A5044842106- Marine animal studies overview
- Fatty Acid Research and Health
- Physiological and biochemical adaptations
- Adipose Tissue and Metabolism
- Meat and Animal Product Quality
- Neuroscience of respiration and sleep
- Thyroid Disorders and Treatments
- Ocean Acidification Effects and Responses
- Animal Behavior and Welfare Studies
- Aquaculture disease management and microbiota
- Cardiovascular and Diving-Related Complications
- Stress Responses and Cortisol
- Effects of Environmental Stressors on Livestock
- Marine Bivalve and Aquaculture Studies
- High Altitude and Hypoxia
- Regulation of Appetite and Obesity
- Cancer, Hypoxia, and Metabolism
- RNA and protein synthesis mechanisms
- Underwater Vehicles and Communication Systems
- Coral and Marine Ecosystems Studies
- Growth Hormone and Insulin-like Growth Factors
- Molecular Biology Techniques and Applications
- interferon and immune responses
- Muscle Physiology and Disorders
- Birth, Development, and Health
National Marine Mammal Foundation
2013-2024
University of California, Santa Cruz
2006-2024
University of Washington Bothell
2020-2024
Old Dominion University
2016-2019
Sonoma State University
2005-2014
Inserm
1987
Institut Pasteur
1987
Centre National de la Recherche Scientifique
1987
Wilfrid Laurier University
1986
Université Laval
1986
The mesopelagic zone of the northeast Pacific Ocean is an important foraging habitat for many predators, yet few studies have addressed factors driving basin-scale predator distributions or inter-annual variability in and breeding success. Understanding these processes critical to reveal how conditions at sea cascade population-level effects. To begin addressing challenging questions, we collected diving, tracking, success, natality data 297 adult female northern elephant seal migrations...
Species that maintain aerobic metabolism when the oxygen (O 2 ) supply is limited represent ideal models to examine mechanisms underlying tolerance hypoxia. The repetitive, long dives of northern elephant seals ( Mirounga angustirostris) have remained a physiological enigma as O stores appear inadequate metabolism. We evaluated hypoxemic and blood depletion by 1) measuring arterial venous partial pressure (Po during with Po /temperature recorder on seals, 2) characterizing -hemoglobin -Hb)...
Abstract Stress hormones, released into circulation as a consequence of disturbance, are classically assayed from blood samples but may also be detected in variety matrices. Blubber and fecal can remotely collected free‐ranging cetaceans without the confounding hormone elevations associated with chase, capture, handling required to collect samples. The relationship between cortisol concentrations that blubber feces, however, is unknown. To assess these associations, we elevated by orally...
Marine protected areas (MPAs), particularly large MPAs, are increasing in number and size around the globe part to facilitate conservation of marine megafauna under assumption that large-scale MPAs better align with vagile life histories; however, this alignment is not well established. Using a global tracking dataset from 36 species across five taxa, chosen reflect span home range highly mobile megafauna, we show most too small encompass complete ranges species. Based on alone, 40% existing...
Free-ranging animals often cope with fluctuating environmental conditions such as weather, food availability, predation risk, the requirements of breeding, and influence anthropogenic factors. Consequently, researchers are increasingly measuring stress markers, especially glucocorticoids, to understand stress, disturbance, population health. Studying free-ranging animals, however, comes numerous difficulties posed by particular characteristics study species. Performing measurements under...
Northern elephant seals endure a 2- to 3-month fast characterized by sustained hyperglycemia, hypoinsulinemia, and increased plasma cortisol free fatty acids, conditions often seen in insulin-resistant humans. We had previously shown that adipose Glut4 expression 5′AMP-activated protein kinase (AMPK) activity increase glucose decreases fasting suggesting AMPK contributes regulation during conditions. To address the hypothesis increases fasting-induced insulin resistance, we performed...
Abstract Stress can compromise an animal’s ability to conserve metabolic stores and participate in energy-demanding activities that are critical for fitness. Understanding how wild animals, especially those already experiencing physiological extremes (e.g. fasting), regulate stress responses is evaluating the impacts of anthropogenic disturbance on physiology fitness, key challenges conservation. However, studies wildlife often limited baseline endocrine measurements few have investigated...
SUMMARY During prolonged fasting physiological mechanisms defend lean tissue from catabolism. In the state, glucose is derived solely gluconeogenesis, requiring some catabolism of amino acids for gluconeogenic substrates. This creates a conflict in animals undergoing fasts concurrently with metabolically challenging activities. study investigated metabolism and developing neonatal elephant seals. Glucose production cycle activity were measured early (2 weeks) late(6 postweaning period....
