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391.
Ri-Cheng Chian Serge Lapointe Marc-Andr Sirard 《Molecular reproduction and development》1995,42(3):318-324
The effect of the active capacitating factor secreted from oviduct epithelial cell monolayers (OECM) in different environments on in vitro fertilization was evaluated. Capacitation was determined as the ability of sperm to fertilize bovine oocytes in vitro. When the mTALP was supplemented with glucose during conditioning, the sperm penetration rate was significantly reduced (P ≤ 0.05) compared to the control (7% ± 1 vs. 30% ± 4). The percentages of sperm penetrated oocytes were higher following insemination in the OECM-conditioned medium derived from the early stage (48% ± 7) of the estrous cycle than in the OECM-conditioned medium derived from either mid (35% ± 2) or late stages (28% ± 3) of the estrous cycle. When the medium was supplemented with 0.1 or 0.5 μg/ml estradiol-17β during medium conditioning, sperm penetration rates increased (P ≤ 0.05) compared to the control group (55% ± 4 vs. 40% ± 3 and 54% ± 2 vs. 41% ± 3, respectively). In addition, the percentages of penetrated oocytes significantly decreased (P ≤ 0.05) following insemination when the OECM-conditioned medium was added to 0.01%, 0.05%, and 0.1% ethanol compared to the control (25% ± 4, 19% ± 2, 18% ± 3, and 45% ± 3, respectively). Sperm penetration rates significantly (P ≤ 0.01) decreased when the OECM-conditioned medium was heated to 100°C for 5 min (10% ± 1 vs. 40% ± 3). These results suggest that the active capacitating factor was sereted by the OECM and that this capacitating factor in the OECM-conditioned medium was inhibited by the presence of glucose. This factor was found to be heat-sensitive and its action was affected by ethanol. The OECM derived from the three phases of the estrous cycle as well as the presence of estradiol-17β influenced the capacity of the OECM to secrete this capacitating factor in Vitro. © 1995 wiley-Liss, Inc. 相似文献
392.
Sustained high yields of Gracilaria (Rhodophyta) grown in intensive large-scale culture 总被引:2,自引:0,他引:2
Thomas R. Capo Juan C. Jaramillo Albert E. Boyd Brian E. Lapointe Joseph E. Serafy 《Journal of applied phycology》1999,11(2):143-147
Gracilaria ferox J. Agardh was grown continuously in large, outdoor tanks under a pulse-fed nutrient regime for four years.
Productivity ranged from 21.4 to 59.2 g d. wt m−2 d−1 with a mean of 39.7 g d. wt m−2 d−1 over the entire study period. Because the cultures were maintained under non-nutrient limiting conditions, productivity was
regulated primarily by seasonal changes in light and temperature, which accounted for 75% of the variability of growth in
algal yields. Salinity ranged from 31.0 to 36.5‰ and had insignificant effects on growth within this range. The original vegetative
strain was maintained over the entire study without the need for additional supplementation from field-collected stock. Because
of the pulse-fed nutrient supply, epiphytic growth on the target species was negligible (< 3% total biomass) throughout the
study. The yields attained in this study rank among the highest reported for any intensively managed photosynthetic crop and
demonstrate the feasibility of growing red macroalgae like Gracilaria at a sustained high yield in a large-scale, land-based
culture system.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
393.
C. S. Yentsch C. M. Yentsch D. A. Phinney B. E. Lapointe S. F. W. Yentsch 《Journal of experimental marine biology and ecology》2004,300(1-2):15-30
In studies of primary production of the open ocean, the measurement of new production is often considered a measure of the degree of eutrophication. Because of new research this is questionable, which in our opinion, calls for a refinement to the original concept. We believe that the measure of variable fluorescence is pivotal to a new understanding. Our research enforces the growing conviction that the measurement of Fv/Fm can be interpreted as an analogue for nutrient stress. We measured variable fluorescence in axenic cultures at the CCMP at the Bigelow Laboratory. The Fv/Fm of cultures, upon transfer to new media reached a maximum followed by a decline after approximately 30 days. The rate of decline does not appear to be species specific. Most of the clones remained relatively high after 30 days. The high Fv/Fm values observed in nutrient-replete cultures are not characteristic of the oligotrophic surface waters off Florida and the Bahamas, but are approached in the eutrophic waters of the Gulf of Maine. In contrast, Fv/Fm measurements of attached macroalgae and coral zooxanthellae are characteristically much higher than microalgae of either oligotrophic or eutrophic regions. Accordingly, we advance the case for interpretation of Fv/Fm in terms of nutrient stress in ecological studies and advocate that the old concept of new production should be modified. 相似文献
394.