Data from: Disruption of gene expression in hybrids of the fire ants Solenopsis invicta and Solenopsis richteri

Transcriptome analysis is a powerful tool for unveiling the distribution
and magnitude of genetic incompatibilities between hybridizing taxa. The
nature of such incompatibilities is closely associated with the
evolutionary histories of the parental species and may differ across
tissues and between the sexes. In eusocial insects, the presence of castes
that experience divergent selection regimes may result in additional
distinct patterns of caste-specific hybrid incompatibilities. We analyzed
levels of expression of >14,000 genes in two life stages of each
caste and sex in the fire ants S. invicta and S. richteri and in their
hybrids. We found strong contributions of both developmental stage and
caste to gene expression patterns. Hybrid incompatibilities were
surprisingly modest: only 32 genes were mis-expressed, indicating low
levels of disruption in gene regulation in hybrids. The castes differed in
numbers of mis-expressed genes, with males and workers each mis-expressing
at least seven times as many genes as queens. Interestingly, homologues of
many of the mis-expressed genes have been implicated in behavioral
variation in Drosophila melanogaster. General expression profiles of
hybrids were more similar to those of S. richteri than S. invicta,
presumably because S. richteri trans-regulatory elements tend to be
dominant to those of S. invicta and/or because there is an overall bias in
the genetic composition of the hybrids towards S. richteri. Altogether,
our results suggest that selection acting on each caste may contribute
differently to interspecific divergence and speciation in this group of
ants.