Evolution of pattern formation in insects

昆虫模式形成的进化

• 批准号: RGPIN-2018-05989
• 负责人: Grbic, Miodrag
• 金额: $ 3.06万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=688465
• 关键词: Evolution; pattern; formation; insects

Polyembryonic development in the parasitic wasp Copidosoma floridanum (Cf) represents one of most extreme forms of development, where 2000 embryos are clonaly produced from a single zygote, exhibiting a radical form of obligatory embryo monozygotic twinning. Furthermore, this wasp produces two morphologically different clonal castes from same zygote: 1) a reproductive caste that pupate and produce adult wasps and 2) a soldier caste that is sterile and serves to defend the reproductive siblings from competitors and plays a role in modification of sex ratio. This type of complex developmental program and clonal caste production represents a challenge to the concepts in the evolution of development and other examples of caste specification in social insects. ******We have already performed whole genome sequencing, assembly and annotation of the Cf genome. In this proposal we propose to explore the role of epigenetic changes focusing on genome methylation in the evolution of development of this wasp. Our preliminary analysis confirmed hallmarks of genome methylation in Cf and we discovered unprecedented proliferation of genes in the DNMT3 protein family of methyltransferases, suggesting that epigenetic changes play an important role in evolution of this mode of development. In this application we propose to: ***1) Perform whole genome bisulfite sequencing of Cf to determine methylated cytosines at basepair resolution and study DNA methylation patterns***2) Perform transcriptome profiling of different developmental stages using RNAseq to gain insight into relationship between methylation and gene expression***3) Perform manipulative experiments using agonists and antagonists of methylation to determine the functional effects of altering genome methylation on development and perform RNAi on the target upregulated and methylated genes******The impact of this research will include fundamental science, generation of new genomic resources, genome browser for research community and applied knowledge applicable to the biological pest control. The fundamental knowledge will dissect the role of genome methylation on development and gene regulation in insects. In addition, it will uncover mechanisms of complex developmental evolution and evolution of developmental novelty. The Cf genome, methylome and manipulative experiments will provide important resources for study of social insect evolution and sociogenomics offering tools to answer key questions in this area: Are conserved genetic pathways repeatedly recruited into functional roles associated with social traits? How does genome architecture influence caste-biased gene expression, and phenotypic novelty? What is the role of novel genes in the origins and elaborations of eusociality? Is the worker phenotype the source of evolutionary novelty in eusocial insects? This program will also provide an outstanding training for HQPs.

多胚发育在寄生蜂Copidosoma floridanum（Cf）中代表了最极端的发育形式之一，其中2000个胚胎是从单个受精卵克隆产生的，表现出一种强制性胚胎单卵双生的根本形式。此外，该蜂从相同的合子产生两种形态上不同的克隆种姓：1）一个生殖种姓，化蛹并产生成年黄蜂和2）一个士兵种姓，是不育的，用于保护生殖同胞免受竞争对手的侵害，并在修改性比中发挥作用。这种类型的复杂的发育程序和克隆种姓生产的发展和社会性昆虫的种姓规格的其他例子进化的概念提出了挑战。* 我们已经对CF基因组进行了全基因组测序、组装和注释。在这个建议中，我们建议探索表观遗传变化的作用，重点是基因组甲基化在这种黄蜂的发展演变。我们的初步分析证实了Cf中基因组甲基化的标志，我们发现了甲基转移酶DNMT3蛋白家族中前所未有的基因增殖，这表明表观遗传变化在这种发育模式的进化中起着重要作用。在本申请中，我们提出：*1）对Cf进行全基因组亚硫酸氢盐测序，以碱基对分辨率确定甲基化胞嘧啶，并研究DNA甲基化模式 *2）使用RNAseq对不同发育阶段进行转录组分析，以深入了解甲基化与基因表达之间的关系 *3）使用甲基化的激动剂和拮抗剂进行操作实验，以确定改变基因组甲基化对发育的功能影响，并对靶向上调和甲基化基因进行RNAi *** 这项研究的影响将包括基础科学、新基因组资源的产生、研究界的基因组浏览器以及适用于生物害虫控制的应用知识。基础知识将剖析基因组甲基化对昆虫发育和基因调控的作用。此外，它将揭示复杂的发展演变和发展新奇的演变机制。Cf基因组、甲基化组和操纵实验将为社会性昆虫进化和社会基因组学的研究提供重要资源，为回答这一领域的关键问题提供工具：保守的遗传途径是否被反复招募到与社会性状相关的功能角色中？基因组结构如何影响种姓偏见的基因表达和表型新奇？新基因在真社会性的起源和发展中发挥什么作用？工蜂表型是真社会性昆虫进化新奇的来源吗？该计划还将为HQP提供出色的培训。