[A simple and universal method for molecular sexing of birds].

It is difficult to sex monomorphic or juvenile birds only according to their appearance or by simple surgical techniques. However, the sex of individual bird has to be identified during breeding. Recently, a sex-linked gene, CHD1, has been discovered in non-ratite birds. Using highly conserved primers flanking the intron of CHD1 and PCR amplification, females are characterized by diaplaying two fragments(CHD1W and CHD1Z), while males only show one fragment(CHD1Z) clearly different in size from the female-specific CHD1W fragment. PCR-based molecular sexing method has been widely used due to its many merits over other techniques. In this work, we successfully sexed 86 bird from 9 species using this technique. All of these birds are listed here as the national first-grade wildlife of China for protection. Our results benefit greatly on breeding rare monomorphic birds and preventing them from distinction.