Fig. 5. Overexpression of mDia1Full prevents F-actin disassembly induced by low-dose LatB treatment. (A) F-actin structures visualized by fluorescent phalloidin before and after 100 nM LatB treatment. Note the well preserved thin actin fiber architecture in cells overexpressing EGFP-mDia1Full (arrowheads), whereas F-actin structures were gradually disrupted in nontransfected cells. Scale bar: 10 µm. (B) Cells transfected with pEGFP-mDia1Full were fixed and stained with fluorescent phalloidin before and 8 minutes after 50 nM LatB treatment. Total intensity of the phalloidin signal was measured in each transfected and nontransfected cell. F-actin did not decrease significantly in EGFP-mDia1-expressing cells [mean ± s.d.; non-transfected cells, n=143 (before), n=265 (after); EGFP-mDia1 positive cells, n=42 (before), n=53 (after)]. Data were analyzed using a two-tailed Student's t-test; ^***P<0.001.