Worm Breeder's Gazette 10(1): 97

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.

Hydrotherapy Cures Unc-23

A.M.E. Bullerjahn and D.L. Riddle

Hermaphrodites homozygous for the unc-23(e324)V mutation have 
dystrophic heads that are dragged or pushed along as they move forward.
The hermaphrodites also appear to be slightly egg-laying deficient.  
This marker is very useful for genetic mapping and we mapped ama-2(
m323), which confers dominant resistance to the fungal toxin alpha-
amanitin, relative to unc-23 in a two-factor cross.  unc-23 progeny of 
unc-23 +/+ ama-2 heterozygotes were placed singly into microtiter 
wells containing alpha-amanitin in a suspension of OP50 in S medium.  
Resistant hermaphrodites that resulted from recombination between unc-
23 and ama-2 produced progeny that grew to adulthood.  When the 
progeny that grew in alpha-amanitin were put onto plates, we noticed a 
curious phenomenon.  Only about one-fourth of the resistant progeny 
displayed the unc-23 phenotype; three-fourths appeared wild-type (i.e.,
they no longer dragged their heads).  After 24 to 48 hours on plates, 
some of those that initially appeared to be wild-type dragged their 
heads, but the rest continued to appear wild-type.  Several of these 
persistently 'wild-type' hermaphrodites were cloned on plates and all 
of their progeny exhibited the unc-23 phenotype (they dragged their 
heads).  These observations lead us to conclude that growth in liquid 
'cures' the unc-23 phenotype at least 50% of the time.  This 
phenomenon may have been observed by others in the past, but we 
haven't heard of it.  It may be the first successful application of 
hydrotherapy in C.  elegans.Incidentally, the ama-2 gene was 
ultimately positioned between the right end of ctDf1 and unc-76.