Ovalbumin, lysozyme, and ovomucoid gene polymorphisms: Implications for hatchability in Japanese quail

This study aimed to evaluate the associations between polymorphisms in genes encoding the main albumen proteins (lysozyme, ovomucoid, and ovalbumin) and hatchability traits in Japanese quail (Coturnix japonica). The experiment involved 118 females of the F33 meat-type line, which were divided into groups with high and low hatchability. Grouping was based on hatch of set (HOS) measured in the present experiment. Eggs from each female were incubated under standardized conditions. Reproductive performance parameters were assessed, including fertility, hatch of set eggs, hatch of fertile eggs, high-quality chicks percentage, and embryo mortality during the early (days 1-14) and late (days 15-18) incubation periods. All exons of the analyzed genes were sequenced, leading to the identification of thirty-seven single nucleotide polymorphisms and one insertion-deletion. Significant associations between polymorphisms and reproductive traits were observed mainly in the high-hatchability group. In the lysozyme gene, five SNPs were associated with fertility (p = 0.011-0.030), hatch of set eggs (p = 0.019-0.036), and the high-quality chicks percentage (p = 0.035-0.047). In the ovomucoid gene, four variants were found to influence fertility (p = 0.001-0.030), hatch of set (p = 0.005-0.039), and the high-quality chicks percentage (p = 0.0001-0.039), whereas in the group with low hatchability, only one variant showed a significant association (p = 0.039). In the ovalbumin gene, polymorphisms located within the 3' untranslated region (3' UTR) were related to embryo mortality during both the early and late stages of incubation (p = 0.009-0.021). Diplotype analysis confirmed the influence of haplotype combinations within the lysozyme and ovomucoid genes on fertility and hatchability traits (p = 0.001-0.036). These findings suggest that genetic variation in the genes encoding the main albumen proteins may influence reproductive performance and embryo survival in Japanese quail. The lysozyme, ovomucoid, and ovalbumin genes could serve as potential molecular markers in breeding programs aimed at improving fertility and hatchability in poultry.