Figure 3.

Enforced expression of constitutively active Akt1 only minimally enhances viability of Puma-deficient cells in the absence of IL-3. (a) Multiple independent clones of FDM cells of the indicated genotypes expressing iAkt1 or ieGFP were cultured in the presence of 4-OHT for 24 h before being starved of IL-3 over a 5-day time course. Cell viability was determined by PI exclusion using flow cytometry. (b) The same cells shown in (a) were removed from liquid culture and plated in semi-solid medium containing 0.3% soft agar and 0.5 ng/ml IL-3. The numbers of colonies were counted after 10 days and expressed relative to the numbers of colonies from time 0 day. Data represent means and standard errors of at least four clones of each genotype, from at least three independent experiments