Immune and endocrine responses play a critical role in allowing animals to adjust environmental perturbations. We measured immune related markers multiple samples from individuals two managed-care care dolphin groups (n = 82 17 dolphins single collected wild populations: Indian River Lagoon, (IRL) FL 26); Charleston, (CHS) SC 19). The systems of were more upregulated than those managed-care-dolphins as shown by higher concentrations IgG increases lysozyme, NK cell function, pathogen antibody...
Many polygynous, capital breeders exhibit sexual dimorphism with respect to body size and composition. Sexual is often facilitated by sex differences in foraging behavior, growth rates patterns of nutrient deposition during development. In species that undergo extended fasts development, metabolic strategies for fuel use have the potential influence future reproductive success directly impacting somatic acquisition traits required successful breeding. We investigated associated fasting...
Fasting is associated with a series of physiological responses that protect body tissues from degradation by efficiently using expendable energy reserves while sparing protein. Lactation requires the mobilization maternal nutrients for milk synthesis. The rare life history trait fasting simultaneous lactation results in conflicting demands provisioning offspring meeting metabolic costs and preserving her own survival future reproduction. Certain continue to require glucose operation during...
Adult female elephant seals (Mirounga angustirostris) combine long-term fasting with lactation and molting. Glycerol gluconeogenesis has been hypothesized as potentially meeting all of the glucose requirements during these fasts. To test this hypothesis, a primed constant infusion [2-(14)C]glycerol was administered to 10 ten adult at 5 21-22 days postpartum additional females immediately after molt. kinetics, rates lipolysis, contribution glycerol production were determined for each period....
Northern elephant seals exhibit the rare strategy of fasting and lactating concomitantly. We investigated hormonal regulation glucose clearance in northern using tolerance tests (GTT) performed early lactation again just prior to weaning. For comparison, identical measurements were made on separate females late molt fast. Serial blood samples used assess hormone responses for 3 h post injection. Plasma remained elevated at end sampling period all groups. Glucose rates not significantly...
Elephant seal weanlings demonstrate rates of endogenous glucose production (EGP) during protracted fasts that are higher than predicted on the basis mass and time fasting. To determine nonoxidative oxidative fate endogenously synthesized glucose, substrate oxidation, metabolic rate, glycolysis, EGP were measured in fasting weanlings. Eight sampled at 14 days fasting, a separate group nine was 49 Metabolic rate determined via flow-through respirometry, substrate-specific oxidation from...
Animals that endure prolonged periods of food deprivation preserve vital organ function by sparing protein from catabolism. Much this is achieved reducing metabolic rate and suppressing gluconeogenesis while fasting. Northern elephant seals ( Mirounga angustirostris) fasts up to 3 mo at multiple life stages. During these fasts, maintain high levels activity energy expenditure associated with breeding, reproduction, lactation, development maintaining rates glucose production typical a...
While much of our understanding stress physiology is derived from biomedical studies, little known about the downstream molecular consequences adaptive responses in free-living animals. We examined effectors hormones cortisol and aldosterone northern elephant seal, a free-ranging study system which extreme physiological challenges fluctuations are routine part life history. stimulated neuroendocrine axis by administering exogenous adrenocorticotropic hormone (ACTH) resultant effects...
The northern elephant seal, Mirounga angustirostris, is a valuable animal model of fasting adaptation and hypoxic stress tolerance. However, no reference sequence currently available for this many other marine mammal study systems, hindering molecular understanding adaptations unique physiology. We sequenced transcriptome M. angustirostris derived from muscle sampled during an acute challenge experiment to identify species-specific markers axis activation recovery. De novo assembly generated...
Stressful disturbances activate the hypothalamic-pituitary-adrenal (HPA) axis and result in release of glucocorticoid (GC) hormones. This characteristic stress response supports immediate energetic demands subsequent recovery from disturbance. Increased baseline GC concentrations may indicate chronic can impair HPA function during exposure to additional stressors. Levels GCs, however, vary seasonally with life-history stage, potentially confounding their interpretation. Our objective was...
Abstract The recent rise of ‘omics and other molecular research technologies alongside improved techniques for tissue preservation have broadened the scope marine mammal research. Collecting biological samples from wild mammals is both logistically challenging expensive. To enhance power research, great effort has been made in field laboratory to ensure scientific integrity collection through processing, supporting long‐term use precious across a broad range studies. However, identifying...
The northern elephant seal pup (Mirounga angustirostris) undergoes a 2-3 month post-weaning fast, during which it depends primarily on the oxidation of fatty acids to meet its energetic demands. concentration non-esterified (NEFAs) increases and is associated with development insulin resistance in late-fasted pups. Furthermore, plasma NEFA concentrations respond differentially an intravenous glucose tolerance test (ivGTT) depending fasting duration, suggesting that effects lipid metabolism...