Mortensen Richard D, Moore Regan P, Fogerson Stephanie M, Chiou Hellen Y, Obinero Chimdindu V, Prabhu Neel K, Wei Angela H, Crawford Janice M, Kiehart Daniel P
Biology Department, Duke University, Durham, NC, 27708, USA.
Biology Department, Duke University, Durham, NC, 27708, USA
G3 (Bethesda). 2018 Jul 2;8(7):2361-2387. doi: 10.1534/g3.118.200233.
Cell sheet morphogenesis characterizes key developmental transitions and homeostasis, in vertebrates and throughout phylogeny, including gastrulation, neural tube formation and wound healing. Dorsal closure, a process during embryogenesis, has emerged as a model for cell sheet morphogenesis. ∼140 genes are currently known to affect dorsal closure and new genes are identified each year. Many of these genes were identified in screens that resulted in arrested development. Dorsal closure is remarkably robust and many questions regarding the molecular mechanisms involved in this complex biological process remain. Thus, it is important to identify all genes that contribute to the kinematics and dynamics of closure. Here, we used a set of large deletions (deficiencies), which collectively remove 98.5% of the genes on the right arm of 2 chromosome to identify "dorsal closure deficiencies". Through two crosses, we unambiguously identified embryos homozygous for each deficiency and time-lapse imaged them for the duration of closure. Images were analyzed for defects in cell shapes and tissue movements. Embryos homozygous for 47 deficiencies have notable, diverse defects in closure, demonstrating that a number of discrete processes comprise closure and are susceptible to mutational disruption. Further analysis of these deficiencies will lead to the identification of at least 30 novel "dorsal closure genes". We expect that many of these novel genes will identify links to pathways and structures already known to coordinate various aspects of closure. We also expect to identify new processes and pathways that contribute to closure.
细胞片层形态发生是脊椎动物及整个系统发育过程中关键发育转变和内稳态的特征，包括原肠胚形成、神经管形成和伤口愈合。背侧闭合是胚胎发育过程中的一个过程，已成为细胞片层形态发生的模型。目前已知约140个基因会影响背侧闭合，并且每年都会鉴定出新的基因。这些基因中的许多是在导致发育停滞的筛选中鉴定出来的。背侧闭合非常稳健，关于这个复杂生物学过程所涉及的分子机制仍有许多问题。因此，识别所有有助于闭合运动学和动力学的基因非常重要。在这里，我们使用了一组大的缺失（缺陷），它们共同去除了2号染色体右臂上98.5%的基因，以识别“背侧闭合缺陷”。通过两次杂交，我们明确鉴定出每个缺陷的纯合胚胎，并在闭合期间对它们进行延时成像。分析图像中细胞形状和组织运动的缺陷。47种缺陷的纯合胚胎在闭合方面有明显的、多样的缺陷，这表明一些离散的过程构成了闭合，并且容易受到突变破坏。对这些缺陷的进一步分析将导致至少30个新的“背侧闭合基因”的鉴定。我们预计这些新基因中的许多将识别出与已知协调闭合各个方面的途径和结构的联系。我们还期望识别出有助于闭合的新过程和途径。
