2.

Chronological changes in expressions of HOXC6 and HOXC11 genes in GOTO cells grown in the presence of BrdU. GOTO cells were grown in the same condition as Fig. 1. Total RNA treated with DNase was subjected to quantitative real-time RT-PCR. The expression levels of HOX genes were determined as the ratio of the HOX gene to the internal reference gene (β-actin). Data are represented as the relative ratio of the HOX gene expression level of GOTO cells treated with BrdU to that of non-treated GOTO cells.