Genetic Architecture of Conspicuous Red Ornaments in Female Threespine Stickleback

• Published in: G3 : genes - genomes - genetics Vol. 6; no. 3; pp. 579 - 588
• Main Authors: Yong, Lengxob, Peichel, Catherine L, McKinnon, Jeffrey S
• Format: Journal Article
• Language: English
• Published: United States Genetics Society of America 01.03.2016; Oxford University Press
• Subjects: Animals; Biological Evolution; Chromosome Mapping; Crosses, Genetic; Female; female ornaments; Gasterosteus aculeatus; Genetic Association Studies; Genetic Linkage; Genome-Wide Association Study; Genotype; Investigations; Male; Phenotype; Pigmentation; QTL mapping; Quantitative Trait Loci; Quantitative Trait, Heritable; red nuptial coloration; sexual dimorphism; Smegmamorpha - genetics; female ornaments; red nuptial coloration; Gasterosteus aculeatus; sexual dimorphism; QTL mapping
• ISSN: 2160-1836; 2160-1836
• DOI: 10.1534/g3.115.024505

Explaining the presence of conspicuous female ornaments that take the form of male-typical traits has been a longstanding challenge in evolutionary biology. Such female ornaments have been proposed to evolve via both adaptive and nonadaptive evolutionary processes. Determining the genetic underpinnings of female ornaments is important for elucidating the mechanisms by which such female traits arise and persist in natural populations, but detailed information about their genetic basis is still scarce. In this study, we investigated the genetic architecture of two ornaments, the orange-red throat and pelvic spine, in the threespine stickleback (Gasterosteus aculeatus). Throat coloration is male-specific in ancestral marine populations but has evolved in females in some derived stream populations, whereas sexual dimorphism in pelvic spine coloration is variable among populations. We find that ornaments share a common genetic architecture between the sexes. At least three independent genomic regions contribute to red throat coloration, and harbor candidate genes related to pigment production and pigment cell differentiation. One of these regions is also associated with spine coloration, indicating that both ornaments might be mediated partly via pleiotropic genetic mechanisms.