Abstract
A method of molecularly determining the sex of birds by comparing the copy number of genes specific for the Z chromosome using qPCR, carried out by isolating DNA from a male and a female of a given species and an individual of unknown sex, at least one reference autosomal gene, at least one control autosomal gene and at least one Z-specific gene are amplified by qPCR, for each sample, the threshold cycle value for each gene is estimated, the dose ratio of the target gene to the reference gene is calculated for each amplified gene, the ratio of the relative gene dose between male and female for each target gene is calculated, the Z-specificity is checked for the presumed Z -specific genes and control autosomal genes and identify the sex of an unknown sex by comparing the dose of the target gene for the Z-specific genes with the results in the male and female, using the LPAR1 gene as the Z-specific gene and the DOCK8, FUT10, PIGG and PSD3 genes in runners, in pilots, the CHRNA6, DDX4, TMEM161B and VPS13A genes.