The actin regulators Enabled and Diaphanous direct distinct protrusive behaviors in different tissues during Drosophila development.
Bottom Line: We found that nonmigratory AS cells produce filopodia that are morphologically and dynamically distinct from those of LE cells.We hypothesized that differing Enabled and/or Diaphanous activity drives these differences.Our data suggest that LE protrusiveness is primarily Enabled driven, whereas Diaphanous plays the primary role in the AS, and reveal each has roles in dorsal closure, but its robustness ensures timely completion in their absence.
Affiliation: Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599.Show MeSH
Related in: MedlinePlus
Mentions: The foregoing data combined with our earlier work suggest that Ena may be the dominant actin elongator acting at the LE. The differences in protrusive profile between the wild-type LE and AS, along with the shift in protrusive profile induced by Dia at the LE, led us to hypothesize that Dia may be more important in the AS. To begin to test this, we elevated either Ena or Dia activity in AS cells, expressing RFP-Ena or HA-Dia∆DAD specifically in the AS using c381-GAL4, and driving sqh-Moe-GFP to visualize protrusions and compare them to wild type (Figure 4, A–C, and Supplemental Movie S6). Elevating levels of these actin regulators did not prevent completion of dorsal closure. HA-Dia∆DAD did not substantially change either the overall process of dorsal closure or its timing, as assessed by area change or canthi migration within the last 90 min of closure (Supplemental Figure S4, A and C–E). Overexpressing Ena did not alter overall closure or the change in AS area, but it did increase the rate of closure as determined by canthi distance (Supplemental Figure S4, A, B, D, and E, and Supplemental Movie S7).
Affiliation: Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599.