Fertility-Associated Polymorphism within Bovine ITGβ5 and Its Significant Correlations with Ovarian and Luteal Traits

SIMPLE SUMMARY: The fertility of bovines is essential for cattle husbandry. ITGβ5, which is suggested to be closely related to fertility, is known to mediate cell adhesion and affect a variety of cellular activities. To investigate the relationship between the ITGβ5 gene and the fertility of bovines, 696 ovarian samples were collected and six potential indel (insertion/deletion) within ITGβ5 were analysed, from which a deletion mutation was found to be polymorphic. The genotype frequency and allele frequency of this locus in the investigated population were calculated and the population genetic parameters analyzed. In addition, this locus was found to be significantly correlated with ovarian width and corpus luteum diameter. Considering the importance of ovary and corpus luteum in reproduction, it is tempting to speculate the crucial effects of ITGβ5 on bovine fertility, which still need further validation. The results of our study might provide a theoretical basis for future breeding to enhance bovine reproduction. ABSTRACT: There is an urgent need to improve bovine fertility, and molecular marker-assisted selection (MAS) can accelerate this process. Genome-wide association studies suggest that Integrin β5 (ITGβ5) might affect fertility in bovines. As a member of the integrins family, ITGβ5 can bind to the extracellular matrix and mediate various cellular processes. In our study, primers spanning six potential insertion/deletion (indel) polymorphisms within the ITGβ5 gene were designed and 696 ovary samples from different individuals, the vast majority not in oestrum were collected for genetic variation detection. A deletion locus, rs522759246, namely P1-D(13-bp), was found to be polymorphic. The allele D frequency was 0.152 and the polymorphism information content (PIC) value was 0.224, indicating a low-degree PIC. This locus did not follow the Hardy–Weinberg equilibrium (p = 1.200E-23). Importantly, associations between P1-D(13-bp) and ovarian morphological traits were established. Polymorphisms of this locus had significant correlations with ovarian width (p = 0.015). The corpus luteum is also linked to fertility and P1-D(13-bp) was significantly correlated with corpus luteum diameter (p = 0.005). In conclusion, an indel mutation within the bovine ITGβ5 gene was identified, which was significantly associated with several ovarian and luteal traits.