Worm Breeder's Gazette 5(1): 31

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.

A Counteraction Between Insect Juvenile Hormone Analouge Methoprene and Antijuvenile Hormone Precocene 2

A. Fodor, P. Deak, I. Kiss

Data presented at Cold Spring Harbor this year showed, that 200 and 
400  g per ml precocene-2 in NGM food dramatically decrease the final 
size of lon-2(e678)/lon-2(e678) hermaphrodites which were placed onto 
these plates at different ages.  It was also demonstrated that the 
same doses proved to be toxic to the adults.  Both effect could be 
partly compensated by different doses of methoprene to the food.  Both 
the precocene and the JHA was more effective in higher concentrations, 
and we might suppose, that the precocene-'mini-adults' represent 
hypojuvenile hormone states.  For to say it we need some more evidence.
Following the life and growth of dauer larvae placed onto precocene 
and control plates we found that the molts happened almost the same 
time, but the size of animals on precocene plates hardly increased.  
By looking at them under a light microscope, these 'mini-adults' look 
like perfectly normal but small adults.  John Sulston was so kind to 
observe some of our animals by Nomarski microscope and he also found 
them normal.  Now we are looking for intermediate developing forms 
having both larval and adult cuticle, gonad and vulva structures.  
Excluding the possibility of the repellent/antifeeding effects of 
precocene, we found that when the worms have a choice of moving to 
bacteria with or without any of the drugs, they choose the latter.  
When they have to choose between JHA and precocene, they prefer JHA, 
but if they could avoid it, they don't lay eggs on it.  (e678 worms 
were used as dauers and scored as adults; e1034 chemotactic mutant was 
the control.)  Looking for chance for genetic differences in the 
reactions to precocene, we compared 22 mutant and N2 stocks on the 
base of adult test and found that one of the mutants resistant to 
levamisole proved to be highly resistant to precocene too.  This 
mutant was isolated and generously provided by Jim Lewis: X37(tmr3).  
We are going to isolate mutants resistant to precocene and also 
looking for developmentally intermediate forms among precocene 'mini-
adults'.