J Exp Biol 2013; 216:1862-71. [DOI: 10.1242/jeb.081323] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Summary
Most marine mammals are hypothesized to routinely dive within their aerobic dive limit (ADL). Mammals that regularly perform deep, long-duration dives have locomotor muscles with elevated myoglobin concentrations and are composed of predominantly large, slow-twitch (Type I) fibers with low mitochondrial volume densities (Vmt). These features contribute to extending ADL by increasing oxygen stores and decreasing metabolic rate. Recent tagging studies, however, have challenged the view that two groups of extreme deep-diving cetaceans dive within their ADLs. Beaked whales (Ziphius cavirostris, Cuvier and Mesoplodon densirostris, Blainville) routinely perform the deepest and longest average dives of any air-breathing vertebrate, and short-finned pilot whales (Globicephala macrorhynchus, Gray) perform high-speed sprints at depth. We investigated the locomotor muscle morphology and estimated total body oxygen stores of these cetaceans to determine whether they (a) shared muscle design features with other deep-divers and (b) performed dives within their calculated ADLs. Muscle of both cetaceans displayed high myoglobin concentrations and large fibers, as predicted, but novel fiber profiles for diving mammals. Beaked whales possessed a sprinter's fiber-type profile, composed of approximately 80% fast-twitch (Type II) fibers with low Vmt. Approximately one-third of the muscle fibers of short-finned pilot whales were slow-twitch, oxidative, glycolytic fibers, a rare fiber-type for any mammal. The muscle morphology of beaked whales likely decreases the energetic cost of diving, while that of short-finned pilot whales supports high activity events. Calculated ADLs indicate that, at low metabolic rates, both cetaceans carry sufficient onboard oxygen to aerobically support their dives.
Collapse
|
35
|
De Miranda MA, Schlater AE, Green TL, Kanatous SB. In the face of hypoxia: myoglobin increases in response to hypoxic conditions and lipid supplementation in cultured Weddell seal skeletal muscle cells. ACTA ACUST UNITED AC 2012; 215:806-13. [PMID: 22323203 DOI: 10.1242/jeb.060681] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A key cellular adaptation to diving in Weddell seals is enhanced myoglobin concentrations in their skeletal muscles, which serve to store oxygen to sustain a lipid-based aerobic metabolism. The aim of this study was to determine whether seal muscle cells are inherently adapted to possess the unique skeletal muscle adaptations to diving seen in the whole animal. We hypothesized that the seal skeletal muscle cells would have enhanced concentrations of myoglobin de novo that would be greater than those from a C(2)C(12) skeletal muscle cell line and reflect the concentrations of myoglobin observed in previous studies. In addition we hypothesized that the seal cells would respond to environmental hypoxia similarly to the C(2)C(12) cells in that citrate synthase activity and myoglobin would remain the same or decrease under hypoxia and lactate dehydrogenase activity would increase under hypoxia as previously reported. We further hypothesized that β-hydroxyacyl CoA dehydrogenase activity would increase in response to the increasing amounts of lipid supplemented to the culture medium. Our results show that myoglobin significantly increases in response to environmental hypoxia and lipids in the Weddell seal cells, while appearing similar metabolically to the C(2)C(12) cells. The results of this study suggest the regulation of myoglobin expression is fundamentally different in Weddell seal skeletal muscle cells when compared with a terrestrial mammalian cell line in that hypoxia and lipids initially prime the skeletal muscles for enhanced myoglobin expression. However, the cells need a secondary stimulus to further increase myoglobin to levels seen in the whole animal.
