Evolution of dorsal-ventral patterning mechanisms in sibling Drosophila species

先前的研究揭示了在不同分类群中建立胚胎组织的分子机制的高度保守性。然而，有长期存在的问题，具有重大意义的模式的形成，仍然在很大程度上是未知的。其中包括缩放机制以及如何获得新的身体结构，同时在进化过程中保留了一些模式。本计画将探讨卵大小不同的物种，其初生胚层沿着背腹轴形成时的缩放特性。为了解决这些问题，研究人员将在最近分化的果蝇中进行跨物种比较，但在卵大小上获得了急剧变化。实验将包括不同果蝇的形态发生梯度和基因表达模式的定量测量。此外，两个密切相关的果蝇物种，可以杂交，D。melanogaster和D. sechellia将允许遗传实验来测试母体与合子形态发生信息对胚胎模式的物种特异性贡献。该项目的结果预计将产生必要的关键定量数据，以分析发展系统的缩放特性，并开发未来的计算模型，以解释模式是如何重新缩放的大小。该项目的更广泛影响包括本科生和研究生一级的培训，将少数群体纳入科学，以及改进发育生物学、进化和建模领域的课程。

Previous studies revealed a high degree of conservation of the molecular mechanisms that establish embryonic tissues in diverse taxa. However, there are long-standing problems of great significance regarding pattern formation that remain largely unknown. Among those are the mechanisms of scaling and how novel body architectures are acquired, while some patterns are preserved during the course of evolution. This project will investigate the scaling properties during the formation of primary embryonic germ layers along the dorso-ventral axis in species that differ in egg size. To address these questions, the investigator will make cross-species comparisons among Drosophilids that diverged recently, but acquired sharp variation in egg size. The experiments will include quantitative measurements of morphogenetic gradients and gene expression patterns in different Drosophilids. In addition, two closely related Drosophila species that can hybridize, D. melanogaster and D. sechellia, will allow genetic experimentation to test species-specific contribution of maternal versus zygotic morphogenetic information to embryonic patterning. The results of this project are expected to produce critical quantitative data necessary to analyze the scaling properties of developmental systems and develop future computational models to explain how patterns are re-scaled with size. Broader impacts of this project include training at undergraduate and graduate levels, inclusion of minority groups to science, and improvement of curricula in the areas of developmental biology, evolution and modeling.