The Melanophilin knockout chicken, as a new alopecia animal model

Avian alopecia, marked by feather loss, is a significant health concern impacting various bird species in both wild and captive environments. This condition arises from multiple factors, including nutritional deficiencies, hormonal imbalances, infectious diseases, environmental stressors, and genetic predispositions. Natural mutations in the Melanophilin (Mlph) gene have been linked to color-diluted alopecia in dogs, while suppression of Rab27a, a key interactor of MLPH, disrupts hair cycle regulation and impairs hair growth in mice. In this study, we utilized an Mlph knockout (HO) chicken model, generated through the CRISPR/Cas9 technique, to report the first observed case of a color-diluted alopecic phenotype in poultry. The study reveals that while Mlph mutations do not initially affect feather quality at hatching, they lead to significant feather deterioration and alopecia-like symptoms as the chickens grow older. These findings suggest that disruption of the Mlph gene caused feather loss, contributing to the alopecic phenotype in chickens. The Mlph knockout chickens represent the first poultry genetic model for studying the link between the Mlph gene and alopecia, providing valuable insights into the pathophysiology of alopecia and facilitating research on genetic selection for this condition in poultry.