Tag: Hamster
Acrosome Biogenesis in the Hamster: DISCUSSION(5)
Immunoblotting and immunofluorescence studies have also identified antigenic changes in acrosomal proteins of guinea pig and mouse late spermatids and spermatozoa consistent with intra-acrosomal protein processing. We have been unable to demonstrate any carbohydrates associated with AM22 or AM29 by lectin staining of Western blots (unpublished data), so the specific nature of potential posttranslational modifications […]
Acrosome Biogenesis in the Hamster: DISCUSSION(4)
The protease(s) responsible for the intra-acrosomal size processing of the 40-kDa polypeptide in the hamster or of the SPlO-related proteins in other species are unidentified. In the hamster, the size processing results in two major polypeptides, AM22 and AM29, as well as a set of minor related bands; however, in other species such as the […]
Acrosome Biogenesis in the Hamster: DISCUSSION(3)
Although the mature AM22 and AM29 polypeptides are assembled into a Triton X-100-insoluble acrosomal matrix assembly in epididymal spermatozoa, the 40-kDa putative precursor protein of the round spermatids is readily soluble in Triton X-100. It is possible that size processing of the precursor polypeptide is required for the assembly of the insoluble matrix elements, and […]
Acrosome Biogenesis in the Hamster: DISCUSSION(2)
The human SP10 proteins have been demonstrated to associate with the outer and inner acrosomal membranes of the anterior acrosome and are also present within the equatorial segment . In the mouse, the SPlO-related polypeptides localize to the acrosome by immunofluorescence , but their incorporation into a stable acrosomal matrix assembly was not demonstrated. Our […]
Acrosome Biogenesis in the Hamster: DISCUSSION(1)
The outer acrosomal membrane of hamster spermatozoa adheres to a stable acrosomal matrix assembly composed of two contiguous but structurally distinct elements . This matrix complex binds proacrosin and N-ace-tylglucosaminidase , and possibly other hydrolases, and it remains intact and associated with the hybrid membrane complex after the acrosome reaction . In the present study, […]
Acrosome Biogenesis in the Hamster: RESULTS(7)
Immunoblotting was performed on Triton X-100-soluble and -insoluble fractions of round spermatids using both polyclonal anti-AM22 and monoclonal anti-AM29/22 (Fig. 11). The Triton Х-100-soluble fraction possessed a polypeptide of 40 kDa that reacted with polyclonal anti-AM22 (Fig. 11, lane 2) and no immunoreactive polypeptide was found in the pellet fraction (Fig. 11, lane 3). In […]
Acrosome Biogenesis in the Hamster: RESULTS(6)
AM22/AM29 Expression during Spermatogenesis Light and electron microscopic immunolabeling was employed to define the temporal expression and localization of the acrosomal matrix polypeptides in spermatogenic cells. When polyclonal anti-AM22 was used, protein expression was noted in the acrosome at all stages of spermatid development (Fig. 9, A, B, D, and E). In late matu-ration-phase spermatids, […]