Collapse
|
36
|
Vázquez-Medina JP, Zenteno-Savín T, Tift MS, Forman HJ, Crocker DE, Ortiz RM. Apnea stimulates the adaptive response to oxidative stress in elephant seal pups. ACTA ACUST UNITED AC 2012; 214:4193-200. [PMID: 22116762 DOI: 10.1242/jeb.063644] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Extended breath-hold (apnea) bouts are routine during diving and sleeping in seals. These apneas result in oxygen store depletion and blood flow redistribution towards obligatory oxygen-dependent tissues, exposing seals to critical levels of ischemia and hypoxemia. The subsequent reperfusion/reoxygenation has the potential to increase oxidant production and thus oxidative stress. The contributions of extended apnea to oxidative stress in adapted mammals are not well defined. To address the hypothesis that apnea in seals is not associated with increased oxidative damage, blood samples were collected from northern elephant seal pups (N=6) during eupnea, rest- and voluntary submersion-associated apneas, and post-apnea (recovery). Plasma 4-hydroxynonenal (HNE), 8-isoprostanes (8-isoPGF(2α)), nitrotyrosine (NT), protein carbonyls, xanthine and hypoxanthine (HX) levels, along with xanthine oxidase (XO) activity, were measured. Protein content of XO, superoxide dismutase 1 (Cu,ZnSOD), catalase and myoglobin (Mb), as well as the nuclear content of hypoxia inducible factor 1α (HIF-1α) and NF-E2-related factor 2 (Nrf2), were measured in muscle biopsies collected before and after the breath-hold trials. HNE, 8-iso PGF(2α), NT and protein carbonyl levels did not change among eupnea, apnea or recovery. XO activity and HX and xanthine concentrations were increased at the end of the apneas and during recovery. Muscle protein content of XO, CuZnSOD, catalase, Mb, HIF-1α and Nrf2 increased 25-70% after apnea. Results suggest that rather than inducing the damaging effects of hypoxemia and ischemia/reperfusion that have been reported in non-diving mammals, apnea in seals stimulates the oxidative stress and hypoxic hormetic responses, allowing these mammals to cope with the potentially detrimental effects associated with this condition.
Collapse
|
37
|
LaRosa DA, Cannata DJ, Arnould JPY, O'Sullivan LA, Snow RJ, West JM. Changes in muscle composition during the development of diving ability in the Australian fur seal. AUST J ZOOL 2012. [DOI: 10.1071/zo11072] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
During development the Australian fur seal transitions from a terrestrial, maternally dependent pup to an adult marine predator. Adult seals have adaptations that allow them to voluntarily dive at depth for long periods, including increased bradycardic control, increased myoglobin levels and haematocrit. To establish whether the profile of skeletal muscle also changes in line with the development of diving ability, biopsy samples were collected from the trapezius muscle of pups, juveniles and adults. The proportions of different fibre types and their oxidative capacity were determined. Only oxidative fibre types (Type I and IIa) were identified, with a significant change in proportions from pup to adult. There was no change in oxidative capacity of Type I and IIa fibres between pups and juveniles but there was a two-fold increase between juveniles and adults. Myoglobin expression increased between pups and juveniles, suggesting improved oxygen delivery, but with no increase in oxidative capacity, oxygen utilisation within the muscle may still be limited. Adult muscle had the highest oxidative capacity, suggesting that fibres are able to effectively utilise available oxygen during prolonged dives. Elevated levels of total creatine in the muscles of juveniles may act as an energy buffer when fibres are transitioning from a fast to slow fibre type.
Collapse
|
38
|
Vázquez-Medina JP, Soñanez-Organis JG, Burns JM, Zenteno-Savín T, Ortiz RM. Antioxidant capacity develops with maturation in the deep-diving hooded seal. ACTA ACUST UNITED AC 2011; 214:2903-10. [PMID: 21832133 DOI: 10.1242/jeb.057935] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Maturation in hooded seals is characterized by the rapid development of their physiological diving capacity and is accompanied by increases in oxidant production but not oxidative damage. To test the hypothesis that the antioxidant system of hooded seals develops as they transition from a terrestrial to an aquatic environment, we obtained the complete cDNA sequence that encodes the NF-E2-related factor 2 (Nrf2), a central regulator of the antioxidant response, and compared Nrf2 mRNA and protein expression levels in muscle samples from neonate, weaned pups and adult hooded seals, along with glutathione (GSH) levels and the activity/protein content of the antioxidant enzymes catalase, glutathione peroxidase (GPx), peroxyredoxin VI (PrxVI), thioredoxin 1 (Trx1), thioredoxin reductase (TrxR), glutaredoxin 1 (Glrx1), glutathione disulphide reductase, glutathione S-transferase and glutamate-cysteine ligase. The Nrf2 of the hooded seal is 1822 bp long and encodes a protein of 606 amino acids with a leucine zipper domain and Keap1-mediated proteosomal degradation residues, which are key for Nrf2 function and regulation. Although neither Nrf2 mRNA nor Nrf2 nuclear protein content are higher in adults than in pups, GSH levels along with GPx, PrxVI, Trx1, TrxR and Glrx1 activity/protein content increase with maturation, suggesting that the potential for peroxide removal increases with development in hooded seals, and that these enzymes contribute to the regulation of the intracellular redox state and the prevention of oxidative damage in these deep-diving mammals.
