Cellular and genetic basis underlying heterochronic brain development

异时性大脑发育的细胞和遗传基础

• 批准号: 427939880
• 负责人: Professor Dr. Gregor Bucher
• 金额: --
• 依托单位: Abteilung Evolutionäre Entwicklungsgenetik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/427939880?language=en
• 关键词: Cellular; genetic; basis; underlying; heterochronic

The brain is the most complex organ of an animal. Due to its essential role for survival, brain function and morphology are under high selective pressure. Indeed, the basic architecture of the brain is highly conserved within insects. However, size and shape of the different brain parts (neuropiles) reflect evolutionary adaptations. For instance, the mushroom bodies required for olfactory learning and memory are enlarged in bees. However, almost nothing is known about the mechanisms of evolution of insect brain morphology neither on the level of the underlying cellular developmental processes nor on the level of the genes that control these. An intriguing adaptation is found when comparing central complex development among insects: In hemimetabolous insects all neuropils of the central body (CB) develop during embryogenesis. This is supposed to be the ancestral condition. The fly Drosophila melanogaster represents an exception in that the CB develops only during late larval stages and metamorphosis. The red flour beetle Tribolium castaneum is an intermediate where the CB neuropils form partly during embryogenesis. In this project, we want to understand the cellular and genetic mechanisms involved in the evolution of heterochronic development by using the CB as study case. We will use Drosophila and Tribolium as model systems for comparison. We have been using genome editing in order to establish tools to mark homologous cells/cell groups in both species. In this project, we will compare the development of homologous cells from neuroblast to the adult circuitry. This analysis will reveal when and how the developmental paths of homologous cells diverge between species during the heterochronic shift. Finally, we want to identify genetic regulators that govern heterochronic development.

大脑是动物最复杂的器官。由于其对生存的重要作用，脑功能和形态处于高选择压力下。事实上，大脑的基本结构在昆虫中是高度保守的。然而，不同大脑部分（神经桩）的大小和形状反映了进化适应。例如，嗅觉学习和记忆所需的蘑菇体在蜜蜂中被扩大。然而，昆虫脑形态的进化机制几乎一无所知，无论是在细胞发育过程的水平上，还是在控制这些过程的基因的水平上。在比较昆虫中央复合体的发育时，发现了一个有趣的适应：在半变态昆虫中，中央体（CB）的所有神经柱都在胚胎发生期间发育。这应该是祖先的状况。果蝇是一个例外，CB只在幼虫晚期和变态期发育。赤拟谷盗Tribolium castaneum是CB神经柱在胚胎发生过程中部分形成的中间体。在这个项目中，我们希望通过使用CB作为研究案例来了解异时发育进化中涉及的细胞和遗传机制。我们将使用果蝇和赤拟谷盗作为比较的模型系统。我们一直在使用基因组编辑来建立标记两个物种中同源细胞/细胞群的工具。在这个项目中，我们将比较同源细胞从成神经细胞到成人回路的发育。这一分析将揭示何时以及如何同源细胞的发育路径分歧物种之间的异时性转变。最后，我们希望确定控制异时发育的遗传调节因子。