The mysterious presence of a 5-methylcytosine oxidase in the Drosophila genome: Possible explanations
Dunwell, T., McGuffin, L., Dunwell, J. and Pfeifer, G. (2013) The mysterious presence of a 5-methylcytosine oxidase in the Drosophila genome: Possible explanations. Cell Cycle, 12 (21). 3357 -3365 . ISSN 1538-4101
Full text not archived in this repository.
To link to this item DOI: 10.4161/cc.26540
5-methylcytosine is an important epigenetic modification involved in gene control in vertebrates and many other complex living organisms. Its presence in Drosophila has been a matter of debate and recent bisulfite sequencing studies of early-stage fly embryos have concluded that the genome of Drosophila is essentially unmethylated. However, as we outline here, the Drosophila genome harbors a well-conserved homolog of the TET protein family. The mammalian orthologs TET1/2/3 are known to convert 5-methylcytosine into 5-hydroxymethylcytosine. We discuss several possible explanations for these seemingly contradictory findings. One possibility is that the 2 modified cytosine bases are generated in Drosophila only at certain developmental stages and in a cell type-specific manner during neurogenesis. Alternatively, Drosophila Tet and its mammalian homologs may carry out catalytic activity-independent functions, and the possibility that these proteins may oxidize 5-methylcytosine in RNA created by the methyltransferase Dnmt2 should also be strongly considered.