Fig. 6. Overexpression of a catalytically inactive mutant form of PTEN promotes neuron and astrocyte differentiation. OBSC cultures from Igf-I^–/– embryos were infected in parallel with a vector expressing PTEN-C/S-GFP or with a vector expressing GFP alone. Three days later, the cells were passaged and cultured for 2-3 days in conditions of differentiation (in the absence of mitogens), in the presence or absence of 100 ng/ml IGF-I. (A,B) Of the total number of GFP-positive cells, the proportion that co-expressed TuJ1 or GFAP was calculated. The data obtained in PTEN-C/S-GFP-infected cultures was expressed as the percentage of the data obtained in GFP-infected cultures that were considered to be 100% (dotted line). The results are expressed as the average ± s.e.m. of data of 4-8 cultures from two experiments. PTEN-C/S-GFP overexpression increased the proportions of TuJ1-positive and GFAP-positive cells by 52% and 42%, respectively, in the absence of IGF-I. (*P<0.05; Student's t-test.)