Worm Breeder's Gazette 10(1): 41

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.

Progress in tpa-1 Gene Cloning

Y. Tabuse, K. Nishiwaki and J. Miwa

We isolated, from the mutator strains NJ82 and NJ204, five 
independent spontaneous TPA resistant mutants assigned to the tpa-1 
gene.  Three of the five mutants contained the 2.4kb fragment that was 
size-altered due to Tc1 insertion.   In the last meeting we proposed 
that the 2.4kb HindIII fragment is at least a portion of the tpa-1 
gene.  Now we have found another spontaneous tpa-1 mutant with the Tc1-
inserted 2.4kb fragment, and this mutant was isolated from yet another 
mutator strain RW7097 (a gift from Dr.  Waterston/Dr.  Mori ) .  This 
result further supports the idea that the 2.4kb fragment constitutes a 
part of the tpa-1 gene.
We have sequenced about 90% of the 2.4kb fragment, so far.  It is a 
fragment with high AT content and several A and T clusters.  To 
understand the relationship between Tc1 insertion and acquisition of 
resistance to TPA, we have also sequenced the Tc1 flanking region of 
two of the three mutants (original isolates for MJ562 and MJ563) 
isolated from NJ82.  We found that Tc1 was inserted in the same 
position in both mutants.   Analysis of insertion sites for other 
mutants are underway.
We have also screened a cDNA library, prepared from mRNA of mixed 
age (kindly provided by Dr.  Kimble/Dr.  Ahringer).  We obtained two 
cDNA clones using a 1.5kb fragment as a probe, which is a Tc1 flanking 
region of the 2.4kb fragment derived from MJ562.  Characterization of 
the cDNA is in progress.