Pigmentation genes
We also assessed the presence of non-synonymous mutations in genes associated to changes in wing pigmentation patterns such ascortex , Wnt and optix . While no amino acid changing mutations were found in the exonic regions of these genes, we detected two fixed intronic variants in Xerces Blue not found in the Silvery Blue: the first is a T to A change in the gene Wnt4 , corresponding to an intronic/downstream variant (FR990046.1: 19485537) and the second is an intronic A to T change in the Wnt11 gene (FR990050.1: 16205523). Although Wnt4 and Wnt11 genes are not known to be involved in butterfly wing colour pattern (13), it can hypothesized that those two variants can be involved in changes at regulatory elements affecting phenotypical differences between both species.