Neutral genetic variability and SNPs under selection
The analysis of genetic structure with Admixture yielded a single more
plausible model that grouped all samples into a single cluster (K = 1,
cv-error = 0.382), indicating no apparent genetic structure between both
populations. Even when forcing the model towards higher values of K
(i.e. less plausible results), we still failed to find any signs of
between-populations genetic structure (K = 2, cv-error = 0.405; Figure
2).
Regarding outliers analyses, Bayescan did not detect any locus subject
to selection (q-values range: 0.883 - 0.910). The largest increase in α,
the magnitude of the locus-specific effect of selection, concentrated on
four maximum (although low) values, two of which could not be annotated
at all (Table 3). Of the other two, one could be annotated with a
marginally non-significant E-value of 0.018 (conventional significance
value = 0.01), which corresponded to the coding region of a repeated
transmembrane ankyrin involved in the cellular response to salicylic
acid (inflammatory response) and the regulation of the immune system.
The other sequence was annotated with a much higher E-value (0.6) as the
coding region of a nuclear photoreceptor protein that regulates gene
expression based on the reception of steroids (described mutations point
to impairments in the bearer’s vision). None of these SNPs presented
allelic frequencies that deviated significantly from those expected
under H-W conditions after applying the Bonferroni sequential correction
(Table 3).