Backman, Natalia; Bell, Mckenzie; Gostick, Anthony; Kiggins, Kendrick; Koller, Christopher; Naylor, Emily; Porter, Tyrel; Rawlings, Bree; Domyan, Eric, Ph.D (Utah Valley University)
Faculty Advisor: Domyan, Eric (Utah Valley University, Biology/Biotechnology)
The domesticated rock pigeon has been the subject of selective breeding for hounds of years and so displays an immense variety of phenotypes. This variety provides opportunities to further understand the genetic basis of phenotypic evolution. Pigmentation of pigeon feathers is controlled by multiple alleles at different loci, which influences the type and amount of melanin deposited in the feathers. A specific phenotype, known as "recessive red", consists of distinctly red plumage and is caused by a mutation that greatly reduces the expression of the gene Sox10. This gene encodes a transcription factor, known to play a key role in melanocyte maturation and proliferation. Sox10 likely regulates the transcription of multiple downstream genes but the identities of these genes are largely unknown. To identify downstream targets of Sox10, we compared the transcriptomes of regenerating feathers from wild-type and recessive red birds to identify genes that had different expression levels between the two groups. We identified 46 genes that are expressed at different levels between wild-type and recessive red birds, and thus are potential targets of Sox101.
While several of the target genes have known roles in pigmentation, the role that many of the targets play in pigmentation has not been studied, making them interesting candidates for further investigation. Using CRISPR-Cas9, we introduced mutations in candidate genes that were chosen because of their unusually low expression in recessive red birds due to the mutation of Sox10. By observing the effects of the mutated genes, we can determine their roles in pigmentation. The genes that we are mutagenizing in our research is Tbx2, Arsg, and Abcb5 to see if they play a role in the melanin synthesis pathway.