Drosophila genetics and epigenetics (URA CNRS 2578)
| Christophe Antoniewski antoniew@pasteur.fr |
piRNAs, miRNAs and siRNAs are at the core of a vast RNA silencing biochemical framework in Drosophila. They associate with Argonaute proteins, which they guide to complementary targets. The resulting silencing may occurs by cleavage, destabilization or inhibition of translation of RNA transcripts (Post Transcriptional Gene Silencing), or by DNA or histone modifications at complementary loci (Transcriptional Gene Silencing). Small RNAs are involved in numerous biological processes including gene regulation, defense against exogenous pathogens as well as endogenous selfish transposons, chromatin and chromosome dynamics and genome rearrangements. The variety of mechanistic and functional outputs reflects the multiplicity of intertwined RNA silencing pathways that potentially compete or interact with each other. We are far from understanding the molecular basis of these variations, as well as their biological impact.
Within this context, we focusing on two main issues:
- How do siRNA and piRNAs modulate chromatin structure, at the genetic as well epigenetic levels ?
- How does the miRNA silencing network diversified to control Drosophila development and homeostasis ?
legendes to figures:
Top. A transgenic system to target RNAi in drosophila A transgenic line expressing GAL4 under the control of a specific driver is crossed with a transgenic line expressing an inverted repeat under the control of UAS regulatory sites.
Bottom. RNAi targeted to Pcaf using a transgenic system. The expression pattern of a double-stranded producing transgene target to Pcaf is revealed by coexpression with a GFP reporter transgene (green), in a leg (top) and a wing (bottom) imaginal disc. Expression of the P/CAF protein revealed by a specific antibody (red) is specifically abolished in the corresponding area.