Molecular insights into anatomy and physiology

Abstract Bowhead whales are some of the largest animals that occupy the Arctic Circle. Despite the challenges of living and giving birth in icy waters, having huge blubber stores, eating a fat-rich diet, and undergoing arduous migrations, bowheads achieved the longest known life span of mammals of 268 years. Their longevity is extended by fixed mutations that prevent DNA damage and cancer and through evolutionary modifications to their metabolism that compensate for an oxygen-poor environment. Recently, the bowhead genome and transcriptome libraries were made publicly available for study. Analyses suggest that their life span has been extended by evolutionary changes that result in the upregulation of DNA repair pathways. Molecular biologists are now undertaking laboratory experiments with whale samples that are informed by the bowhead genome and transcriptome to tackle questions that were inaccessible using classical model organisms such as rodents or fish. Biomedical researchers are also applying insights gained from research on bowheads into investigations of potential therapies for aging, senescence, and cancer. Moreover, researchers are using these results to inform our understanding of the evolutionary history of these traits. This chapter reviews the molecular basis for bowhead whale longevity and survival in their unique habitat and offers insights for further exploration into the molecular mechanisms that shape the extraordinary lives of these animals.