The genetic dissection of seamless tube shape control in the Drosophila trachea

果蝇气管无缝管形状控制的遗传解析

• 批准号: 9123783
• 负责人: Jeffrey B Rosa
• 金额: $ 4.36万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-15 至 2019-09-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9123783
• 关键词: Actins; Actomyosin; Address; Adopted; Affect; Apical; Architecture; Binding; Biogenesis; Biological; Blood Vessels; Cells; Chitin; Chitin Synthase; Complex; Contracts; Cyst; Defect; Disease; Dissection; Drosophila genus; Drosophila melanogaster; Endothelial Cells; Epithelial; Epithelial Cells; Epithelium; Exhibits; Extracellular Matrix; Fiber; Fibrinogen; Filament; Gases; Genes; Genetic; Glycocalyx; Glycoproteins; Growth; Health; Homeostasis; Imaging Techniques; Immunofluorescence Immunologic; In Situ; Individual; Insecta; Larva; Lasers; Lead; Measures; Mediating; Membrane; Modeling; Molecular; Morphogenesis; Morphology; Myosin ATPase; Myosin Type II; Nature; Nutrient; Organ; Pathway interactions; Phenocopy; Polycystic Kidney Diseases; Polysaccharides; Positioning Attribute; Property; Proteins; Proteoglycan; Regulation; Resolution; Role; Shapes; Stereotyping; Structure; Surface; System; Testing; Tissues; Trachea; Transmission Electron Microscopy; Tube; Tubular formation; Vascular System; Zinc Fingers; apical membrane; asthmatic; base; cerebral cavernous malformations; dosage; genetic approach; innovation; live cell imaging; loss of function; mutant; neovascularization; non-muscle myosin; novel; overexpression; polarized cell; programs; public health relevance; research study; respiratory; transcription factor; tumor

 DESCRIPTION (provided by applicant): To build a functional vascular network, endothelial tubes must adopt stereotyped topologies. Both multicellular and unicellular tube topologies are observed in vertebrate vasculatures. Seamless tubes are unicellular and unbound by junctions. Seamless tubes are found in multiple contexts within vertebrate vascular networks. The functional roles of seamless tubes in these contexts are poorly understood because the cellular mechanisms of seamless tube morphogenesis are poorly understood. Nevertheless, seamless tubes are conserved across phyla, including in the respiratory (tracheal) system of Drosophila melanogaster larvae, where powerful forward genetic approaches can be utilized to study seamless tube morphogenesis. To build a functional vascular network, endothelial tubes must also adopt a stereotyped shape. Endothelial cells secrete a luminal (apical) extracellular matrix (aECM) called the glycocalyx, comprised of secreted and membrane-bound glycoproteins and proteoglycans. Defects in glycocalyx structure lead to defects in endothelial tube expansion. Indeed, aECMs have a conserved role in regulating tube growth, including in Drosophila tracheal tubes. The seamless tubes of the Drosophila trachea secrete a chitin-based aECM called the cuticle, whose role in seamless tube morphogenesis not known. We have a poor understanding of molecular pathways through which individual secreted matrix factors are organized into an ordered aECM. Moreover, the molecular pathways through which aECMs shape the apical membrane to regulate tube morphogenesis are entirely unknown. I will use the seamless tubes of the Drosophila larval tracheal system as a model to elucidate novel genetic pathways controlling seamless tube shape by regulating aECM structure/function. I have identified a role for the seamless tube aECM in regulating tube shape and integrity. Chitin synthase-deficient terminal cells exhibit apical membrane cysts and discontinuities. I have also identified a set of novel mutants (ichor and asthmatic) that phenocopy "chitin biogenesis" mutants. I hypothesize that these mutants may affect novel pathway(s) regulating the structure or function of a seamless tube aECM. ichor and asthmatic encode zinc- finger transcription factors (CG11966 and zif, respectively), suggesting they regulate the expression or targeting of aECM components to the lumen. In Specific Aim 1, I will identify the genetic requirements for aECM organization in seamless tubes, including testing the role of a conserved polarity factor known to be downstream of Zif, in targeting aECM components to the lumen. In Specific Aim 2, I will identify cellular and molecular pathways through which the seamless tube aECM regulates tube shape. I will test a role for the seamless tube aECM in regulating apical actomyosin organization using both genetic and innovative live cell imaging techniques.

 描述（由适用提供）：要构建功能性血管网络，内皮管必须采用刻板印象的拓扑结构。在脊椎动物血管中观察到多细胞和单细胞管拓扑。无缝的管是单细胞的，无界的连接。无缝试管在脊椎动物血管网络中的多种情况下发现。无缝试管在这些情况下的功能作用知之甚少，因为对无缝管形态发生的细胞机制知之甚少。然而，无缝的管子在整个门中都是保守的，包括在果蝇的呼吸道（气管）系统中，可以利用强大的前进遗传方法来研究无缝的管形形态发生。要构建功能性血管网络，内皮管也必须采用刻板印象。内皮细胞向称为糖脂的腔内（顶）细胞外基质（AECM），由分泌和膜结合的糖蛋白和蛋白聚糖组成。糖脂结构中的缺陷导致内皮管扩张中的缺陷。实际上，AECM在确定管的生长中具有保守的作用，包括在果蝇气管管中。果蝇气管秘密的无缝管基于几丁质的AECM，称为角质层，其在无缝的管形形态发生中的作用尚不清楚。我们对分子途径的理解很糟糕，通过这些途径将单个分泌的基质因子组织成有序的AECM。此外，AECM塑造顶膜以调节管形形态发生的分子途径完全未知。我将使用果蝇幼虫气管系统的无缝试管作为模型，以通过调节AECM结构/功能来阐明控制无缝管形的新型遗传途径。我已经确定了无缝管AECM在控制管形和完整性中的作用。有数有缺陷的末端细胞暴露于顶端膜囊肿和不连续性。我还确定了一组新型突变体（iChor和哮喘），这些突变体“几丁质生物发生”突变体。我假设这些突变体可能会影响新的途径（S），以应对无缝管AECM的结构或功能。 ICER和哮喘编码锌指转录因子（分别为CG11966和ZIF），表明它们调节AECM成分对管腔的表达或靶向。在特定的目标1中，我将确定无缝管中AECM组织的遗传要求，包括测试已知的极性因子在ZIF下游的作用，在将AECM组件靶向腔内。调节管形。我将使用遗传和创新的活细胞成像技术来测试无缝管AECM在调节的顶肌球蛋白组织中的作用。