The spermatheca serves an important function in nematode reproduction. In C. elegans it is the site of sperm storage and fertilization of ovulated oocytes. The spermatheca is a highly secretory, tubular organ consisting of 24 epithelial cells. Passage of oocytes through the spermatheca is tightly regulated by specialized valve structures. Few genes have been identified that function during spermatheca development. However, our lab has recently determined that the nuclear receptor transcription factor NHR-6 is a critical regulator of spermatheca development (see abstract by Kelley et al.). NHR-6 is a member of the NR4A group of nuclear receptors that have important roles in mammalian organogenesis. The organogenesis functions of NHR-6 suggest that activities of this nuclear receptor group are conserved in C. elegans and that NR4A functions can be dissected using the C. elegans spermatheca as an organ model. To further understand the genetic control of spermatheca development we have initiated a genome-wide RNAi screen to identify spermatheca development genes. To specifically identify spermatheca genes we screen for a specific set of phenotypes known to be associated with
nhr-6 mutants. The range of phenotypes include sterility, decreased brood size, abnormal egg morphology, and an adult degeneration phenotype that typically arises in nematodes with abnormally formed somatic gonad structures. Genes identified in this first phase of the screen are then re-screened using the spermathecal differentiation marker
ajm-1::GFP. This screen also employed an RNAi sensitized background since
nhr-6 is refractory to RNAi in the wild-type background, suggesting that other spermatheca genes may also be refractory to RNAi. We have completed a screen of chromosome III and have identified an initial set of 193 genes that are currently in the process of second round screening. Interestingly, many of the genes identified in our screen were not previously known to have reproductive functions.