We are in the process of cloning and sequencing the
osm-3 gene. A mutant in
osm-3 was originally isolated by Colotti and Russell 1978. Mutation in
osm-3 in C. elegans affects the ciliary structure of the sensory amphid neurons (Perkins et al 1986). Previously, we have reported that
osm-3 mutant phenotype is rescued by microinjecting a mixture of cosmid DNA using
rol-6 DNA as a marker, WBG: 12, No. 1 ,
p21 ,1991. We have checked the RFLP profile of different alleles of
osm-3 after hybridizing with the specific cosmid DNA probe which can rescue the
osm-3 phenotype , among them one allele SQ141 has an additional 4.5kb band in comparison to N2 and RW7097 ,this band is also detected in the recombinants using
dpy-13 (
e184 )and
unc-17 (
e113 ). On using the different restriction fragments of the cosmid DNA as a probe, we found that 1.8kb of the cosmid DNA hybridized with the 4.5kb band similar to the intact cosmid DNA on southern hybridization. Northern blot analysis of N2 poly A RNA using the 1.8kb cosmid DNA as a probe reveals a single band. These results suggest that 1.8kb cosmid DNA may correspond to the
osm-3 gene. The nucleotide sequence determination of the cDNA clones corresponding to the 1.8kb cosmid DNA fragment is in progress. We thank Dr.'s. R. Herman and J. Vowels for providing the different alleles of
osm-3 and Dr.'s. J. Miwa and H. Yasuda for helpful discussions.