bta-mir-129: Bta-mir-129 is a type of bovine microRNA (miRNA) that has been identified as a key regulatory factor in bovine physiology [PMC9821774]. It is involved in the regulation of IGF-1 expression, along with other miRNAs and circular RNAs [PMC9821774]. Specifically, bta-mir-129, in conjunction with novel_circ_016821, has been highlighted as a main regulatory factor influencing IGF-1 expression [PMC9821774]. The expression of bta-mir-129 is dynamic and shows variation during the estrous cycle; it was notably increased at day 7 but was not detected at day 3 [PMC4156418]. Additionally, bta-mir-129 was among the miRNAs that were up-regulated in pregnant cows but not detected across the estrous cycle, suggesting its potential role in pregnancy [PMC7969882]. The up-regulation of bta-mir-129 has also been observed in ovarian follicular fluid small extracellular vesicles (OF-sEV) from pregnant cows [PMC7969882]. Furthermore, its expression is time-dependent and part of a group of miRNAs that are overexpressed at parturition [PMC9445238], indicating its involvement in reproductive events. Overall, bta-mir-129 appears to be an important miRNA for bovine reproductive regulation and pregnancy.