Sex Identification of Black Swan (Cygnus atratus): Possible at the First Day of Hatching

The immature black swans are hardly identified by morphological characteristics. However, concise sex identification at the stage of initial growth is very important to conserve and increase their population. Here, sex of black swans was identified by using CHD genes from DNA of eggshell membranes and feathers. DNA sample was extracted using a phenol : chloroform : isoamyl alcohol (PCIA) method. Following PCR and electrophoresis, two bands were observed for females, while only one band was detected for males. It was worthy of note that two experiment results of eggshell membrane and feathers were exactly same and that accounted for possibility to identify sex in the immature, even at the first day of hatching. According to sequencing of CHD genes, the length of CHD-Z was 443 bp, while the length of CHD-W was 362 bp.