Evolution of pattern formation in insects

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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.