Worm Breeder's Gazette 8(3): 95

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.

Expression of an MSP-beta Glucuronidase Fusion Gene in Transformed Worms

M.R. Klass

Working in collaboration with Richard Jefferson in David Hirsh's lab 
at MCDB in Boulder we have been studying the expression of transformed 
genes in C.  elegans.  Using an MSP promoter from C.  elegans in pUC9 
recombinant plasmids have been constructed bearing an MSP promoter 
fused in-frame to the structural sequence for E.  coli  -glucuronidase 
followed by an MSP terminator sequence.  This plasmid (pMSP 2.1: UIDA) 
has been injected into the gonads of adult hermaphrodites.  Progency 
have been found bearing pMSP 2.1:UIDA sequences as extrachromosomal 
long tandern repeats with a copy number of approximately 200.  These 
extrachromosomal elements are 80% stable ie., 80% of the progeny from 
a positive adult contain the plasmid.  DAPI staining of oocytes during 
late diplotene reveals small chromosome like fragments in addition to 
the 6 tetrads.  These fragments are approximately 1/10 the intensity 
and size of a C.  elegans chromosome.  Some oocytes are observed to 
contain more than one such element and 3 and 4 elements have been seen 
in some oocytes.  Some oocytes do not contain any elements.  
Significant levels of  -glucuronidase are present in the transformed 
worms (DH 408-762) in contrast to no activity in the nontransformed (
DH 408) strain.  We are currently investigating the regulation of the  
-glu gene by Northern blot analysis and by the in situ localization of 
the enzyme.  We are also searching among the transformants for stable 
integrated copies of the plasmid.