O gene asip e a coloração da pelagem de jumentos da raça pêga.

Abstract

Donkeys (Equus asinus) were domesticated in Africa and introduced to Brazil during the colonial period, giving rise to the Pêga breed, recognized for its morphofunctional qualities, hardiness, and broad diversity of coat colors—a trait valued for both its aesthetic appeal and adaptive potential. Among the genes involved in coat color determination, the ASIP gene stands out, as it regulates the synthesis of eumelanin (dark pigment) and pheomelanin (light pigment), being the second most important gene in pigmentation in mammals. In this context, the objective of this study was to characterize the ASIP gene and investigate its relationship with coat color patterns in the Pêga breed. Nineteen coat color variations were evaluated in animals registered with the Brazilian Association of Pêga Donkey Breeders (ABCJPêga). DNA was extracted from tail hair follicles, followed by amplification of the three ASIP exons by PCR and sequencing. The sequences obtained were aligned using CodonCode Aligner and compared to the reference genome (NCBI NC_052191.1). For the previously reported SNP, c.349T>C, all animals showed the T/T genotype, confirming the presence of the Light Points (LP) phenotype. This is consistent with Pêga donkey coat patterns that exhibit light areas on the muzzle and belly, regardless of the overall coat color. No other variants were identified in the analyzed exons, suggesting that ASIP is not involved in the tonal differences observed in the breed. These findings indicate that coat color in Pêga donkeys is regulated by yet unknown genetic mechanisms and highlight the need for studies involving new candidate genes and broader genomic approaches to better understand the genetic architecture of this complex trait