Fig. 3. Comparison of cell numbers of ICMs of blastocysts generated from intercross matings of mice heterozygous for gp130, in diapause for 2 or 6 days. Wt/het, combined gp130^+/+ and gp130^+/- genotypes; null, gp130^-/-. Error bars denote standard deviation. For 2 days of delay there is no significant difference in the mean inside cell number (P>0.1 by Student’s t-test). For 6 days of delay there is a highly significant difference between the mean numbers of inside cells by Student’s t-test (P<0.001). Comparing mean inside cell numbers from null embryos delayed for 2 days with those delayed for 6 days the difference is significant by Student’s t-test (P<0.002).