"
tlk-1(RNAi) experiments were performed in C. elegans strains harboring transgenes in which the regulatory regions of RNAPII-dependent embryonically expressed genes had been fused to a GFP reporter. When hermaphrodites were fed HT115 bacteria transformed with the RNAi feeding vector L440 without an insert, embryonic GFP expression was readily apparent in the four strains tested (
med-1::GFP [28],
end-3::GFP [29],
elt-2::GFP [30], and
myo-2::GFP;
pes-10::GFP [M. Edgley, J. Liu, D. Riddle, and A. Fire, personal commjnication]). GFP expression was not detectable in RNAPII/ama-1(RNAi) embryos and was greatly reduced in
tlk-1(RNAi) embryos (Figure 3)."