Figure 4.

Increased engrailed expression in HPRT-deficient human M17 neuroblastoma cells. Quantitative PCR for En1 and En2 mRNA was done for each mutant subline (TG1, TG3, TG5, TG8), determined in quadruplicate and normalized to a simultaneously processed control mRNA (Myl6), where the raw data showed little variation among the lines. Results from the HPRT⁻ human M17 sublines are presented as percent changes relative to a simultaneously processed sample of the HPRT⁺ parent line. The overall ANOVA was significant for both En1 (F = 109.2, P < 0.001) and En2 (F = 59.5, P < 0.001). Post hoc Tukey t-tests revealed significant differences at the P < 0.05 level between the parent and each subline as indicated by asterisk.