Architecture of a Genetic Network Governing Morphogenesis

细胞形态发生是动物发育和生长的重要组成部分。在这个过程中，细胞 协调地改变形状，迁移，并可能融合。这些过程是由称为 “效应器”。这种效应器已经在几个模型系统中被识别，并包括细胞骨架和 细胞极性的决定因素。形态发生的性别、组织、位置和时间的特异性被确定 由“调节者”，如转录因子。转录调控因子如何与细胞中的效应器相联系 形态发生的基因网络(GN)几乎在任何系统中都不被很好地理解，但这样的知识是 需要用来预测扰动如何导致发育、癌症和 形式的进化。阐明这种GN也将影响我们对伤口愈合和 再生。我们的长期目标是完全描绘出支配形态发生的GN架构 秀丽隐杆线虫的尾尖是一种新颖的、简单的和性别二态的模型结构。尾尖是 由四个细胞组成的，这些细胞--仅在雄性--在幼虫末期从根本上改变它们的形状和位置 发展。以前的研究发现了尾尖形态发生(TTM)的“主调节器”，即 转录因子DMD-3(与人类DMRT1同源，决定男性命运)。如果没有DMD-3， TTM完全失败了。此外，DMD-3在两性异位表达时足以引起TTM。 在这里，我们将测试DMD-3是如何与TTM的效应器相连的。特定目标1将通过以下方式验证此假设 用DMD-3和TTM的一组关键效应子进行了一系列成对的分子上位性实验 惠誉实验室此前在胚胎后RNAi筛查中发现了这一基因。在这些实验中，X基因(例如DMD-3) 会被击倒并对基因的转录、翻译或亚细胞定位产生影响 将对产品Y进行分析。网络分析将用于识别自动监管、反馈、前馈或 对GN很重要的其他系统控制。特定目标2解决了哪些其他基因是 DMD-3的下游以及DMD-3对TTM的充足贡献。特定于尾尖 转录组分析将在野生型雄性和两性的雄性样本上进行。 缺乏DMD-3，两性人错误表达DMD-3。预期成果是 DMD-3下游的GN架构以及对其如何管理本地化或表达的理解 细胞形状变化的关键效应者。这个GN将为今后关于 这些相互作用背后的分子机制以及它们如何影响细胞-生物模块。这些结果 有望对医学产生积极影响，因为他们可以识别控制 形态发生，从而为药物提供新的靶点，以减轻形态发生缺陷或 癌症，或帮助伤口愈合。

Cellular morphogenesis is an essential part of animal development and growth. During this process, cells coordinately change shape, migrate, and may fuse. These processes are executed by molecules called "effectors". Such effectors have been identified in several model systems and include the cytoskeleton and determinants of cell polarity. The sex-, tissue-, position-, and time-specificity of morphogenesis is determined by "regulators", such as transcription factors. How transcriptional regulators are linked to the effectors in a gene network (GN) for morphogenesis is not well understood in nearly any system, but such knowledge is required to predict how perturbations could lead to morphogenetic changes during development, cancer, and the evolution of form. Elucidating this GN would also impact our understanding of wound healing and regeneration. Our long-term goal is to completely delineate the GN architecture governing the morphogenesis of a novel, simple and sexually dimorphic model structure, the tail tip of Caenorhabditis elegans. The tail tip is composed of four cells which-in males only-radically alter their shape and position at the end of larval development. Previous studies identified a "master regulator" for tail tip morphogenesis (TTM), the transcription factor DMD-3 (homologous to DMRT1 in humans, which specifies male fates). Without DMD-3, TTM completely fails. Also, DMD-3 is sufficient to cause TTM when ectopically expressed in hermaphrodites. Here, we will test how DMD-3 is linked to the effectors of TTM. Specific Aim 1 will test this hypothesis by a series of pairwise molecular epistasis experiments with DMD-3 and a set of key effectors of TTM which the Fitch lab previously identified in a postembryonic-RNAi screen. In these experiments, a gene X (e.g. DMD-3) will be knocked down and the effect on the transcription, translation or subcellular localization of a gene product Y will be analyzed. Network analysis will be used to identify auto-regulatory, feedback, feed-forward, or other system controls important for the GN. Specific Aim 2 addresses the question of which other genes are downstream of DMD-3 and what contributes to the sufficiency of DMD-3 for TTM. Tail-tip-specific transcriptome analyses will be performed on samples from wild-type males and hermaphrodites, males deficient for DMD-3, and hermaphrodites misexpressing DMD-3. The expected outcome is a framework for the GN architecture downstream of DMD-3 and an understanding of how it governs the localization or expression of key effectors of cell shape change. This GN will lay the requisite foundation for future studies on the molecular mechanisms underlying these interactions and how they affect cell-biological modules. These results are expected to have a positive impact on medicine, as they could identify key conserved genes that control morphogenesis, thus providing new targets for drugs to mitigate the effects of morphogenetic defects or cancer, or to aid wound healing.