EFFECTS OF MALE ACCESSORY SEX GLANDS ON DEOXYRIBONUCLEIC-ACID SYNTHESIS IN THE FIRST CELL-CYCLE OF GOLDEN-HAMSTER EMBRYOS

To study the paternal effect, particularly of accessory sex gland secr etions, on DNA synthesis in golden hamster zygotes, the glands were su rgically removed from golden hamsters resulting in 4 groups: SH, sham- operated; AGX, bilateral excision of ampullary glands; VPX, bilateral excision of ventral prostates; and TX, excision of all accessory sex g lands. Each female was mated with one male and killed at 6, 8, 10, or 12 h postcoitus (p.c.). Embryos were collected, and zygotes in S-phase were identified by immunocytochemical techniques after pulse-labeling with 50 mu M 5-bromo-2'-deoxyuridine-5'-monophosphate (BrdU) in Tyrod e's albumin lactate pyruvate medium for 30 min. In another experiment, embryos at 6 h p.c. were incubated in 50 mu M BrdU for 6 h. Presumpti ve zygotes were stained with propidium iodide to visualize pronuclei. The BrdU pulse-labeling results showed that the percentages of embryos with 1 or 2 pronuclei in S-phase at 8 h p.c. in VPX (44.3 +/- 10.4) a nd TX (41.6 +/- 10.6) groups were significantly lower (p < 0.05) than that in the SH group (69.0 +/- 5.5). In the AGX group, although the pe rcentage of embryos with 1 or 2 pronuclei in S-phase was not significa ntly different from that of the SH group, the percentage of 8-h embryo s with 2 pronuclei in S-phase was 51.6 +/- 2.8, significantly lower th an in the SH control (68.1 +/- 6.0, p < 0.05). When the embryos were l abeled with BrdU for 6 h, the percentages of embryos with 1 or 2 pronu clei in S-phase were not different among the 4 groups. However, the pe rcentage of embryos showing 2 pronuclei in S-phase was significantly l ower in the AGX group (78.4 +/- 6.7) than in the SH group (91.8 +/- 2. 9, p < 0.05). These results suggest that accessory sex glands can affe ct DNA synthesis in hamster zygotes and that the mechanisms by which a mpullary gland and ventral prostrate secretions affect the first cell cycle are probably different. A significantly higher incidence (p < 0. 001) of polyspermy was observed in embryos sired by males without ampu llary glands (5.2 +/- 1.0%) compared with those sired by the SH group (0.8 +/- 0.3%).