TC013606

The most notable effects of argos RNAi in our study were mortality and a lack of morphological changes seen in surviving adult beetles. Only 5 of the Tribolium castaneum injected survived to adulthood. In Drosophila melanogaster, the LOF phenotype of argos is enlarged eyes which are rough in appearance and an increased vein structure in the wings. However, we did not observe these results in Tribolium castaneum. It is possible this is because those affected by RNAi died before adult stage. We did see some signs of abnormal ommatidia, as well as wing decay in pupae. However, the beetles surviving to adulthood had overall morphology that paralleled that of the wild type and implying that those surviving to adulthood escaped the RNAi. One exception was a single GFP scope image showing abnormalities in the adult eye. The scope image had a few dark spots within the ommatidia cells, indicating missing GFP protein in the center of the eyes. Overall, our results support a conservation of function from Drosophila to Tribolium concerning argos effect on EGFR. Mortality resulting from lack of inhibition of EGFR is not surprising considering it large downstream pathway with effects on cell survival, differentiation, and proliferation. Another possibility is that knocking out the gene argos, an inhibitor of EGFR does not have an apparent morphological effect. Although, RNAi of argos could have other, unseen effects on Tribolium castaneum. Further analysis could bring to light discreet or unseen effects. For example, sectional analysis of the eyes and the general eye area is a future option to see if there were effects on photoreceptors or other cells. Looking at proteins downstream of EGFR is also another option. Looking at proteins downstream of EGFR would allow for a more targeted experimental approach, rather than affecting overarching targeted pathway that affects several different downstream cascades. Research, performed by Dr. Tomoyasu, knocked out EGFR, which resulted in smaller eyes (Tomoyasu, person-to-person communication). Compared with these results, it is possible that RNAi of argos, an inhibitor of EGFR, does not affect morphology to the same degree as knocking out EGFR itself since we did not observe larger eyes in beetles which underwent argos RNAi.