Investigating the role of the teneurin Ten-M in planar polarisation of Myosin II during Drosophila axis extension

主题：世界级支撑生物科学在后生动物发育的初始阶段，单个细胞种群被分成一系列独立的亚种群。每个亚群的命运由各种模式和分化信号决定，这些信号改变了细胞内的基因调控网络。因此，每组细胞发展出不同的身份和功能，使不同的组织类型能够从单一的原始细胞团产生。(Francois Fagotto 2015)。在发育中的有机体中存在的组织边界防止不同的细胞组混合，并确保细胞在胚胎中保持特定的空间位置，以便它们在整个发育过程中接收正确的调节信号。在后生动物中，存在各种不同的边界类型。组织间边界在物理上分隔不同类型的组织。或者，也存在组织内边界，将单个组织内不同的细胞组分开。相比之下，间隔边界阻止不同谱系的细胞在组织内混合。关于间隔边界的潜在问题之一是边界如何在物理上限制细胞的混合。在果蝇翼盘的D-V边界的研究表明，肌动球蛋白在边界上的作用是丰富的，其中F-肌动蛋白和肌球蛋白II在附着连接的水平上被证明是丰富的(梅杰和欧文2005年；梅杰和欧文2006年)。此外，在翼盘A-P交界处，激光消融显示该交界处的机械张力比机翼内其他交界处高2.5倍(Landsberg等人)。2009年)。然而，阻止细胞跨越边界混合的物理机制首先在果蝇生殖带段旁边界(PSB)显示，在那里，使用生色团辅助激光灭活(CALI)去除肌球蛋白II，导致增殖细胞破坏尖锐的边界。研究还表明，肌动球蛋白电缆沿着边界延伸，通过粘连连接连接并列的细胞，这建立了张力并限制了细胞混合(Monier等人)。2010)。在脊椎动物中，肌动球蛋白电缆在分隔斑马鱼菱形突起的隔间边界上也显示了类似的作用(Calzolari，Terriente和Pujade，2014)。在肌动球蛋白浓缩的调节方面，无翼信号是维持PSB所必需的，而Notch信号维持D-V翼盘边界(Monier等人)。该项目的目的：1.确定细胞表面受体的组合，负责在果蝇的轴延伸过程中形成段旁边界和细胞的正确分选。研究由细胞表面受体表达水平定义的细胞特性的差异是否有助于肌动球蛋白在生殖带中的浓缩。探讨肌动球蛋白向PSB募集的分子机制。

Theme: World-Class Underpinning BioscienceDuring the initial stages of development in metazoa, a single population of cells is split into a series of separate sub-populations. The fate of each sub-population is determined by a variety of patterning and differentiation signals, which alter the gene regulatory networks within cells. Therefore, each group of cells develops a distinct identity and function, enabling a diverse range of tissue types to arise from a single original mass of cells. (Francois Fagotto 2015). Tissue boundaries present within the developing organism prevent distinct groups of cells from mixing, and ensure cells maintain a specific spatial position in the embryo so they receive the correct regulatory signals throughout development.Within metazoan organisms, a variety of different boundary types are present. Inter-tissue boundaries physically separate different types of tissue. Alternately, intra-tissue boundaries also exist, which separate distinct groups of cells within a single tissue. In comparison, compartmental boundaries prevent cells of distinct lineage from mixing within the tissue.One of the underlying questions regarding compartmental boundaries was how the boundary physically restricts the mixing of cells. A role for actomyosin enrichment at the boundary emerged from studies at the D-V boundary of the Drosophila wing disc, where F- actin and myosin II were shown to be enriched at the level of the adherens junction (Major and Irvine 2005; Major and Irvine 2006). Further, at the wing disc A-P boundary, laser ablation showed the mechanical tension at this interface is 2.5-fold higher than at other interfaces within the wing (Landsberg et al. 2009). However, the physical mechanism preventing the mixing of cells across a boundary was first shown at Drosophila germ-band parasegmental boundaries (PSBs), where the removal of myosin II using chromophore- assisted laser inactivation (CALI), caused proliferating cells to disrupt the sharp boundary. It was also shown that an actomyosin cable runs alongside the boundary, connecting between juxtaposing cells through adherens junctions, which establishes tension and restricts cell mixing (Monier et al. 2010). In vertebrates, a similar role for an actomyosin cable has been shown at compartmental boundaries separating Zebrafish rhombomeres (Calzolari, Terriente, and Pujades 2014). In terms of regulation of actomyosin enrichment, Wingless signalling is required for maintenance of PSBs whilst Notch signalling maintains the D-V wing disc boundary (Monier et al. 2010; Major and Irvine 2005; Dahmann, Oates, and Brand 2011).Aims of the Project:1. Identify the combination of cell surface receptors responsible for the formation of parasegmental boundaries and the correct sorting of cells during axis extension in Drosophila.2. Investigate whether differences in cell identity, as defined by cell surface receptor expression levels, facilitates actomyosin enrichment in the germ-band.3. Explore the molecular mechanism of actomyosin recruitment to PSBs.