In Caenorhabditis elegans , five ram ( Ra y M orphology Abnormal) genes have been identified to play key roles guiding ray morphogenesis in the male tail. There are additional collagen and dpy genes involved in this process. In this study, we focus on two of these ram genes,
ram-1 and
ram-3 , to characterize their mutant phenotypes, which may provide clues to their functions. Genetic rescue by cosmids is currently performed for these genes. Using ray cell specific reporters, we have examined the cellular defects in the ram mutant ray cells. Rays of
ram-1 mutant worms have both the structural cells and hypodermis are both swollen. Similar defects are noted in
ram-3 mutant males, which has the most severe Ram phenotype among all ram mutants. Individual rays are usually indistinguishable. In addition,
ram-3 maled had abnormal cell bodies trapped within their fans, another features that has been observed in strong
dpy-11 and
ram-4 mutants. These extra cells are not the result of incorrect cell lineage or failure of cell death. Instead, they are confirmed to be neurons and structural cells, which should normally migrate anteriorly into the body. Such results prompt us to investigate if
ram-3 has additional phenotype associated with cell migration. We constructed double mutants of
ram-3 and
unc-5, which turns out to have reduction in progeny viability. A reduced hatch rate was observed although a normal number of eggs were laid by the double mutants . These data suggest that there may be possible interactions between these two genes. Since
unc-5 encodes a membrane bound protein (netrin receptor) required for autonomous function in neurons going through migration, genes involved in such axonal migration process are tested for potential interaction with
ram-3 . Additional genes, such as the
unc-6 nectrin,
unc-40 DCC,
unc-44 ankyrin and
unc-34 are being tested. Our preliminary data suggest that they do produce more severe phenotype including lethality. The cellular defects and their potential biochemical interaction will be further investigated.