In investigating how response to neurotransitters is modulated we have defined a series of mutants that are hypersensitive to serotonin with respect to their egg laying behavior. Mutants of
unc-10 fall into this category. In addition to being serotonin hypersensitive, they are aldicarb resistant, indicating defects in acetylcholine synthesis or transmission. Taken together, these two phenotypes lend to our model that acetylcholine plays a role in modulating the response of certain neurons in the egg-laying circuit to serotonin. In addition,
unc-10 mutants lay eggs in M9, a phenotype shared with other serotonin hypersensitive mutants. Since the phenotype of
unc-10 suggests that it may encode a protein involved in the regulation of neurotransmission, we decided to clone it. In the process of trying to clone
unc-10 we have found it necessary to perform mapping experiments to reestablish the map position. It seems that the previous map position assigned to
unc-10 is located too far to the right on the X chromosome. Currently, experiments are underway to map
unc-10 with respect to nearby STS sites and
dpy-7, a gene thought to be relatively close to
unc-10. Once the map position has been reassigned, experiments will be initiated to clone
unc-10.