金黄滴虫细胞核微丝系统的初步观察

金黄滴虫细胞核内经常存在着许多直径约为7nm的微丝。这些徽丝大多组合成走向不定的徽丝束,微丝束交织而成遍布核内的网架。核被下面微丝束较多,它们的存在常使核被外凸而成隆脊。核内微丝与核内结构如核仁、染色质等似乎都是相连的。有些微丝横跨核被,一端位于核内,另一端位于核周腔中,并靠近叶绿体。核周腔和内质网腔中也存在着微丝和另一种纤维,印管状纤维。用细胞松弛素B处理后,细胞核、核周腔和内质网腔中的微丝均消失,细胞核的形态也发生变化,似乎微丝网架有支持细胞核的作用。核内微丝可能是在内质网中组装,然后经核周腔进入核内的。

MICROFILAMENT-FRAMEWORK IN THE NUCLEUS OF OCHROMONAS DANICA

By means of electron microscopy, a framework of mierofilaments has been revealed in the nucleus of the flagellate Ochromonas danica. The diameter of the individual mierofilaments is about 7 nm. Most of the mierofilaments accumulate into bundles which run in various directions and are interlaced with each other. The filaments are usually associated with or attached to the nuclear membrane. Mierofilaments have also been found in the perinuclear cavity and the canaliculi of BE, where tubular fibrils or ma-stigonemes are present too. In the perinuclear cavity neighboring upon the chloroplast, some of the mierofilaments are seen to pass through the partly disintegrated nuclear membrane and extend to the nucleus. When the cells are treated with cytochalasin B, mierofilaments disappear and the nucleus usually swells and becomes separated from the chloroplast, while the tubular fibrils remain intact It seems that the intranuclear mierofilaments originate in the BE where they are assembled and are then transported to the nucleus via the perinuclear cavity.