Jean Claude Nicolle

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The aim of the present study was to assess whether the whole meiotic process of spermatogenic cells is able to take place in vitro. Fragments of seminiferous tubules from 20- to 22- or 28-day-old rats were seeded in medium containing 0.2% fetal calf serum in bicameral chambers and then cultured for 4 weeks in a chemically defined medium. The differentiation(More)
The aim of the present study was to set up a culture system allowing most of the meiotic phase of rat spermatogenesis to occur in vitro. For that purpose, the differentiation of spermatogenic cells was monitored by three criteria: 1) examination of expression of genes specifically expressed at a high level in pachytene spermatocytes (the phosphoprotein p19(More)
Cryopreservation and freezing-thawing effects on the fertilizing ability of human spermatozoa commonly are evaluated by post-thaw motility. Various studies have depicted the ultrastructural changes caused by freezing-thawing, yet the chromatin alterations have been studied very limitedly. Our aim was to determine the extent to which freezing-thawing alters(More)
Freezing-thawing effects on the nuclei of porcine and human spermatozoa were studied by determining native DNA percentage from fluorescence after acridine orange (AO) staining and by analyzing chromatin structure by a quantitative microspectrophotometric study of Feulgen-DNA complexes before and after freezing. The study of boar spermatozoa revealed no(More)
New staining methods and automated instruments are now available to evaluate the sperm cell in vitro. Individual compartments of the sperm cell, such as the nucleus and the plasma and acrosomal membranes, may be investigated, as well as the cell function as shown by mitochondria activity and capacitation. Various probes are used and they can be analyzed by(More)
Three enterocyte cell clones were established in vitro from the intestine of a PA12 hen embryo. These cells exhibited epithelioid morphology and grew as monolayers. The cells were continuously propagated in culture up to 250 passages. Gradual increase in growth rate with time and in anchorage-independent growth in both agar and agarose showed that the three(More)
Spleen cells from mice infected with the rough Brucella melitensis strain B115 were fused with NSO myeloma cells. Hybridoma supernatants were screened in ELISA with cell walls (CW), sonicated cell extracts (CE) and rough lipopolysaccharide (R-LPS) of B. melitensis strain B115 and whole B. melitensis B115 cells. Surprisingly, 22 monoclonal antibodies (mAbs)(More)
In vitro capacitation of human spermatozoa is commonly evaluated by the progressive motility percent. However its effects on sperm chromatin have hardly been studied. Our aim was to determine the extent to which in vitro capacitation with two treatments (B2 or human follicular fluid) alters the chromatin of human spermatozoa, by using two analytical(More)
Intact and Triton X-100 demembranated boar spermatozoa possess two main heavy chains with molecular masses (M(r)) of 430 and 460 kDa. These heavy chains were photo-cleaved within the axoneme under V1 conditions and produced two main fragments at 245 kDa and 185 kDa. Two minor fragments at 170 and 90 kDa were also obtained. In the presence of low Mg2+ (1 mM)(More)