Gender identification of Himantopus himantopus using PCR-based method.

Abstract

The black-winged stilt (Himantopus himantopus: Recurvirostridae) has a wide distribution in nature. In Thailand, there are residents and migratory birds. The adult birds have very long pink legs and black wings. Crown and hindneck patterns vary from white to dusky-grey. In general, the gender can be identified by crown and hindneck color, white in female and black in male. However, in breeding season (April - June) of resident bird at Bung Boraphet where the largest freshwater swamp in central Thailand, most of their crown and hindneck are white. So, this species are not clearly sexually dimorphic and the color of their crown and hindneck are not directly correlated with sex. In this work, a molecular approach was used to assess differences in coloration of feathers in relation to gender. DNA was amplified from the chromo-helicase-DNA-binding (CHD) gene that located on both Z (CHD-Z) and W (CHD-W) chromosomes. Using FTA®card and genomic DNA which extracted from a small volume of blood samples were used in this experiment. The resulting PCR products from 2550F/2718R primer showed fragments on a conventional agarose gel electrophoresis with size differences ranging from 150 bp between the two ZW alleles. Males were identified by the presence of a single band about 650 bp (CHD-Z) and females were identified by the presence of a second additional fragment length of approximately 500 bp (CHD-W). For the resident bird included 32 white and 2 black head, female: male were 18: 16 which 2 black heads are male. On the other hand, the migratory bird included 32 white head, 12 black hindneck, 43 grey head and 5 grey crown. The migratory bird includes 37 female and 46 male. Our results showed clear evidence for a sex- related decrease in the color on the heads of black-winged stilt.