Beyond thermoregulation: metabolic function of cetacean blubber in migrating bowhead and beluga whales.

Title

Beyond thermoregulation: metabolic function of cetacean blubber in migrating bowhead and beluga whales.

Creator

Ball H C; Londraville R L; Prokop J W; George John C; Suydam R S; Vinyard C; Thewissen J G M; Duff R J

Publisher

Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology

Date

2017
2017-01

Description

The processes of lipid deposition and utilization, via the gene leptin (Lep), are poorly understood in taxa with varying degrees of adipose storage. This study examines how these systems may have adapted in marine aquatic environments inhabited by cetaceans. Bowhead (Balaena mysticetus) and beluga whales (Delphinapterus leucas) are ideal study animals-they possess large subcutaneous adipose stores (blubber) and undergo bi-annual migrations concurrent with variations in food availability. To answer long-standing questions regarding how (or if) energy and lipid utilization adapted to aquatic stressors, we quantified variations in gene transcripts critical to lipid metabolism related to season, age, and blubber depth. We predicted leptin tertiary structure conservation and assessed inter-specific variations in Lep transcript numbers between bowheads and other mammals. Our study is the first to identify seasonal and age-related variations in Lep and lipolysis in these cetaceans. While Lep transcripts and protein oscillate with season in adult bowheads reminiscent of hibernating mammals, transcript levels reach up to 10 times higher in bowheads than any other mammal. Data from immature bowheads are consistent with the hypothesis that short baleen inhibits efficient feeding. Lipolysis transcripts also indicate young Fall bowheads and those sampled during Spring months limit energy utilization. These novel data from rarely examined species expand the existing knowledge and offer unique insight into how the regulation of Lep and lipolysis has adapted to permit seasonal deposition and maintain vital blubber stores.

Subject

*Lipid Metabolism; Adipose Tissue/*metabolism; Aging/metabolism; Amino Acid Sequence; Animals; Base Sequence; Beluga Whale/*physiology; Blubber; Body Temperature Regulation; Bowhead whale; Bowhead Whale/*physiology; Development; Female; Humans; Inbred C57BL; Leptin; Leptin/genetics; Leptin/genetics/metabolism; Lipase/genetics; Long-Evans; Male; Metabolic activity; Mice; Rats; Receptors; Seasons

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

235–252

Issue

1

Volume

187

Citation

Ball H C; Londraville R L; Prokop J W; George John C; Suydam R S; Vinyard C; Thewissen J G M; Duff R J, “Beyond thermoregulation: metabolic function of cetacean blubber in migrating bowhead and beluga whales.,” NEOMED Bibliography Database, accessed June 23, 2021, https://neomed.omeka.net/items/show/3174.

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