Paro

Project Title: Epigenetic Control of Regeneration and Transdetermination in Drosophila imaginal discs

Tissue regeneration induces considerable remodeling of gene expression patterns in the cells required to restructure the lost parts. By analyzing regeneration of imaginal discs in Drosophila we identified signaling cascades and epigenetic reprogramming events required for tissue repair. We observe that regeneration induces down-regulation of the PcG by the JNK signaling pathway. We established a continuous GFP-labeling system for tracing blastema cells in regenerating imaginal discs of Drosophila larvae. This technique enabled us to specifically isolate regenerating cells and subject them to expression profiling. We observed that ligands for several signaling cascades, Upd/JAK-STAT signaling, dpp/TGF-beta signaling, are up-regulated in a JNK-dependent manner. Repression of PcG silencing results in a spatially and temporally distinct reactivation of a diverse set of signaling cascades and developmental regulators, thereby, enabling cellular reprogramming at the site of tissue injury.