Polar bear evolution is marked by rapid changes in gene copy number in response to dietary shift
Abstract
Copy number variation describes the degree to which contiguous genomic regions differ in their number of copies among individuals. Copy number variable regions can drive ecological adaptation, particularly when they contain genes. Here, we compare differences in gene copy numbers among 17 polar bear and 9 brown bear individuals to evaluate the impact of copy number variation on polar bear evolution. Polar bears and brown bears are ideal species for such an analysis as they are closely related, yet ecologically distinct. Our analysis identified variation in copy number for genes linked to dietary and ecological requirements of the bear species. These results suggest that genic copy number variation has played an important role in polar bear adaptation to the Arctic.
- Publication:
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Proceedings of the National Academy of Science
- Pub Date:
- July 2019
- DOI:
- Bibcode:
- 2019PNAS..11613446R