Researchers pinpoint the gene behind white earlobes in Mediterranean chickens
Scientists have identified the genetic basis for white earlobe color in Mediterranean chicken breeds, narrowing in on the MC1R gene through whole-genome analysis. The finding could improve selective breeding programs and demonstrates a novel poultry application for a gene previously known only for skin and hair pigmentation in humans and other animals.
Originaltitel: Whole-genome selective sweep analyses identifies the region and candidate gene associated with white earlobe color in Mediterranean chickens
<p>We compared the genomes of multiple domestic chicken breeds with red and white earlobes to identify the differentiated regions between groups of breeds differing in earlobe color. This was done using a selective sweep mapping approach based on whole-genome sequence data. The most significant selective sweep was identified on chromosome 11, where the white earlobe chicken breeds originated from Mediterranean share a common haplotype, and where multiple candidate genes are located. The most plausible functional candidate gene is the Melanocor-tin 1 Receptor (MC1R), a receptor known to regulate pigmentation in the skin and hair, and it is also the gene with the strongest positional support from the haplotype-based analyses. It, however, still needs to be explored experimentally to identify effects also on chicken earlobe color variation. Our study is the first exploration of the genetic basis of white earlobe color in Mediterranean chickens using a selective sweep mapping method based on whole-genome sequencing data and shows its value for identifying likely func-tional genes mediating the pigmentation in earlobe. It also indicates a potential novel role of MC1R in birds and exemplifies how selection on fancy traits has influenced the genome during formation of the modern chicken breeds.</p>