Mérot C, Berdan E, Cayuela H, Djambazian H, Ferchaud AL, Laporte M, Normandeau E, Ragoussis J, Wellenreuther M, Bernatchez L.
Mol Biol Evol. 2021 May 7:msab143. doi:10.1093/molbev/msab143
Locally adaptive inversions modulate genetic variation at different geographic scales in a seaweed fly.
“We sampled the seaweed fly Coelopa frigida along a bioclimatic gradient stretching across 10° of latitude, a salinity gradient and a range of heterogeneous, patchy habitats. We generated a chromosome-level genome assembly to analyse 1,446 low-coverage whole genomes collected along those gradients.“ “Analyses of more than 1,400 whole genomes of C. frigida flies revealed four large chromosomal inversions affecting a large fraction of the genome (36.1Mb, 15%), and three low recombining genomic regions.” “Among the 124,701 candidate SNPs identified by the GWAS, more than 99.8% were located in Cf-Inv(1)” “At a finer geographic scale, outlier SNPs associated with wrackbed abiotic characteristics (depth, temperature and salinity) were strongly enriched in the inverted region Cf-Inv(1) with an odds ratio of 5, including outliers with very strong support”