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McHuron EA, Adamczak S, Costa DP, Booth C. Estimating reproductive costs in marine mammal bioenergetic models: a review of current knowledge and data availability. CONSERVATION PHYSIOLOGY 2023; 11:coac080. [PMID: 36685328 PMCID: PMC9845964 DOI: 10.1093/conphys/coac080] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 11/26/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
Abstract
Reproductive costs represent a significant proportion of a mammalian female's energy budget. Estimates of reproductive costs are needed for understanding how alterations to energy budgets, such as those from environmental variation or human activities, impact maternal body condition, vital rates and population dynamics. Such questions are increasingly important for marine mammals, as many populations are faced with rapidly changing and increasingly disturbed environments. Here we review the different energetic costs that marine mammals incur during gestation and lactation and how those costs are typically estimated in bioenergetic models. We compiled data availability on key model parameters for each species across all six marine mammal taxonomic groups (mysticetes, odontocetes, pinnipeds, sirenians, mustelids and ursids). Pinnipeds were the best-represented group regarding data availability, including estimates of milk intake, milk composition, lactation duration, birth mass, body composition at birth and growth. There were still considerable data gaps, particularly for polar species, and good data were only available across all parameters in 45% of pinniped species. Cetaceans and sirenians were comparatively data-poor, with some species having little or no data for any parameters, particularly beaked whales. Even for species with moderate data coverage, many parameter estimates were tentative or based on indirect approaches, necessitating reevaluation of these estimates. We discuss mechanisms and factors that affect maternal energy investment or prey requirements during reproduction, such as prey supplementation by offspring, metabolic compensation, environmental conditions and maternal characteristics. Filling the existing data gaps highlighted in this review, particularly for parameters that are influential on bioenergetic model outputs, will help refine reproductive costs estimated from bioenergetic models and better address how and when energy imbalances are likely to affect marine mammal populations.
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Affiliation(s)
- Elizabeth A McHuron
- Corresponding author: Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington, Seattle, WA, 98105, USA.
| | - Stephanie Adamczak
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
| | - Daniel P Costa
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
| | - Cormac Booth
- SMRU Consulting, Scottish Oceans Institute, St Andrews, UK
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2
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Ursids evolved early and continuously to be low-protein macronutrient omnivores. Sci Rep 2022; 12:15251. [PMID: 36085304 PMCID: PMC9463165 DOI: 10.1038/s41598-022-19742-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 09/02/2022] [Indexed: 11/21/2022] Open
Abstract
The eight species of bears world-wide consume a wide variety of diets. Some are specialists with extensive anatomical and physiological adaptations necessary to exploit specific foods or environments [e.g., polar bears (Ursus maritimus), giant pandas (Ailuropoda melanoleuca), and sloth bears (Melursus ursinus)], while the rest are generalists. Even though ursids evolved from a high-protein carnivore, we hypothesized that all have become low-protein macronutrient omnivores. While this dietary strategy has already been described for polar bears and brown bears (Ursus arctos), a recent study on giant pandas suggested their macronutrient selection was that of the ancestral high-protein carnivore. Consumption of diets with inappropriate macronutrient profiles has been associated with increased energy expenditure, ill health, failed reproduction, and premature death. Consequently, we conducted feeding and preference trials with giant pandas and sloth bears, a termite and ant-feeding specialist. Both giant pandas and sloth bears branched off from the ursid lineage a million or more years before polar bears and brown bears. We found that giant pandas are low-protein, high-carbohydrate omnivores, whereas sloth bears are low-protein, high-fat omnivores. The preference for low protein diets apparently occurred early in the evolution of ursids and may have been critical to their world-wide spread.
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3
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Yu Z, Lei Y, Zhao P, Fu S, Zhang D, Shen J, Zan L, Liu Y. Nutritional and physical characteristics evaluation of giant panda (Ailuropoda melanoleuca) milk in comparison with bovine and caprine milk. Int Dairy J 2022. [DOI: 10.1016/j.idairyj.2022.105502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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4
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Robbins CT, Tollefson TN, Rode KD, Erlenbach JA, Ardente AJ. New insights into dietary management of polar bears (Ursus maritimus) and brown bears (U. arctos). Zoo Biol 2021; 41:166-175. [PMID: 34793606 DOI: 10.1002/zoo.21658] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 09/23/2021] [Accepted: 11/08/2021] [Indexed: 11/06/2022]
Abstract
Although polar bears (Ursus maritimus) and brown bears (U. arctos) have been exhibited in zoological gardens for centuries, little is known about their nutritional needs. Multiple recent studies on both wild and captive polar bears and brown bears have found that they voluntarily select dietary macronutrient proportions resulting in much lower dietary protein and higher fat or digestible carbohydrate concentrations than are currently fed in most zoos. These lower protein concentrations selected by both species maximized growth rates and efficiencies of energy utilization in brown bears and may play a role in reducing kidney, liver, and cardiovascular diseases in both species. Therefore, we propose the need for the development of new dietary regimens for both species in managed care that better reflect their macronutrient needs. We developed a new kibble that is higher in fat and lower in protein than typical diets that have been fed in managed care, has a fatty acid profile more consistent with wild bear diets, and has been readily consumed by both brown bears and polar bears. The kibble can be fed as the sole diet or as part of more complex diets with additional fruits, meats, or vegetables. Because many nutritional deficiencies and related diseases can take months or years to appear, we urge caution and continued long-term monitoring of bears and their diets to ensure their optimal health.
