Lin H, Spradling A C
Howard Hughes Medical Institute Research Laboratories, Carnegie Institution of Washington, Baltimore, Maryland 21210.
Dev Biol. 1993 Sep;159(1):140-52. doi: 10.1006/dbio.1993.1228.
Germline and somatic stem cells reside within the anterior region (or "germarium") of each ovariole in the Drosophila ovary. When individual germaria were dissected free of developing eggs and sheath tissue and transplanted into the abdominal cavity of a host fly, they regenerated ovariole-like structures and continuously supported the entire process of oogenesis, indicating that the stem cells remained functional. This system allowed us to measure the duration of several stages in oogenesis and to analyze the role of specific germarial cells in providing stem cell function. Laser ablation of presumptive germline stem cells near the apical tip prior to transplantation blocked the production of new germline cysts, but allowed previously initiated cysts to complete development. This confirmed the location of germline stem cells and showed that subsequent development of preexisting cysts did not require continued cyst production. Ablation of a distinct group of somatic cells lying close to the germline stem cells ("the terminal filament") increased the rate of oogenesis by approximately 40%, suggesting that the terminal filament may negatively regulate stem cell division.
生殖系干细胞和体细胞干细胞存在于果蝇卵巢每个卵巢管的前部区域（即“生殖腺”）。当将单个生殖腺从发育中的卵子和鞘组织中分离出来并移植到宿主果蝇的腹腔中时，它们会再生出类似卵巢管的结构，并持续支持卵子发生的整个过程，这表明干细胞仍然具有功能。这个系统使我们能够测量卵子发生几个阶段的持续时间，并分析特定生殖腺细胞在提供干细胞功能方面的作用。在移植前对顶端附近的推定生殖系干细胞进行激光消融，阻止了新的生殖系囊肿的产生，但允许先前启动的囊肿完成发育。这证实了生殖系干细胞的位置，并表明先前存在的囊肿的后续发育不需要持续产生囊肿。消融靠近生殖系干细胞的一组不同的体细胞（“终丝”）使卵子发生的速率提高了约40%，这表明终丝可能对干细胞分裂起负调节作用。
