Publication
Genomic consequences of domestication of the Siamese fighting fish
Publisher:
Cold Spring Harbor Laboratory
Date:
30-04-2021
DOI:
10.1101/2021.04.29.442030
Abstract: Siamese fighting fish, commonly known as betta, are among the world’s most popular and morphologically erse pet fish, but the genetic processes leading to their domestication and phenotypic ersification are largely unknown. We assembled de novo the genome of a wild Betta splendens and whole-genome sequenced multiple in iduals across five species within the B. splendens species complex, including wild populations and domesticated ornamental betta. Given our estimate of the mutation rate from pedigrees, our analyses suggest that betta were domesticated at least 1,000 years ago, centuries earlier than previously thought. Ornamental betta in iduals have variable contributions from other Betta species and have also introgressed into wild populations of those species. We identify dmrt1 as the main sex determination gene in ornamental betta but not in wild B. splendens , and find evidence for recent directional selection at the X-allele of the locus. Furthermore, we find genes with signatures of recent, strong selection that have large effects on color in specific parts of the body, or the shape of in idual fins, and are almost all unlinked. Our results demonstrate how simple genetic architectures paired with anatomical modularity can lead to vast phenotypic ersity generated during animal domestication, and set the stage for using betta as a modern system for evolutionary genetics. Genomic analyses reveal betta fish were domesticated more than 1,000 years ago and the genes that changed in the process.