Worm Breeder's Gazette 11(4): 51

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.

daf-4, a Gene Controlling Dauer Larva Development, Encodes a Serine/Threonine Kinase

M. Estevez, P.S. Albert and D.L. Riddle

Loss-of-function mutations in daf-4 confer a dauer-constitutive 
phenotype.  Two transposon-tagged alleles of daf-4 have been isolated, 
and Southern blots probed with the labeled transposon sequence 
revealed a novel restriction fragment in the mutant DNA that was 
absent in non-mutant DNA.  A transposon-containing fragment was cloned,
and sequences flanking the transposon were used to screen Bob 
Barstead's cDNA library and Chris Link's genomic library.  Four 
overlapping genomic clones and five cDNA clones were isolated.  
Microinjection of one of the genomic clones into the germline of daf-4 
mutants transforms their progeny to wild type.  Approximately 1 kb of 
contiguous cDNA sequence has been determined, and the deduced amino 
acid sequence shows 30% identity to the C.  elegans 
brane receptor kinase (Georgi et al., 1990, 
Cell 61: 635) over a 222 amino acid region in the catalytic domain.  
The deduced amino acid sequence also shares 37% identity with PSK-J3 (
from HeLa cells), a member of the cdc2/CDC28 kinase family over a 107 
amino acid region in the catalytic domain.  Since genetic interactions 
suggest that daf-4 acts downstream of the daf-1 receptor, we propose 
that it mediates the second step in a kinase cascade that normally 
acts to prevent dauer larva development, and permit growth.