Figure 5. GLD-1 Has the Opposite Sex Determination Function in C. elegans and C. briggsae For (A) and (B) the distal end of the gonad arm is indicated by the asterisk, and regions of the germline are delimited by dashed vertical lines as follows: M, mitotic zone; TZ, transition zone; P, pachytene; Pa, abnormal pachytene; and S, spermatocytes. For both (A) and (B) staining indicated is as follows: DAPI, blue, nuclear DNA; GLD-1, green; and MSP, red. (A) RNAi of C. briggsae
gld-1 results in masculinization of the germline. Paired DAPI-stained (left) and GLD-1- and MSP-stained (right) images of dissected young adult hermphrodite germlines. Top four panels illustrate the similarity between C. elegans and C. briggsae germline morphology and polarity (DAPI, blue; GLD-1, green; MSP, red). In both species, sperm (''sperm'' arrow) are produced first before switching to oogenesis (''oocytes'' arrow), and the pattern of cytoplasmic GLD-1 accumulation (green) is identical. GFP-injected controls were identical to wild-type animals. C. briggsae
gld-1 RNAi animals exhibit masculinization of the germline (lower panels). A vast excess of sperm extends to the loop region (''sperm'' arrows), and spermatogenesis extends further distally (solid line). Masculinization is confirmed by a corresponding extension in MSP staining beyond the loop (compare lower right to controls above). (B) RNAi of
gld-1 and
fog-3 in C. elegans and C. briggsae results in a similar tumorous germline phenotype. C. elegans (top) and C. briggsae (bottom) have normal mitotic, transition, and entry into pachytene, but abnormal progression through pachytene, based on DAPI morphology. Both MSP and GLD-1 staining were below the level of detection in both cases.