Chromosome Fissions and Fusions Act as Barriers to Gene Flow between Brenthis Fritillary Butterflies.

Autor:	Mackintosh A; Institute of Ecology and Evolution, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom., Vila R; Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37, ESP-08003 Barcelona, Spain., Laetsch DR; Institute of Ecology and Evolution, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom., Hayward A; Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Cornwall TR10 9FE, United Kingdom., Martin SH; Institute of Ecology and Evolution, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom., Lohse K; Institute of Ecology and Evolution, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom.
Jazyk:	angličtina
Zdroj:	Molecular biology and evolution [Mol Biol Evol] 2023 Mar 04; Vol. 40 (3).
DOI:	10.1093/molbev/msad043
Abstrakt:	Chromosome rearrangements are thought to promote reproductive isolation between incipient species. However, it is unclear how often, and under what conditions, fission and fusion rearrangements act as barriers to gene flow. Here we investigate speciation between two largely sympatric fritillary butterflies, Brenthis daphne and Brenthis ino. We use a composite likelihood approach to infer the demographic history of these species from whole-genome sequence data. We then compare chromosome-level genome assemblies of individuals from each species and identify a total of nine chromosome fissions and fusions. Finally, we fit a demographic model where effective population sizes and effective migration rate vary across the genome, allowing us to quantify the effects of chromosome rearrangements on reproductive isolation. We show that chromosomes involved in rearrangements experienced less effective migration since the onset of species divergence and that genomic regions near rearrangement points have a further reduction in effective migration rate. Our results suggest that the evolution of multiple rearrangements in the B. daphne and B. ino populations, including alternative fusions of the same chromosomes, have resulted in a reduction in gene flow. Although fission and fusion of chromosomes are unlikely to be the only processes that have led to speciation between these butterflies, this study shows that these rearrangements can directly promote reproductive isolation and may be involved in speciation when karyotypes evolve quickly. Competing Interests: Conflicts of interest. The authors declare no conflicts of interest. (© The Author(s) 2023. Published by Oxford University Press on behalf of Society for Molecular Biology and Evolution.)
Databáze:	MEDLINE
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