Figure 3. The motif pair in
pas-5 promoter is required for germline and somatic gonad expression. (A) Structure of the
pas-5p::GFP reporter. 1,245 bp of
pas-5 promoter were fused to GFP. The sequence of the wild-type and mutated motifs are shown. (B) A scheme of an adult C. elegans hermaphrodite. The gonad is made of two symmetric U-shaped arms. Each of the arms terminates at the spermatheca. Oocytes are fertilized in the spermatheca, embryos mature in the uterus and laid through the vulva. (C) The germline cells of the gonad. Germ cells proliferate (mitotic zone) in the distal region of the gonad and as they move proximally (transition zone) they enter meiosis and differentiate into sperm or oocyte. (D) The somatic gonad is composed of the distal tip cell (DTC), gonadal sheath, spermatheca (sp), spermathecal-uterine (sp-ut) valve, and uterus. The sheath and DTCs are physically associated with the germline cells and have critical roles in their development and function. The DTCs control gonad migration and regulate entry of the germline cells into mitosis versus meiosis (Kimble and White 1981). The sheath cells are smooth muscle-like cells necessary for oocyte maturation and ovulation (McCarter et al. 1999). (E) Expression pattern of wild-type
pas-5p::GFP versus pas-5pM12::GFP reporters in the adult gonad. Expression is detected in the mitotic region of the germline (blue asterisk), the meiotic region (pair of blue asterisks), the DTC (red asterisk and curve) and the gonadal sheath cells (green asterisks). Additional images are shown in Supp. Fig. 6.