Worm Breeder's Gazette 12(3): 46 (June 15, 1992)
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.
Our laboratory is currently involved in the molecular analysis of the dpy-20 gene. dpy-20 lies on chromosome IV, immediately to the right of let-60 and 0.2 map units to the left of unc-22 .There are nine known dpy-20 mutant alleles whose phenotypes range from somewhat dumpy to severely piggy. At least two of the nine alleles of this gene are temperature sensitive and are inviable at 15°C suggesting that this gene may serve an essential function during development. The dpy-20 gene was cloned using the method of Tc1 transposon tagging. A transposon-induced dpy-20 allele was provided by D. Riddle and P. Alberts. A 1.4kb plasmid clone consisting of the sequence flanking the Tc1 was isolated. This plasmid clone was used to screen a Charon 4 genomic library constructed by T. Snutch and a dpy-20 genomic phage was recovered. This phage was used to place dpy-20 on the physical map by A. Coulson and J. Sulston. It was found to lie within cosmid C35H3 and this cosmid was used to rescue a dpy-20 mutant. The 1.4kb plasmid clone of the flanking sequence was also used to screen a cDNA library supplied to us by B. Barstead and a cDNA was isolated. Both the cDNA and genomic DNA have been sequenced. The Tc1 -induced dpy-20 allele has also been sequenced and the Tc1 insertion site has been identified. Searches of the Genbank databank with both the cDNA and genomic DNA sequences were performed using the BLAST search algorithm. No similarity to any existing sequence was found. Some dpy genes are known to be collagen genes. However, dpy-20 has no similarity to any collagen gene in the databank and therefore, its dumpy phenotype must reflect some other role in establishing body morphology. A C. briggsae dpy-20 homologue has been isolated after screening a C. briggsae genomic library constructed by T. Snutch. We are in the process of sequencing and analyzing the C. briggsae dpy-20 homologue.
This research was supported by NSERC and MDA (Canada) grants to DLB.