Data from: An intronic transposon insertion associates with a trans-species color polymorphism in Midas cichlid fishes

<p><span><span><span><span><span><span><span><span><span><span><span>Polymorphisms have fascinated biologists for a long time, but their genetic underpinnings often remained elusive. Here, we aimed to uncover the genetic basis of the gold/dark polymorphism that is eponymous of Midas cichlid fish (<i>Amphilophus </i>spp.) adaptive radiations in Nicaraguan crater lakes. While most Midas cichlids are of the melanic "dark morph", about 10% of individuals lose their melanic pigmentation during their ontogeny and transition into a conspicuous "gold morph". Using a new haplotype-resolved long-read assembly we discovered an 8.2kb, transposon-derived inverted repeat in an intron of an undescribed gene, which we term <i>goldentouch</i> in reference to the Greek myth of King Midas. The gene <i>goldentouch</i> is differentially expressed between morphs, likely due to structural implications of inverted repeats in both DNA and RNA (cruciform and hairpin formation). The near-perfect association with the phenotype across several independent populations suggests that this insertion likely underlies this trans-specific, stable polymorphism.</span></span></span></span></span></span></span></span></span></span></span></p>