Morphogenesis: Biophysics and Genetics of Dorsal Closure

在脊椎动物形态发生过程中，细胞片的形态发生在发育里程碑中起着至关重要的作用。 包括原肠形成和神经管、心脏和上颚的形成。它也是对 伤口愈合。细胞机制和驱动和调节的信号级联的协调 形态发生是关键--调控不当会导致发育和伤口愈合缺陷，这可能是致命的。 我们专注于细胞片形态发生是如何被驱动、调节和协调的基本生物学 在果蝇的背部闭合过程中。分子、细胞和组织结构的保守性 使闭合成为询问形态发生的分子基础的理想模型系统。 在闭合过程中，外侧表皮片向前推进以闭合背部开口。关闭是多种多样的。 不同的实验方法，我们率先将闭包作为一个模型系统进行研究，特别是通过 实时成像策略的使用。我们确定了四个有助于关闭的流程，并演示了 没有任何一种力量是绝对必要的。因此，闭包是健壮的、有弹性的和冗余的 在后生动物系统发育过程中保守的分子成分。我们最近的工作集中在离子通量是如何 有助于闭合，并提出了一个热力学模型来理解闭合过程中的组织重塑。我们 阐述来自图案化和极性基因产物的信号如何聚合以调节细胞形状和变化 以形态发生为特征的细胞形状。我们启动了一项正向基因筛查，直接评估 闭合的运动学，并研究闭合的健壮性和弹性的遗传基础。140多个 以前已知的基因对DC有贡献，我们已经发现了另外23个遗传间隔 在Just？/的引导屏幕中关闭所需的？苍蝇基因组的。在未来五年内，我们计划 使用基因发现来识别关闭所需的新基因。我们将使用高分辨率的4D成像 为了定量记录表征野生型和突变型动物闭合的细胞形状变化， 然后使用生物物理策略来确定这些新基因如何对强制生产和调节做出贡献。 关门大吉。我们计划解决的关键概念差距是胚胎模式在建立 胚胎闭合初期的细胞和亚细胞构筑以及离子如何流动 有助于结案。我们将调查触发关闭和反馈开始的一个或多个信号 补偿遗传或身体上对闭合进程的侮辱的机制。我们将继续 探索产生力量的细胞骨架组件如何定位、协调和调节，并研究如何 黏附复合体既传递力量，又允许细胞移动。 我们独一无二地准备解决现有的关键问题，这些问题表征了细胞片的基本生物学 苍蝇的形态发生。由于形态发生在分子、细胞和组织水平上高度保守， 我们的工作直接告知脊椎动物在发育和伤口愈合过程中的形态发生。

Cell sheet morphogenesis plays crucial roles in developmental milestones during vertebrate morphogenesis, including gastrulation and the formation of the neural tube, the heart, and the palate. It is also essential for wound healing. Coordination of the cellular machineries and the signaling cascades that drive and regulate morphogenesis is critical – misregulation results in developmental and wound healing defects that can be fatal. We focus on the fundamental biology of how cell sheet morphogenesis is powered, regulated and coordinated during dorsal closure in Drosophila melanogaster. Conservation of molecular, cellular and tissue archictecture make closure an ideal model system for interrogating the molecular basis of morphogenesis. During closure, lateral epidermal sheets advance to close a dorsal opening. Closure is amenable to a wide variety of diverse experimental approaches and we pioneered the study of closure as a model system, especially through the use of live imaging strategies. We identified four processes that contribute to closure and demonstrated that no single force that contributes is absolutely required. Thus, closure is robust, resilient and redundant using molecular components that are conserved across metazoan phylogeny. Our recent work focuses on how ion fluxes contribute to closure and proposes a thermodynamic model to understand tissue remodeling during closure. We address how signals from patterning and polarity gene products converge to regulate cell shape and the changes in cell shape that characterize morphogenesis. We initiated a forward genetic screen that directly assesses the kinematics of closure and investigates the genetic basis for closure's robustness and resilience. More than 140 genes were previously known to contribute to DC and we have already discovered 23 additional genetic intervals that are required for closure in a pilot screen of just ¹/? of the fly genome. During the next five years we plan to use gene discovery to identify new genes that are required for closure. We will use high-resolution 4D imaging to document quantitatively the cellular shape changes that characterize closure in wild type and mutant animals, then use biophysical strategies to determine how these new genes contribute to force production and regulation of closure. Key conceptual gaps we plan to address are what roles embryonic patterning plays in establishing the cellular and subcellular architectures that characterizes the embryo at the onset of closure and how ion fluxes contribute to closure. We will investigate the signal (or signals) that triggers the onset of closure and feedback mechanisms that compensate for genetic or physical insults to the progress of closure. We will continue to explore how force-generating cytoskeletal components are positioned, coordinated and regulated and study how adhesion complexes both transmit forces and allow cell movements. We are uniquely poised to address key extant questions that characterize the basic biology of cell sheet morphogenesis in flies. Because morphogenesis is highly conserved at the molecular, cellular and tissue levels, our work directly informs vertebrate morphogenesis in development and wound healing.