| Research Abstract |
Changes in the intramembranous particles (Imps) of the sperm plasma membrane during epididymal transport Spermatozoa taken from the various parts of the epididymis were studied by freeze fracture in several mammalian species. In general, large and small IMPs could be distinguished in the peri-acrosomal plasma membrane (PAPM). In hamsters, rats rabbits and boars, hexagonal arrangement was temporally formed by the small IMPs, but it was not found in the human spermatozoa, whose IMP- density was low. From these observations, following conditions may be needed for the IMP-pattern formation; (1) the presence of similarly sized numerous IMPs, (2) the movement of the IMPs, (3) the presence of IMP gathering factors such as a barrier for their movement.
Increase of membrane sterol density in the hamster spermatozoa during their epididymal passage The density of filipin-sterol complexes (FSCs),was 390/mum^2 in the PAPM of the hamster spermatozoa taken from the initial segment of the epididymis and it became to about 500/mum^2. when the spermatozoa passed the caput flexure. The increase of FSC density may contribute to stabilize the membrane.
Changes of the sperm plasma membrane during in vitro capacitation in the golden hamster Spermatozoa were incubated in Tyrode solution, and they were examined by freeze fracture. At two hours after incubation, FSC density in the PAPM reduced by 70-80%. At three hours after incubation, when the spermatozoa were capacitated, the majority of small IMPs had disappeared, and wide IMP free- area were formed in the PAPM.
Production of monoclonal antibody Monoclonal antibodies were produced against extracted proteins from the isolated spermatogenic cells in mice. One of such antibody, 13D3, recognized hsc7l, which belongs to 7OkDa heat shock protein family,. Indirect immunofluorescence showed that hsc7l was present throughout the cytoplasm in the young spermatogenic cells, but localized in the middle piece of the spermatozoa.
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