Mechanism of Erasure, Establishment and Maintenance of Mammalian Genomic Imprinting
ZHAO Ruolin, JIA Chenqi, LI Aicong, ZHANG Yong, SU Jianmin*
Epigenetics modification of genomic imprinting results in single allelic gene expression in many mammals, which are mainly regulated by DNA methylation of imprinted genes. Imprint erasure occurs in the PGCs stage, and its main pathway is demethylation mediated by AID and TET. The imprinting is established during gametogenesis, with marked differences between males and females. Maintenance of imprinting is accomplished under the combined action of various ffactors, including Dnmt1, Dppa3, KAP1, ZFP57, etc. Maintenance of imprinting runs through the whole development stage and is inherited to offspring through cell division. The normal growth and development of organism depends on the normal expression of imprinted genes. With the discovery of IGF2R, the first imprinted gene, the study of imprinting mechanism has been advancing. The paper will summarize the mechanism of establishment, maintenance and erasure of genomic imprinting and the abnormal reprogramming of methylation in cloned animals.
CN
EN