A Functional 67-bp Duplication Locating at the Core Promoter Region within the Bovine ADIPOQ Gene Is Associated with Ovarian Traits and mRNA Expression

<i>ADIPOQ</i> plays a crucial role in regulating the reproductive system, but there are few reports on the effects of <i>ADIPOQ</i> on ovarian in dairy cows. Previous studies have verified the presence of a 67-bp mutation in the promoter region of the <i>ADIPOQ</i> gene. Hence, we employed ovarian tissues <i>(n</i> = 2111) and blood samples (<i>n</i> = 108) from Chinese Holstein cows as experimental samples to examine the association between <i>ADIPOQ</i> promoter variants and ovarian traits. We extracted DNA from these samples and conducted genetic typing identification on each sample using advanced techniques like PCR and agarose gel electrophoresis. Consequently, the DD, ID, and II genotypes were discovered. and it has been observed that the mutation frequency of this locus is low in the Chinese Holstein cow. Importantly, the correlational analysis unveiled a significant relationship (<i>p</i> < 0.05) between the weight of ovaries in late estrus and the width of ovaries during the estrus interval with the mutation. Result of the RT-PCR revealed that the ID genotype partially diminished the expression of the <i>ADIPOQ</i> gene. The results of this study suggest that the identified variable duplication could serve as a potential genetic marker for enhancing the ovarian traits of Chinese Holstein cows.