Sexage et phylogénie, à partir des gènes CHD (-Z et -W) et COX-1, des oiseaux de proie du Québec et de perroquets d’attrait vétérinaire
Knowing the sex of a bird is important for many disciplines, notably for veterinary, ecological and evolutionary studies, not to mention for bird breeders who need to form pairs for reproduction. For many species of birds, juveniles and adults do not display a sexual dimorphism. The use of DNA, derived from a sample of blood, muscle, feathers or feces, is a rapid method to determine a bird’s sex. However, this method must be validated for each species, and ideally, standardised. The first objective of this work was to develop a method of sexing birds by sequencing portions of their CHD gene, for birds of prey and parrots seen in veterinary clinics in Quebec. A second objective was to identify the species being sexed, first of all using the mitochondrial gene COX-1, and second of all using the CHD-Z and CHD-W sequences used for sexing. The third objective of these studies was to evaluate the sequences obtained (CHD-Z, CHD-W and COX-1) for performing phylogenetic studies. DNA was extracted from 27 species of parrots, 34 species of birds of prey, from one species of crow (Corvus brachyrhynchos) and from the chicken (Gallus gallus). A PCR amplification was performed for partial exons 23 and 24 of the CHD gene. Sequencing this amplicon resulted in simple CHD-Z sequences for a male and overlapping CHD-Z and CHD-W sequences for a female, allowing sexing of the bird. In order to obtain distinct CHD-W sequences, a sub-cloning was performed for females of each species. In this fashion, partial sequences of the CHD gene, both -Z and –W, were generated for the species studied. A phylogenetic study was performed using COX-1, CHD-Z and CHD-W sequences and the site “Clustal-Omega”. The method of sexing birds by sequencing was found to be standard and efficient. The COX-1 gene permitted a better resolution of closely related species, while the CHD-Z gene was the most useful for estimating deep phylogenetic relationships.
CHD-Z CHD-W COX-1 Birds Sexing Avian