Fig. 1 – Phylogeny of MCHR1 and MCHR1-like
Depicted here is the sequence-level variation found between tawny owl colour morphs in MCHR1 loci and the respective phylogenetic contextualization which suggests a duplication event prior to speciation and a putative role of MCHR1-like as a pseudogene. We focused the alignments on the regions where tawny owl’s colour-specific SNPs were detected.
Fig. 2Single and combined effect of GWAS identified genotypes on tawny owl coloration
The multiple GWAS approaches detected 2 loci significantly associated with colour phenotypes. Here we show their effect size via the percentage of individuals with genotype combinations of candidate loci for each morph. We did it for individual locus (outside the Punnett square diagram) and for combination of loci (Punnett square). Note that “N” represents the number of individuals carrying each respective genotype and/or genotype combinations. The genomic landscape on which candidate loci was found in the tawny owl genome (shown by a thin red bar) is depicted parallel to Punnett’s square axis. Yellow polygons represent exons and blue polygons introns as predicted by the annotation tool. Below the Punnett square diagram, we present the orthology of the β-keratin (BISK1)-FTCD-CO6A2 region across bird genomes, whose accession number can be consulted in the supplemental information document.
Fig. 3 – Hypothetical framework to investigate the molecular basis of melanin-associated phenotypes
In this figure we attempt to propose research directions to investigate whether the molecular basis of melanin-associated phenotypes is linked to structural variation, as our results suggest, driven by regulatory mechanisms of a conserved gene region, such as the differential gene expression found in barn owls, or epigenetic mechanisms yet to be found. We further explained our next research avenues in the tawny owl system specifically focused on the findings of this work (depicted with stars).