Worm Breeder's Gazette 12(2): 47 (January 1, 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.
Mutations in daf-7 result in constitutive formation of dauer larvae, even in abundant food. This gene has been localized by a combination of genetic and RFLP mapping, DNA transformation, and Tc1 tagging. On a chromosomal walk toward fem-2 ,one of us (D. Pilgrim) identified a cosmid (DE9) that transformed a daf-7 mutant to wild-type when injected into the mutant germline. Cosmid DE9 was used to probe a cDNA library constructed by Stuart Kim. Twenty cDNA clones of various sizes up to 2.3kb were isolated from the library. Hybridization results indicate that all these clones share common sequences. Probing restriction digested genomic DNA isolated from the Tc1 -insertionmutant DR1039 , daf-7 ( m434 ),revealed differences consistent with a 1.6kb Tc1 insertion in DR1039 DNA when compared with non-mutant DNA. For example, when probed with cDNA a 11kb BamHI fragment found in wild-type genomic DNA corresponds to a 12.6kb fragment in mutant DNA. We sequenced both ends of the largest (2.3kb) cDNA clone, and have orfs totaling 460 amino acids. Unfortunately, no appropriate initiator codon or poly A addition site are evident in the cDNA. Therefore, we are screening Bob Barstad's cDNA library to identify a more complete clone. The sequence so far shows no strong homology to anything in the NBRF-PIR data base, although it does have weak homology to some calcium dependent ATPases.