Maves L, Schubiger G
Department of Zoology NJ-15, University of Washington, Seattle 98195, USA.
Development. 1995 May;121(5):1263-72. doi: 10.1242/dev.121.5.1263.
Drosophila imaginal discs, the precursors of the adult fly appendages, have been the subject of intensive developmental studies, particularly on cell determination. Cultured disc fragments are recognized not only for the ability to maintain their determined state through extra cell divisions but also for the ability to transdetermine, or switch to the determined state of a different disc. An understanding of transdetermination at a molecular level will provide further insight into the requirements for maintaining cell determination. We find that ectopic expression of the Drosophila gene wingless induces transdetermination of foreleg imaginal disc cells to wing cells. This transdetermination occurs in foreleg discs of developing larvae without disc fragmentation. The in situ-transdetermining cells localize to the dorsal region of the foreleg disc. This wingless-induced transdetermination event is remarkably similar to the leg-to-wing switch that occurs after leg disc culture. Thus we have identified a new approach to a molecular dissection of transdetermination.
果蝇成虫盘是成年果蝇附肢的前体，一直是深入发育研究的对象，尤其是在细胞决定方面。培养的盘片段不仅因其能够通过额外的细胞分裂维持其决定状态而受到认可，还因其能够转决定，即转变为不同盘的决定状态而受到认可。在分子水平上对转决定的理解将为维持细胞决定的要求提供进一步的见解。我们发现果蝇无翅基因的异位表达诱导前腿成虫盘细胞转决定为翅膀细胞。这种转决定发生在发育中的幼虫的前腿盘中，而无需盘片段化。原位转决定细胞定位于前腿盘的背侧区域。这种无翅诱导的转决定事件与腿盘培养后发生的腿到翅膀的转变非常相似。因此，我们确定了一种对转决定进行分子剖析的新方法。
