Ultrastructure of extrusomes in hypotrichous ciliate Pseudourostyla nova

The ultrastructure of extrusomes of the hypotrichous ciliate Pseudourostyla nova was observed in scanning and transmission electron microscopy and enzyme-cytochemistry. The results show that the distribution, morphological characteristics, morphogenesis process, and extrusive process of the extrusomes in P. nova are different from the trichocysts in Paramecium, suggesting that the extrusomes of P. nova can respond to environmental stimuli, play an important role in the defense of this species, and cannot be regarded as "trichocysts". The results also suggest that the extrusomes might be originated from the Golgi apparatus and mature in the cytoplasm; after the extrusion of mature extrusomes, the residual substance might be reabsorbed and reused by the ciliate cell via food vacuoles, and take part in material recycling of the cell.

新伪尾柱虫腹皮层纤毛器微管胞器的形态和形态发生

应用荧光紫杉醇直接荧光标记法显示,腹毛目纤毛虫新伪尾柱虫(Pseudourostyla nova)腹皮层纤毛器微管胞器由口围带、波动膜、额腹横棘毛和左右缘棘毛等纤毛器微管及纤毛器基部附属微管组成。口围带基部含小膜托架及与托架相联系的肋壁微管,其中领部小膜托架间由"∧"形微管相联接;额腹横棘毛基部含前纵微管束、后纵微管束、横微管束和周围微管束,其微管在不同棘毛基部的发达程度不一;缘棘毛基部含前纵微管束、后纵微管束。同时,对新伪尾柱虫纤毛器微管胞器的形态发生和生理改组过程进行了详细的追踪研究,并对细胞皮层的额腹棘毛定位及组成特征进行了补充报道。此外,发现形态发生末期新纤毛器微管形成时,残存部分老额棘毛、横棘毛和缘棘毛,此后老结构逐渐被吸收。结果表明,新伪尾柱虫的纤毛器基部微管具有其种的特异性,新纤毛器微管分化过程中老结构可能具有定位和物质贡献作用。

新伪尾柱虫皮层纤毛器的超微结构

应用透射电镜术显示了腹毛目纤毛虫新伪尾柱虫(Pseudourostyla nova)的皮层表膜及表膜下细胞质、皮层微管胞器和其他细胞质胞器。结果显示:新伪尾柱虫纤毛器基部附属微管较为短小,细胞表膜下成束排列的微管结构与进化程度较高的纤毛虫的微管胞器表现出诸多差异,认为腹毛目纤毛虫棘毛基部微管的发达程度是与其各类群细胞的分化程度密切联系的。