Y. Ying et al., Effects of male accessory sex glands on sperm decondensation and oocyte activation during in vivo fertilization in golden hamsters, INT J ANDR, 22(2), 1999, pp. 68-76
Removal of paternal male accessory sex glands (ASG) could cause a delay in
DNA synthesis in hamster zygotes fertilized in vivo. In view of the fact th
at this process is closely related to pronuclear development which, in part
, depends on sperm nuclear decondensation and oocyte activation during fert
ilization, we carried out a series ol experiments were undertaken to determ
ine whether ASG also has an effect on these early events. (1) Oocytes were
collected ham females mated with SH (sham-operated control), AGX (bilateral
excision of ampullary glands), VPX (bilateral excision of ventral prostate
s) or TX (excision of all ASG) males (n = 8 per group) at 4, 5 and 6 h post
coitus. (2) Epididymal spermatozoa were incubated with total ventral prost
ate (VP) secretion to study its effect on dithiothreitol-induced sperm deco
ndensation. (3) Histone H-1 kinase activity in oocytes collected as describ
ed in (1) was determined. (4) Exocytosed cortical granules on oocytes were
labelled with FITC-LCA and quantified by a Metamorph Imaging System. Result
s showed that sperm decondensation and resumption of meiosis in oocytes in
VPX and TX groups were significantly slower compared with SH. VP secretion
augmented sperm decondensation in vitro. At 4 h post coitus, the relative a
ctivity of histone H1 kinase in the TX and VPX groups was significantly hig
her than that in the SH group (p < 0.01). Cortical granule exocytosis in th
e AGX group was consistently weaker at all time points studied and was sign
ificantly lower than that of the control at 4 h post coitus (p < 0.05), whi
le the percentage of polyspermic fertilization in the AGX group was signifi
cantly higher compared with that in the SH group (p < 0.05). Taken together
, these results show that the lack of exposure of spermatozoa to secretions
of the ASC does not jeopardize their ability to penetrate ova, although ot
her aspects of their function in the early stages of gamete interaction and
subsequent initiation of embryonic development are affected.