Insights into the genetic basis of bilateral head asymmetry in a scale-eating cichlid fish.

ABSTRACT: Almost all animals are bilaterally symmetrical, and only rarely is this universality broken and maintained as a stable polymorphism. One such case is Perissodus microlepis, a scale-eating cichlid fish endemic to Lake Tanganyika. This species is polymorphic with left- or right-headed morphs, each specialized for scraping scales from the opposite side of their prey. This polymorphism is stably maintained around a 50:50 ratio and is likely driven by negative frequency-dependent selection, a classic form of balancing selection. Using a genome-wide dataset, including a de novo haplotype-resolved reference genome, whole-genome sequences, and microcomputed tomography scans of 102 individuals, we identified 72 genetic loci linked to head asymmetry. Nearby genes are enriched for roles in sym

SUBMITTER: Tian X 

PROVIDER: S-EPMC12309687 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature