Evolution and functionality of Wnt genes in the fruit fly Drosophila melanogaster

果蝇Wnt基因的进化和功能

• 批准号: 351217092
• 负责人: Dr. Franziska Anni Franke
• 金额: --
• 依托单位: Evolution of Animal Development and Morphology Group
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/351217092?language=en
• 关键词: Evolution; functionality; Wnt; genes; fruit

Wnt signalling regulates many biological processes during animal development, including cell fate specification, division and patterning. There are thirteen subfamilies of Wnt ligands in metazoans, seven of which are represented in the fruit fly Drosophila melanogaster. Most metazoan species have retained a large number of Wnts. Although some Wnt genes appear to have overlapping roles in Drosophila, it is thought they act cooperatively in Wnt landscapes and in some contexts they perform unique functions. To date, however, the molecular basis for the functional diversification of Wnt proteins and their individual interactions with receptors and other proteins remains unknown. For the project, I will use a novel reintegration system to identify the protein sequences responsible for functional divergence between Wnt genes. The CRISPR/Cas9 system will be applied for genomic engineering to delete specific genomic sequences and to simultaneously reintroduce exogenous DNA using targeting vectors. This system offers a remarkable opportunity to directly analyse and compare functions of Wnt ligands and hence test if the ligands can rescue each others functions to understand the molecular basis of their differences. Therefore, I will test if wg and Wnt6 can be replaced by each other in regards to their phenotypes after a gene loss in Drosophila. Next, I will analyse if Wnt10 and Wnt9 can rescue each others functions during embryogenesis. Since it is unlikely that one Wnt gene can completely and functionally replace another Wnt gene, I will reintroduce chimeric ligands of different Wnt genes to identify domains responsible for the diversification of two Wnt ligands. Thus, I will introduce chimeric wg-Wnt6 and Wnt9-Wnt10 genes, respectively, and assay for improved rescue. In the unlikely event that Wg and Wnt6 or Wnt9 and Wnt10 are fully functionally compatible, I will use the next closest related Wnt ligand Wnt8, and chimeric ligands thereof. This project will identify the molecular basis of functional differences among Wnt ligands, which will help to clarify how Wnt ligands regulate developmental processes individually and in combination. The findings may provide further insights into the role of Wnt signalling in developmental and degenerative diseases, including various types of cancer.

Wnt 信号传导调节动物发育过程中的许多生物过程，包括细胞命运规范、分裂和模式。后生动物中有 13 个 Wnt 配体亚科，其中 7 个以果蝇 Drosophila melanogaster 为代表。大多数后生动物物种保留了大量的Wnt。尽管一些 Wnt 基因在果蝇中似乎具有重叠的作用，但人们认为它们在 Wnt 景观中协同作用，并且在某些情况下发挥独特的功能。然而，迄今为止，Wnt 蛋白功能多样化的分子基础及其与受体和其他蛋白的单独相互作用仍然未知。在该项目中，我将使用一种新颖的重新整合系统来识别导致 Wnt 基因之间功能分歧的蛋白质序列。 CRISPR/Cas9系统将应用于基因组工程，删除特定的基因组序列，同时使用靶向载体重新引入外源DNA。该系统提供了一个绝佳的机会来直接分析和比较 Wnt 配体的功能，从而测试配体是否可以拯救彼此的功能，以了解其差异的分子基础。因此，我将测试果蝇基因丢失后wg和Wnt6的表型是否可以相互替代。接下来我将分析Wnt10和Wnt9在胚胎发生过程中是否可以互相拯救彼此的功能。由于一个 Wnt 基因不太可能在功能上完全取代另一个 Wnt 基因，因此我将重新引入不同 Wnt 基因的嵌合配体，以鉴定负责两个 Wnt 配体多样化的结构域。因此，我将分别引入嵌合 wg-Wnt6 和 Wnt9-Wnt10 基因，并进行分析以改善救援。万一 Wg 和 Wnt6 或 Wnt9 和 Wnt10 功能完全兼容，我将使用下一个最接近的相关 Wnt 配体 Wnt8 及其嵌合配体。该项目将确定Wnt配体之间功能差异的分子基础，这将有助于阐明Wnt配体如何单独和组合调节发育过程。这些发现可能有助于进一步了解 Wnt 信号在发育和退行性疾病（包括各种类型的癌症）中的作用。