The evolution of developmental system drift in axial specification in Spiralia

螺旋体轴向规格发育系统漂移的演变

• 批准号: BB/Y004221/1
• 负责人: Jose Martin Duran
• 金额: $ 82.64万
• 依托单位: Queen Mary University of London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FY004221%2F1
• 关键词: evolution; developmental; system; drift; axial

Similar organs in different animals often form slightly differently during development in the egg or the mother's womb. For example, humans and fishes have a spine on their backs, made of vertebrae with a nerve running through them. Yet, how cells behave and how the core units that comprise our genetic information--the genes--interact during the development of the spine in these animals are not entirely identical. This is paradoxical because the common expectation is that differences in how equivalent organs form should result in changes in how they look at birth. The phenomenon by which similar organs form through varying mechanisms is called 'developmental system drift', and researchers do not fully understand why and how it happens.Animals as diverse as mussels, snails and earthworms look alike at the very first steps of their development. Indeed, we have shown that, in many cases, they use similar molecules and signals to define the blueprint of their adult morphology while they develop in their eggs. However, we have also found that different worms can use two distinct signals to define the organs that form along the body axis that goes from their backs to their bellies, the so-called dorsoventral axis. Our project wants to use this puzzling observation as a study system to investigate the process of 'developmental system drift' and, thereby, solve a fundamental and long-standing knowledge gap in Evolution and Developmental Biology.In this project, we will investigate how changes in the formation of the back-to-belly axis in marine segmented worms originated. We will do this by applying advanced methodologies that allow recording the activity of genes at the level of individual cells. We will use these techniques in two worms that form the back-to-belly axis differently and perturb their development with chemical drugs to reconstruct how their genes interact during the critical phase of forming that body axis. By comparing the two species, we will identify similarities and differences at the level of single genes and single cells during their development, thereby inferring the changes in gene activity and regulation that cause 'developmental system drift' during the development of these species. Moreover, we will study the formation of the back-to-belly axis in a new species of worm to test the hypothesis that changes in the signals controlling this axis correlate with transitions to a mode of reproduction that relies on molecules that the mother deposits into the eggs.Together, our project will establish new methods and species for the study of animal development and produce unparalleled datasets that will reveal the principles underpinning 'developmental system drift', a widespread and fundamental phenomenon in animals. We will thus generate new concepts, predictions and approaches that will likely apply to many other animals, providing a better understanding of the rules that govern the most critical phase of our lives.

不同动物的相似器官在卵细胞或母体子宫中发育过程中形成的方式往往略有不同。例如，人类和鱼类的背部都有脊椎，由椎骨组成，神经贯穿其中。然而，在这些动物的脊柱发育过程中，细胞的行为方式和构成我们遗传信息的核心单位--基因--如何相互作用并不完全相同。这是自相矛盾的，因为人们普遍认为，等效器官形成方式的差异应该导致它们出生时外观的变化。相似器官通过不同机制形成的现象被称为“发育系统漂移”，研究人员尚不完全了解其发生的原因和方式。贻贝、蜗牛和蚯蚓等多种动物在发育的第一步看起来都很相似。事实上，我们已经证明，在许多情况下，它们在卵中发育时使用相似的分子和信号来定义其成年形态的蓝图。然而，我们也发现，不同的蠕虫可以使用两种不同的信号来定义沿着从背部到腹部的身体轴形成的器官，即所谓的背腹轴。本研究课题的目的是，将这一令人困惑的现象作为研究系统，探讨“发育系统漂移”的过程，从而解决进化与发育生物学中长期存在的基本知识空白。本研究课题将探讨海洋分节蠕虫的背腹轴的形成变化是如何发生的。我们将通过应用先进的方法来实现这一点，这些方法允许在单个细胞的水平上记录基因的活性。我们将在两种形成背腹轴不同的蠕虫中使用这些技术，并用化学药物扰乱它们的发育，以重建它们的基因在形成身体轴的关键阶段如何相互作用。通过比较这两个物种，我们将在它们的发育过程中确定单基因和单细胞水平上的相似性和差异性，从而推断在这些物种的发育过程中引起“发育系统漂移”的基因活性和调控的变化。此外，我们将研究一种新的蠕虫物种中背部到腹部轴的形成，以检验控制该轴的信号的变化与依赖于母亲沉积到卵中的分子的繁殖模式的转变相关的假设。我们的项目将为动物发育研究建立新的方法和物种，并产生无与伦比的数据集，揭示动物发育的原理。这是动物普遍存在的基本现象。因此，我们将产生可能适用于许多其他动物的新概念，预测和方法，从而更好地理解管理我们生命中最关键阶段的规则。