Collapse
Affiliation(s)
- José Pablo Vázquez-Medina
- School of Natural Sciences, University of California Merced, 5200 N Lake Road, Merced, CA 95343, USA.
| | | | | | | | | |
Collapse
|
39
|
Shero MR, Andrews RD, Lestyk KC, Burns JM. Development of the aerobic dive limit and muscular efficiency in northern fur seals (Callorhinus ursinus). J Comp Physiol B 2011; 182:425-36. [PMID: 22001970 DOI: 10.1007/s00360-011-0619-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Revised: 09/16/2011] [Accepted: 09/19/2011] [Indexed: 10/17/2022]
Abstract
Northern fur seal (Callorhinus ursinus; NFS) populations have been declining, perhaps due to limited foraging ability of pups. Because a marine mammal's proficiency at exploiting underwater prey resources is based on the ability to store large amounts of oxygen (O(2)) and to utilize these reserves efficiently, this study was designed to determine if NFS pups had lower blood, muscle, and total body O(2) stores than adults. Pups (<1-month old) had a calculated aerobic dive limit only ~40% of adult females due to lower blood and, to a much greater extent, muscle O(2) stores. Development of the Pectoralis (Pec) and Longissimus dorsi (LD) skeletal muscles was further examined by determining their myosin heavy chain (MHC) composition and enzyme activities. In all animals, the slow MHC I and fast-twitch IIA proteins typical of oxidative fiber types were dominant, but adult muscles contained more (Pec ~50%; LD ~250% higher) fast-twitch MHC IID/X protein characteristic of glycolytic muscle fibers, than pup muscles. This suggests that adults have greater ability to generate muscle power rapidly and/or under anaerobic conditions. Pup muscles also had lower aerobic and anaerobic ATP production potential, as indicated by lower metabolically scaled citrate synthase, β-hydroxyacyl CoA dehydrogenase, and lactate dehydrogenase activities (all P values ≤0.001). In combination, these findings indicate that pups are biochemically and physiologically limited in their diving capabilities relative to adults. This may contribute to lower NFS first year survival.
Collapse
Affiliation(s)
- Michelle R Shero
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK 99508, USA.
| | | | | | | |
Collapse
|
40
|
Vázquez-Medina JP, Zenteno-Savín T, Forman HJ, Crocker DE, Ortiz RM. Prolonged fasting increases glutathione biosynthesis in postweaned northern elephant seals. ACTA ACUST UNITED AC 2011; 214:1294-9. [PMID: 21430206 DOI: 10.1242/jeb.054320] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Northern elephant seals experience prolonged periods of absolute food and water deprivation (fasting) while breeding, molting or weaning. The postweaning fast in elephant seals is characterized by increases in the renin-angiotensin system, expression of the oxidant-producing protein Nox4, and NADPH oxidase activity; however, these increases are not correlated with increased oxidative damage or inflammation. Glutathione (GSH) is a potent reductant and a cofactor for glutathione peroxidases (GPx), glutathione-S transferases (GST) and 1-cys peroxiredoxin (PrxVI) and thus contributes to the removal of hydroperoxides, preventing oxidative damage. The effects of prolonged food deprivation on the GSH system are not well described in mammals. To test our hypothesis that GSH biosynthesis increases with fasting in postweaned elephant seals, we measured circulating and muscle GSH content at the early and late phases of the postweaning fast in elephant seals along with the activity/protein content of glutamate-cysteine ligase [GCL; catalytic (GCLc) and modulatory (GCLm) subunits], γ-glutamyl transpeptidase (GGT), glutathione disulphide reductase (GR), glucose-6-phosphate dehydrogenase (G6PDH), GST and PrxVI, as well as plasma changes in γ-glutamyl amino acids, glutamate and glutamine. GSH increased two- to four-fold with fasting along with a 40-50% increase in the content of GCLm and GCLc, a 75% increase in GGT activity, a two- to 2.5-fold increase in GR, G6PDH and GST activities and a 30% increase in PrxVI content. Plasma γ-glutamyl glutamine, γ-glutamyl isoleucine and γ-glutamyl methionine also increased with fasting whereas glutamate and glutamine decreased. Results indicate that GSH biosynthesis increases with fasting and that GSH contributes to counteracting hydroperoxide production, preventing oxidative damage in fasting seals.
