Molecular sexing of birds
The absence of sexual dimorfism in the majority of birds, specially exotic species, or the appearence of said dimorfism only at adult stages, makes it necessary to use alternative methods to determine without mistake the sex of the animal at any stage of development.
Birds, unlike mammals, show heterogametic sex in females, as shown by the pair of chromosomes ZW. Males, on the other hand, have homogametic sex represented by chromosomes ZZ. Based on these differences and the presence of a gene (chd)of the W chromosome, a technique has been developed to determine the sex of the bird. It is based on the analysis of a DNA fragment of the chd gene by PCR (Polymerase Chain Reaction) and the resolution on an agarose gel by elecrophoresis.
The advantages of this molecular method compared to other physical or surgical methods are the following:
- · Reliability: It is an objective method that is not based on external characters.
- · Safety: It is a non invasive method that bears no harm whatsoever to the animal.
- · Speed: We obtain the results in a few days