Bohrmann J, Haas-Assenbaum A
Institut für Biologie I (Zoologie), Universität Freiburg, Germany.
Cell Tissue Res. 1993 Jul;273(1):163-73. doi: 10.1007/BF00304623.
The analysis of chimeras has shown that communication between germ-line and soma cells plays an important role during Drosophila oogenesis. We have therefore investigated the intercellular exchange of the fluorescent tracer molecule, Lucifer yellow, pressure-injected into the oocyte of vitellogenic follicles of Drosophila. The dye reached the nurse cells via cytoplasmic bridges and entered, via gap junctions, the somatic follicle cells covering the oocyte. The percentage of follicles showing dye-coupling between oocyte and follicle cells was found to increase with the developmental stage up to stage 11, but depended also on the status of oogenesis, i.e., the stage-spectrum, in the respective ovary. During late stage 10B and stage 11, dye-coupling was restricted to the follicle cells covering the anterior pole of the oocyte. No dye-coupling was observed from stage 12 onwards. During prolonged incubation in vitro, the dye was found to move from the follicle cells back into the oocyte; this process was suppressable with dinitrophenol. Dye-coupling was inhibited when prolonged in vitro incubation preceded the dye-injection. Moreover, dye-coupling was inhibited with acidic pH, low [K+], high intracellular [Ca2+], octanol, dinitrophenol, and NaN3, but not with retinoic acid, basic pH, or high extracellular [Ca2+]. Dye-coupling was stimulated with a juvenile hormone analogue and with 20-hydroxyecdysone. Thus, gap junctions between oocyte and follicle cells may play an important role in intercellular communication during oogenesis. We discuss the significance of our findings with regard to the electrophysiological properties of the follicles, and to the coordinated activities of the different cell types during follicle development and during the establishment of polarity in the follicle.
对嵌合体的分析表明，生殖细胞与体细胞之间的通讯在果蝇卵子发生过程中起着重要作用。因此，我们研究了荧光示踪分子荧光黄的细胞间交换情况，该分子通过压力注射到果蝇卵黄生成卵泡的卵母细胞中。染料通过细胞质桥到达滋养细胞，并通过间隙连接进入覆盖卵母细胞的体细胞卵泡细胞。发现显示卵母细胞与卵泡细胞之间染料偶联的卵泡百分比随着发育阶段的增加而增加，直至11期，但也取决于各自卵巢中卵子发生的状态，即阶段谱。在10B晚期和11期，染料偶联仅限于覆盖卵母细胞前极的卵泡细胞。从12期开始未观察到染料偶联。在体外长时间孵育期间，发现染料从卵泡细胞回到卵母细胞中；这个过程可被二硝基苯酚抑制。在染料注射之前进行长时间的体外孵育时，染料偶联受到抑制。此外，酸性pH、低[K+]、高细胞内[Ca2+]、辛醇、二硝基苯酚和NaN3可抑制染料偶联，但视黄酸、碱性pH或高细胞外[Ca2+]则不能。一种保幼激素类似物和20-羟基蜕皮激素可刺激染料偶联。因此，卵母细胞与卵泡细胞之间的间隙连接可能在卵子发生过程中的细胞间通讯中起重要作用。我们讨论了我们的发现对于卵泡电生理特性以及卵泡发育和卵泡极性建立过程中不同细胞类型的协调活动的意义。
