Application of the ubiquitin associated protein 2 gene marker for sex identification across poultry species

1. In many poultry species, the absence of pronounced sexual dimorphism or its delayed onset until adulthood complicates visual sex identification. This directly hinders effective breeding and conservation management protocols.2. Sex identification analysis of 11 poultry species was performed, based on the gene ubiquitin-associated protein 2 (UBAP2). Blood and feather samples obtained from both males and females were used for genomic DNA extraction. Subsequent PCR amplification was conducted with UBAP2 primers. The amplification outcomes were characterised using both agarose gel electrophoresis and capillary electrophoresis plots. The obtained gene fragments were sequenced to perform a phylogenetic analysis of the UBAP2 sequences across the species under study.3. The length polymorphism between UBAP2-W and UBAP2-Z homologous genes allowed clear sex discrimination by agarose gel electrophoresis in chicken, turkey, quail, chukar partridge and pheasant. However, in Muscovy duck, mule duck, goose, guinea fowl sexing was achieved using capillary electrophoresis. Duck and pigeon exhibited a single band or peak, regardless of sex.4. As sequences of species within a family were clustered together, it was predicted that those closely related to each other shared similar UBAP2 sequences. The results demonstrated that UBAP2 is an effective marker for genetic sex identification in nine poultry species.