title: Sex identification of the black swan (Cygnus atratus) using the locus-specific PCR and implications for its reproduction.
abstract: Over the last 4-5 years the small captive population of black swans (Cygnus atratus) has consistently failed to reproduce at the Chengdu Research Base of Giant Panda Breeding. The probable cause was hypothesized to be an abnormal sex distribution of the population. The black swan is an example of a sexually monomorphic species. The locus-specific polymerase chain reaction (PCR) approach based on the chromo-helicase-DNA-binding 1 (CHD1) gene, was adopted for the sex determination of the black swans. For this purpose, F1, F2 and R primers were designed using the primerselect software for amplification of the CHD1 gene region. DNA agarose gel electrophoresis showed that the female control displayed two bands, whereas only a single band was found in the male control. Sequence analyses of all seven unknown sex black swans demonstrated the sex-specific DNA band for female. Therefore, it was inferred that all the individuals of the black swan population are females, which has resulted in unfertilized eggs and reproduction failure. This method can be extended to the sexing of other monomorphic avian species and will assist in the design of breeding projects.
authors.affiliation: College of Life Sciences, Key Laboratory of Conservation Genetics and Reproductive Biology for Endangered Wild Animals, Ministry of Education and State Conservation Center for Gene Resources of Endangered Wildlife, Zhejiang University, Hangzhou, China.
authors.forename: P-J
authors.initials: PJ
authors.lastname: He
authors.forename: J-Q
authors.initials: JQ
authors.lastname: Yu
authors.forename: S-G
authors.initials: SG
authors.lastname: Fang
mesh_terms: D000818:Animals; D046090:Anseriformes / Q000235:genetics*; D030161:Avian Proteins; D001483:Base Sequence; D004247:DNA / Q000032:analysis / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000235:genetics; D004587:Electrophoresis, Agar Gel; D005260:Female; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012098:Reproduction; D012732:Sex Determination Analysis / Q000379:methods / Q000662:veterinary*
chemical_list: D030161:Avian Proteins; C489845:CHD-W protein, Gallus gallus; D004268:DNA-Binding Proteins; D004247:DNA