Can demographic histories explain long-term isolation and recent pulses of asymmetric gene flow between highly divergent grey fox lineages?

Autor: Preckler-Quisquater S; Mammalian Ecology and Conservation Unit, Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis, California, USA., Kierepka EM; North Carolina Museum of Natural Sciences, Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina, USA., Reding DM; Department of Biology, Luther College, Decorah, Iowa, USA., Piaggio AJ; USDA, Wildlife Services, National Wildlife Research Center, Wildlife Genetics Lab, Fort Collins, Colorado, USA., Sacks BN; Mammalian Ecology and Conservation Unit, Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis, California, USA.; Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, California, USA.
Jazyk: angličtina
Zdroj: Molecular ecology [Mol Ecol] 2023 Oct; Vol. 32 (19), pp. 5323-5337. Date of Electronic Publication: 2023 Aug 26.
DOI: 10.1111/mec.17105
Abstrakt: Secondary contact zones between deeply divergent, yet interfertile, lineages provide windows into the speciation process. North American grey foxes (Urocyon cinereoargenteus) are divided into western and eastern lineages that diverged approximately 1 million years ago. These ancient lineages currently hybridize in a relatively narrow zone of contact in the southern Great Plains, a pattern more commonly observed in smaller-bodied taxa, which suggests relatively recent contact after a long period of allopatry. Based on local ancestry inference with whole-genome sequencing (n = 43), we identified two distinct Holocene pulses of admixture. The older pulse (500-3500 YBP) reflected unidirectional gene flow from east to west, whereas the more recent pulse (70-200 YBP) of admixture was bi-directional. Augmented with genotyping-by-sequencing data from 216 additional foxes, demographic analyses indicated that the eastern lineage declined precipitously after divergence, remaining small throughout most of the late Pleistocene, and expanding only during the Holocene. Genetic diversity in the eastern lineage was highest in the southeast and lowest near the contact zone, consistent with a westward expansion. Concordantly, distribution modelling indicated that during their isolation, the most suitable habitat occurred far east of today's contact zone or west of the Great Plains. Thus, long-term isolation was likely caused by the small, distant location of the eastern refugium, with recent contact reflecting a large increase in suitable habitat and corresponding demographic expansion from the eastern refugium. Ultimately, long-term isolation in grey foxes may reflect their specialized bio-climatic niche. This system presents an opportunity for future investigation of potential pre- and post-zygotic isolating mechanisms.
(© 2023 The Authors. Molecular Ecology published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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