DNMT3L interacts with Piwi and modulates the expression of piRNAs

The epigenetic modulator, DNMT3L, has been shown to be involved in nuclear reprogramming. Previous work from our laboratory had shown the accumulation and inheritance of epimutations across multiple generations when DNMT3L was ectopically expressed in transgenic DNMT3L Drosophila. Here, we show interaction of DNMT3L with Piwi, a member of a family of proteins known to perform their function through their association with piRNAs. Importantly, DNMT3L expression caused a significant alteration in the piRNA profile across multiple generations in transgenic Drosophila. As piRNAs are known to be passed on from one generation to another, we believe that the DNMT3L through its interaction with Piwi act to modify the inherited pool of piRNAs, which in turn allows accumulation of aberrant epigenetic modifications in subsequent generation. Furthermore, we show the interaction of DNMT3L with Histone H1, a non-core histone involved in higher order chromatin organisation. In light of these observations, it is proposed that in addition to its role in modulating core histone modifications, DNMT3L allows for inheritance of non-genetic information through its collaboration with Piwi, piRNAs and histone H1.