Genetic and cellular analysis of zebrafish fin development.

斑马鱼鳍发育的遗传和细胞分析。

• 批准号: RGPIN-2018-06854
• 负责人: Akimenko, MarieAndrée
• 金额: $ 6.12万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=745556
• 关键词: Genetic; cellular; analysis; zebrafish; fin

My research program involves the comparative analysis of fin and limb development, and the molecular mechanisms that may have contributed to the evolution of tetrapod limbs from paired fins (pectoral, pelvic). During early development, the early pectoral fin bud shows a lot of similarity with the limb bud but fin development quickly diverges starting with: 1) the formation of a fin fold; 2) migration of mesenchymal cells in the fold; 3) formation of actinotrichia, rigid fibers that act as a scaffold for mesenchymal cell migration and as a skeletal support for the growing fin fold. These migrating mesenchymal cells (named hereafter MMCs) play a fundamental role in the formation of the larval fin and the fin rays, however their exact role is not fully understood. Such MMCs are not present in developing limb buds suggesting that these cells have been lost or contribute to different tissues in tetrapod species. We recently characterized two gene regulatory regions, 2Pepi and m-Inta11 that are active in MMCs arising at the onset of fin fold formation in zebrafish embryonic fins. 2Pepi is responsible for actinodin 1 (and1) expression in a population of MMCs. And1 is a fish-specific gene that encodes for structural components of actinotrichia; the and gene family has been lost from the tetrapod genomes during evolution. In another study, we also showed that ablation of the m-Inta11 expressing MMCs impairs early fin development. We think MMC migration and function depends on the proper formation and maintenance of actinotrichia. We propose both of these processes are mediated by the expression of 5'hoxa/hoxd genes.In the coming five years, my research program will integrate data and reagents from our previous work to investigate the role of MMCs and their relationship to the actinotrichia to better understand their contribution to fin development. This project will allow us to better understand fin development and provide a better insight into the fin-to-limb transition. More specifically, I propose the following 4 aims:1) to use a cell lineage tracing approach to determine the fate of specific subsets of MMCs. 2) to investigate the long-term effects of the ablation of the and1-expressing MMCs on fin development. 3) to examine the effects of the genetic disruption of actinotrichia formation on MMCs and resulting consequences on fin development. 4) to examine the 5'hoxa/hoxd regulation of and1 mesenchymal expression. Investigating the role and fate of the MMCs, including their contributions to actinotrichia, fin fold, and ray development gives us an opportunity to better understand the mechanisms of fin development and provides a better insight into morphological changes underlying the fin-to-limb transition. In addition, understanding the regulatory link between and1 and 5'HoxA/D proteins could shed light on how regulatory changes contributed to the loss of the actinodin genes from the tetrapod genome.

我的研究项目涉及鳍和肢体发育的比较分析，以及可能有助于从成对鳍（胸鳍、骨盆）进化成四足动物肢体的分子机制。在早期发育过程中，早期的胸鳍芽与肢芽有很多相似之处，但鳍的发育很快就开始分化：1）鳍褶的形成； 2）皱襞内间充质细胞的迁移； 3）形成放线菌，刚性纤维，充当间充质细胞迁移的支架和生长的鳍褶的骨骼支撑。这些迁移的间充质细胞（以下称为MMC）在幼虫鳍和鳍条的形成中发挥着重要作用，但它们的确切作用尚不完全清楚。这种MMCs不存在于发育中的肢芽中，这表明这些细胞已经丢失或在四足动物物种中形成不同的组织。我们最近鉴定了两个基因调控区 2Pepi 和 m-Inta11，它们在斑马鱼胚鳍鳍褶形成开始时产生的 MMC 中活跃。 2Pepi 负责 MMC 群体中 Actinodin 1 (and1) 的表达。 And1 是鱼类特有的基因，编码放线菌的结构成分；在进化过程中， 和 基因家族已从四足动物基因组中丢失。在另一项研究中，我们还表明，表达 MMC 的 m-Inta11 的消融会损害早期鳍的发育。我们认为 MMC 的迁移和功能取决于放线菌的正确形成和维持。我们认为这两个过程都是由 5'hoxa/hoxd 基因的表达介导的。在未来五年中，我的研究计划将整合我们之前工作中的数据和试剂，以研究 MMC 的作用及其与放线菌的关系，以期更好地了解他们对鳍发展的贡献。 该项目将使我们能够更好地了解鳍的发育，并更好地了解鳍到肢体的过渡。 更具体地说，我提出以下 4 个目标：1) 使用细胞谱系追踪方法来确定 MMC 特定子集的命运。 2）研究消融表达and1的MMC对鳍发育的长期影响。 3) 检查放线菌形成的遗传破坏对MMC的影响以及由此对鳍发育的影响。 4)检查and1间充质表达的5'hoxa/hoxd调节。研究MMC的作用和命运，包括它们对放线菌、鳍折叠和鳍条发育的贡献，使我们有机会更好地了解鳍发育机制，并更好地了解鳍到肢转变背后的形态变化。此外，了解 and1 和 5'HoxA/D 蛋白之间的调控联系可以揭示调控变化如何导致四足动物基因组中放线菌素基因的丢失。