Fig. 4. The effect of FGFR-1 activation on wild-type and tFGFR-1 sperm capacitation induced tyrosine phosphorylation. (A) A comparison of tyrosine phosphorylation patterns of wild-type sperm +/- 10 ng/ml bFGF under capacitating conditions for the times indicated. The relative absorbance of tyrosine phosphorylation was determined and all data was normalized to ß-tubulin, n=3. (B) A comparison of ERK 1/2 activation in wild-type mouse sperm +/- 10 ng/ml bFGF under capacitating conditions. The relative absorbance of ERK phosphorylation for each sample was determined and all data was normalized to the expression of ß-tubulin, n=3. (C) A comparison of PI3K activation in wild-type mouse sperm +/- 10 ng/ml bFGF under capacitating conditions. The relative absorbance of p85 phosphorylation for each sample was determined and all data normalized to the expression ß-tubulin. ^*P<0.05, ^**P<0.01, ^***P<0.001.