Worm Breeder's Gazette 2(2): 10a

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.

Title unknown.

Authors unknown.

A series of mutants affected in dauer larva formation is being used 
to determine the nature of the genetic program for this aspect of 
development.  Mutant genes have been ordered with respect to one 
another in a genetic pathway based on analysis of epistatic 
relationships.  The genes already characterized apparently specify a 
signal pathway (or pathways) for dauer formation.  One class of mutant 
is non-chemotactic and exhibits abnormal sensory ultrastructure.
A search for mutants which are temperature-sensitive in their 
ability to recover from the dauer state was based on selection of SDS-
resistant larvae in populations recovering from starvation.  As 
expected, this selection turned out to be a good method for obtaining 
dauer-constitutive mutants, since slow recovery is often associated 
with constitutive entry into the dauer state.  Furthermore, starved 
plates usually contain F3 dauers, so that constitutive mutants with 
maternal effects are readily detected.  Four new alleles of a 
previously characterized dauer-constitutive gene, daf 1, have been 
obtained.  All mutant alleles of this gene exhibit a maternal effect 
except for one allele which is lethal.
The only recovery-defective mutants isolated were non-ts, but 
extremely leaky.  This result is consistent with other genetic 
evidence suggesting that the process of recovery shares common steps 
with the entry process.  Good recovery mutants probably cannot be 
found by direct selection because many of these mutants are, in fact, 
dauer-defectives.  When dauer-defective mutants are forced to enter 
the dauer state by the introduction of an epistatic ts dauer-
constitutive mutation the dauers formed are unable to recover even at 
the permissive temperature.  This strongly suggests that the genes 
normally required for entry are required for recovery as well.