The role of myosin copy number variation (CNV) in adaptive evolution of sticklebacks
Abstract/Contents
- Abstract
- Copy number variations (CNV) are a common source of genomic variation that have been linked to many diseases in humans. To look for copy number changes that may also contribute to advantageous traits during vertebrate evolution, we looked for recurrent CNVs that are positively associated with particular ecological environments in threespine stickleback fish. Freshwater sticklebacks show an expanded number of tandemly arranged myosin heavy chain 3 (MYH3) genes compared to marine fish. In a global analysis of many populations, we find that increased MYH3 copy numbers have evolved repeatedly in many recently derived postglacial freshwater locations. Interestingly, differences in copy number are maintained even in the presence of gene flow between hybridizing marine-stream species-pairs within single rivers, and between benthic and limnetic species-pairs within individual lakes. These results strongly suggest that the repeated copy number differences contribute to adaptive divergence between ecotypes. We identify a muscle regulatory enhancer within the duplicated MYH3 region, and show that elevated copy number is associated with increased MYH3 RNA levels in skeletal muscle. Finally, we provide a dynamic test of MYH3 evolution by monitoring changes in copy number following replicated experimental transplants of marine fish into freshwater lakes in Alaska. Significant MYH3 copy number changes evolve within only 5 to 7 generations following colonization of the new freshwater environments. These results provide a compelling new example of adaptive copy number changes in sticklebacks, and suggest copy number changes can provide an important source of advantageous variants when vertebrates adapt to rapidly changing environmental conditions.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2017 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Daugherty, Rhea R |
|---|---|
| Associated with | Stanford University, Department of Genetics. |
| Primary advisor | Kingsley, David M. (David Mark) |
| Thesis advisor | Kingsley, David M. (David Mark) |
| Thesis advisor | Ashley, Euan A |
| Thesis advisor | Sherlock, Gavin |
| Thesis advisor | Urban, Alexander |
| Advisor | Ashley, Euan A |
| Advisor | Sherlock, Gavin |
| Advisor | Urban, Alexander |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Rhea R. Daugherty. |
|---|---|
| Note | Submitted to the Department of Genetics. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2017. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2017 by Rhea Renee Daugherty
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