Hojyo T, Fujiwara H
Department of Biological Sciences, Graduate School of Sciences, University of Tokyo, Japan.
Dev Growth Differ. 1997 Oct;39(5):599-606. doi: 10.1046/j.1440-169x.1997.t01-4-00007.x.
The wingless mutant flügellos (fl) of the silkworm lacks all four wings. Although wing discs of the fl seem to develop normally until the fourth larval instar, wing morphogenesis stops after the fourth larval ecdysis, probably caused by aberrant expression of an unidentified factor, referred to as fl. To characterize factor fl, the wing discs dissected from the wild-type (WT) and fl larvae were transplanted into other larvae and developmental changes of the discs were examined. When the wing disc from a WT larva was transplanted into another WT larva and allowed to grow until emergence, a small wing appeared that was covered with scales. Thus, the transplanted wing discs can develop autonomously, form scales and evert from adult skin. The WT wing discs transplanted into the fl larvae also developed at a high rate. However, the fl wing discs transplanted into the WT larvae did not develop during the larval to pupal developmental stages. These data suggest that the fl gene product (factor fl) works in the wing disc cells during wing morphogenesis. Its function cannot be complemented by hemolymph in the WT larva. It is also implied that the level of humoral factors and hormones required for wing morphogenesis are normally maintained in the fl larva.
家蚕的无翅突变体“flügellos”（fl）没有所有的四片翅膀。尽管fl的翅芽在幼虫四龄期之前似乎发育正常，但在幼虫第四次蜕皮后翅形态发生停止，这可能是由一种未鉴定的因子（称为fl）的异常表达引起的。为了表征因子fl，将从野生型（WT）和fl幼虫中分离出的翅芽移植到其他幼虫中，并检查翅芽的发育变化。当将WT幼虫的翅芽移植到另一只WT幼虫中并使其生长至羽化时，会出现一个覆盖着鳞片的小翅膀。因此，移植的翅芽可以自主发育，形成鳞片并从成虫皮肤中翻出。移植到fl幼虫中的WT翅芽也有很高的发育率。然而，移植到WT幼虫中的fl翅芽在幼虫到蛹的发育阶段没有发育。这些数据表明，fl基因产物（因子fl）在翅形态发生过程中在翅芽细胞中起作用。其功能不能被WT幼虫中的血淋巴所补充。这也意味着fl幼虫中翅形态发生所需的体液因子和激素水平通常是维持正常的。
