Accepted_test

The role of non-coding RNAs in the epigenetic conversion of gene loci
by Bespalova A.V. | Kulikova D.A. | Funikov S.Y. | Engelhardt Institute of Molecular Biology, RAS, Moscow, Russia | Engelhardt Institute of Molecular Biology, RAS, Moscow, Russia | Engelhardt Institute of Molecular Biology, RAS, Moscow, Russia
Abstract ID: 648
Event: BGRS-abstracts
Sections: [Sym 1] Section “Regulatory genomics”

The phenomenon of paramutation describes the interaction between two alleles, in which one allele initiates inherited epigenetic changes in the other allele without affecting the DNA sequence. Epigenetic conversion due to paramutation involves changes in methylation pattern of histones and/or DNA of a paramutable allele, and affects gene expression. The mechanism of epigenetic conversion of alleles during paramutation remains poorly understood, however, all previously described cases are united by the fact that the main effector molecules necessary for the initiation and maintenance of epigenetic modifications are small non-coding RNAs.

Paramutation in drosophila is based on the biochemical pathway of piRNAs (short non-coding RNAs associated with the Piwi protein) and the mechanism of co-transcriptional silencing by piRNA/Piwi complex. The biogenesis of piRNAs occurs exclusively in the reproductive organs of animals and is aimed at suppressing the activity of transposable elements. However, in rare cases, during epigenetic silencing of transposons, the protein complex of piRNA biogenesis may mistakenly target protein-coding genes and suppress their expression. In D. virilis, rRNA-mediated suppression of the cdi allele is an example of such “unintended" regulation. In addition, maternal inheritance of piRNA to cdi transcripts leads to epigenetic transformation of the homologous locus due to paramutation.

Herein, we analyzed the repertoire of genic piRNAs in D. virilis strains from various geographical and laboratory populations, investigated their diversity and pathways of origin, and also studied whether maternal inheritance of piRNAs targeted mRNA of protein-coding genes can lead to epigenetic conversion of gene loci as a result of paramutation.