Collapse
Affiliation(s)
- José Pablo Vázquez-Medina
- School of Natural Sciences, University of California Merced, Merced, CA 95343, USA. jvazquez-medina@ucmerced
| | | | | | | | | |
Collapse
|
41
|
Verrier D, Guinet C, Authier M, Tremblay Y, Shaffer S, Costa DP, Groscolas R, Arnould JP. The ontogeny of diving abilities in subantarctic fur seal pups: developmental trade-off in response to extreme fasting? Funct Ecol 2011. [DOI: 10.1111/j.1365-2435.2011.01846.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
42
|
Vázquez-Medina JP, Olguín-Monroy NO, Maldonado PD, Santamaría A, Königsberg M, Elsner R, Hammill MO, Burns JM, Zenteno-Savín T. Maturation increases superoxide radical production without increasing oxidative damage in the skeletal muscle of hooded seals (Cystophora cristata). CAN J ZOOL 2011. [DOI: 10.1139/z10-107] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Diving vertebrates represent unique models for the study of the physiological responses to reactive oxygen species (ROS) production and oxidative stress because of their adaptability to cope with dive-derived ROS production. We hypothesized that in the skeletal muscle of a diving mammal, the hooded seal ( Cystophora cristata (Erxleben, 1777)), ROS production increases with maturation but the accumulation of oxidative damage does not. To test this, we analyzed the tissue capacity to produce ROS, the accumulation of oxidative damage, and the activity and protein content of the cooper, zinc, and manganese dependent superoxide dismutases (Cu,ZnSOD, MnSOD) in skeletal muscle from neonates, weaned pups, and adult hooded seals. Our results showed higher tissue capacity to produce ROS, higher Cu,ZnSOD and MnSOD activities, and higher MnSOD protein content in adult seals than in pups. No differences in oxidative damage to lipids, proteins, or DNA were detected among groups. Results suggest that increased SOD activity likely counters the oxidative damage commonly associated with increased ROS production. These findings highlight the unusual tolerance of skeletal muscle of seals to increased ROS production.
Collapse
Affiliation(s)
- J. P. Vázquez-Medina
- Planeación Ambiental y Conservación, Centro de Investigaciones Biológicas del Noroeste, S.C, Mar Bermejo 195, Playa Palo de Santa Rita, La Paz, B.C.S., 23090, Mexico
- Laboratorio de Patología Vascular Cerebral, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Bioenergética y Envejecimiento Celular, Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Avenida San Rafael Atlixco No. 186, Colonia Vicentina, Delegación Iztapalapa, Mexico City, 09340, Mexico
- Institute of Marine Sciences, University of Alaska Fairbanks, P.O. Box 757220, Fairbanks, AK 99775-7220, USA
| | - N. O. Olguín-Monroy
- Planeación Ambiental y Conservación, Centro de Investigaciones Biológicas del Noroeste, S.C, Mar Bermejo 195, Playa Palo de Santa Rita, La Paz, B.C.S., 23090, Mexico
- Laboratorio de Patología Vascular Cerebral, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Bioenergética y Envejecimiento Celular, Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Avenida San Rafael Atlixco No. 186, Colonia Vicentina, Delegación Iztapalapa, Mexico City, 09340, Mexico
- Institute of Marine Sciences, University of Alaska Fairbanks, P.O. Box 757220, Fairbanks, AK 99775-7220, USA
| | - P. D. Maldonado
- Planeación Ambiental y Conservación, Centro de Investigaciones Biológicas del Noroeste, S.C, Mar Bermejo 195, Playa Palo de Santa Rita, La Paz, B.C.S., 23090, Mexico
- Laboratorio de Patología Vascular Cerebral, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Bioenergética y Envejecimiento Celular, Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Avenida San Rafael Atlixco No. 186, Colonia Vicentina, Delegación Iztapalapa, Mexico City, 09340, Mexico
- Institute of Marine Sciences, University of Alaska Fairbanks, P.O. Box 757220, Fairbanks, AK 99775-7220, USA
| | - A. Santamaría
- Planeación Ambiental y Conservación, Centro de Investigaciones Biológicas del Noroeste, S.C, Mar Bermejo 195, Playa Palo de Santa Rita, La Paz, B.C.S., 23090, Mexico
