We found that the I10E transgene could not rescue the development of the EndoA nulls.
A third integration, UAS-endoAA66W 4.1, was also unable to rescue the development of endoA nulls to adult flies capable of eclosing (Figure 2).
In accordance with this result, we found that the transgene carrying the homologous mutation in Drosophila, I10E (Figure 1A), could not rescue the development of the endoA nulls (Figure 2).
Interestingly, UAS-endoAEndoA(Arf -HA rescued the development of endoArf -HAmutants to adulthood, although the rescuedwas somewhathenferior to that providevelopmentwild type coftrol transgendoA(Figure 2).
Above, we have only considered the possibility that the failure of some UAS-endoA* transgenes to rescue the development of the endoA nulls is due to the mutation carried by those transgenes.
Because the ectopic Drosophila Syndapin RNA could rescue the development of pacsin3 MO-injected embryos with high frequency, we utilized this morphologic complementation assay to assess the functional significance of the PACSIN/Syndapin EFC and SH3 domains (Figure 7A F).
We found that UAS-endoAΔLQPNP, in which the homologous five residues of dEndoA-BAR were deleted (Figure 1A), failed to rescue the development of endoA nulls to adulthood (Figure 2).
Interestingly, when dnPKA mRNA and Dmrt2b-MO are co-injected, the dnPKA can efficiently rescue the development of slow muscle fibers and muscle pioneers in the morphant embryos (Figure 4I, J).
Hence, our finding that the EEE transgene failed to rescue the development of endoA nulls suggests that curvature sensing alone is not sufficient for endophilin-A to fulfill its function in synaptic endocytosis.
Biologically, this would apply to situations in germline mosaics where genetic modifiers uniquely expressed by donor spermatogonia could potentially rescue the development of endogenous spermatogonial lines that harbor undesirable genetic traits.
