Effect of the homokaryotic state of the uvs-2 allele in Neurospora crassa on formaldehyde-induced killing and ad-3 mutation.
Formaldehyde was tested for its killing and mutagenic activities in the ad-3 forward-mutation test in Neurospora crassa. The test was conducted in 3 two-component heterokaryons (dikaryons) of N. crassa in order to determine the effect of the uvs-2 allele, which causes a defect in nucleotide excision repair, on formaldehyde-induced killing and the induction of ad-3 mutants. These dikaryons were homokaryotic for uvs-2+ (H-12), homokaryotic for usv-2 (H-59), and heterokaryotic for uvs-2 (H-71). Formaldehyde induced killing and ad-3 mutants in H-12, but the presence of uvs-2 in the homokaryotic state (H-59) resulted in a 9-fold increase in killing and a 40-fold increase in the induction of ad-3 mutants. This increased sensitivity to formaldehyde-induced killing and mutation conferred by uvs-2 in the homokaryotic state (H-59 vs. H-12) is similar to that noted by others in Escherichia coli. Salmonella typhimurium and Saccharomyces cerevisiae. The dikaryon heterokaryotic for uvs-2 (H-71) has the same sensitivity to formaldehyde-induced ad-3 mutation as H-12, indicating that uvs-2 is recessive to uvs-2+.
de Serres
F J
FJ
Center for Life Sciences and Toxicology, Research Triangle Institute, Research Triangle Park, NC 27709.
Brockman
H E
HE
Hung
C Y
CY
D004260:DNA Repair; D004305:Dose-Response Relationship, Drug; D005557:Formaldehyde / Q000633:toxicity*; D005799:Genes, Dominant; D005800:Genes, Fungal; D005808:Genes, Recessive; D009154:Mutation / Q000187:drug effects*; D009491:Neurospora / Q000235:genetics*; D009492:Neurospora crassa / Q000187:drug effects / Q000235:genetics*; D014466:Ultraviolet Rays
D005557:Formaldehyde