Worm Breeder's Gazette 4(1): 37

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.

Update on the X-linked Lethals

P. Meneely, B. Herman

A report on our previous work is in press (Genetics).  The paper 
describes 21 recessive lethal mutations balanced by mnDp1 which define 
14 genes in the vicinity of unc-3 X.  We also report the production of 
19 overlapping deficiencies that divide this region into at least 10 
Since then we have added 11 new lethal mutations to our collection; 
10 of these have been fully complemented.  Our procedure is to map 
each new mutation to one segment by the deficiencies, then do 
complementation tests with genes in that same segment.  The 31 
mutations which have been complemented (plus 3 sent to us from other 
labs) lie in 18 genes; 6 genes have more than one allele, and 4 have 3 
or more alleles.  One gene, let-2, has 8 alleles, all temperature-
sensitive embryonic lethals showing partial complementation.  The 2 
alleles (mn106 and mn132) of let-5 have the same unusual phenotype.  
mnDp1/+;unc-3 let-5 hermaphrodites give unc-3  
These survive and reproduce, but their progeny die at about L3.  
Hemizygous unc-3 f20 (a relatively small deficiency)
and heterozygous unc-3 mn106/unc-3 mn132 individuals have the same 
phenotype as unc-3  one of the most extreme 
maternal effects we are aware of.  The new mutations and genes do not 
change our estimate of at least 30 essential genes covered by mnDp1.