Structure of the C. elegans hermaphrodite germline and expression of cgh-1 mRNA. Structure of the C. elegans hermaphrodite germline and expression of cgh-1 mRNA. (A) Diagram of the hermaphrodite germline. As described, two gonad arms each produce approximately 1000 germ cells (Schedl, 1997). A somatic distal tip cell (DTC) maintains germ cell proliferation. As germ cells enter meiotic prophase, a central gonad core appears that is more prominent in hermaphrodites. This common core disappears as oocyte precursors cellularize and progress from the pachytene to the diakinesis stage of meiosis. Prior to fertilization in the spermatheca each oocyte undergoes maturation, including breakdown of the nuclear envelope. D, distal, L, loop, P, proximal, O, oocytes; S, spermatheca; E, embryo and U, uterus. (B) Presence of cgh-1 mRNA in germline mutant strains. Total RNA from synchronized cultures grown at the restrictive temperature was extracted from the wild type (N2) and indicated strains. fem-1(hc17) produce only oocytes, fem-3(q20gf) produce only sperm, and in glp-4(bn2) the germ line is underproliferated. RNA was blotted and hybridized to a full-length cgh-1 cDNA. Expression levels were normalized to a ribosomal protein gene, rpp-1, and indicated at the bottom. (C-F) cgh-1 expression assayed by in situ hybridization. Hybridization was performed on wild type synchronized worms using the cgh-1 cDNA clone yk85e1 (DDBJ/GenBank accession number D74793) as a probe. (C) L1 larval stage. Low levels of expression are detected in the germ cells Z2 and Z3. (D) L2/L3. (E) Early L4 and (F) young adult. h, head; l, loop; p, proximal; d, distal; v, vulva. Rosa E. Navarro et al. Development 2001;128:3221-3232 © 2001.