Cytogenetics Section, Department of Zoology, Banaras Hindu University, Varanasi 221 005, India.
J Biosci. 2011 Aug;36(3):531-44. doi: 10.1007/s12038-011-9092-3.
Drosophila metamorphosis is characterized by the histolysis of larval structures by programmed cell death, which paves the way for the establishment of adult-specific structures under the influence of the steroid hormone ecdysone. Malpighian tubules function as an excretory system and are one of the larval structures that are not destroyed during metamorphosis and are carried over to adulthood. The pupal Malpighian tubules evade destruction in spite of expressing apoptotic proteins, Reaper, Hid, Grim, Dronc and Drice. Here we show that in the Malpighian tubules expression of apoptotic proteins commences right from embryonic development and continues throughout the larval stages. Overexpression of these proteins in the Malpighian tubules causes larval lethality resulting in malformed tubules. The number and regular organization of principal and stellate cells of Malpighian tubules is disturbed, in turn disrupting the physiological functioning of the tubules as well. Strikingly, the localization of beta-tubulin, F-actin and Disclarge (Dlg) is also disrupted. These results suggest that the apoptotic proteins could be having non-apoptotic function in the development of Malpighian tubules.
果蝇变态的特征是通过程序性细胞死亡对幼虫结构进行组织溶解，这为在蜕皮激素等类固醇激素的影响下建立成虫特有的结构铺平了道路。马氏管作为排泄系统，是变态过程中不被破坏并延续到成虫期的幼虫结构之一。尽管蛹期的马氏管表达凋亡蛋白 Reaper、Hid、Grim、Dronc 和 Drice，但它们仍能逃避破坏。我们在这里表明，凋亡蛋白在马氏管中的表达从胚胎发育开始就已经开始，并贯穿整个幼虫阶段。在马氏管中过度表达这些蛋白会导致幼虫死亡，从而导致马氏管畸形。马氏管的主细胞和星状细胞的数量和正常组织受到干扰，反过来也会破坏马氏管的生理功能。引人注目的是，β-微管蛋白、F-肌动蛋白和 Disclarge（Dlg）的定位也受到干扰。这些结果表明，凋亡蛋白在马氏管的发育过程中可能具有非凋亡功能。
