Genetic basis of male colour dimorphism in a Lake Tanganyika cichlid fish

Takahashi, T. , Sota, T., Hori, M.,
Molecular Ecology
Volume 22, Issue 11, June 2013, Pages 3049-3060

Phenotypic polymorphisms can be applied to study the micro-evolutionary forces that maintain genetic variation and can mediate speciation, but it can be difficult to determine the genetic basis of polymorphisms. Recently, restriction-site-associated DNA (RAD) sequencing has become popular, which can easily produce multiple single nucleotide polymorphisms from whole genomes. Here, we combined RAD sequencing, allele-specific PCR and Sanger sequencing to determine the genetic basis underlying male colour dimorphism of a Lake Tanganyika cichlid fish, Cyprichromis leptosoma. Our analyses using both a cross-family (two parents and 12 F2 males) and 64 wild individuals do not contradict a hypothesis that two alleles of one-locus control male colour dimorphism. Also, the locus may be located on a genome region that experiences reduced levels of recombination. Although more analyses will be needed to conclude these findings, this study is the first to suggest the genetic basis of a colour polymorphism using

Marta

To jedna z konkluzji dotycząca ubarwienia ogona u badanych cyprichromisów:

"The yellow-tailed males have blue colours on the dor-sal part of body and the dorsal and anal fins, and the blue-tailed males have yellow colour on the pectoral fins (Fig. 1). These facts suggest that the colour dimorphism on caudal fin is not attributed to the presence/absence of ability to produce chromatophores (e.g. xanthophores or iridophores), but to the difference in
pigment pattern development. One or a few genes mayhave regulated the pigment pattern like zebra fish (e.g.Inaba et al. 2012)"

Marta