Figure 2. Intra-Nuclear Actin Rods Assemble in Heat-Stressed Embryos.
(A) Surface views show G-actinRed in furrow tips in live wild-type (WT) embryos at indicated temperatures. Intra-nuclear rods assemble at 32°C (yellow arrows, higher-magnification inset).
(B) Surface views show FRAP of a rod (G-actinRed) in a WT embryo at 32°C. Higher-magnification time-lapse images show boxed ROI, and yellow arrows indicate bleached mid-section of a rod. FRAP kinetics for that rod plotted below.
(C and D) Rod abundance (rods/nucleus) versus free nuclear actin fluorescence in live WT embryos at 18°C (C) and 32°C (D) (n ≥ 31 embryos, with rod abundance counted in ≥ 60 nuclei per embryo; free actin fluorescence averaged from three nuclei per embryo). Each gray point represents one embryo, and black points represent binned data (mean ± SE). The green line represents the binned data fitted to a Hill function with Hill coefficient = 4. Related data are shown in Figure S1.