This chapter introduces the methods to establish the genetically engineered S. typhimurium tester strain expressing human CYP and reductase (OR) and to describes the procedure of mutation assay with the established S. typhimurium tester strain.
Table 1 Mutagenic effect of water samples from different sites of Harike wetland in TA 98 tester strain of Salmonella typhimurium in Ames assay S. no.
Tester strain TA1535 (Molecular Toxicology Inc., Boone, NC) was used because it has a –G G G– DNA target and is susceptible to the same base substitutions that AFB1 induces (Foster et al. 1983).
The MATa VGIV strains (LA390 and LA392) reported herein were co-cultured with each reference tester strain.
The production of both human polymerases in yeast did not change the rate of spontaneous forward mutations to canavanine resistance in our tester strain (Table 1).
Only three of 21 R. delemar strains were capable of producing zygospores when paired with the tester strain CBS346.36 (3/21 or 14%).
The mating type was confirmed by mating experiments with the C. gattii, serotype C, MATα reference tester strain NIH312 [27] as well as with the MATα supermater strain JF101 [28] (Figure 2).
We also identified the putative protein-coding gene [16] with an ORF that was located between the TPT gene and the HMG gene in both the genome strain RA99-880 and the tester strain CBS346.36.
To determine the input ration of wild type : tester cells, the mixes were titered on both TRP (selective for wild type) and ADE (selective for tester strain) dropout media.
Following individual mass matings of the diploid deletion strains with haploid MATa and MATα strains, we observed aberrant mating with either the MATα tester strain (ctk1Δ, hfi1Δ and nup133Δ) or both the MATa and MATα tester strains (ctf4Δ).
