Fig. 6.

Role of PYK2 in gamete fusion and sperm incorporation. The timing and extent of sperm-oocyte fusion was quantified in WT (white bars) and pyk2^−/− (grey bars) oocytes pre-loaded with DRAQ5 as in Fig. 3. Samples of oocytes were collected at 60, 90, and 120 m.p.i. to correlate with the sperm incorporation timecourse (below). Sperm heads bound to the oocyte surface that accumulated DRAQ5 from the oocyte were considered to have fused with the oocyte plasma membrane (panel A). Values represent the mean of 4 experiments including 116 WT oocytes and 126 pyk2^−/− oocytes. The timing and extent of sperm incorporation was quantified in separate experiments (Panel B) where WT (white bars) and pyk2^−/− (grey bars) oocytes were fixed and labeled with DRAQ 5 to label all sperm heads and with alexa 568-phalloidin to label the cortical actin layer. Sperm heads that were located within the oocyte cytoplasm and which showed evidence of nuclear decondensation were considered to be incorporated. Values in panel B represent the mean of 5 groups including 123 WT oocytes and 133 pyk2^−/− oocytes +/− SEM. (*) f-test indicated that the WT and pyk2^−/− means were significantly different (P=0.01).