The Imprinting Status Of Insulin-like Growth Factor 2 Receptor Gene In MicroRNA-375-overexpressed Transgenic Mice

MicroRNA is a kind of endogenous small non-coding RNA, its regulation belongs to epigenetic aspects. In addition, include:genomic imprinting, RNA editing, DNA methylation, histone acetylation, etc.; imprinted genes IGF2, H19 and IGF2R are directly related to individual growth and development. The overexpression of miR-375 transgenic mouse model was constructed by Dr. Xia Huaqiang in our Institute. Confirmed by the preliminary study, the phenomenon of the Gender-related growth differences in male and female transgenic mice is a good model for epigenetic research.Objective:To study if there were imprinting disorder in the imprinted gene IGF2R in transgenic mice and from the epigenetic point of view to explain the reasons of the Gender-related growth differences phenomenon in transgenic mice.Methods:In the current study, the method of Real-time PCR was applied to detect IGF2R mRNA and Air RNA in several tissues, such as liver, lung, kidney in normal and transgenic mice. And then we used the method of Bisulfite DNA Sequencing to detect DNA methylation status of IGF2R DMR1(DNA differentially methylated region 1, DMR1) and DMR2(DNA differentially methylated region 2, DMR2) Results:In male transgenic mice, the IGF2R mRNA were down-regulated in liver, lung, kidney tissues, but Air RNA were up-regulated, compared with normal mice; they were expressed reciprocally. In female transgenic mice, the IGF2R mRNA and Air RNA were down-regulated in liver; the IGF2R mRNA were up-regulated in kidney, but without significant variation in Air RNA abundance when compared with a nomal mice; there were not significant variation of the IGF2R mRNA and Air RNA abundance between female transgenic mice and normal mice in lung; DMR1 and DMR2 were hypermethylation in male transgenic mice compared with a nomal mice, but the DNA methylation without significant variation between female transgenic mice and normal mice in DMR1 and DMR2.Conclusions:The imprinted gene IGF2R in male and female transgenic mice were express imprinted disorder.