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Affiliation(s)
- Charles T Robbins
- School of the Environment and School of Biological Sciences, Washington State University, Pullman, Washington, USA
| | - Troy N Tollefson
- Mazuri® Exotic Animal Nutrition, Land O'Lakes Inc., St. Louis, Missouri, USA
| | - Karyn D Rode
- U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska, USA
| | - Joy A Erlenbach
- U.S. Fish and Wildlife Service, Kodiak National Wildlife Refuge, Kodiak, Alaska, USA
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5
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Rode KD, Robbins CT, Stricker CA, Taras BD, Tollefson TN. Energetic and health effects of protein overconsumption constrain dietary adaptation in an apex predator. Sci Rep 2021; 11:15309. [PMID: 34321600 PMCID: PMC8319126 DOI: 10.1038/s41598-021-94917-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 07/19/2021] [Indexed: 12/02/2022] Open
Abstract
Studies of predator feeding ecology commonly focus on energy intake. However, captive predators have been documented to selectively feed to optimize macronutrient intake. As many apex predators experience environmental changes that affect prey availability, limitations on selective feeding can affect energetics and health. We estimated the protein:fat ratio of diets consumed by wild polar bears using a novel isotope-based approach, measured protein:fat ratios selected by zoo polar bears offered dietary choice and examined potential energetic and health consequences of overconsuming protein. Dietary protein levels selected by wild and zoo polar bears were low and similar to selection observed in omnivorous brown bears, which reduced energy intake requirements by 70% compared with lean meat diets. Higher-protein diets fed to zoo polar bears during normal care were concurrent with high rates of mortality from kidney disease and liver cancer. Our results suggest that polar bears have low protein requirements and that limitations on selective consumption of marine mammal blubber consequent to climate change could meaningfully increase their energetic costs. Although bear protein requirements appear lower than those of other carnivores, the energetic and health consequences of protein overconsumption identified in this study have the potential to affect a wide range of taxa.
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Affiliation(s)
- Karyn D Rode
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK, 99508, USA.
| | - Charles T Robbins
- School of the Environment and School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Craig A Stricker
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, CO, 80526, USA
| | - Brian D Taras
- Division of Wildlife Conservation, Alaska Department of Fish and Game, Fairbanks, AK, 99701, USA
| | - Troy N Tollefson
- Mazuri Exotic Animal Nutrition, Land O'Lakes, Inc., St. Louis, MO, 63166, USA
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6
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Sadovnikova A, Garcia SC, Hovey RC. A Comparative Review of the Cell Biology, Biochemistry, and Genetics of Lactose Synthesis. J Mammary Gland Biol Neoplasia 2021; 26:181-196. [PMID: 34125364 PMCID: PMC8236053 DOI: 10.1007/s10911-021-09490-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 05/20/2021] [Indexed: 12/18/2022] Open
Abstract
Lactose is the primary carbohydrate in the milk of most mammals and is unique in that it is only synthesized by epithelial cells in the mammary glands. Lactose is also essential for the development and nutrition of infants. Across species, the concentration of lactose in milk holds a strong positive correlation with overall milk volume. Additionally, there is a range of examples where the onset of lactose synthesis as well as the content of lactose in milk varies between species and throughout a lactation. Despite this diversity, the precursors, genes, proteins and ions that regulate lactose synthesis have not received the depth of study they likely deserve relative to the significance of this simple and abundant molecule. Through this review, our objective is to highlight the requirements for lactose synthesis at the biochemical, cellular and temporal levels through a comparative approach. This overview also serves as the prelude to a companion review describing the dietary, hormonal, molecular, and genetic factors that regulate lactose synthesis.
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Affiliation(s)
- Anna Sadovnikova
- Graduate Group in Nutritional Biology, Physician Scientist Training Program, University of California, Davis, CA, USA.
- Department of Animal Science, University of California, Davis, CA, USA.
| | - Sergio C Garcia
- School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - Russell C Hovey
- Department of Animal Science, University of California, Davis, CA, USA
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7
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Dominique M, Letcher RJ, Rutter A, Langlois VS. Comparative review of the distribution and burden of contaminants in the body of polar bears. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:32456-32466. [PMID: 32556983 DOI: 10.1007/s11356-020-09193-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 05/05/2020] [Indexed: 06/11/2023]
Abstract
Historical (or legacy) contaminants, such as metals and persistent organic pollutants (POPs; e.g., polychlorinated biphenyls) have been measured in circumpolar subpopulations of polar bears, especially from Hudson Bay, East Greenland, and Svalbard, but substantially less is currently known about new and/or emerging contaminants such as polychlorinated naphthalenes, current-use pesticides, organotins, and polycyclic aromatic compounds (PACs). The polar bear (Ursus maritimus) is an apex Arctic predator that accumulates high levels of bioaccumulative POPs and mercury (Hg), but there is currently no comprehensive profiling of the present knowledge on contaminants in tissue and body compartments in polar bears. Based on current literature reports and data, and including archived museum samples (as far back as the 1300s) and up to 2018, the aim of this review is to utilize available data to examine the comparative distribution and burden of mainly lipophilic contaminants in kidney, liver, fat, and other body compartments, such as milk, blood, and brain. Highlight outcomes from this review include the following: (1) the kidneys are one of the most important tissue depots of contaminants in polar bears; (2) there is a critical lack of data concerning the presence of metals of concern (other than Hg); and (3) there currently are no data available on the concentrations of many newer and emerging contaminants, such as PACs, which is especially relevant given the increasing oil and gas development in regions, such as the Beaufort Sea (Canada). Additionally, given the vulnerability of polar bear populations worldwide, there is a need to develop non-invasive approaches to monitor contaminant exposure in polar bears.
