Male accessory sex gland secretions affect oocyte Ca2+ oscillations during in-vitro fertilization in golden hamsters

To evaluate the effect of male accessory sex gland secretions on Ca2+ oscillations of oocytes, epididymal or ejaculated spermatozoa recovered from uteri were used to inseminate oocytes. Ca2+ oscillations were measured by Fura 2 fluorescence imaging (F340/F380). We showed that although Ca2+ oscillations induced by ejaculated spermatozoa had a pattern similar to those induced by epididymal spermatozoa, the amplitude of the first Ca2+ transient in the former group was significantly higher (P < 0.05) and the duration was significantly longer (P < 0.01). Oocytes inseminated with ejaculated spermatozoa recovered from uteri from males had ampullary glands or ventral prostates removed showed significantly lower Ca2+ oscillations compared to the controls (P < 0.05, P < 0.01 respectively). Moreover, the relative area of the first Ca2+ transient in treatment groups was significantly smaller than the control. In addition, a significantly higher percentage of oocytes (52%) inseminated by spermatozoa from males with all accessory sex glands removed showed non-oscillatory Ca2+ transients, compared to the controls (5%, P < 0.05). These results indicate that accessory sex gland secretions can affect Ca2+ oscillations. The differences between Ca2+ oscillations induced by epididymal and uterine spermatozoa from males with all accessory sex glands removed suggest that uterine factors may also influence this process.