Cuticle differentiation in the embryo of the fruit fly Drososphila melanogaster

角质层是被分类为节肢动物和相关类群的大多数动物物种所共有的广泛的细胞外结构，并且是一个进化上成功的概念，以保护其拥有者免受脱水，捕食者和病原体的侵害，以支持身体形状并同时用作外骨骼。为了实现其多种功能，角质层被细分为三个具有不同组成的水平层。实现角质层结构的分子机制尚未研究。我们理解表皮分化的策略是在果蝇胚胎发生过程中研究这一过程，从这一经典模式生物提供的丰富优势中获益。在过去的几年里，我们已经能够确定几个重要的角质层因素允许角质层分化的机制的发现和部分解剖。总之，对这些因素的研究强调了顶端质膜的重要性，以及角质层定型组织控制分泌的必要性。这些数据使我们现在能够解决角质层不同功能单位如何同时分化的问题。我们正在集中我们的努力在转录调控和分泌控制来回答这个问题，而我们继续我们的遗传方法来分离和纯化角质层分化过程中起作用的其他成分。特别是，我们感兴趣的是登记有效的转录组角质层分化的转录因子Grainyhead，βFtzF1和CrebA的靶基因的识别，已知在胚胎发育后期的分化过程中管理。与此同时，我们试图解开分泌机制指导协调建设的细胞外基质，将成为角质层。这些系统性的冒险将伴随着基于RNAi的遗传搜索，以寻找更多的角质层分化效应子，其特征将使我们能够进一步剖析潜在的分子机制。本课题以组织学的扎实知识为基础，期待将角质层分化作为器官分化研究领域的开拓者。

The cuticle is a widespread extracellular structure shared by most animal species classified as arthropods and related taxa, and is an evolutionary successful concept to protect its possessor against dehydration, predators and pathogens, to support the body shape and to serve at the same time as an exoskeleton. To fulfil its multiple functions, the cuticle is subdivided into three horizontal layers with distinct compositions. The molecular mechanisms that implement the cuticle architecture had not been investigated yet. Our strategy to understand cuticle differentiation is to study this process during Drosophila embryogenesis profiting from the wealth of advantages this classic model organism offers. In the last few years, we have been able to identify several essential cuticle factors allowing the discovery and partial dissection of mechanisms of cuticle differentiation. In summary, the work on these factors underlines the importance of the apical plasma membrane and the need for controlled secretion for a stereotypic organisation of the cuticle. These data enable us now to tackle the problem of how different functional units of the cuticle differentiate simultaneously. We are focussing our efforts on transcriptional regulation and secretion control to answer this question, while we continue our genetic approach to isolate and characterise additional components acting during cuticle differentiation. In particular, we are interested in registering the effective transcriptome of cuticle differentiation by the identification of the target genes of the transcription factors Grainyhead, βFtzF1 and CrebA that are known to govern differentiation processes during late embryogenesis. In parallel, we seek to unravel the secretion mechanisms directing coordinated construction of the extracellular matrix that will become the cuticle. These systematic ventures will be accompanied by an RNAi-based genetic search for more effectors of cuticle differentiation, the characterisation of which will enable us to further dissect the underlying molecular mechanisms. With this project strengthened by our solid knowledge in histology, we expect to launch cuticle differentiation as a pathfinder of the research field of organ differentiation.