- Laboratorio de Patología Vascular Cerebral, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Bioenergética y Envejecimiento Celular, Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Avenida San Rafael Atlixco No. 186, Colonia Vicentina, Delegación Iztapalapa, Mexico City, 09340, Mexico
- Institute of Marine Sciences, University of Alaska Fairbanks, P.O. Box 757220, Fairbanks, AK 99775-7220, USA
| | - M. Königsberg
- Planeación Ambiental y Conservación, Centro de Investigaciones Biológicas del Noroeste, S.C, Mar Bermejo 195, Playa Palo de Santa Rita, La Paz, B.C.S., 23090, Mexico
- Laboratorio de Patología Vascular Cerebral, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Bioenergética y Envejecimiento Celular, Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Avenida San Rafael Atlixco No. 186, Colonia Vicentina, Delegación Iztapalapa, Mexico City, 09340, Mexico
- Institute of Marine Sciences, University of Alaska Fairbanks, P.O. Box 757220, Fairbanks, AK 99775-7220, USA
| | - R. Elsner
- Planeación Ambiental y Conservación, Centro de Investigaciones Biológicas del Noroeste, S.C, Mar Bermejo 195, Playa Palo de Santa Rita, La Paz, B.C.S., 23090, Mexico
- Laboratorio de Patología Vascular Cerebral, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Bioenergética y Envejecimiento Celular, Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Avenida San Rafael Atlixco No. 186, Colonia Vicentina, Delegación Iztapalapa, Mexico City, 09340, Mexico
- Institute of Marine Sciences, University of Alaska Fairbanks, P.O. Box 757220, Fairbanks, AK 99775-7220, USA
| | - M. O. Hammill
- Planeación Ambiental y Conservación, Centro de Investigaciones Biológicas del Noroeste, S.C, Mar Bermejo 195, Playa Palo de Santa Rita, La Paz, B.C.S., 23090, Mexico
- Laboratorio de Patología Vascular Cerebral, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Bioenergética y Envejecimiento Celular, Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Avenida San Rafael Atlixco No. 186, Colonia Vicentina, Delegación Iztapalapa, Mexico City, 09340, Mexico
- Institute of Marine Sciences, University of Alaska Fairbanks, P.O. Box 757220, Fairbanks, AK 99775-7220, USA
| | - J. M. Burns
- Planeación Ambiental y Conservación, Centro de Investigaciones Biológicas del Noroeste, S.C, Mar Bermejo 195, Playa Palo de Santa Rita, La Paz, B.C.S., 23090, Mexico
- Laboratorio de Patología Vascular Cerebral, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Bioenergética y Envejecimiento Celular, Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Avenida San Rafael Atlixco No. 186, Colonia Vicentina, Delegación Iztapalapa, Mexico City, 09340, Mexico
- Institute of Marine Sciences, University of Alaska Fairbanks, P.O. Box 757220, Fairbanks, AK 99775-7220, USA
| | - T. Zenteno-Savín
- Planeación Ambiental y Conservación, Centro de Investigaciones Biológicas del Noroeste, S.C, Mar Bermejo 195, Playa Palo de Santa Rita, La Paz, B.C.S., 23090, Mexico
- Laboratorio de Patología Vascular Cerebral, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía “Dr. Manuel Velasco Suárez”, Insurgentes sur 3877, Colonia La Fama, Tlalpan, Mexico City, 14269, Mexico
- Laboratorio de Bioenergética y Envejecimiento Celular, Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Avenida San Rafael Atlixco No. 186, Colonia Vicentina, Delegación Iztapalapa, Mexico City, 09340, Mexico
- Institute of Marine Sciences, University of Alaska Fairbanks, P.O. Box 757220, Fairbanks, AK 99775-7220, USA
| |
Collapse
|
43
|
Effects of Age and Body Mass on Development of Diving Capabilities of Gray Seal Pups: Costs and Benefits of the Postweaning Fast. Physiol Biochem Zool 2010; 83:911-23. [DOI: 10.1086/656925] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
44
|
Ponganis PJ, Welch TJ, Welch LS, Stockard TK. Myoglobin production in emperor penguins. J Exp Biol 2010; 213:1901-6. [DOI: 10.1242/jeb.042093] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
SUMMARY
