Siying  Zou, Yu  Du, Lishi  Zhang, 
    Genistein Induced Hemizygous-Type Loss of Heterozygosity in Thymidine Kinase Gene of L5178Y Cells,
    Journal of Animal and Veterinary Advances,
    Volume 11,Issue 24,
    2012,
    Pages 4655-4659,
    ISSN 1680-5593,
    javaa.2012.4655.4659,
    (https://makhillpublications.co/view-article.php?doi=javaa.2012.4655.4659)
    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 (<I>TK</I>) gene was identified by DNA sequencing and analyzed 
  by Real-Time quantitative PCR (qRT-PCR). The Total Mutation Frequency (TMF) 
  increased from 59.07x10<SUP>-6</SUP> to 1038.47x10<SUP>-6</SUP> in a dose-dependent 
  manner after genistein exposure. The difference in the TMF between the vehicle 
  control and genistein groups (5, 10 and 20 &#956;g mL<SUP>-1</SUP>) was statistically 
  significant (p&lt;0.01). DNA sequencing identified an overlapping-peak (T/G) 
  heterozygote at the 64th base of exon6 in the <I>TK</I> 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 &#956;g mL<SUP>-1</SUP>) induced TK mutations in a 
  dose-dependent manner in L5178Y cells and the mutations were mainly hemizygous-type 
  LOH in <I>TK</I> gene.
    Keywords: Genistein;mouse lymphoma assay;DNA sequencing;real-time quantitative-PCR;mutagenicity;loss of heterozygosity