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Affiliation(s)
- Mélanie Dominique
- Centre Eau Terre Environnement, Institut national de la recherche scientifique (INRS), Québec City, QC, Canada
| | - Robert J Letcher
- Ecotoxicology and Wildlife Health Division, Wildlife and Landscape Science Directorate, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON, Canada
| | - Allison Rutter
- School of Environmental Studies, Queen's University, Kingston, ON, Canada
| | - Valerie S Langlois
- Centre Eau Terre Environnement, Institut national de la recherche scientifique (INRS), Québec City, QC, Canada.
- Ecotoxicology and Wildlife Health Division, Wildlife and Landscape Science Directorate, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON, Canada.
- Ecotoxicogenomics and Endocrine Disruption, Centre Eau Terre Environnement, Institut national de la recherche scientifique (INRS), 490, rue de la Couronne, Québec, QC, G1K 9A9, Canada.
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8
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Watson DG, Pomeroy PP, Al-Tannak NF, Kennedy MW. Stockpiling by pups and self-sacrifice by their fasting mothers observed in birth to weaning serum metabolomes of Atlantic grey seals. Sci Rep 2020; 10:7465. [PMID: 32366923 PMCID: PMC7198541 DOI: 10.1038/s41598-020-64488-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 04/15/2020] [Indexed: 12/23/2022] Open
Abstract
During the uniquely short lactations of true seals, pups acquire a greater proportion of maternal body resources, at a greater rate, than in any other group of mammals. Mothers in many species enter a period of anorexia but must preserve sufficient reserves to fuel hunting and thermoregulation for return to cold seas. Moreover, pups may undergo a period of development after weaning during which they have no maternal care or nutrition. This nutritionally closed system presents a potentially extreme case of conflict between maternal survival and adequate provisioning of offspring, likely presenting strains on their metabolisms. We examined the serum metabolomes of five mother and pup pairs of Atlantic grey seals, Halichoerus grypus, from birth to weaning. Changes with time were particularly evident in pups, with indications of strain in the fat and energy metabolisms of both. Crucially, pups accumulate certain compounds to levels that are dramatically greater than in mothers. These include compounds that pups cannot synthesise themselves, such as pyridoxine/vitamin B6, taurine, some essential amino acids, and a conditionally essential amino acid and its precursor. Fasting mothers therefore appear to mediate stockpiling of critical metabolites in their pups, potentially depleting their own reserves and prompting cessation of lactation.
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Affiliation(s)
- David G Watson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, Scotland, UK.
| | - Patrick P Pomeroy
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife, Scotland, United Kingdom
| | - Naser F Al-Tannak
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, Scotland, UK.,Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kuwait University, P.O. Box 23924, Safat, 13110, Kuwait City, Kuwait
| | - Malcolm W Kennedy
- Institute of Biodiversity, Animal Health & Comparative Medicine, Graham Kerr Building, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK.
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9
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Fowler M, Champagne C, Crocker D. Adiposity and fat metabolism during combined fasting and lactation in elephant seals. J Exp Biol 2018. [DOI: 10.1242/jeb.161554] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
ABSTRACT
Animals that fast depend on mobilizing lipid stores to power metabolism. Northern elephant seals (Mirounga angustirostris) incorporate extended fasting into several life-history stages: development, molting, breeding and lactation. The physiological processes enabling fasting and lactation are important in the context of the ecology and life history of elephant seals. The rare combination of fasting and lactation depends on the efficient mobilization of lipid from adipose stores and its direction into milk production. The mother elephant seal must ration her finite body stores to power maintenance metabolism, as well as to produce large quantities of lipid and protein-rich milk. Lipid from body stores must first be mobilized; the action of lipolytic enzymes and hormones stimulate the release of fatty acids into the bloodstream. Biochemical processes affect the release of specific fatty acids in a predictable manner, and the pattern of release from lipid stores is closely reflected in the fatty acid content of the milk lipid. The content of the milk may have substantial developmental, thermoregulatory and metabolic consequences for the pup. The lactation and developmental patterns found in elephant seals are similar in some respects to those of other mammals; however, even within the limited number of mammals that simultaneously fast and lactate, there are important differences in the mechanisms that regulate lipid mobilization and milk lipid content. Although ungulates and humans do not fast during lactation, there are interesting comparisons to these groups regarding lipid mobilization and milk lipid content patterns.
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10
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Lowe AD, Bawazeer S, Watson DG, McGill S, Burchmore RJS, Pomeroy PPP, Kennedy MW. Rapid changes in Atlantic grey seal milk from birth to weaning - immune factors and indicators of metabolic strain. Sci Rep 2017; 7:16093. [PMID: 29170469 PMCID: PMC5700954 DOI: 10.1038/s41598-017-16187-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 11/08/2017] [Indexed: 11/21/2022] Open
Abstract
True seals have the shortest lactation periods of any group of placental mammal. Most are capital breeders that undergo short, intense lactations, during which they fast while transferring substantial proportions of their body reserves to their pups, which they then abruptly wean. Milk was collected from Atlantic grey seals (Halichoerus grypus) periodically from birth until near weaning. Milk protein profiles matured within 24 hours or less, indicating the most rapid transition from colostrum to mature phase lactation yet observed. There was an unexpected persistence of immunoglobulin G almost until weaning, potentially indicating prolonged trans-intestinal transfer of IgG. Among components of innate immune protection were found fucosyllactose and siallylactose that are thought to impede colonisation by pathogens and encourage an appropriate milk-digestive and protective gut microbiome. These oligosaccharides decreased from early lactation to almost undetectable levels by weaning. Taurine levels were initially high, then fell, possibly indicative of taurine dependency in seals, and progressive depletion of maternal reserves. Metabolites that signal changes in the mother’s metabolism of fats, such as nicotinamide and derivatives, rose from virtual absence, and acetylcarnitines fell. It is therefore possible that indicators of maternal metabolic strain exist that signal the imminence of weaning.
