Data from: Hybrid incompatibility between D. virilis and D. lumei is stronger in the presence of transposable elements

Mismatches between parental genomes in selfish elements are frequently
hypothesized to underlie hybrid dysfunction and drive speciation. However,
because the genetic basis of most hybrid incompatibilities is unknown,
testing the contribution of selfish elements to reproductive isolation is
difficult. Here we evaluated the role of transposable elements (TEs) in
hybrid incompatibilities between Drosophila virilis and D. lummei by
experimentally comparing hybrid incompatibility in a cross where active
TEs are present in D. virilis (TE+) and absent in D. lummei, to a cross
where these TEs are absent from both D. virilis (TE-) and D. lummei
genotypes. Using genomic data, we confirmed copy number differences in TEs
between the D. virilis (TE+) strain and the D. virilis (TE-) strain and D.
lummei. We observed F1 postzygotic reproductive isolation exclusively in
the interspecific cross involving TE+ D. virilis but not in the cross
involving TE- D. virilis. This precisely mirrors the intraspecies dysgenic
phenotype where teste atrophy only occurs when TE+ D. virilis is the
paternal parent. A series of backcross experiments, designed to account
for alternative models of hybrid incompatibility, showed that both F1
hybrid incompatibility and intrastrain dysgenesis is consistent with the
action of TEs rather than other, genic, interactions. A further Y-autosome
interaction contributes to additional, sex-specific, inviability in one
direction of this cross combination. These experiments demonstrate that
TEs that cause intraspecies dysgenesis can increase reproductive isolation
between closely related lineages, thereby adding to the processes that
consolidate speciation.