Figure 1

Oocyte activation after ICSI with sperm from mice with NPYq deficiency. (a) Epididymal sperm from males with severe NPYq deficiency (9/10NPYq- and NPYq-²) but not from males with moderate NPYq gene loss (2/3NPYq-) were less able to activate oocytes than epididymal sperm from their appropriate controls, as revealed by Fisher's exact test (d, P < 0.0001 versus matching sperm type in control). Epididymal sperm from males with severe NPYq deficiency (9/10NPYq- and NPYq-²) but not from males with moderate NPYq gene loss (2/3NPYq-) were less able to activate oocytes than testicular sperm, as revealed by Mantel-Haenszel chi square analysis (**P < 0.01, ***P < 0.001). (b) Genotype/source interaction revealed by ANOVA, showing that NPYq deficiency preferentially impairs oocyte activation with epididymal sperm (P = 0.038). Two males were used per genotype; four sperm groups (epididymal, frozen epididymal, testicular and frozen testicular) were examined per male; approximately 25 (24.88 ± 8.03) oocytes were scored per sperm group per male.