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Affiliation(s)
- Amanda D Lowe
- Institute of Biodiversity, Animal Health & Comparative Medicine, and School of Life Sciences, Graham Kerr Building, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK
| | - Sami Bawazeer
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, Scotland, UK
| | - David G Watson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, Scotland, UK
| | - Suzanne McGill
- Institute of Infection, Immunity and Inflammation, and Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Garscube Campus, Glasgow, G12 1QH, Scotland, UK
| | - Richard J S Burchmore
- Institute of Infection, Immunity and Inflammation, and Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Garscube Campus, Glasgow, G12 1QH, Scotland, UK
| | - P P Paddy Pomeroy
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife, United Kingdom
| | - Malcolm W Kennedy
- Institute of Biodiversity, Animal Health & Comparative Medicine, and School of Life Sciences, Graham Kerr Building, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK.
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11
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Akter R, Abedini A, Ridgway Z, Zhang X, Kleinberg J, Schmidt AM, Raleigh DP. Evolutionary Adaptation and Amyloid Formation: Does the Reduced Amyloidogenicity and Cytotoxicity of Ursine Amylin Contribute to the Metabolic Adaption of Bears and Polar Bears? Isr J Chem 2017; 57:750-761. [PMID: 29955200 PMCID: PMC6018008 DOI: 10.1002/ijch.201600081] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Much of our knowledge of diabetes is derived from studies of rodent models. An alternative approach explores evolutionary solutions to physiological stress by studying organisms that face challenging metabolic environments. Polar bears eat an enormously lipid-rich diet without deleterious metabolic consequences. In contrast, transgenic rodents expressing the human neuropancreatic polypeptide hormone amylin develop hyperglycemia and extensive pancreatic islet amyloid when fed a high fat diet. The process of islet amyloid formation by human amylin contributes to β-cell dysfunction and loss of β-cell mass in type-2 diabetes. We show that ursine amylin is considerably less amyloidogenic and less toxic to β-cells than human amylin, consistent with the hypothesis that part of the adaptation of bears to metabolic challenges might include protection from islet amyloidosis-induced β-cell toxicity. Ursine and human amylin differ at four locations: H18R, S20G, F23L, and S29P. These are interesting from a biophysical perspective since the S20G mutation accelerates amyloid formation but the H18R slows it. An H18RS20G double mutant of human amylin behaves similarly to the H18R mutant, indicating that the substitution at position 18 dominates the S20G replacement. These data suggest one possible mechanism underpinning the protection of bears against metabolic challenges and provide insight into the design of soluble analogs of human amylin.
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Affiliation(s)
- Rehana Akter
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
| | - Andisheh Abedini
- Diabetes Research Program, NYU School of Medicine, 522 First Avenue, New York, NY 10016
| | - Zachary Ridgway
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
| | - Xiaoxue Zhang
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
| | - Joel Kleinberg
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
| | - Ann Marie Schmidt
- Diabetes Research Program, NYU School of Medicine, 522 First Avenue, New York, NY 10016
| | - Daniel P. Raleigh
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400
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12
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Zhang T, Watson DG, Zhang R, Hou R, Loeffler IK, Kennedy MW. Changeover from signalling to energy-provisioning lipids during transition from colostrum to mature milk in the giant panda (Ailuropoda melanoleuca). Sci Rep 2016; 6:36141. [PMID: 27808224 PMCID: PMC5093549 DOI: 10.1038/srep36141] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/11/2016] [Indexed: 01/07/2023] Open
Abstract
Among the large placental mammals, ursids give birth to the most altricial neonates with the lowest neonatal:maternal body mass ratios. This is particularly exemplified by giant pandas. To examine whether there is compensation for the provision of developmentally important nutrients that other species groups may provide in utero, we examined changes in the lipids of colostrum and milk with time after birth in giant pandas. Lipids that are developmental signals or signal precursors, and those that are fundamental to nervous system construction, such as docosahexaenoic acid (DHA) and phosphatidylserines, appear early and then fall dramatically in concentration to a baseline at 20–30 days. The dynamics of lysophosphatidic acid and eicosanoids display similar patterns, but with progressive differences between mothers. Triglycerides occur at relatively low levels initially and increase in concentration until a plateau is reached at about 30 days. These patterns indicate an early provision of signalling lipids and their precursors, particularly lipids crucial to brain, retinal and central nervous system development, followed by a changeover to lipids for energy metabolism. Thus, in giant pandas, and possibly in all bears, lactation is adapted to provisioning a highly altricial neonate to a degree that suggests equivalence to an extension of gestation.
