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Title: Biased gene retention in the face of introgression obscures species relationships
Abstract Phylogenomic analyses are recovering previously hidden histories of hybridization, revealing the genomic consequences of these events on the architecture of extant genomes. We applied phylogenomic techniques and several complementary statistical tests to show that introgressive hybridization appears to have occurred between close relatives of Arabidopsis, resulting in cytonuclear discordance and impacting our understanding of species relationships in the group. The composition of introgressed and retained genes indicates that selection against incompatible cytonuclear and nuclear-nuclear interactions likely acted during introgression, while linkage also contributed to genome composition through the retention of ancient haplotype blocks. We also applied divergence-based tests to determine the species branching order and distinguish donor from recipient lineages. Surprisingly, these analyses suggest that cytonuclear discordance arose via extensive nuclear, rather than cytoplasmic, introgression. If true, this would mean that most of the nuclear genome was displaced during introgression, while only a small proportion of native alleles were retained.  more » « less
Award ID(s):
2021753
NSF-PAR ID:
10182300
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
Genome Biology and Evolution
ISSN:
1759-6653
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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