Figure 5.—

OCR-2 functions in the uv1 and utse cells to control egg-laying behavior. (A) Schematic showing the lineal origins of cells that express OCR-2. The AB.a-derived neurons are ADLL, ADLR, ADFL, and ADFR (four head neurons). The AB.p-derived neurons are AWAL, AWAR, ASHL, and ASHR (four head neurons); PHAL, PHAR, PHBL, and PHBR (four tail neurons); and PVDL and PVDR (PVDs). Two additional unidentified head neurons that express OCR-2 are not shown, but are likely AB derived, since AB is the precursor of the vast majority of neurons. The lineal separation of uv1 and utse from all other OCR-2-expressing cells makes it convenient to isolate genetic mosaics to assess the function of OCR-2 in uv1 and utse. (B) OCR-2∷GFP expression in the uv1 and utse cells is necessary and sufficient to rescue the ocr-2(vs29) egg-laying defect. ocr-2(vs29) animals transformed with an extrachromosomal transgene that expresses full-length OCR-2 fused to GFP (OCR-2∷GFP) under the control of the ocr-2 promoter and the 3′ regulatory regions were scored for the presence of GFP fluorescence in individual cells and for the number of eggs held in utero. During development, the extrachromosomal transgene is lost in a mosaic manner, resulting in the expression of OCR-2∷GFP (as evidenced by GFP fluorescence) in all, none, or a subset of the cells that express OCR-2. Only animals that expressed OCR-2∷GFP in the uv1 and utse cells held a normal number of eggs in utero (16 ± 4 in animals with expression only in uv1 and utse cells vs. 15 ± 0.6 eggs in wild-type animals). Ten animals were scored for each mosaic pattern of OCR-2∷GFP expression. Errors indicate standard deviation.