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Affiliation(s)
- Tong Zhang
- Strathclyde Institute of Pharmacy and Biomedical Sciences, 161, Cathedral Street, Glasgow G4 0RE, Scotland, UK
| | - David G Watson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, 161, Cathedral Street, Glasgow G4 0RE, Scotland, UK
| | - Rong Zhang
- Strathclyde Institute of Pharmacy and Biomedical Sciences, 161, Cathedral Street, Glasgow G4 0RE, Scotland, UK.,Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, No. 12 Jichang Road, Guangzhou 510405, P.R. China
| | - Rong Hou
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, 1375 Panda Road, Northern Suburb, Chengdu, Sichuan Province 610081, P.R. China
| | - I Kati Loeffler
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, 1375 Panda Road, Northern Suburb, Chengdu, Sichuan Province 610081, P.R. China
| | - Malcolm W Kennedy
- Institute of Biodiversity, Animal Health and Comparative Medicine, and Institute of Molecular Cell and Systems Biology, College of Medical, Veterinary, and Life Sciences, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, Scotland, UK
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13
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Rezaei R, Wu Z, Hou Y, Bazer FW, Wu G. Amino acids and mammary gland development: nutritional implications for milk production and neonatal growth. J Anim Sci Biotechnol 2016; 7:20. [PMID: 27042295 PMCID: PMC4818943 DOI: 10.1186/s40104-016-0078-8] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 03/10/2016] [Indexed: 01/22/2023] Open
Abstract
Milk is synthesized by mammary epithelial cells of lactating mammals. The synthetic capacity of the mammary gland depends largely on the number and efficiency of functional mammary epithelial cells. Structural development of the mammary gland occurs during fetal growth, prepubertal and post-pubertal periods, pregnancy, and lactation under the control of various hormones (particularly estrogen, growth hormone, insulin-like growth factor-I, progesterone, placental lactogen, and prolactin) in a species- and stage-dependent manner. Milk is essential for the growth, development, and health of neonates. Amino acids (AA), present in both free and peptide-bound forms, are the most abundant organic nutrients in the milk of farm animals. Uptake of AA from the arterial blood of the lactating dam is the ultimate source of proteins (primarily β-casein and α-lactalbumin) and bioactive nitrogenous metabolites in milk. Results of recent studies indicate extensive catabolism of branched-chain AA (leucine, isoleucine and valine) and arginine to synthesize glutamate, glutamine, alanine, aspartate, asparagine, proline, and polyamines. The formation of polypeptides from AA is regulated not only by hormones (e.g., prolactin, insulin and glucocorticoids) and the rate of blood flow across the lactating mammary gland, but also by concentrations of AA, lipids, glucose, vitamins and minerals in the maternal plasma, as well as the activation of the mechanistic (mammalian) target rapamycin signaling by certain AA (e.g., arginine, branched-chain AA, and glutamine). Knowledge of AA utilization (including metabolism) by mammary epithelial cells will enhance our fundamental understanding of lactation biology and has important implications for improving the efficiency of livestock production worldwide.
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Affiliation(s)
- Reza Rezaei
- />Department of Animal Science, Texas A&M University, College Station, TX 77843 USA
| | - Zhenlong Wu
- />State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, 100193 China
| | - Yongqing Hou
- />Hubei Key Laboratory of Animal Nutrition and Feed Science, Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan Polytechnic University, Wuhan, 430023 China
| | - Fuller W. Bazer
- />Department of Animal Science, Texas A&M University, College Station, TX 77843 USA
| | - Guoyao Wu
- />Department of Animal Science, Texas A&M University, College Station, TX 77843 USA
- />State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, 100193 China
- />Hubei Key Laboratory of Animal Nutrition and Feed Science, Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety, Wuhan Polytechnic University, Wuhan, 430023 China
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Zhang Z, Hou R, Lan J, Wang H, Kurokawa H, Takatsu Z, Kobayashi T, Koie H, Kamata H, Kanayama K, Watanabe T. Analysis of the breast milk of giant pandas (Ailuropoda melanoleuca) and the preparation of substitutes. J Vet Med Sci 2016; 78:747-54. [PMID: 26781707 PMCID: PMC4905826 DOI: 10.1292/jvms.15-0677] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The first milk substitute for giant panda cubs was developed in 1988 based on limited
data about giant panda breast milk and that of certain types of bear. Mixtures of other
formulas have also been fed to cubs at some facilities. However, they are not of
sufficient nutritional quality for promoting growth in panda cubs. Here, we report
analysis of giant panda breast milk and propose new milk substitutes for cubs, which were
developed based on the results of our analysis. The Chengdu Research Base of Giant Panda
Breeding obtained breast milk samples from three giant pandas. Up to 30
ml of breast milk were collected from each mother by hand. Then, the
milk samples were frozen and sent to Nihon University. The levels of protein, fat,
carbohydrates, ash, moisture, vitamins, minerals, total amino acids, fatty acids, lactose
and other carbohydrates in the milk were analyzed. The breast milk samples exhibited the
following nutritional values: protein: 6.6–8.5%, fat: 6.9–16.4%, carbohydrates: 2.5–9.1%,
ash: 0.9–1.0% and moisture: 67–83%. We designed two kinds of milk substitutes based on the
data obtained and the nutritional requirements of dogs, cats and rodents. The nutritional
composition of the milk substitutes for the first and second stages was as follows:
protein: 38 and 26%, fat: 40 and 40%, carbohydrates: 13 and 25%, ash: 6 and 6% and
moisture: 3 and 3%, respectively. In addition, the substitutes contained vitamins,
minerals, taurine, docosahexaenoic acid, lactoferrin, nucleotides and other nutrients.
