Gene Editing in Nasonia to Create an Epigenetic Model Organism

Drosophila is regarded as the archetypal organism for insect genetic studies. One feature which makes Drosophila melanogaster an ideal genetic model organism is the ease of integrating foreign DNA through the attP-attB C31 integrase mediated recombination system. In addition to this, systems such as the UAS-Gal system allows for precise temporal and spatial expression of transgenic DNA. The combination of these techniques results in deep genomic investigations in Drosophila which are unmatched in other model organisms.

One limitation of Drosophila as a model organism is its lack of CpG methylation. Epigenetics is the heritable change in gene expression without a change in DNA sequence, and DNA methylation is the most extensively researched epigenetic modification. Nasonia like all hymenoptera possess a functional methylation system, and consequently is emerging as an important model organism for epigenetic studies. Our lab has recently created an equivalent attP-attB recombinant Nasonia line with an attP docking site using CRISPR/Cas9 mediated homology-directed repair. This opens up enormous possibilities for both genetic and epigenetic studies in the Nasonia system.

Here we hope to develop the first insect epigenetic model organism by creating Nasonia lines with altered methylation levels at a given loci. We will apply these transgenic lines for the ongoing Nasonia study investigating epigenetic, transcriptional and phenotypic response to photoperiod changes. Additionally, we aim to use the UAS-Gal4 system in Drosophila as a proof-of-concept that we can introduce any vector containing attP elements into the Nasonia genome. By proving that we can control gene expression at such a fine resolution in Nasonia, there is the potential that any gene in any context could be expressed in future Nasonia research projects. Consequentially, this could result in Nasonia becoming a model organism of greater biological scope than Drosophila.