Increased oxygen storage is essential to the diving capacities of marine mammals and seabirds. However, the molecular mechanisms underlying this adaptation are unknown. Myoglobin (Mb) and Mb mRNA concentrations were analyzed in emperor penguin (Aptenodytes forsteri) adults and chicks with spectrophotometric and RNase protection assays to evaluate production of their large Mb-bound O2 stores. Mean pectoral Mb concentration and Mb mRNA content increased throughout the pre-fledging period and were 15-fold and 3-fold greater, respectively, in adults than in 3.5 month old chicks. Mean Mb concentration in 5.9 month old juveniles was 2.7±0.4 g 100 g−1 muscle (44% that of wild adults), and in adults that had been captive all their lives it was 3.7±0.1 g 100 g−1 muscle. The Mb and Mb mRNA data are consistent with regulation of Mb production at the level of transcription as in other animals. Significant Mb and Mb mRNA production occurred in chicks and young juveniles even without any diving activity. The further increase in adult Mb concentrations appears to require the exercise/hypoxia of diving because Mb concentration in captive, non-diving adults only reached 60% of that of wild adults. The much greater relative increase in Mb concentration than in Mb mRNA content between young chicks and adults suggests that there is not a simple 1:1 relationship between Mb mRNA content and Mb concentration. Nutritional limitation in young chicks and post-transcriptional regulation of Mb concentration may also be involved.
Collapse
Affiliation(s)
- P. J. Ponganis
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0204, USA
| | - T. J. Welch
- National Center for Cool and Cold Water Aquaculture, Agricultural Research Service, USDA, Kearneysville, WV 25430, USA
| | - L. S. Welch
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0204, USA
| | - T. K. Stockard
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0204, USA
| |
Collapse
|
45
|
Burns JM, Skomp N, Bishop N, Lestyk K, Hammill M. Development of aerobic and anaerobic metabolism in cardiac and skeletal muscles from harp and hooded seals. ACTA ACUST UNITED AC 2010; 213:740-8. [PMID: 20154189 DOI: 10.1242/jeb.037929] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In diving animals, skeletal muscle adaptations to extend underwater time despite selective vasoconstriction include elevated myoglobin (Mb) concentrations, high acid buffering ability (beta) and high aerobic and anaerobic enzyme activities. However, because cardiac muscle is perfused during dives, it may rely less heavily on Mb, beta and anaerobic pathways to support contractile activity. In addition, because cardiac tissue must sustain contractile activity even before birth, it may be more physiologically mature at birth and/or develop faster than skeletal muscles. To test these hypotheses, we measured Mb levels, beta and the activities of citrate synthase (CS), beta-hydroxyacyl-CoA dehydrogenase (HOAD) and lactate dehydrogenase (LDH) in cardiac and skeletal muscle samples from 72 harp and hooded seals, ranging in age from fetuses to adults. Results indicate that in adults cardiac muscle had lower Mb levels (14.7%), beta (55.5%) and LDH activity (36.2%) but higher CS (459.6%) and HOAD (371.3%) activities (all P<0.05) than skeletal muscle. In addition, while the cardiac muscle of young seals had significantly lower [Mb] (44.7%) beta (80.7%) and LDH activity (89.5%) than adults (all P<0.05), it was relatively more mature at birth and weaning than skeletal muscle. These patterns are similar to those in terrestrial species, suggesting that seal hearts do not exhibit unique adaptations to the challenges of an aquatic existence.
Collapse
Affiliation(s)
- J M Burns
- Department of Biological Sciences, University of Alaska, Anchorage, AK 99508, USA.
| | | | | | | | | |
Collapse
|
46
|
Remarkable development of diving performance and migrations of hooded seals (Cystophora cristata) during their first year of life. Polar Biol 2009. [DOI: 10.1007/s00300-009-0718-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|