Planarian MBD2/3 is required for adult stem cell pluripotency independently of DNA methylation.
Bottom Line: Here we show the planarian methyl-CpG Binding Domain 2/3 (mbd2/3) gene is required for pASC differentiation during regeneration and tissue homeostasis.The genome does not have detectable levels of 5-methylcytosine (5(m)C) and we find no role for a potential DNA methylase.We conclude that MBD proteins may have had an ancient role in broadly controlling animal stem cell pluripotency, but that DNA methylation is not involved in planarian stem cell differentiation.
Affiliation: Department of Zoology, Tinbergen Building, South Parks Road, University of Oxford, Oxford OX1 3PS, United Kingdom.Show MeSH
Mentions: Some MBD proteins are thought to act through binding 5mC and affect gene expression (Hendrich and Bird, 1998; Jaenisch and Bird, 2003). We looked for evidence for the presence 5mC in genomic DNA (gDNA) and for genes encoding potential DNA methyltransferases. We identified a single gene with identity to known DNA methyltransferases, Smed-dnmt2 (Supplementary Fig. 5A and B). Neither the observed expression, which was confined to the germline (Wang et al., 2007) (Fig. 7A), nor RNAi experiments indicated any role in regeneration (Supplementary Fig. 5C and D). Another recent study reported a DMNT1 gene in S. mediterranea (Zeng et al., 2013), but we have found only a DMNT2 ortholog in line with a recent study that only found DMNT2 encoding genes across the platyhelminthes (Geyer et al., 2013).
Affiliation: Department of Zoology, Tinbergen Building, South Parks Road, University of Oxford, Oxford OX1 3PS, United Kingdom.