Characterization of the dynamic change of microRNA expression in mice hypothalamus during the time of female puberty.

Puberty onset is a milestone in sexual development. A tumor suppress gene (TSG) network had been reported to be involved in the regulation of female puberty onset. The observations in rodents and primates showed a potential link between microRNAs and puberty onset. To figure out what miRNAs play roles in this important biological process, profilings of microRNAs in the hypothalamus of female mice from three different pubertal stages, juvenile [postnatal day (P10)], early pubertal (P25) and pubertal (P30) were performed on the Affymetrix GeneChip miRNA 3.0 Arrays, the cerebral cortex (CTX) was used as a control tissue. 20 miRNAs were shown to be differentially expressed in hypothalamus (fold change > 1.5, P < 0.05), but not in CTX during the transition from juvenile to pubertal. Four of them were validated by real-time quantitative RT-PCR (qRT-PCR) method. 1018 genes were predicted as the targets of these miRNAs. Further bioinformatics analysis suggested that these target genes were involved in many important signaling pathways, especially in the cancer related pathways. We also found that about 90% of these target genes were expressed in the hypothalamus, as well as in the immortalized GnRH-producing GT1-7 cells, which provided additional evidence that these miRNAs could be female puberty onset related. Here we present a novel comprehensive data set of miRNA gene expression during the puberty onset; and it provides an important recourse for the future functional characterization of individual miRNAs and their targets in mouse hypothalamus and in GT1-7 cells.