Figure 2.

bad^−/−but not bim^−/−bad^−/− mice have abnormally increased numbers of platelets. (a) Peripheral blood platelet numbers were determined from 6–12 week old bim^−/−bad^−/−, bim^−/−, bad^−/− or wt mice by automated counting (Advia 2120, Bayer). Data represent absolute numbers (x10⁹/mL) of 6–12 mice of each genotype. *P<0.05. (b) Western blot showing expression of Bad in wt platelet lysates and its absence in platelets derived from bad^−/− mice. The positive control (+) for Bad expression was a lysate of wt mouse embryonic fibroblasts and the negative control (−) a lysate of bad^−/− mouse embryonic fibroblasts. Results are representative of two independent experiments. (c) Platelet half-life in the circulation was determined in 6–12 week old bim^−/−bad^−/− (n=6), bim^−/− (n=10), bad^−/− (n=8) or wt (n=16) mice by injection of biotin and flow cytometric analysis of the disappearance of CD41⁺biotin⁺ platelets (see Materials and Methods). Data represent mean ± standard error. (d) The half-life of transplanted Bad-deficient platelets in the circulation of 8 week old wt recipient mice (n=8) was determined by adoptive transfer. Alexa488 labelled platelets, derived from bad^−/− (n=4) or wt (n=4) donor mice, were injected into wt recipients and the disappearance of CD41⁺Alexa488⁺ platelets monitored by flow cytometry (see Materials and Methods). Data represent mean ± standard error.