Sahut-Barnola Isabelle, Dastugue Bernard, Couderc Jean-Louis
INSERM U384, Laboratoire de Biochimie, UFR M6decine, F-63001, Clermont-Ferrand, France.
Rouxs Arch Dev Biol. 1996 May;205(7-8):356-363. doi: 10.1007/BF00377215.
The adult ovary of Drosophila is composed of approximately twenty parallel repetitive structures called ovarioles. The ovarioles appear at the prepupal stage and their formation requires the presence of stacks of discshaped cells called the terminal filaments. Terminal filaments form in a progressive manner during the third larval instar. We have looked at the beginning of formation of both the terminal filaments and ovarioles at an ultrastructural level. Moreover, we studied the pattern of division of the terminal filament cell precursors using the base analog, BrdU. Two main waves of division are observed. The first wave consists of divisions of almost all the terminal filament cell precursors during a short period of time at the transition between the second and third larval instar. The second wave, in which the precursors carry out their final divisions before differentiating, occurs gradually, going from the medial to the lateral side of the ovary during the first half of the third larval instar.
果蝇的成年卵巢由大约二十个平行的重复结构组成，这些结构称为卵巢小管。卵巢小管在蛹前期出现，其形成需要存在称为终丝的盘状细胞堆叠。终丝在第三龄幼虫期以渐进方式形成。我们在超微结构水平上观察了终丝和卵巢小管形成的开始阶段。此外，我们使用碱基类似物5-溴脱氧尿嘧啶核苷（BrdU）研究了终丝细胞前体的分裂模式。观察到两个主要的分裂波。第一个波由几乎所有终丝细胞前体在第二龄和第三龄幼虫过渡的短时间内的分裂组成。第二个波，其中前体在分化之前进行其最后的分裂，逐渐发生，在第三龄幼虫期的前半段从卵巢的内侧向外侧进行。
