Recent genetic screens for transposon defence and embryonic development identified several splicing regulators as crucial factors for silencing transposons in Drosophila ovaries. We found that the splicing of piwi gene, central factor of piRNA pathway, is affected in the mutant ovaries. We showed that two distinct previously unrecognised mechanisms mediated by the Exon Junction Complex (EJC) and a poorly characterised splicing factor Scaf6 are required for the correct splicing of intron4 and intron1, respectively. Intriguingly, both intron4 and intron1 have transposon insertions that rendered them dependent on sophisticated splicing “rescue” pathways. These “incidents” represent a constant fight between transposons and the host where transposons try to harm defence mechanism and the host detoxifies the transposon insertions. We aim to molecularly characterise these newly emerging splicing regulations and to investigate their roles in non-germline tissues such as brain and muscles.
Techniques involved: Basic molecular biology and biochemistry, Drosophila genetics, high-throughput RNAi screen, high-end sequencing techniques such as ChIP-seq, CLIP-seq, TT-seq and Oxford nanopore sequencing, and accompanying computational analysis.