Assessment of gene expression levels upon overexpession of Retinitis pigmentosa associated Prp8 mutant proteins in the Drosophila eye antennal imaginal discs

Retinitis pigmentosa (RP) represents a heterogeneous group of hereditary eye disorders characterized by a progressive loss of vision. Mutations in thirty different genes have been linked to the autosomal dominant form of RP (adRP), with nearly one-quarter of them encoding the core components of the spliceosome, a macromolecular machine that removes introns from nascent pre-mRNAs, generating mature transcripts. Here we establish the Drosophila melanogaster model for RP13 linked to the mutations in the most conserved protein of the spliceosome, PRPF8/Prp8. We demonstrate negative impact of the nine different RP-associated Prp8 mutant proteins on the developmental timing when expressed in the endocrine cells specialized to produce the major insect molting hormone. In the developing eye primordium, actively cycling cells rather than differentiated photoreceptors showed sensitivity to Prp8 malfunction. The overexpression of the two most toxic RP variants Prp8S>F and Prp8H>R induced apoptosis and disturbances of the adult eye morphology. While the affected tissue mounted the stress and cytoprotective response, the genetic programs underlying neuronal function were attenuated. Importantly, the expressivity and penetrance among the RP-Prp8 mutations differed and increased under prp8 heterozygosity. Tissue-specific overexpression of RP-Prp8 mutant proteins (designated as Prp8F>L "Lilac", Prp8H>R "Russet" and Prp8S>F "Fuchsia") and wild-type Drosophila Prp8 (Prp8wt) in Drosophila eye-antennal imaginal discs; tissues were dissected in three replicates, and RNA was extracted for next-generation sequencing