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Nutritional status affects the microRNA profile of the hypothalamus of female sheep
Recent studies on the seasonal regulation of the estrous cycle in sheep have focused mainly on the responses to photoperiod. However, the brain systems that control reproductive activity also respond to nutritional inputs, although the involved molecular mechanisms are not completely understood. One possibility is that small, non-coding RNAs, such as micro-RNAs (miRNAs)is of significant influence. In the present study, the amounts and characteristics of miRNAs in hypothalamic tissue from estrous and anestrous ewes, fed Low or High nutrition, were compared through using Illumina HiSeq sequencing technology. In total, 398 miRNAs, including 261 novel miRNAs, were identified in ewes with an enhanced nutritional status (HEN) through assessing HEN library for this group. However, 384 miRNAs, including 247 novel miRNAs, were identified in the ewes with a lesser nutritional status (HAN) through assessing the HAN library, among which there were eight conserved and 140 novel miRNAs in differential amounts between the two libraries. Based on poly (A) q-PCR, six miRNAs were assessed to verify the accuracy of the library database. Moreover, the correlation between the miRNA-target and the upstream and downstream genes in the estrus-related pathways were also verified in the hypothalamus nerve cells. According to the results, nutritional status plays important roles in estrous regulation in sheep, including the responses to nutrition. The hypothalamic processes and pathways induced by nutritional signals are different from those induced by photoperiodic regulation of estrus, including tyrosine and folic acid are involved in the estrus pathways during the anestrous season, respectively. We have expanded the repertoire of sheep miRNAs that could contribute to the molecular mechanisms that regulate initiation of estrous cycles in anestrous ewes, involving the influences of nutritional status.
RD17179 Accepted 21 October 2017
© CSIRO 2017