Authors : Siying Zou, Yu Du and Lishi Zhang
Abstract: This aim of this was to evaluate the mutagenic effect and mechanisms of genistein. The mutagenic effect of genistein was assessed by the mouse lymphoma assay in L5178Y cells treated with genistein for 3 and 24 h. To investigate the characteristics of mutagenesis, the specific mutation point of Thymidine Kinase (TK) gene was identified by DNA sequencing and analyzed by Real-Time quantitative PCR (qRT-PCR). The Total Mutation Frequency (TMF) increased from 59.07x10-6 to 1038.47x10-6 in a dose-dependent manner after genistein exposure. The difference in the TMF between the vehicle control and genistein groups (5, 10 and 20 μg mL-1) was statistically significant (p<0.01). DNA sequencing identified an overlapping-peak (T/G) heterozygote at the 64th base of exon6 in the TK gene. By comparison in the induced and spontaneous mutant colonies, a single-peak (G) existed at the same position which was the reflected Loss of Heterozygosity (LOH). The qRT-PCR results showed that the proportion of hemizygous LOH in spontaneous mutant colonies was 29.03% which increased to 84.38% in genistein-induced mutant colonies. Genistein (5-20 μg mL-1) induced TK mutations in a dose-dependent manner in L5178Y cells and the mutations were mainly hemizygous-type LOH in TK gene.
Siying Zou, Yu Du and Lishi Zhang, 2012. Genistein Induced Hemizygous-Type Loss of Heterozygosity in Thymidine Kinase Gene of L5178Y Cells. Journal of Animal and Veterinary Advances, 11: 4655-4659.