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Affiliation(s)
- Zhihe Zhang
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, Sichuan, P. R. China
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Zhang T, Zhang R, Zhang L, Zhang Z, Hou R, Wang H, Loeffler IK, Watson DG, Kennedy MW. Changes in the Milk Metabolome of the Giant Panda (Ailuropoda melanoleuca) with Time after Birth--Three Phases in Early Lactation and Progressive Individual Differences. PLoS One 2015; 10:e0143417. [PMID: 26630345 PMCID: PMC4668050 DOI: 10.1371/journal.pone.0143417] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 11/04/2015] [Indexed: 12/24/2022] Open
Abstract
Ursids (bears) in general, and giant pandas in particular, are highly altricial at birth. The components of bear milks and their changes with time may be uniquely adapted to nourish relatively immature neonates, protect them from pathogens, and support the maturation of neonatal digestive physiology. Serial milk samples collected from three giant pandas in early lactation were subjected to untargeted metabolite profiling and multivariate analysis. Changes in milk metabolites with time after birth were analysed by Principal Component Analysis, Hierarchical Cluster Analysis and further supported by Orthogonal Partial Least Square-Discriminant Analysis, revealing three phases of milk maturation: days 1–6 (Phase 1), days 7–20 (Phase 2), and beyond day 20 (Phase 3). While the compositions of Phase 1 milks were essentially indistinguishable among individuals, divergences emerged during the second week of lactation. OPLS regression analysis positioned against the growth rate of one cub tentatively inferred a correlation with changes in the abundance of a trisaccharide, isoglobotriose, previously observed to be a major oligosaccharide in ursid milks. Three artificial milk formulae used to feed giant panda cubs were also analysed, and were found to differ markedly in component content from natural panda milk. These findings have implications for the dependence of the ontogeny of all species of bears, and potentially other members of the Carnivora and beyond, on the complexity and sequential changes in maternal provision of micrometabolites in the immediate period after birth.
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Affiliation(s)
- Tong Zhang
- Strathclyde Institute of Pharmacy and Biomedical Sciences, Glasgow, Scotland, United Kingdom
| | - Rong Zhang
- Strathclyde Institute of Pharmacy and Biomedical Sciences, Glasgow, Scotland, United Kingdom
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, P.R. China
| | - Liang Zhang
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Northern Suburb, Chengdu, Sichuan Province, P.R. China
| | - Zhihe Zhang
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Northern Suburb, Chengdu, Sichuan Province, P.R. China
| | - Rong Hou
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Northern Suburb, Chengdu, Sichuan Province, P.R. China
| | - Hairui Wang
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Northern Suburb, Chengdu, Sichuan Province, P.R. China
| | - I. Kati Loeffler
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Northern Suburb, Chengdu, Sichuan Province, P.R. China
| | - David G. Watson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, Glasgow, Scotland, United Kingdom
| | - Malcolm W. Kennedy
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary, and Life Sciences, Graham Kerr Building, University of Glasgow, Glasgow, Scotland, United Kingdom
- * E-mail:
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16
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Griffiths K, Hou R, Wang H, Zhang Z, Zhang L, Zhang T, Watson DG, Burchmore RJS, Loeffler IK, Kennedy MW. Prolonged transition time between colostrum and mature milk in a bear, the giant panda, Ailuropoda melanoleuca. ROYAL SOCIETY OPEN SCIENCE 2015; 2:150395. [PMID: 26587250 PMCID: PMC4632522 DOI: 10.1098/rsos.150395] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 09/21/2015] [Indexed: 06/05/2023]
Abstract
Bears produce the most altricial neonates of any placental mammal. We hypothesized that the transition from colostrum to mature milk in bears reflects a temporal and biochemical adaptation for altricial development and immune protection. Comparison of bear milks with milks of other eutherians yielded distinctive protein profiles. Proteomic and metabolomic analysis of serial milk samples collected from six giant pandas showed a prolonged transition from colostrum to main-phase lactation over approximately 30 days. Particularly striking are the persistence or sequential appearance of adaptive and innate immune factors. The endurance of immunoglobulin G suggests an unusual duration of trans-intestinal absorption of maternal antibodies, and is potentially relevant to the underdeveloped lymphoid system of giant panda neonates. Levels of certain milk oligosaccharides known to exert anti-microbial activities and/or that are conducive to the development of neonatal gut microbiomes underwent an almost complete changeover around days 20-30 postpartum, coincident with the maturation of the protein profile. A potential metabolic marker of starvation was detected, the prominence of which may reflect the natural postpartum period of anorexia in giant panda mothers. Early lactation in giant pandas, and possibly in other ursids, appears to be adapted for the unique requirements of unusually altricial eutherian neonates.
