Worm Breeder's Gazette 1(1): 8

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.

General Description of Hirsh Lab Activities

D. Hirsh

As most people are probably aware by now, I first started by 
collecting a large number of temperature-sensitive mutants that are 
blocked in the reproductive life cycle.  These mutants were then 
placed into six phenotypic categories.  The zygote-defective mutants 
are those that lay fertilized eggs that fail to hatch.  Gonadogenesis-
defective mutants are those that when reared at restrictive 
temperature produce neither fertilized eggs nor progeny.  
Spermatogenesis mutants are those that when reared at restrictive 
temperature, can be rescued for progeny production by mating with wild 
type males at restrictive temperature.  The accumulators are those 
that grow to an intermediate larval stage and either stop growing or 
die at an immature stage.  The abnormal F1 are mutants that when 
placed at restrictive temperature grow up to be adults, produce 
progeny, but those progeny grow up to be sterile adults.  In addition, 
a few temperature sensitive morphological mutants were isolated.
Rebecca Vanderslice and I originally studied in greater detail three 
particular mutants in the zygote-defective category.  They were 
interesting in two respects.  (1) Not only did they show zygote-
defective phenotype when the adults were placed in restrictive 
temperature, they also showed gonadogenesis-defective phenotype if 
they had been reared from L1 onward at high temperature.  (2) Each of 
the three mutants is a maternal-effect mutant.  At the present time, 
Becky Vanderslice and Bill Wood are re-examining the zygote-defective 
class and the gonadogenesis-defective class to find out which are and 
which are not maternal-effect mutants.
One of the central questions we are asking is, what is the 
distribution of critical times of temperature sensitivity among the 
mutants and which of these are maternal effect mutants?  We're asking 
how far into development do the mutants go with maternal contributions.

At the same time, Tina Carlson, an undergraduate working in my 
laboratory, is working on the twenty-five spermatogenesis mutants to 
determine the critical times of temperature sensitivity and to begin 
characterizing them genetically in terms of linkage groups.  Due to a 
recent conversation with Bob Edgar, we're worried about interallelic 
complementation and Tina is now doing mapping of these spermatogenesis 
Lastly, we are again involved in getting two-dimensional gels going. 
Pat O'Farrell, a graduate student working here, developed a very 
reliable two-dimensional gel electrophoresis system that probably most 
of you know about (it appeared in JBC this year).  Michael Klass and 
Stephen Carr are now trying to improve the sensitivity so smaller 
amounts of radioactivity can be used.  We hope soon to have a complete 
set of two-dimensional patterns for adult nematodes and different 
developmental stages.