Evaluation of methods for molecular sex-typing of three heron species from different DNA sources

Abstract

Genetic markers are a useful tool for bird population monitoring, especially when combined with ringing data, and particularlyso in vulnerable species. This study compared the effectiveness of two DNA extraction methods: a standard protocol and a commerciallyavailable kit. The molecular sex-typing was performed using PCR-based methods with a 2550F/2718R set of primers in three species ofherons: Great Egret, Purple Heron, and Grey Heron. Genomic DNA was isolated from feathers, eggshells, and eggshell swabs from 26individuals. Overall, better DNA yields and purity were obtained by using the standard protocol isolation method. The highest DNAyield was obtained from the pin feathers compared to the contour feathers and eggshells, both of which had lower yields. Eggshellswabs indicated possible contamination with parental/sibling DNA. Our evaluation demonstrates that the optimization of laboratoryprocedures is beneficial, particularly when different types of noninvasive tissue samples are available.