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. 2007 Feb 5;104(7):2283–2288. doi: 10.1073/pnas.0610877104

Fig. 4.

Fig. 4.

Conditional induction of recCaspase-3 activity in muscle cells. (A) Expression of only the p17 subunit of the recCaspase-3 from the heat shock promoter [(Phsp-16 cz::caspase-3(p17)] had no effect on survival of body wall muscle. (A and B) GFP fluorescence from the muscle-specific myo-3 promoter (A and B Upper); a DIC image of the same animal (A and B Lower). For both animals, newly hatched L1 larvae were heat shocked for two hours and photographed 24 h later. (B) Expression of Pmyo-3 caspase-3(p12)::nz (causing the p12 subunit of recCaspase to be expressed in muscles) in combination with Phsp-16 cz::caspase-3(p17) resulted in death of the body wall muscles. (C) Enlargement of the DIC image of the animal in B showing the vacuolated deaths of muscle cells. (D) Superimposed DIC and fluorescence (Pmyo-3gfp) images of an embryo heat shocked for 30 min and photographed 8 h later. Arrows indicate some of the apoptotic nuclei, which show the characteristic refractile, flat disk-like morphology. (E) Occurrence of muscle cell death with induction of recCaspase activity at different times. Animals were heat shocked at the indicated times and scored 48 h later for paralysis caused by the death of muscle cells. Data from the expression of the single subunit (from Phsp-16; green line) as well as both the subunits (from Phsp-16 and Pmyo-3; blue line) of recCaspase are shown. Data from at least two stable lines (50 animals per line) and three independent experiments were used to calculate mean and SEM. (F) Time course of induction of recCaspase activity. First-stage larvae expressing both the subunits of the recCaspase were collected 12 h after hatching and subjected to a 2-h heat shock. At the indicated times after heat shock, animals were scored as completely paralyzed (blue), partially paralyzed (red), or wild type. Data from three stable lines and at least 100 animals per line were used to calculate mean and SEM. The mean values of partially and completely paralyzed animals were added to obtain the total number of animals affected (black) at each time point.