Worm Breeder's Gazette 12(1): 21 (September 1, 1991)

These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.

Cosmid DNA rescue of the osm-3 mutant phenotype

M. A. Shakir, Shahid Siddiqui

Lab. of Molecular Biology, Toyohashi Univ. of Technology, Tempaku-cho, Toyohashi,441 Japan

We are in the process of molecularly cloning the osm-3 gene. Mutant in osm-3 was originally isolated by Culotti and Russell as osmotic avoidance in behavior. The ultrastructural studies of the sensory amphid cilia in osm-3 mutant was presented by Perkins et al.

We have previously reported our efforts to clone the osm-3 gene [WBG 11,(4), p.16, 1990 and C. elegans 1991 meeting's abstract #290]. Besides the transposon tagging of the osm-3 gene that we reported earlier, currently we have performed rescue of the osm-3 mutant phenotype using transformation by cosmid DNA. The cosmids were selected based on the refined genetic mapping of the osm-3 gene using dpy-13 ( e184 )and unc-17 ( e113 )markers. A mixture of three cosmids (kindly provided by Dr. A. Coulson) F42G3 , W07G9 and K09B3 is coinjected with rol-6 DNA as a marker (kindly provided by Dr. J. Kramer through Dr. J. Miwa) in osm-3 ( p802 )animals (obtained from CGC) and found cotransformation in the subsequent generations i.e., rollers are segregating with osm-3 . Phenotype is selected by observing the concentration of FITC dye in amphid and phasmid neurons in wild type (and in the rescued transformed animals) and its absence in the osm-3 mutant. Experiments are in progress to identify and characterize the smallest restriction fragment of a particular cosmid DNA which can rescue the osm-3 phenotype.