Small RNA deep sequencing reveals roles of microRNAs in ovine mammary gland development during peak-lactation and non-lactating periods

MicroRNAs (miRNAs) are small non-coding RNAs that have been shown to be involved in mammary gland (MG) development and lactation in some livestock animals. However, little is known about roles of miRNAs in ovine MG development including peak-lactation and non-lactating periods. In this study, expression profiles of miRNAs of the MG of peak-lactation and non-lactating in Small-Tailed Han sheep were investigated using Illumina/Solexa high-throughput sequencing technology. These results suggest that miRNAs may play important roles in ovine MG development during peak-lactation and non-lactating periods, and these miRNAs could provide an in-depth understanding of the molecular mechanisms of MG development and lactation in sheep.