Worm Breeder's Gazette 1(2): 19b

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.

Association of Kynurenine Hydroxylase Activity with Mitochondria in C. elegans

S.S. Siddiqui, P. Babu

The flu-2 (previously called fl-II; M.G.G.  135 39-44) mutants were 
picked up for the altered autofluorescence of the gut as the phenotype.
These mutants have very much reduced activity of kynureninase 
compared to the wild-type.  Crude extracts of alleles of this gene 
have been assayed for this enzyme activity; three of them, flu-2-2, 
s than 5% specific activity of 
the wild type whereas flu-2-1 has about 12%.
In an attempt to make revertants of flu-2 using EMS it was noticed 
that these mutants were highly sensitive to EMS.  A quantitative 
measure to EMS sensitivity was made by subjecting young larvae of N2 
as well as flu-2 mutants to 300 min of 0.05 M EMS and estimating the 
fraction of larvae which continue to grow and become adults.  About 
30% of N2 larvae survive this treatment whereas only about 4% of flu-2-
1 and about 0.5% of the other three alleles of flu-2 survive.  Thus 
these mutants show high degree of sensitivity to EMS; further this 
sensitivity appears to be correlated to the level of residual 
kynureninase activity as indicated by the data shown above.
Flu-2 mutants also show enhanced sensitivity to gamma-rays; however 
there is no significant difference in the sensitivities of N2 and flu-
2 mutants to UV irradiation.