Genetic control of C. elegans gastrulation

描述（由申请人提供）：原肠胚形成是早期发育的关键时期，此时细胞根据它们将成为什么在胚胎内进行空间组织。原肠胚形成的细胞运动必须受到密切控制，以防止可能导致出生缺陷或流产的胚胎组织的灾难性缺陷，但我们对原肠胚形成控制的影响知之甚少。特别是，虽然它是明确的工作在几个模式物种，细胞命运规范基因可以直接原肠胚运动，控制原肠胚形成的下游效应的身份和功能在很大程度上是未知的。这项建议的具体目标是确定和表征基因的功能下游的细胞命运规范基因，以控制原肠胚运动。我们的长期目标是要有一个完整的图片细胞命运的规范基因，原肠胚形成控制基因，以及基本的细胞骨架和细胞极性蛋白的功能，共同诱导，影响和协调原肠胚运动。在这个提议中，我们利用C.线虫胚胎，以确定和表征原肠胚形成控制基因。由于保守的细胞机制似乎在原肠胚形成过程中起作用，我们的研究利用了C。在其他脊椎动物和无脊椎动物模式生物中的独特补充研究。C.线虫内胚层细胞的转录是由转录因子END-1和END-3触发的，这两个因子也是内胚层特化所必需的。然而，下游效应的END-1和END-3重要的原肠胚形成是未知的。在初步研究中，我们进行了微阵列实验，以确定一组以前未知的END效应基因。在这里，我们提出了遗传和细胞生物学实验，以确定和表征那些重要的原肠胚形成，和额外的实验，以确定肌动球蛋白调节蛋白，可能接口与END效应控制原肠胚形成。最后，我们提出的实验，以确定Wnt信号是否有直接的作用，促进原肠胚形成，最近提出的，或Wnt信号是否有助于原肠胚形成间接通过其已知的作用，指定内胚层。这些实验将为理解C.原肠形成由于原肠胚形成的许多细胞生物学事件是保守的，我们预计我们的发现-以及由此产生的未来研究-将有助于更好地了解人类胚胎发育的这一关键而神秘的阶段。公共卫生相关性：在人类胚胎发育过程中，当基本的身体计划通过受调节的细胞运动建立时，这项计划的目标是确定对原肠胚细胞运动重要的基因，并了解这些基因的功能。这些研究将有助于了解人类出生缺陷和异常原肠胚形成导致的流产的原因。

DESCRIPTION (provided by applicant): Gastrulation is a critical time in early development when cells organize themselves spatially within the embryo according to what they will become. The cell movements of gastrulation must be intimately controlled to prevent catastrophic defects in organization of the embryo that can cause birth defects or miscarriage, yet we know little about how gastrulation control is effected. In particular, although it is clear from work in several model species that cell fate specification genes can direct gastrulation movements, the identities and functions of the downstream effectors controlling gastrulation are largely unknown. The specific goal of this proposal is to identify and characterize genes that function downstream of cell fate specification genes to control gastrulation movements. Our long-term goal is to have a complete picture of how cell fate specification genes, gastrulation control genes, and basic cytoskeletal and cell polarity proteins function together to induce, effect, and coordinate gastrulation movements. In this proposal, we take advantage of the optical clarity and genetic manipulability of the C. elegans embryo to identify and characterize gastrulation control genes. Because conserved cellular mechanisms appear to operate during gastrulation, our studies take advantage of the strengths of C. elegans to uniquely complement studies in other vertebrate and invertebrate model organisms. Gastrulation of C. elegans endodermal cells is triggered by the transcription factors END-1 and END-3, which are also required for endoderm specification. However, downstream effectors of END-1 and END-3 important for gastrulation are unknown. In preliminary studies, we have performed microarray experiments to identify a set of previously unknown END effector genes. Here, we propose genetic and cell biological experiments to identify and characterize those important for gastrulation, and additional experiments to identify the actomyosin regulatory proteins that likely interface with the END effectors to control gastrulation. Finally, we propose experiments to determine whether Wnt signaling has a direct role in promoting gastrulation, as recently proposed, or whether Wnt signaling contributes to gastrulation indirectly through its known role in specifying endoderm. These experiments will provide the first foundation for understanding the genetic logic of C. elegans gastrulation. Because many of the cell biological events of gastrulation are conserved, we anticipate that our findings - and future studies that arise from them - will lead to a better understanding of this critical yet mysterious stage of human embryonic development. PUBLIC HEALTH RELEVANCE: Gastrulation is a critical stage in human embryonic development when the basic body plan is established through regulated cell movements. The goal of this proposal is to identify the genes important for gastrulation cell movements and learn how these genes function. These studies will help in understanding the cause of human birth defects and miscarriages that result from abnormal gastrulation.