Worm Breeder's Gazette 11(4): 85

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.

Genetic Analysis of the rol-3 Gene of LGV(left)

William Bradley Barbazuk, Robert C. Johnsen, Raja E. Rosenbluth and David L. Baillie

We are currently involved in the genetic analysis of the rol-3 gene 
of Caenorhabditis elegans.  The rol-3 gene resides on the eT1 balanced 
region of LGV(left) within zone 18 as defined by the deficiencies 
sDf35 and mDf3 (1).  The original rol-3 allele (e754) was EMS induced 
by Brenner(2).  Worms homozygous for e754 display left-handed helical 
treads along the length of their bodies as opposed to linear ones, and 
have left-handed helical musculature as well.  The roller mutant 
displays an abnormal crawl.  Rather than moving in the sinusoidal 
fashion characteristic of the wild-type worm the rol-3 homozygote 
rotates along its long axis in a left-hand helical fashion, resulting 
in a semi-circular path.(3)
Over the past four years our lab has isolated twelve more alleles of 
rol-3.  Eight of these alleles come from EMS screens over the entire 
eT1 balanced region.  Two alleles were gamma induced and two more were 
generated during EMS screens for selected regions of LGV(left) (1) .  
All of these are recessive lethal with the exception of s1040 which is 
homozygous viable at 15 C.  Alleles s501 and s742 are the products of 
gamma mutagenesis while s126, s422, s833, s1030, s1040, s1408, s1409, 
s1473, s1494, s1519 are the EMS products.  The calculated average EMS 
hit frequency for genes in the eT1 balanced region is 1.25, while that 
of rol-3 is 6 times greater.  Furthermore, some of these alleles 
display different phenotypes.  Whereas e754 is viable, s126, and s501 
are early larval lethals, s422, s742, and s833 are mid larval lethals, 
and s1040 is homozygous viable roller at 15 C which displays mid 
larval lethality at 20 C.  These phenotypic differences suggest that 
the rol-3 gene product may be required at more than one developmental 
stage.  let-412(s1598) is a sterile adult which has been mapped to 
zone 18.  This allele displays a weak roller phenotype.  Analysis 
aimed at constructing a complementation map of the rol-31 
i in order to determine whether or not this 
is a complex locus is currently under way.
In order to help identify genes whose products interact with rol-3 
during development, we are currently trying to identify and 
characterize mutations which suppress the temperature sensitive mid 
larval lethal phenotype of rol-3(s1040).  We have isolated two gamma 
induced and six putative E.M.S.  induced revertants.  The nature of 
these suppressors is currently under investigation.