Sexing and genetic diversity in the genus Charadrius based on CHD gene

Abstract

Charadrius spp. are migratory shorebirds in Thailand during the non-breeding season inwhich adult plumages are not clearly sexually dimorphic. In this work, a molecular approach was used to determine the gender and genetic diversity. Amplification of intron length polymorphisms in chromo-helicase-DNA-binding ( CHD ) genes on both Z and W chromosomes of three Charadrius spp. included 87 lesser sand plover ( Charadrius mongolus ), 27 greater sand plover ( C. leschenaultii ) and 3 kentish plover ( C. alexandrinus ). The resulting PCR products from 2550F/2718R primer showed fragments on a conventional agarose gel electrophoresis with size differences ranging from 200 bp between the two respective ZW allele. Males were identified by the presence of a single band about 650 bp ( CHD-Z ). Heterogametic females were identified by the presence of a second additional fragment length of approximately 450 bp ( CHD-W ). The CHD-Z fragments were purified and analysed by sequencing. The multiple sequence comparison was accomplished using ClustalX and PHYLIP software. These data demonstrate that the CHD-Z sequence related with morphology and can be used for genetic diversity study. The results of molecular sex determination and genetic diversity analyses will also have implications for shorebird conservation.