MICROAEROPHILY IN CILIATES - RESPONSES OF AN EUPLOTES SPECIES (HYPOTRICHIDA) TO OXYGEN-TENSION
MICROAEROPHILY IN CILIATES - RESPONSES OF AN EUPLOTES SPECIES (HYPOTRICHIDA) TO OXYGEN-TENSION
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DOI：
10.1016/s0003-9365(89)80015-6
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发表时间：
1989-01-01
期刊：
影响因子：
--
通讯作者：
GIANNI, A
中科院分区：
文献类型：
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作者：
FENCHEL, T;FINLAY, BJ;GIANNI, A
我们研究了一种海洋游标动物（纤毛纲、亚毛纲）对氧气的反应。纤毛虫喜欢约 5% atm sat 的氧张力。并且它表现出化学感应行为，因此细胞倾向于在氧气梯度中积累在这个水平。在首选氧压下呼吸频率几乎达到最大。纤毛虫可以在较高的氧张力下生长，但其世代时间较长，生长效率较低。在严格的厌氧条件下，纤毛虫可以存活并保持活力数周，但分裂率下降，并且它们似乎无法维持恒定的分裂率。在长期缺氧期间，线粒体及其嵴都不会退化，但它们确实表现出一些特征性的变化。这表明线粒体在无氧发电中发挥作用。其他一些研究的游标动物物种也表现出类似的行为，但它们首选的 pO2 约为 20% atm sat。微需氧可能是纤毛虫中广泛分布的现象，对其生态和进化意义进行了讨论。
We have studied the responses to oxygen by a marine species of Euplotes (Ciliophora, Hypotrichida). The ciliate prefers an oxygen tension of about 5% atm sat. and it displays chemosensory behaviour, so cells tend to accumulate at this level in oxygen gradients. The respiratory rate is almost maximal at the preferred oxygen tension. The ciliate can grow at higher oxygen tensions, but it then has a longer generation time and a lower growth efficiency. Under strict anaerobic conditions the ciliates survive and remain viable for many weeks, but division rate declines and they do not seem to be able to sustain a constant rate of division. Neither mitochondria nor their cristae degenerate during prolonged anoxia, but they do show some characteristic changes. This suggests that mitochondria play a role in anaerobic power generation. A few other studied species of Euplotes show a similar behaviour, but their preferred pO2 is around 20% atm sat. Microaerophily is probably a widely distributed phenomenon among ciliates and its ecological and evolutionary implications are discussed.