A fast molecular tool for sexing Gibber Italicus, song thrush, and redwing birds

Gibber Italicus, song thrush (Turdus philomelus), and redwing (Turdus iliacus) are 3 bird species in which sexual dimorphism is not readily apparent. Therefore, molecular sexing is a valuable tool for breeding, selection, and conservation purposes. We compared DNA extraction by commercial kit and an alkaline method from feathers, then developed a molecular method for sexing these species using the P2/P8 and CHD1F/CHD1R primer pairs. Both protocols were successful in extracting DNA; the alkaline method is more cost-effective, whereas the commercial kit protocol is easier to standardize. All DNA samples were successfully amplified using both the P2/P8 and CHD1F/1R primer pairs. The use of the CHD1F/1R primer pair is notably advantageous as it produces fragments of different lengths of the sex chromosomes, making them easily distinguishable via electrophoresis. The sequence analysis of the amplicons obtained with the CHD1F/1R primer pair revealed specific single-nucleotide polymorphisms for song thrush and redwing, which could be used as markers to differentiate between the 2 species if required.