Gene Editing in Nasonia to Create an Epigenetic Model Organism

果蝇被认为是昆虫遗传学研究的原型生物。使果蝇成为理想的遗传模式生物的一个特征是通过attP-attB C31整合酶介导的重组系统容易整合外源DNA。除此之外，UAS-Gal系统等系统允许精确的转基因DNA的时间和空间表达。这些技术的结合导致了对果蝇的深入基因组研究，这在其他模式生物中是无法比拟的。果蝇作为模式生物的一个限制是它缺乏CpG甲基化。表观遗传学是指在不改变DNA序列的情况下可遗传的基因表达变化，而DNA甲基化是研究最广泛的表观遗传学修饰。像所有膜翅目一样，膜翅目具有甲基化系统，因此成为表观遗传学研究的重要模式生物。我们的实验室最近利用CRISPR/Cas9介导的同源定向修复创建了一个带有attP对接位点的等同的attP-attB重组Nasonia系。这为Nasonia系统中的遗传和表观遗传学研究打开了巨大的可能性。在这里，我们希望通过创建在给定基因座上甲基化水平改变的Nasonia系来开发第一个昆虫表观遗传模式生物。我们将把这些转基因品系用于正在进行的Nasonia研究，调查表观遗传、转录和表型对光周期变化的反应。此外，我们的目标是在果蝇中使用UAS-Gal4系统作为一种概念验证，即我们可以将任何包含attP元件的载体引入Nasonia基因组。通过证明我们可以在Nasonia中以如此精细的分辨率控制基因表达，在未来的Nasonia研究项目中，任何背景下的任何基因都有可能表达出来。因此，这可能导致纳斯尼亚成为比果蝇具有更大生物学范围的模式生物。

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.