Table 2.
Expression pattern of arg-1 promoter segments in wild-type, hlh-8 (-) and hlh-2 RNAi animals
| arg-1 promoter region (bp) | genotypes/treatment | GFP expression pattern
|
|||
|---|---|---|---|---|---|
| vm1 a | hmc & enteric muscles | gonadal sheath cells | pm6 & pm7 | ||
| pZJ02 [−6240 to −1] | WT | + | + | + | − |
| hlh-8 (-) b | − | − | − | − | |
| hlh-2 RNAi c | −/+d | + e | + f | − | |
| pZJ05 [−6240 to −2972] | WT | − | − | + | + |
| hlh-8 (-) | − | − | + | + | |
| hlh-2 RNAi | − | − | + f | + | |
| pZJ04 [−2824 to −1] | WT | + | + | − | − |
| hlh-8 (-) | − | − | − | − | |
| hlh-2 RNAi | −/+ | + | − | − | |
| pZJ19 [−436 to −1] | WT | + | + | − | − |
| hlh-8 (-) | − | − | − | − | |
| hlh-2 RNAi | −/+ | + | − | − | |
Abbreviations used: hmc, head mesodermal cell; vm1, type 1 vulval muscles; enteric muscles, left and right intestinal muscles, anal sphincter and anal depressor; pm6 and pm7, pharyngeal muscles 6 and 7; hlh-8 (-), hlh-8 (nr2061).
hlh-8 (-) mutation is a predicted null allele (Corsi et al., 2000).
L1 larvae were fed bacteria harboring an hlh-2 RNAi vector or an L4440 empty vector (data not shown), and the GFP expression pattern was observed in at least 30 adult worms for each RNAi treatment.
Residual GFP expression in the vm1 was observed in < 25% of the hlh-2 RNAi treated animals; in contrast, GFP expression in the vm1 was observed in at least 91% of the animals in RNAi control group (not shown).
GFP expression in the hmc and enteric muscles was unaffected possibly because these cells are already formed during embryogenesis prior to the RNAi treatment.
The amount of GFP expression in the gonadal sheath cells was essentially unchanged after hlh-2 RNAi treatment compared to the control group. However, the morphology of the cells was abnormal because the hlh-2 RNAi treatment disrupted their development. Sterility and protruding vulva phenotypes were also observed in the hlh-2 RNAi-treated animals.