Characterization of microRNA profiles in the mammary gland tissue of dairy goats at the late lactation, dry period and late gestation stages
The mammary gland redeveloped to the pre-pregnancy state during involution, which shows that the mammary cells have the characteristics of remodeling. The rapidity and degree of mammary gland involution are different between mice and dairy livestock (dairy cows and dairy goats). However, the molecular genetic mechanism of miRNA in involution and remodeling of goat mammary gland has not yet been clarified. Therefore, this study carried out the RNA-sequencing of nonlactating mammary gland tissue of dairy goats in order to reveal the transcriptome characteristics of miRNA in nonlactating mammary tissues and clarify the molecular genetic mechanism of miRNA in mammary cell involution and remodeling. Overall design: This research used nine healthy, disease-free Laoshan dairy goats raised at the Qingdao Aote goat breeding farm (Qingdao, Shandong, China). The goats were provided with the farm's standard feeding and management environment. All goats were of third parity, and their average age was four years. Mammary gland tissues were collected during late lactation (LL) (n = 3, 240 d postpartum), the dry period (DP) (n = 3, 300 d postpartum), and late gestation (LG) (n = 3, 140 d after mating). And high-throughput transcriptome sequencing was conducted on these samples.