Oviductal Epithelial Cells (oviductal + epithelial_cell)

Distribution by Scientific Domains

Selected Abstracts

How does polyspermy happen in mammalian oocytes?

Wei-Hua Wang
Abstract Polyspermy is one of the most commonly observed abnormal types of fertilization in mammalian oocytes. In vitro fertilization (IVF) provides approaches to study the mechanisms by which oocytes block polyspermic fertilization. Accumulated data indicate that oocyte, sperm and insemination conditions are all related to the occurrence of polyspermic fertilization. A high proportion of immature and aged oocytes showed polyspermy as compared with mature oocytes. Preincubation of oocytes and/or sperm with oviductal epithelial cells or collected oviductal fluid before IVF reduces polyspermic penetration. Recently, it was found that an abnormal zona pellucida is one of main causes of polyspermy in human eggs. A high proportion of polyspermy has resulted from the use of a high concentration of capacitated spermatozoa at the site of fertilization, irrespective of in the in vivo or in vitro environment. Oviductal secretions or oviductal epithelial cells themselves can regulate the number of spermatozoa reaching or binding to the zona pellucida thus reducing multiple sperm penetration. Suboptimal in vitro conditions, such as supplementations in IVF media, pH, and temperature during IVF, also induce polyspermic fertilization in some mammals. Species-specific differences are present regarding the relationship between insemination conditions and polyspermy. Microsc. Res. Tech. 61:335,341, 2003. 2003 Wiley-Liss, Inc. [source]

Impact of in vitro production techniques on the expression of X-linked genes in bovine (bos taurus) oocytes and pre-attachment embryos

Maria I. Nino-Soto
Abstract Our previous studies showed that expression patterns of X-linked genes in cultured cells are different from those of their tissues of origin. This investigation analyses the transcription pattern of the X-linked genes BIRC4, GAB3, MECP2, RPS4X, SLC25A6, and XIST in bovine in vitro matured oocytes and in vitro fertilized embryos, and their in vivo counterparts. In vitro-derived pools of mature oocytes and pre-attachment embryos were obtained by: (a) TCM-199/serum with bovine oviductal epithelial cells as co-culture, and (b) synthetic oviductal fluid/BSA. Pools of in vivo-derived morulae and blastocysts were provided by a commercial embryo transfer operation. Total RNA was extracted for quantification of gene-specific transcript levels using real-time quantitative PCR. Statistical analysis was performed using a mixed model factorial ANOVA with ,,=,0.05. The effect of the in vitro environmental conditions on X-linked gene transcription was most evident during the fourth cell cycle, at the period of activation of the embryonic genome, and seemed to be less pronounced at later developmental stages, with the exception of BIRC4. The levels of X-linked genes transcripts in in vivo-derived embryos were lower relative to their in vitro counterparts for all genes tested. Finally, the pattern of expression of XIST in bovine oocytes and embryos was similar to that reported in humans. These results highlight the possibility that X-linked gene expression analysis is a useful tool to monitor the impact of reproductive biotechnologies on the developmental potential of embryos and aid in their improvement. Mol. Reprod. Dev. 2006 Wiley-Liss, Inc. [source]

Surface mapping of binding of oviductin to the plasma membrane of golden hamster spermatozoa during in vitro capacitation and acrosome reaction

Frederick W.K. Kan
Abstract Oviductins are high-molecular-weight glycoproteins synthesized and secreted by nonciliated oviductal epithelial cells and have been shown to play a role in fertilization and early embryo development. The present study was carried out to examine the in vitro binding capacity of hamster oviductin to homologous sperm and to determine the sites of its localization in untreated, capacitated, and acrosome-reacted spermatozoa. Freshly prepared epididymal and capacitated sperm as well as acrosome-reacted sperm were incubated with oviductal fluid prepared from isolated hamster oviducts, fixed and then probed with a monoclonal antibody against hamster oviductin. Results obtained with pre-embedding immunolabeling experiments revealed binding of oviductin to the acrosomal cap and the apical aspect of the postacrosomal region. Immunolabeling of both regions appeared to be more intense in capacitated spermatozoa. Acrosome-reacted sperm showed an immunoreaction of moderate intensity over the postacrosomal region. The plasma membrane overlying the equatorial segment also exhibited a weak labeling. Quantitative analysis obtained with the surface replica technique indicated that oviductin had a higher binding affinity for the acrosomal cap than the postacrosomal region and that the binding of oviductin to the latter plasma membrane domain was enhanced during capacitation. Binding of oviductin to the postacrosomal region, however, was attenuated after acrosome reaction. Immunolabeling for oviductin was found to be the weakest over the equatorial segment regardless of the experimental conditions. The binding of hamster oviductin to specific membrane domains of the homologous sperm and the changes in its distribution during capacitation and acrosome reaction may be important for the function of hamster oviductin preceding and during fertilization. Mol. Reprod. Dev. 2006 Wiley-Liss, Inc. [source]

Co-culture of Buffalo Preantral Follicles with Different Somatic Cells

HS Ramesh
Contents The effect of co-culture of buffalo preantral follicles (PFs) with different somatic cells, i.e, cumulus, granulosa, ovarian mesenchymal and oviductal epithelial cells was studied. Large PFs (250,450 ,m) were isolated by microdissecting the trypsin (1%) digested ovarian cortical slices. Cumulus cells were isolated by repeated pipetting of oocytes, granulosa cells were isolated by aspirating from punctured PFs and ovarian mesenchymal cells were isolated from ovarian cortex by scraping the cortical slices and passing through 20 ,m filter. Preantral follicles were cultured in standard culture medium without somatic cells or co-cultured with cumulus cells, granulosa cells, ovarian mesenchymal cells and oviductal epithelial cells for 80 days. The growth rate (,m/day) of the PFs was monitored by measuring follicular diameter on day 0, 30, 60 and 80 days of culture. The viability of PFs was evaluated by trypan blue staining. The results indicated that PFs co-cultured with cumulus, granulosa and ovarian mesenchymal cells had a better development and survivality compared with control and those co-culture with oviductal epithelial cells. Maximum growth and survivality of PFs were achieved when cultured with cumulus cells. It is concluded that inclusion of somatic cells in PF culture media had beneficial effect on the growth of PFs and cumulus cells supported maximum growth and survivality of PFs in vitro of all somatic cells tested. [source]