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Affiliation(s)
- Kate Griffiths
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Graham err Building, Glasgow, G12 8QQ, UK
| | - Rong Hou
- The Sichuan Key Laboratory for Conservation Biology on Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, 1375 Panda Road, Northern Suburb, Chengdu, Sichuan Province 610081, People’s Republic of China
| | - Hairui Wang
- The Sichuan Key Laboratory for Conservation Biology on Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, 1375 Panda Road, Northern Suburb, Chengdu, Sichuan Province 610081, People’s Republic of China
| | - Zhihe Zhang
- The Sichuan Key Laboratory for Conservation Biology on Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, 1375 Panda Road, Northern Suburb, Chengdu, Sichuan Province 610081, People’s Republic of China
| | - Liang Zhang
- The Sichuan Key Laboratory for Conservation Biology on Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, 1375 Panda Road, Northern Suburb, Chengdu, Sichuan Province 610081, People’s Republic of China
| | - Tong Zhang
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
| | - David G. Watson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
| | - Richard J. S. Burchmore
- Institute of Infection, Immunity and Inflammation and Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Garscube Campus, Glasgow, G12 1QH, UK
| | - I. Kati Loeffler
- The Sichuan Key Laboratory for Conservation Biology on Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, 1375 Panda Road, Northern Suburb, Chengdu, Sichuan Province 610081, People’s Republic of China
| | - Malcolm W. Kennedy
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Graham err Building, Glasgow, G12 8QQ, UK
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17
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Oftedal O, Eisert R, Barrell G. Comparison of analytical and predictive methods for water, protein, fat, sugar, and gross energy in marine mammal milk. J Dairy Sci 2014; 97:4713-32. [DOI: 10.3168/jds.2014-7895] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 04/19/2014] [Indexed: 11/19/2022]
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18
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Liu S, Lorenzen ED, Fumagalli M, Li B, Harris K, Xiong Z, Zhou L, Korneliussen TS, Somel M, Babbitt C, Wray G, Li J, He W, Wang Z, Fu W, Xiang X, Morgan CC, Doherty A, O'Connell MJ, McInerney JO, Born EW, Dalén L, Dietz R, Orlando L, Sonne C, Zhang G, Nielsen R, Willerslev E, Wang J. Population genomics reveal recent speciation and rapid evolutionary adaptation in polar bears. Cell 2014; 157:785-94. [PMID: 24813606 PMCID: PMC4089990 DOI: 10.1016/j.cell.2014.03.054] [Citation(s) in RCA: 227] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 12/20/2013] [Accepted: 03/04/2014] [Indexed: 12/22/2022]
Abstract
Polar bears are uniquely adapted to life in the High Arctic and have undergone drastic physiological changes in response to Arctic climates and a hyper-lipid diet of primarily marine mammal prey. We analyzed 89 complete genomes of polar bear and brown bear using population genomic modeling and show that the species diverged only 479-343 thousand years BP. We find that genes on the polar bear lineage have been under stronger positive selection than in brown bears; nine of the top 16 genes under strong positive selection are associated with cardiomyopathy and vascular disease, implying important reorganization of the cardiovascular system. One of the genes showing the strongest evidence of selection, APOB, encodes the primary lipoprotein component of low-density lipoprotein (LDL); functional mutations in APOB may explain how polar bears are able to cope with life-long elevated LDL levels that are associated with high risk of heart disease in humans.
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Affiliation(s)
- Shiping Liu
- BGI-Shenzhen, Shenzhen 518083, China; School of Bioscience and Biotechnology, South China University of Technology, Guangzhou 510641, China
| | - Eline D Lorenzen
- Department of Integrative Biology, 3060 Valley Life Sciences Building, University of California, Berkeley, CA 94720, USA; Centre for GeoGenetics, Natural History Museum, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen K, Denmark
| | - Matteo Fumagalli
- Department of Integrative Biology, 3060 Valley Life Sciences Building, University of California, Berkeley, CA 94720, USA
| | - Bo Li
- BGI-Shenzhen, Shenzhen 518083, China
| | - Kelley Harris
- Department of Mathematics, 970 Evans Hall, University of California, Berkeley, CA 94720, USA
| | | | - Long Zhou
- BGI-Shenzhen, Shenzhen 518083, China
| | - Thorfinn Sand Korneliussen
- Centre for GeoGenetics, Natural History Museum, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen K, Denmark
| | - Mehmet Somel
- Department of Integrative Biology, 3060 Valley Life Sciences Building, University of California, Berkeley, CA 94720, USA
| | - Courtney Babbitt
- Department of Biology, 124 Science Drive, Duke Box # 90338, Duke University, Durham, NC 27708, USA; Institute for Genome Sciences & Policy, 101 Science Drive, DUMC Box 3382, Duke University, Durham, NC 27708, USA
| | - Greg Wray
- Department of Biology, 124 Science Drive, Duke Box # 90338, Duke University, Durham, NC 27708, USA; Institute for Genome Sciences & Policy, 101 Science Drive, DUMC Box 3382, Duke University, Durham, NC 27708, USA
| | | | - Weiming He
- BGI-Shenzhen, Shenzhen 518083, China; School of Bioscience and Biotechnology, South China University of Technology, Guangzhou 510641, China
| | - Zhuo Wang
- BGI-Shenzhen, Shenzhen 518083, China
| | | | - Xueyan Xiang
- BGI-Shenzhen, Shenzhen 518083, China; College of Life Sciences, Sichuan University, Chengdu 610064, China
| | - Claire C Morgan
- Bioinformatics and Molecular Evolution Group, School of Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Aoife Doherty
- Bioinformatics and Molecular Evolution Unit, Department of Biology, National University of Ireland, Maynooth, Co. Kildare, Ireland
| | - Mary J O'Connell
- Bioinformatics and Molecular Evolution Group, School of Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - James O McInerney
- Bioinformatics and Molecular Evolution Unit, Department of Biology, National University of Ireland, Maynooth, Co. Kildare, Ireland
| | - Erik W Born
- Greenland Institute of Natural Resources, c/o Government of Greenland Representation in Denmark, Strandgade 91, 3. Floor, PO Box 2151, 1016 Copenhagen K, Denmark
| | - Love Dalén
- Department of Bioinformatics and Genetics, Swedish Museum of Natural History, PO Box 50007, 10405, Stockholm, Sweden
| | - Rune Dietz
- Department of Bioscience, Arctic Research Centre, Aarhus University, Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark
| | - Ludovic Orlando
- Centre for GeoGenetics, Natural History Museum, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen K, Denmark
| | - Christian Sonne
- Department of Bioscience, Arctic Research Centre, Aarhus University, Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark
| | - Guojie Zhang
- BGI-Shenzhen, Shenzhen 518083, China; Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Rasmus Nielsen
- BGI-Shenzhen, Shenzhen 518083, China; Department of Integrative Biology, 3060 Valley Life Sciences Building, University of California, Berkeley, CA 94720, USA; Department of Statistics, 367 Evans Hall, University of California, Berkeley, CA 94720, USA; Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen Ø, Denmark.
