The Crest Phenotype in Domestic Chicken Is Caused by a 195 bp Duplication in the Intron of HOXC10

The study determined that the crest phenotype in domestic chickens was caused by a 195 bp duplication in the intron of the HOXC10 gene on chromosome 33. This mutation led to ectopic expression of HOXC genes in the cranial skin, resulting in the development of larger crest feathers. The duplication was present in all crested chickens across multiple breeds and absent in non-crested chickens, indicating its necessity for crest development. The research involved whole-genome sequencing and identified three alleles associated with the duplication. The study suggested that the duplication might function as a regulatory element, influencing gene expression and potentially altering chromatin structure. Further studies were recommended to explore the functional significance of these genetic variations.