Genomics along an inversion cline

SNIC 2018/8-15


SNAC Small

Principal Investigator:

Emma Berdan


Göteborgs universitet

Start Date:


End Date:


Primary Classification:

10615: Evolutionary Biology




Coelopa frigida is an important coastal invertebrate along the Scandinavian coastline that inhabits “wrackbeds” (accumulations of decomposing seaweed) and has an inversion polymorphism on chromosome I (spanning 10% of the genome and containing at least 100 genes) that consists of an α and β version. I have re-sequenced the genomes of individuals from 6 populations along the cline. Preliminary analysis of this data shows that α and β are highly diverged compared to collinear regions (average FST of 0.71 within the inversion compared to 0 in collinear regions), heterokaryotypes have significantly more genetic variation than homokaryotypes, and that the inversion carries more genetic variation between populations than collinear regions. Continued analyses will examine divergence between the α and β will be estimated using the Hidden Markov model approach developed by Soria-Carrasco et al. Divergence is predicted to be highest at the breakpoints then decreasing with distance creating a “suspension bridge” pattern. I will test this using Spearman’s rank correlations on 1 Mb segments moving away from the breakpoints. A clinal analysis will be conducted for all loci with a change in frequency greater than 20%. I will use regression models to estimate clinal parameters four times, separating out the location of the loci (α/β or collinear) as well as individuals genotyped (αα or ββ).