Bird J, Porter E K, Dickinson H G
J Cell Sci. 1983 Jan;59:27-42. doi: 10.1242/jcs.59.1.27.
An electron microscopic investigation of the events associated with meiosis in Lilium has revealed a number of changes in both the organellar population and the other cytoplasmic components. Ribosome numbers decrease significantly in early prophase and are later replenished in the tetrads, a process most likely involving the newly arising cytoplasmic nucleoloids. The organelles show a cycle of de- and redifferentiation and later in meiosis unusual internal structures can be seen before these organelles enter a division phase resulting in increased numbers. The localization of acid phosphatase during these changes has also been studied using electron microscopic cytochemical methods. In early prophase, considerable amounts of acid phosphatase are found in vesicles scattered through the cytoplasm; activity is also found in association with most membranous surfaces and often markedly associated with condensing mitochondria. Later in prophase the enzyme activity decreases to normal levels. Electron microscopic autoradiography revealed that DNA is synthesized in both plastids and mitochondria during meiotic prophase with activity reaching a peak during zygotene and ceasing by diakinesis and tetrad formation. These changes point to a certain independence of organelles from nuclear control during meiosis. The events are also evaluated in relation to a cytoplasmic clearing mechanism, which may occur in preparation for the changeover from sporophytic to gametophytic control and the development of gametes.
对百合减数分裂相关事件的电子显微镜研究揭示了细胞器群体和其他细胞质成分中的一些变化。核糖体数量在前期早期显著减少，随后在四分体中得到补充，这一过程很可能涉及新出现的细胞质核仁。细胞器呈现出一个去分化和再分化的循环，在减数分裂后期，在这些细胞器进入分裂阶段导致数量增加之前，可以看到异常的内部结构。还使用电子显微镜细胞化学方法研究了这些变化过程中酸性磷酸酶的定位。在前期早期，在散布于细胞质中的小泡中发现了大量酸性磷酸酶；在大多数膜表面也发现了活性，并且常常与浓缩的线粒体明显相关。在前期后期，酶活性降至正常水平。电子显微镜放射自显影显示，在减数分裂前期，质体和线粒体中都有DNA合成，活性在偶线期达到峰值，在终变期和四分体形成时停止。这些变化表明在减数分裂过程中细胞器在一定程度上独立于核控制。这些事件也与一种细胞质清除机制相关联进行了评估，这种机制可能发生在为从孢子体控制向配子体控制的转变以及配子发育做准备的过程中。
