Analysis of the Function of Apoptosis during Imaginal Wing Disc Regeneration in Drosophila melanogaster

Regeneration is the ability that allows organisms to replace missing organs or lost tissue after injuries. This ability requires the coordinated activity of different cellular processes, including programmed cell death. Apoptosis plays a key role as a source of signals necessary for regeneration in different organisms. The imaginal discs of Drosophila melanogaster provide a particularly well-characterised model system for studying the cellular and molecular mechanisms underlying regeneration. Although it has been shown that signals produced by apoptotic cells are needed for homeostasis and regeneration of some tissues of this organism, such as the adult midgut, the contribution of apoptosis to disc regeneration remains unclear. Using a new method for studying disc regeneration in physiological conditions, we have defined the pattern of cell death in regenerating discs. Our data indicate that during disc regeneration, cell death increases first at the wound edge, but as regeneration progresses dead cells can be observed in regions far away from the site of damage. This result indicates that apoptotic signals initiated in the wound spread throughout the disc. We also present results which suggest that the partial inhibition of apoptosis does not have a major effect on disc regeneration. Finally, our results suggest that during disc regeneration distinct apoptotic signals might be acting simultaneously.

再生是生物体在遭受损伤后，替代缺失器官或丢失组织的能力。该能力依赖于多种细胞过程的协同调控，其中包括程序性细胞死亡（programmed cell death）。凋亡（Apoptosis）作为不同生物体再生所需信号的来源，发挥着关键作用。黑腹果蝇（Drosophila melanogaster）的成虫盘（imaginal discs）是研究再生相关细胞与分子机制的经典模式系统。尽管已有研究表明，凋亡细胞产生的信号对于该生物体部分组织（如成体中肠）的稳态维持与再生是必需的，但凋亡对成虫盘再生的具体贡献仍不明确。本研究通过一种用于生理状态下成虫盘再生研究的新方法，明确了再生过程中成虫盘的细胞死亡模式。我们的数据显示，在成虫盘再生过程中，细胞死亡首先在伤口边缘增加；随着再生进程推进，远离损伤位点的区域也可观察到死亡细胞。该结果表明，伤口处启动的凋亡信号可扩散至整个成虫盘。本研究同时得到的结果提示，部分抑制凋亡并不会对成虫盘再生产生显著影响。最终，我们的研究结果表明，在成虫盘再生过程中，不同的凋亡信号可能同时发挥作用。