Quantitative trait loci underlying a speciation phenotype

Abstract

Sexual signalling traits and their associated genetic components play a crucial role in the speciation process, as divergence in these traits can contribute to sexual isolation. Despite their importance, our understanding of the genetic basis of variable sexual signalling traits linked to speciation remains limited. In this study, we present new genetic evidence of Quantitative Trait Loci (QTL) underlying divergent sexual signalling behaviour, specifically pulse rate, in the Hawaiian cricket Laupala. By performing RNA sequencing on the brain and central nervous system of the parental species, we annotate these QTL regions and identify candidate genes associated with pulse rate. Our findings provide insights into the genetic processes driving reproductive isolation during speciation, with implications for understanding the mechanisms underlying species diversity.

The biogeographic and evolutionary processes shaping population divergence in Laupala

“…In Laupala, rapid speciation has been accompanied by divergences in a number of speciation phenotypes, most conspicuously the male mating song (Mendelson & Shaw, 2005). Several genomic regions are known to be involved in song divergence (Blankers et al, 2019;Shaw et al, 2007;Waller et al, 2023), harbouring small-effect alleles that accumulate in confined genomic regions during the process of speciation; moreover, the same genomic regions are involved in multiple independent species divergences (Blankers et al, 2019;Wiley et al, 2012;Xu & Shaw, 2021) and close physical linkage couples male song and female song preference loci (Shaw & Lesnick, 2009;Xu & Shaw, 2019. The present study revealed, in the most recently diverged population pairs of L. cerasina, a significant negative correlation between genetic differentiation/divergence and distance of mating song rhythm QTL known to underlie species differences.…”