| | - Eske Willerslev
- Centre for GeoGenetics, Natural History Museum, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen K, Denmark.
| | - Jun Wang
- BGI-Shenzhen, Shenzhen 518083, China; Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen Ø, Denmark; Princess Al Jawhara Center of Excellence in the Research of Hereditary Disorders, King Abdulaziz University, Jeddah 21589, Saudi Arabia; Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau 999078, China; Department of Medicine, University of Hong Kong, Sassoon Road, Pokfulam, Hong Kong.
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Differential regulation of TauT by calcitriol and retinoic acid via VDR/RXR in LLC-PK1 and MCF-7 cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 776:291-305. [PMID: 23392891 DOI: 10.1007/978-1-4614-6093-0_27] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
The interaction between taurine and the absorption of fat-soluble -vitamins, such as vitamin A and D, has been an interesting topic in the field of -nutrition science, because taurine-conjugated bile acid optimizes fat and fat-soluble vitamin absorption. However, whether the hormone calcitriol (1,25-dihydroxyvitamin D(3)) and retinoic acid regulate the expression of the TauT gene is unknown. In this study, we test the hypothesis that the TauT gene is regulated by vitamin D(3) (VD(3)) and retinoic acid (RA) via activation of the vitamin D receptor (VDR) and retinoic acid receptor (RXR). Taurine uptake, Western blotting, gene reporter assay, and immunohistochemical analysis of TauT, VDR, and RXR were used in VD(3)- and/or RA-treated LLC-PK1 and MCF-7 cells. We demonstrated that VD(3) alone had little effect on TauT expression in both LLC-PK1 and MCF-7 cells. Expression of TauT was significantly increased by RA, which was synergized by the addition of VD(3) after RXR activation in LLC-PK1 cells. In contrast, expression of TauT was significantly decreased by the combination of VD(3) and RA in MCF-7 cells. Regulation of TauT by VD(3)/RA appears to occur at the transcriptional level, as determined by a reporter gene assay of the TauT promoter. Immunohistochemical study showed that VDR and RXR were activated by VD(3) and RA, respectively, in both LLC-PK1 and MCF-7 cells. The activated VDR and RXR also colocated in nuclei of both cells, suggesting that a VDR/RXR complex is involved in the transcriptional regulation of TauT. Our results show that expression of TauT is differentially regulated by VD(3) and RA via formation of VDR and RXR complexes in the nuclei in a cell type-dependent manner.
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Knott KK, Boyd D, Ylitalo GM, O'Hara TM. Lactational transfer of mercury and polychlorinated biphenyls in polar bears. CHEMOSPHERE 2012; 88:395-402. [PMID: 22464860 DOI: 10.1016/j.chemosphere.2012.02.053] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 01/12/2012] [Accepted: 02/20/2012] [Indexed: 05/31/2023]
Abstract
We examined concentrations of total mercury (tHg, inorganic and methylated forms) and polychlorinated biphenyls (PCBs) in blood and milk from free-ranging Southern Beaufort-Chukchi Sea polar bears (Ursus maritimus) to assess maternal transfer of contaminants during lactation and the potential health risk to nursing young. Concentrations of contaminants in the blood of dependent and juvenile animals (ages 1-5 years) ranged from 35.9 to 52.2 μg kg(-1) ww for tHg and 13.9 to 52.2 μg kg(-1) ww (3255.81-11067.79 μg kg(-1) lw) for ΣPCB(7)s, similar to those of adult females, but greater than adult males. Contaminant concentrations in milk ranged from 5.7 to 71.8 μg tHg kg(-1)ww and 160 to 690 μg ΣPCB(11)s kg(-1) ww (547-5190 μg kg(-1) lw). The daily intake levels for tHg by milk consumption estimated for dependent young were below the tolerable daily intake level (TDIL) of tHg established for adult humans. Although the daily intake levels of PCBs through milk consumption for cubs of the year exceeded the TDIL thresholds, calculated dioxin equivalents for PCBs in milk were below adverse physiological thresholds for aquatic mammals. Relatively high concentrations of non-dioxin like PCBs in polar bear milk and blood could impact endocrine function of Southern Beaufort-Chukchi Sea polar bears, but this is uncertain. Transfer of contaminants during mid to late lactation likely limits bioaccumulation of dietary contaminants in female polar bears during spring. As polar bears respond to changes in their arctic sea ice habitat, the adverse health impacts associated with nutritional stress may be exacerbated by tHg and PCBs exposure, especially in ecologically and toxicologically sensitive polar bear cohorts such as reproductive females and young.
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Affiliation(s)
- Katrina K Knott
- Institute of Arctic Biology and Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
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