Cross-Species Validation of Pigeon-Specific CHD1 Primers for Molecular Sexing in Pet Birds

Young and adult birds of a large number of species are sexually monomorphic. The development of molecular methodologies for sexing birds has overcome these difficulties, allowing reliable sex differentiation. An important gene in sex determination across a variety of bird species is the CHD1 gene, which encodes Chromodomain-helicase DNA binding protein-1 and is located on the avian Z and W chromosomes. The aim of the study is to evaluate the cross-species performance of pigeon-specific CHD1 primers in identifying the molecular sex of birds from five different families, alongside the universal CHD1F/CHD1R primers. The samples were collected from birds of different ages from five different families (Psittaculidae, Psittacidae, Columbidae, Fringillidae, and Phasianidae). Using universal primer sets, the PCR products that were electrophoresed in agarose gel revealed an average size of 510 pb for the CHD1 gene on the Z chromosome, while females had two bands with one of 330 pb for the CHD1 gene on the W chromosome. When pigeon primers were used, the PCR products showed a single band of an size average of 470 pb for males, and two bands in females, with one of them measuring 320 pb. Even though there were small variations in fragment sizes resulting from species-specific intronic differences, these preliminary findings suggest that pigeon CHD1 primers can be used for sexing birds of professional interest with minimally invasive sample collection.