Figure 5.

Effects of expression of EGL-47B(gf) or activated GOA-1 in the HSNs and egg-laying muscles. A, Adult with GFP expression driven from the pNSM/HSN promoter. The large arrowhead indicates the fluorescent NSMs; the small arrowhead indicates the fluorescent HSN cell body; the asterisk indicates the position of the vulva. The HSN process can be seen passing the vulva and extending to the head. The intestine, a large structure running the length of the body, shows prominent punctate autofluorescence but does not express GFP. B, Adult with GFP expression driven by the pNSM promoter. The large arrowhead indicates the fluorescent NSMs. No HSN expression is evident. C, D, HSN morphology in animals expressing EGL-47B(gf) (C) or activated GOA-1 (D) in the HSNs, revealed by GFP fluorescence. High-magnification micrographs of the vulval region are shown. The large arrowheads indicate HSN processes; small arrowheads indicate the HSN cell bodies; asterisks indicate the vulvas. HSN morphology appeared unaffected by expression of either EGL-47B(gf) or activated GOA-1 (compare with Fig. 1 D). E, Effects of expression of EGL-47B(gf) or activated GOA-1 in specific cells of the egg-laying system. Promoters pNSM or pNSM/HSN were used to drive expression of cDNAs for EGL-47B(gf) or activated GOA-1 (carrying the Q205L mutation), as indicated. In addition, promoter pELM was used to express GOA-1(Q205L) in egg-laying muscles. In every case, GFP was coexpressed to visualize cell morphology, as shown in A-D. As negative controls, GFP was expressed alone, i.e., without EGL-47(gf) or GOA-1(Q205L). At least five independent lines were assayed for each experiment. Lines were defined as Egl if >20% of adults contained at least 30 eggs. Activation of EGL-47 in the HSNs or activation of GOA-1 in the HSNs inhibited egg laying similarly, suggesting that EGL-47 activates GOA-1 in the HSNs to inhibit egg laying.