Basic Analysis Of Methylation Of Polycomb Gene Family In Rice

Polycomb played an important role in controlling epigenetics. The process of PcG genes support us konwing the genetic mechanism of seeds which earlier development in Arabidopsis. We isolated these PcG genes from mutants of fertilization-independent endosperm. At present, we isolated OsCLF,OsiEZ1(OsSET1), OsFIE1,OsFIE2, MSI1, OsEMF2a, OsEMF2b in rice.Rice is an important crop, though a great deal of research, however epigenetics of PcG genes in rice genome was very limited. In this text, with bisulfite sequencing,author detected methylation level of CG island and other regions of FIE gene, Ezl gene of leaf and endosperm in wild type and in mutant rice. Main results are as follows:1.The methylation level at CG island of Fie2A gene in wild leaf of before tiller,Ezl heterozygous mutant gene,Ezl homozygous mutant gene reduced successively, it means that Ezl gene mutant had influence in methylation level at CG island of Fie2A gene. We concluded that Ezl gene has influence in expression of Fie2A gene. Besides, vegetative organ of wild rice had a high methylation level of Fie2A gene, endosperm of Fie2A gene revealed a high level expression.2.With MSRE-PCR detecting methylation level of Fie2A gene at different sites, it showed that crossed seeds F1 has a low methylation level of Fie2A gene,and after hybridization Fie2A gene revealed a high level expression. We thought there may has an mechanisms activating gene expression, or enhancing expression of Fie2A gene.3.The methylation level of wild leaf compared with DAP11 endosperm, endosperm had a low methylation level. In our lab, RT-PCR revealed that Ezl gene of leaf has a low expression.it indicated that Ezl gene has a much high methylation level, much high expression level.4. The methylation level of CG island of Ezl gene in wild and Ezl homozygous mutant rice had little change. We could explain like that:gene mutant itself did not cause changing of methylation level in Ezl gene;but there was difference in Fie2A gene of wild rice and Ezl homozygous mutant rice. Studies in Arabidopsis, it showed FIE gene interacting with MEA gene, and Ezl gene in rice was homology of FIE in Arabidopsis, we understood that FIE gene interacted with MEA gene in rice.5.Based on the method of BSP, we used nest-PCR to increase the specificity of PCR product, and hot start PCR had not obvious influence in PCR.In tnis artical methylation state of PcG rice gene families(Ezl and FIE gene),the research on molecular mechanisms for rice growth may have certain reference significance to the further study.