Abstract
AbstractPolymorphisms have fascinated biologists for a long time, but their genetic underpinnings often remain elusive. Here, we aim to uncover the genetic basis of the gold/dark polymorphism that is eponymous of Midas cichlid fish (Amphilophus 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 discover an 8.2 kb, transposon-derived inverted repeat in an intron of an undescribed gene, which we term goldentouch in reference to the Greek myth of King Midas. The gene goldentouch is differentially expressed between morphs, presumably due to structural implications of inverted repeats in both DNA and/or RNA (cruciform and hairpin formation). The near-perfect association of the insertion with the phenotype across independent populations suggests that it likely underlies this trans-specific, stable polymorphism.
Publisher
Springer Science and Business Media LLC
Subject
General Physics and Astronomy,General Biochemistry, Genetics and Molecular Biology,General Chemistry,Multidisciplinary
Reference43 articles.
1. Ford, E. B. in The New Systematics. (ed. Julian Huxley) 493–513 (Clarendon Press, 1940).
2. Jamie, G. A. & Meier, J. I. The persistence of polymorphisms across species radiations. Trends Ecol. Evol. 35, 795–808 (2020).
3. Barlow, G. W. Competition between color morphs of the polychromatic Midas Cichlid Cichlasoma citrinellum. Science 179, 806–807 (1973).
4. Barlow, G. W. in Investigations of the ichthyofauna of Nicaraguan lakes (ed. Thomas B. Thorson) Ch. 23, 333–358 (University of Nebraska-Lincoln, 1976).
5. Kautt, A. F. et al. Contrasting signatures of genomic divergence during sympatric speciation. Nature 588, 106–111 (2020).