DNA fragility in the parallel evolution of pelvic reduction in stickleback fish

Xie, Kathleen T.; Wang, Guliang; Thompson, Abbey C.; Wucherpfennig, Julia I.; Reimchen, Thomas E.; MacColl, Andrew D. C.; Schluter, Dolph; Bell, Michael A.; Vasquez, Karen M.; Kingsley, David M.

Abstract

Evolution generates a remarkable breadth of living forms, but many traits evolve repeatedly, by mechanisms that are still poorly understood. A classic example of repeated evolution is the loss of pelvic hindfins in stickleback fish (Gasterosteus aculeatus). Repeated pelvic loss maps to recurrent deletions of a pelvic enhancer of the Pitx1 gene. Here, we identify molecular features contributing to these recurrent deletions. Pitx1 enhancer sequences form alternative DNA structures in vitro and increase double-strand breaks and deletions in vivo. Enhancer mutability depends on DNA replication direction and is caused by TG-dinucleotide repeats. Modeling shows that elevated mutation rates can influence evolution under demographic conditions relevant for sticklebacks and humans. DNA fragility may thus help explain why the same loci are often used repeatedly during parallel adaptive evolution.

Citation

Xie, K. T., Wang, G., Thompson, A. C., Wucherpfennig, J. I., Reimchen, T. E., MacColl, A. D. C., …Kingsley, D. M. (2019). DNA fragility in the parallel evolution of pelvic reduction in stickleback fish. Science, 363(6422), 81-84. https://doi.org/10.1126/science.aan1425

• Journal Article Type: Article
• Acceptance Date: Nov 28, 2018
• Online Publication Date: Jan 3, 2019
• Publication Date: Jan 4, 2019
• Deposit Date: Jan 9, 2019
• Publicly Available Date: Jul 4, 2019
• Journal: Science
• Print ISSN: 0036-8075
• Electronic ISSN: 1095-9203
• Publisher: American Association for the Advancement of Science
• Peer Reviewed: Peer Reviewed
• Volume: 363
• Issue: 6422
• Pages: 81-84
• DOI: https://doi.org/10.1126/science.aan1425
• Public URL: https://nottingham-repository.worktribe.com/output/1457924
• Publisher URL: http://science.sciencemag.org/content/363/6422/81
• Contract Date: Jan 9, 2019