Discrimination of PCR products by colour and size improves the accuracy of sex-typing in avian species

Gender determination of endangered birds with no sexual dimorphism is needed in captive-breeding and conservation projects. Several molecular approaches have been developed, focusing on different species. In this study, we successfully tested a protocol for sex identification, based on the amplification of fluorescently labeled products in 63 species listed in the Convention of Washington (CITES) Appendix I, and belonging to Psittaciformes, Accipitriformes, Falconiformes, Strigiformes, Pelecaniformes, Ciconiiformes, Gruiformes, Passeriformes, and Sphenisciformes. We designed a multiplexed PCR that produces a single amplicon in males and two distinct amplicons, respectively coloured in blue and green, in females. This procedure generates digitally coloured electropherograms that yield a reliable and quick sexing.