Cell-cell fusion during C. elegans male tail morphogenesis
Cell-cell fusion is an essential process in the development and formation of body structures. The nematode Caenorhabditis elegans serves as a good model organism for studying cell-cell fusion, since about one-third of its cells undergo fusion during development.
Specifically, I am interested in Rn.p (n = 1-9) male-specific hypodermal cells in the tail, which fuse during its morphogenesis to form the male copulatory structure, an important organ for its mating behavior. The Rn.p cells fuse into two distinct groups – R1.p to R5.p cells fuse together to form the male tail seam (SET), while R6.p to R9.p cells fuse with the largest hypodermal syncytium, hyp7. However, it remains unknown which fusion protein/s (i.e. fusogen/s) mediate the fusion of Rn.p cells. My results suggest that two known fusogens in C. elegans – EFF-1 and AFF-1 participate in the formation of the SET. However, only EFF-1 appears to mediate the fusion of R6.p to R9.p with hyp7 syncytium. This functional separation between more than one fusogen suggests that the formation of the SET is a highly regulated process.
