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Antigenic change on the surface of immature oocytes of Ascaris occurred during passage through the oviduct. Using immunodiffusion and immunoelectrophoretic techniques we examined the possible relationship between the antigenic change of immature oocytes and the junctional fluid (JF) which is present in the fertilization chamber. From the immunodiffusion it was found that the anti-immature oocyte serum (A-I serum) had more immunoprecipitation arcs than did the anti-mature oocyte serum (A-M serum) when reacted against the junctional fluid. This indicated that A-I serum contained more immunoglobulins that reacted with junctional fluid than did the A-M serum. This result was substantiated by using immunoelectrophoretic analysis and two dimension crossed immunoelectrophoresis. Our results suggest that during the migration toward the oviduct-uterine junction the immature oocytes might shed surface proteins into the luminal fluid. Alternatively, the membrane surface of mature oocytes may be altered by the interaction with the substances present in the junctional fluid. 相似文献
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The environmental texture hypothesis (ETH) proposes that the spatial geometry or texture of the environment influences the
rate at which species are accumulated in space or time. Specifically, the ETH suggests that regions, and spatial scales, that
exhibit a larger rate of environmental distance decay (DD) should exhibit more rapid rates of species turnover. The ETH should
apply over any range of scales where the environment is driving species distributions. To examine the relevance of the ETH
at local spatial scales, we tested for a positive relationship between the rate of change in soil chemical properties and
vascular plant species composition in grassland and woodland habitats. We recorded presence–absence data along a 1.883 km
transect in each habitat and estimated the rate of turnover and environmental DD for spatial lags of 1–41 m. We found that
the soil environment explained spatial patterns of species composition more accurately in the grassland habitat compared to
the woodland habitat. Consequently the rate of change in soil properties as a function of spatial distance was significantly
positively correlated with the rate of species turnover in the grassland but not the woodland. Our study suggests that one
of the central premises of the ETH is relevant for local patterns of species turnover if the environment appears to influence
species composition. 相似文献
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