TY - JOUR

T1 - Inter and Intraspecific Genomic Divergence in Drosophila montana Shows Evidence for Cold Adaptation

AU - Parker, Darren J

AU - Wiberg, R Axel W

AU - Trivedi, Urmi

AU - Tyukmaeva, Venera I

AU - Gharbi, Karim

AU - Butlin, Roger K

AU - Hoikkala, Anneli

AU - Kankare, Maaria

AU - Ritchie, Michael G

PY - 2018/8/1

Y1 - 2018/8/1

N2 - The genomes of species that are ecological specialists will likely contain signatures of genomic adaptation to their niche. However, distinguishing genes related to ecological specialism from other sources of selection and more random changes is a challenge. Here, we describe the genome of Drosophila montana, which is the most extremely cold-adapted Drosophila species known. We use branch tests to identify genes showing accelerated divergence in contrasts between cold- and warm-adapted species and identify about 250 genes that show differences, possibly driven by a lower synonymous substitution rate in cold-adapted species. We also look for evidence of accelerated divergence between D. montana and D. virilis, a previously sequenced relative, but do not find strong evidence for divergent selection on coding sequence variation. Divergent genes are involved in a variety of functions, including cuticular and olfactory processes. Finally, we also resequenced three populations of D. montana from across its ecological and geographic range. Outlier loci were more likely to be found on the X chromosome and there was a greater than expected overlap between population outliers and those genes implicated in cold adaptation between Drosophila species, implying some continuity of selective process at these different evolutionary scales.

AB - The genomes of species that are ecological specialists will likely contain signatures of genomic adaptation to their niche. However, distinguishing genes related to ecological specialism from other sources of selection and more random changes is a challenge. Here, we describe the genome of Drosophila montana, which is the most extremely cold-adapted Drosophila species known. We use branch tests to identify genes showing accelerated divergence in contrasts between cold- and warm-adapted species and identify about 250 genes that show differences, possibly driven by a lower synonymous substitution rate in cold-adapted species. We also look for evidence of accelerated divergence between D. montana and D. virilis, a previously sequenced relative, but do not find strong evidence for divergent selection on coding sequence variation. Divergent genes are involved in a variety of functions, including cuticular and olfactory processes. Finally, we also resequenced three populations of D. montana from across its ecological and geographic range. Outlier loci were more likely to be found on the X chromosome and there was a greater than expected overlap between population outliers and those genes implicated in cold adaptation between Drosophila species, implying some continuity of selective process at these different evolutionary scales.

KW - Acclimatization

KW - Animals

KW - Cold Temperature

KW - Diapause

KW - Drosophila/classification

KW - Genome, Insect

KW - Molecular Sequence Annotation

KW - Phylogeny

U2 - 10.1093/gbe/evy147

DO - 10.1093/gbe/evy147

M3 - Article

C2 - 30010752

VL - 10

SP - 2086

EP - 2101

JO - Genome Biology and Evolution

JF - Genome Biology and Evolution

SN - 1759-6653

IS - 8

ER -