Discovery and Comparative Transcriptome Profiling of Dairy Goat MicroRNAs from Dry Period and Peak Lactation Mammary Gland Tissues

In this study, two small RNA libraries were constructed using dry period and peak lactation dairy goat mammary gland tissues and sequenced by the Illumina Solexa high-throughput sequencing system. A total of 346 conserved and 95 novel miRNAs were identified in the dairy goat. The expression of miRNAs was confirmed by qRT-PCR in nine tissues and the mammary gland during development cycles. In addition, several candidate miRNAs that may be involved in mammary gland development and lactation were found by the comparison of miRNA expression profiles among different tissue and developmental stages of the mammary gland. This study provides the identification and profile of miRNAs related to the biology of the mammary gland in the dairy goat. The identification of these miRNAs could contribute to understanding the molecular mechanisms of lactation physiology and the development of the mammary gland in the dairy goat. Overall design: Examination of 2 different developmental stages of the mammary gland