Myoblast cytonemes mediate Wg signaling from the wing imaginal disc and Delta-Notch signaling to the air sac primordium.
Myoblast cytonemes mediate Wg signaling from the wing imaginal disc and Delta-Notch signaling to the air sac primordium.
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DOI：
10.7554/elife.06114
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发表时间：
2015-05-07
期刊：
影响因子：
7.7
通讯作者：
Kornberg TB
中科院分区：
文献类型：
--
作者：
Huang H;Kornberg TB
果蝇成虫的飞行肌、背气囊、翅叶和胸部表皮协同作用，它们的祖细胞在翅成虫盘内共同发育。翅盘通过产生骨形态发生蛋白（Decapentaplegic）和成纤维细胞生长因子（Fibroblast growth factor）来协调背气囊的发育，这些因子通过特定的细胞突起（cytonemes）传递，以便向气囊原基（ASP）发出信号。在此，我们报道细胞突起还将飞行肌祖细胞（成肌细胞）与盘细胞以及ASP连接起来，使成肌细胞能够在盘和ASP之间传递信号。含卷曲蛋白（Frizzled，Fz）的成肌细胞突起从盘中摄取无翅蛋白（Wingless，Wg），含Delta（Dl）的成肌细胞突起有助于ASP中的Notch激活。Wg信号负调控成肌细胞中Dl的表达。这些结果揭示了细胞突起在Wg和Notch信号传导以及成肌细胞中的信号中继系统中起着至关重要的作用。
DOI: http://dx.doi.org/10.7554/eLife.06114.001
果蝇幼虫经历显著的生理转变成为成虫。在此转变过程中，幼虫的组织转变为成虫中的结构。例如，成虫的翅膀、飞行肌以及协调飞行所需的其他结构由一对称为翅成虫盘的盘状组织形成。
为了使这些结构正确发育，翅成虫盘中的细胞需要接收关于它们需要变成何种细胞的协调指令。在翅盘中，称为细胞突起的指状突起将特定细胞连接在一起，使信号分子能够在细胞之间移动；这控制着翅盘本身以及称为背气囊的结构的发育，背气囊为成虫的飞行肌提供氧气。然而，尚不清楚细胞突起是否允许在参与飞行所需其他结构形成的细胞之间交换信号分子。
在此，黄（Huang）和科恩伯格（Kornberg）研究了细胞突起在果蝇飞行肌发育中的作用。实验表明，称为成肌细胞的细胞——它们稍后将成为飞行肌细胞——与其他细胞形成两组细胞突起。一组将成肌细胞与发育中的气囊细胞连接起来，这使得一种称为Delta的信号蛋白能够从成肌细胞向气囊细胞发出信号。另一组细胞突起将成肌细胞与翅盘细胞连接起来。这使得在翅盘细胞中产生的另一种信号分子无翅蛋白能够进入成肌细胞并阻断Delta的产生。
黄和科恩伯格的发现揭示了细胞突起在协调飞行肌和背气囊发育中的新作用。未来的挑战将是了解单个细胞突起如何能够连接到特定细胞。
DOI: http://dx.doi.org/10.7554/eLife.06114.002
The flight muscles, dorsal air sacs, wing blades, and thoracic cuticle of the Drosophila adult function in concert, and their progenitor cells develop together in the wing imaginal disc. The wing disc orchestrates dorsal air sac development by producing decapentaplegic and fibroblast growth factor that travel via specific cytonemes in order to signal to the air sac primordium (ASP). Here, we report that cytonemes also link flight muscle progenitors (myoblasts) to disc cells and to the ASP, enabling myoblasts to relay signaling between the disc and the ASP. Frizzled (Fz)-containing myoblast cytonemes take up Wingless (Wg) from the disc, and Delta (Dl)-containing myoblast cytonemes contribute to Notch activation in the ASP. Wg signaling negatively regulates Dl expression in the myoblasts. These results reveal an essential role for cytonemes in Wg and Notch signaling and for a signal relay system in the myoblasts. DOI: http://dx.doi.org/10.7554/eLife.06114.001 Fruit fly larvae undergo a remarkable physical transformation to become an adult fly. During this transformation, the tissues in the larvae change into the structures found in the adult. For example, the adult wings, flight muscles, and other structures needed for coordinated flight form from a pair of disc-like tissues called the wing imaginal discs. For these structures to develop correctly, the cells in the wing imaginal discs need to receive coordinated instructions about what types of cells they need to become. Within the wing discs, finger-like projections called cytonemes link specific cells together to allow signal molecules to move between the cells; this controls the development of the wing disc itself as well as structures called dorsal air sacs, which supply oxygen to the flight muscles in the adult fly. However, it is not known if cytonemes allow the exchange of signal molecules between cells involved in the formation of other structures needed for flight. Here, Huang and Kornberg investigated the role of cytonemes in the development of the flight muscles in fruit flies. The experiments reveal that cells called myoblasts—which will later become the flight muscle cells—form two sets of cytonemes with other cells. One set connects the myoblasts to cells in the developing air sac, which allows a signal protein called Delta to signal from the myoblasts into the air sac cells. The other set of cytonemes connects the myoblasts to wing disc cells. This enables another signal molecule called Wingless, which is produced in wing disc cells, to move into the myoblasts and block the production of Delta. Huang and Kornberg's findings reveal a new role for cytonemes in coordinating the development of the flight muscles and the dorsal air sacs. A future challenge will be to understand how individual cytonemes are able to connect to specific cells. DOI: http://dx.doi.org/10.7554/eLife.06114.002