Dna Cytosine C5, Specific Re-methyltransferase Enzyme Cdna Cloning And Alternative Splicing Expression

DNA methylation is common in bacteria, plants and mammals. It has profound effects on biological processes in mammals, including gene expression and developmental regulation, differentiation, genomic imprinting, X chromosome inactivation and biological defense etc.. The aberrant DNA methylation is implicated in mammal carcinogenesis and some human diseases. DNA methylation in mammal is catalyzed by DNA cytosine-5 specific methyltransferase which has been proved to be involved in normal development of mouse embryo.Although the biological significance of DNA methylation has been recognized to some extent, the mechanisms of DNA methylation regulation and of the establishment of tissue-specific DNA methylation pattern in somatic cells are still unclear, since the knowledge of the enzymes responsible for de novo DNA methylation and demethylation of DNA is very limited and up to now only two functional DNA methyltransferases in mammals have been cloned . In addition, to investigate how a few DNA methyltransferases can be responsible for different DNA methylation patterns at various CpG sites is essential.To clone novel genes related to embryonic development with extensive study of molecular events during development is important. In 1997 we screened out clone 2# from mouse embryonic cDNA library and obtained 1235 bp sequence by primer walking sequencing. No known gene was found after homology search of nucleic acid database with clone 2# as query. Meanwhile we retrieved a 455 bp EST derived...