The Improved Polymerase Chain Reaction Method Applied for Sex Identification of Crested Ibis, Nipponianippon

Given the necessity for increased conservation of endangered birds such as the Crested ibis, it is crucial to identify the gender of individuals from species with similar external morphologies among females(ZW) and males(ZZ) to establish a self-sustainable population for restoration of the species. Moreover, raising young chicks during the juvenile period based on sex determination encourages familiarity, which might increase mating success rates. Thus, this study was carried out to determine the sex of Crested ibis chicks using three primers designed to check their identity. A set of polymerase chain reaction(PCR) primers was used to amplify a 276 bp chromo-helicase-DNA binding protein region(CHD) on the Z chromosome in both sexes, whereas the other set was used to amplify a 169 bp female-specific CHD sequence on the W chromosome. The sequences have been submitted to NCBI(GenBank Accession Number: AB620020, AB620021). This method will enable researchers to determine the gender of Crested ibis more simply and quickly.