Fig. 5.

The antiapoptotic potential of pea aphid IAPs assessed in Drosophila eyes. Five pea aphid IAP genes (Ap-iap-A1, Ap-iap-A2, Ap-iap-A4, Ap-iap-B1, and Ap-deterin-1) were targeted to the eye to measure the level of suppression of rpr-induced apoptosis. Near complete suppression of apoptosis is seen upon coexpression with diap1 (A), Ap-iap-A1 (B), Ap-iap-A2 (C), and Ap-iap-A4 (D). The coexpression of Ap-iap-B1 (E) and Ap-deterin-1 (F) only partially rescued this phenotype. A comparison of eye surface/head surface ratio in control (white; only the gene rpr is expressed) and rescue (gray; the gene rpr is coexpressed with a pea aphid iap gene) flies from the different transgenic lines confirmed those results. The coexpression of an Acyrthosiphon pisum iap with rpr systematically led to a significant increase in eye surface/head surface ratio due to an increase in eye size. This increase was more prominent for the genes Ap-iap-A1, Ap-iap-A2, and Ap-iap-A4, with a ratio similar to what was observed for diap1. The pea aphid IAPs with the strongest antiapoptotic potential are the ones containing two RING domains. The statistical significance was evaluated using the two-sided Mann–Whitney U test; ****P < 0.0001.