Distinct functions of Dnmt3a and Dnmt3b de novo DNA methyltransferases in ES cell proliferation and differentiation
Author(s) -
Yoshie Umehara,
Kazunori Hanaoka,
Dai Watanabe
Publication year - 2013
Publication title -
stem cell discovery
Language(s) - English
Resource type - Journals
eISSN - 2161-6787
pISSN - 2161-6760
DOI - 10.4236/scd.2013.32017
Subject(s) - methyltransferase , biology , dnmt3b , transfection , microbiology and biotechnology , dna methylation , cellular differentiation , cell growth , dna methyltransferase , stem cell , homeobox protein nanog , mitotic index , mitosis , methylation , embryonic stem cell , gene expression , induced pluripotent stem cell , cell culture , dna , gene , genetics
Two de novo DNA methyltransferases, Dnmt3a and Dnmt3b, have been identified in humans and mice to contribute to the methylation of unmodified DNA. We recently showed a transition of de novo DNA methyltransferase expression from Dnmt3b to Dnmt3a during mouse embryogenesis and in tissue-specific stem cells, suggesting distinct functions of Dnmt3a and Dnmt3b during these processes. In this study, to characterize the functions of Dnmt3a and Dnmt3b in pluripotent stem cells, we exogenously transfected ES cells with Dnmt3a and Dnmt3b cDNAs linked to an internal ribosome entry site-green fluorescent protein gene, and then analyzed the effects of expression of these de novo DNA methyltransferases on ES cell growth and differentiation. ES cells expressing Dnmt3b showed specific downregulation of pluripotency marker genes such as Nanog and Oct 3/4. In addition, Dnmt3a-transfected ES cells showed a specific increase in mitotic index, while Dnmt3b-transfected ES cells showed a decrease in mitotic index. These results suggest that Dnmt3b has important physiological roles in the initial process of stem cell differentiation and that Dnmt3a has a function in stem cell proliferation.
Open Access