Fig. 4.

Expression of RNAi triggers in sid-1(−) tissues can silence target genes in sid-1(+) tissues. (A) Representative sid-1(−) young adult that expresses GFP in the pharynx, gut, and bwm, but that expresses gfp-hpRNA only in the pharynx (phar::hp-gfp). Only GFP expression in the pharynx is silenced as indicated. (Inset): bright-field image. (B) Representative young adult of the same genotype as in A, but in which wild-type sid-1 cDNA (sid-1(+)) and DsRed have been coexpressed in the gut. Red channel showing specific expression of sid-1(+) in the gut (Left); green channel showing specific silencing of gfp expression in the pharynx and in the gut (Middle); and merge of images from both channels (Right) are shown. (Insets): bright-field images. (Scale bar, 100 μm.)