Meeting Abstract

42-6  Friday, Jan. 5 09:15 - 09:30  Blue fish, yellow fish, same fish: The epigenetic regulation of endothelin signalling contributes to yellow and blue coloration of male A. burtoni color morphs ALVARADO, SG*; BASHIER , R; BYRNE, A; BLAKKAN, D; LEE, G; FERNALD, RD; Stanford University, Palo Alto; Stanford University, Palo Alto; Stanford University, Palo Alto; Stanford University, Palo Alto; Stanford University, Palo Alto; Stanford University, Palo Alto salvarad@stanford.edu https://sebcredible.wordpress.com/

Dynamic coloration is an important trait across the animal kingdom as it aids in concealment and social communication. In cichlid fish, body coloration is a particularly important trait that has driven sexual selection between conspicuously colored males and cryptic females. In males of Astatotilapia burtoni fish can be one of two reversible color morphs that are accompanied with different social outcomes . While many reports provide support for the role of genetics in developmental coloration, little remains known about how such static substrates become plastic in response to various environmental stimuli. Epigenetic mechanisms, such as DNA methylation, provide dynamic substrates capable of altering gene function. DNA methylation involves transcriptional silencing through the covalent addition of a methyl moiety to cytosine residues in the promoter of a gene. Here, we provide evidence supporting the role of DNA methylation in regulating color changes in A. burtoni males. We measured molecular changes to transcription and DNA methylation in candidate regulators of pigmentation in male A. burtoni transitioning between color morphs. Following this screen we revealed reversible DNA methylation at a single CpG dinucleotide within endothelin receptor B (EdnRB). Pharmacological manipulation of EDNRB resulted in a cell-specific aggregation of yellow chromatophores in fish fin tissue. Taken together, we provide support suggesting that DNA methylation tunes coloration within A. burtoni by sensitizing yellow chromatophores to endogenous endothelins.