Biliński Szczepan M, Klag Jerzy, Kubrakiewicz Janusz
Department of Systematic Zoology, Institute of Zoology, Jagiellonian University, 30-060, Kraków, Poland.
Institute of Zoology, University of Wrocław, 50-335, Wrocław, Poland.
Rouxs Arch Dev Biol. 1995 Sep;205(1-2):54-61. doi: 10.1007/BF00188843.
Oocytes of hymenopterans are equipped with peculiar organelles termed accessory nuclei. These organelles originate from the germinal vesicle (oocyte nucleus) and gather preferentially at the anterior pole. To gain insight into the mechanism of uneven (asymmetrical) distribution of accessory nuclei, the organization of the microtubule cytoskeleton in the oocytes of two hymenopterans Chrysis ignita and Cosmoconus meridionator has been studied. It is shown that during late previtellogenesis two networks of microtubules are present along the contact zone between the oocyte and enveloping follicular epithelium. The external one is associated with belt desmosomes connecting neighbouring follicular cells. The internal network is composed of randomly orientated microtubules and separates transparent, organelle-free periplasm from the endoplasm. All cellular organelles and the germinal vesicle are localized in the endoplasm. Accessory nuclei are accumulated in the anterior endoplasm; they always lie in direct contact with the subcortical network. Treatment with colchicine results in the disappearance of the periplasm as well as in the redistribution of cellular organelles including accessory nuclei. Presented findings suggest that subcortical microtubules play an important role in the positioning of accessory nuclei throughout the ooplasm.
膜翅目昆虫的卵母细胞配备有称为副核的特殊细胞器。这些细胞器起源于生发泡（卵母细胞核），并优先聚集在前极。为了深入了解副核不均匀（不对称）分布的机制，研究了两种膜翅目昆虫——火红隧蜂和南方锥角蜂卵母细胞中微管细胞骨架的组织情况。结果表明，在前卵黄发生后期，沿着卵母细胞与包围它的滤泡上皮细胞的接触区存在两个微管网络。外部网络与连接相邻滤泡细胞的带状桥粒相关。内部网络由随机取向的微管组成，将透明的、无细胞器的周质与内质区分开。所有细胞器和生发泡都位于内质中。副核积聚在内质的前端；它们总是与皮质下网络直接接触。用秋水仙碱处理会导致周质消失，以及包括副核在内的细胞器重新分布。现有研究结果表明，皮质下微管在整个卵质中副核的定位中起着重要作用。
