Early Events in Pharyngeal Pouch Patterning

咽袋图案化的早期事件

• 批准号: RGPIN-2016-06536
• 负责人: Drysdale, Thomas
• 金额: $ 2.26万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=629018
• 关键词: Early; Events; Pharyngeal; Pouch; Patterning

The pharynx is a complex region of the embryo because it is formed from all three germ layers in addition to interactions with the adjacent, migrating neural crest. The pharynx forms the foregut but is also responsible for the formation of some endodermal organs including the thyroid, parathyroid and thymus. The pharynx forms a cavity with distinct polarity both in the anterior-posterior (AP) and dorsal-ventral (DV) axis. Several signaling cues are necessary for patterning along the AP axis including sonic hedgehog (Shh), Bmp, Fgf, and Wnt signaling. These pathways converge to define transcriptional networks that define each segment. The DV pathway is less defined but we have found it to be critical in proper patterning of the pharynx. The slits that will form only occur at the lateral sides of the pharynx while the endodermal organs form from the ventral pharyngeal endoderm. We hypothesize that distinct signaling pathways are necessary for AP and DV patterning of the pharynx and these are critical for formation of the pharyngeal gill slits and the endodermal organs derived from the pharynx. Our goal is to discover the key signaling pathways that define regions of the pharynx using a combination of specific inhibitors, antisense morpholinos, and Crispr technology. Specific pathways that investigated include the Shh pathway, Fgf pathway, and canonical Wnt signaling. We predict that that the Fgf pathway is necessary for the overall competency of the pharynx to respond to regional cues. The Shh pathway is required for both AP and DV patterning although each axis has distinct temporal requirements for the signal. Wnt signaling will be required for establishing the ventral pharynx and is necessary for formation of all organs arising from the pharyngeal endoderm. Bmp signaling will be required for formation of the anterior pharynx. In addition to the signaling pathways, we will define roles for specific transcription factors in defining the regions of the pharynx. A number of transcription factors are well established in defining the segments of the pharynx, including members of the Hox family. We propose to test the role of several of these in pharyngeal patterning including Hand1, Gcm2, Satb2, and Tbx3. We will use antisense morpholino and Crispr technology to reduce the activity of these transcription factors and examine the pharynx of manipulated embryos for differentiation and patterning defects within the pharynx.

咽是胚胎的一个复杂区域，因为它除了与相邻的迁移神经嵴相互作用外，还由所有三个胚层形成。咽形成前肠，但也负责形成一些内胚层器官，包括甲状腺，甲状旁腺和胸腺。咽形成一个腔，在前后（AP）和背腹（DV）轴上具有不同的极性。几种信号传导线索对于沿AP轴的沿着模式化是必需的，包括音刺猬（Shh）、BMP、Fgf和Wnt信号传导。这些途径会聚以定义定义每个片段的转录网络。DV通路不太明确，但我们发现它在咽部的正确模式中至关重要。将形成的狭缝仅发生在咽的侧面，而内胚层器官从腹侧咽内胚层形成。 我们假设，不同的信号通路是必要的AP和DV图案的咽，这些是至关重要的形成咽鳃裂和内胚层器官来自咽。 我们的目标是发现使用特定抑制剂，反义morpholinos和Crispr技术的组合来定义咽部区域的关键信号通路。研究的具体途径包括Shh途径、Fgf途径和经典Wnt信号传导。我们预测，成纤维细胞生长因子途径是必要的咽部的整体能力，以响应区域线索。Shh通路是AP和DV模式所需的，尽管每个轴对信号具有不同的时间要求。Wnt信号传导将是建立腹咽所必需的，并且是形成由咽内胚层产生的所有器官所必需的。前咽的形成需要Bmp信号。 除了信号通路，我们将定义特定转录因子在定义咽部区域中的作用。许多转录因子在定义咽部的节段中被很好地建立，包括Hox家族的成员。我们建议测试的作用，其中几个在咽部图案，包括手1，Gcm 2，Satb 2，和Tbx 3。我们将使用反义morpholino和Crispr技术来降低这些转录因子的活性，并检查操纵胚胎的咽部，以检查咽部内的分化和图案缺陷。