Erin Bonner and Maritza Vazquez

Dr. Gregory Davis

Biology Department

Parental RNA interference of embryonic genes in the pea aphid


RNA interference (RNAi) has yet to achieve successful results in the study of gene function in the pea aphid, Acyrthosiphon pisum. Developing a successful method of parental RNAi of genes expressed in the early embryo is critical to our understanding of the roles of developmental genes in the pea aphid, and of our understanding of the way in which a single genome is capable of directing different mechanisms of development. Early in embryonic development, a molecular “switch” determines whether pea aphid embryos will develop sexually or asexually. In order to identify the genes that regulate this switch and to elucidate their function in the developing embryo, a functional test such as RNAi is required to knock down gene expression. In the past, RNAi using small interfering RNAs (siRNAs) has yielded insignificant results. By injecting double-stranded RNA (dsRNA) of the developmental genes Distal-less (Dll) and Ultrabithorax (Ubx) into the hemolymph of both sexual- and asexual-producing mothers, we hope to knock down expression of Dll and Ubx in the developing embryos. If the dsRNA is successfully taken up by the embryonic cells and knocks down gene expression, the progeny will display developmental defects (shortened appendages for Dll and errors in body segmentation for Ubx) which will signify that RNAi was successful. As a comparison, milkweed bugs (Oncopeltus fasciatus), which in the past have exhibited successful results for RNAi, will also be injected with dsRNA following the same protocol.