Worm Breeder's Gazette 7(2): 16

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.

Embryonic Lethal Amber Mutations on Linkage Group II

P. Meneely, P. Pesavento, B. Wood

In the last newsletter, we described a selection of lethal amber 
mutations linked to dpy-10, using sup-7.  We have revised this 
procedure slightly to take advantage of the balancer chromosome C1.  
Our current procedure is to mutagenize unc-4(e120); )
hermaphrodites and mate them with sup-7 males.  Neither marker is 
suppressed by sup-7.  From the F1 progeny, we pick wild-type animals 
and score their F2 progeny.  Broods that have fertile Uncs and Dpys, 
but no fertile Unc Dpys are candidates for an amber lethal linked to 
unc-4.  We have been outcrossing such candidates with C1/unc-4 males 
to establish stocks of genotype C/unc-4 am, which segregate am am 
mutant homozygotes.  We also have been establishing stocks of genotype 
C1/unc-4 am; sup-7/sup-7.  This is readily distinguished from the 
former stock not only by the suppressible lethal, but also by the 
suppression of unc-52(e669), one of the markers on the C1 balancer.  
Thus far, we have isolated more than thirty candidates, and have 
outcrossed about half.  From these, two separate amber mutants have 
been maintained in both suppressed and nonsuppressed stocks.  The 
balancer makes stock maintenance and mutant complementation much 
easier.  We hope to identify amber mutations of genes known only by 
temperature-sensitive alleles, as well as new essential genes.