Ecdysone promotes growth of imaginal discs through the regulation of Thor in D-melanogaster
Ecdysone promotes growth of imaginal discs through the regulation of Thor in D-melanogaster
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DOI：
10.1038/srep12383
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发表时间：
2015-07-22
影响因子：
4.6
通讯作者：
Barrio, Rosa
中科院分区：
文献类型：
--
作者：
Herboso, Leire;Oliveira, Marisa M.;Barrio, Rosa
动物具有确定的物种特异性体型，这是激素和调节生长速率和持续时间的信号通路的联合作用的结果。在果蝇中，类固醇激素蜕皮激素控制发育过渡，从而调节生长期的持续时间。在这里，我们表明，蜕皮激素促进成虫盘在中期三龄幼虫的生长，因为成虫盘幼虫减少或没有蜕皮激素合成小于野生型由于更小，更少的细胞。我们发现，胰岛素样肽的产生和分泌正常的幼虫蜕皮激素的合成减少，和上游组件的胰岛素/胰岛素样信号被激活在他们的光盘。相反，蜕皮激素似乎通过Thor/4 E-BP调节成虫盘的生长，Thor/4 E-BP是胰岛素/胰岛素样生长因子/Tor途径下游的负生长调节剂。蜕皮激素合成减少的幼虫的圆盘具有升高的Thor水平，而Thor的突变部分地挽救了它们的生长。蜕皮激素对器官生长的调节在半代谢昆虫中是进化保守的，正如我们使用德国小蠊获得的结果所示。总之，我们的数据提供了新的见解，胰岛素/胰岛素样/Tor和蜕皮激素途径的控制器官生长的组件之间的关系。
Animals have a determined species-specific body size that results from the combined action of hormones and signaling pathways regulating growth rate and duration. In Drosophila, the steroid hormone ecdysone controls developmental transitions, thereby regulating the duration of the growth period. Here we show that ecdysone promotes the growth of imaginal discs in mid-third instar larvae, since imaginal discs from larvae with reduced or no ecdysone synthesis are smaller than wild type due to smaller and fewer cells. We show that insulin-like peptides are produced and secreted normally in larvae with reduced ecdysone synthesis, and upstream components of insulin/insulin-like signaling are activated in their discs. Instead, ecdysone appears to regulate the growth of imaginal discs via Thor/4E-BP, a negative growth regulator downstream of the insulin/insulin-like growth factor/Tor pathways. Discs from larvae with reduced ecdysone synthesis have elevated levels of Thor, while mutations in Thor partially rescue their growth. The regulation of organ growth by ecdysone is evolutionarily conserved in hemimetabolous insects, as shown by our results obtained using Blattella germanica. In summary, our data provide new insights into the relationship between components of the insulin/insulin-like/Tor and ecdysone pathways in the control of organ growth.