Genome Compositional Domains of Hymenopteran Insects and Representatives of Five Other Insect Orders

RESEARCH ABSTRACT The compositional structures of eukaryotic genomes have long been known for their non-uniformity. Molecular evolutionists have proposed theories and models to describe eukaryotic genome architecture. Genome sequencing of the European honey bee (Apis mellifera), a model for the biology and evolution of eusocial behavior, has revealed unusual genome compositional characteristics, including a low but heterogeneous GC content and a biased tendency of genes to be located in low GC regions. In this study, we sought to determine whether those striking features are common in eusocial Hymenopteran insect species. Using a recursive segmentation algorithm, we partitioned 26 insect genomes and compared their compositional domains. We found that the genomes of Apis species have the most heterogeneous GC content, and bimodal distribution in GC content is unique to Apis. We also recognized that Hymenopteran's genes tend to be located in low GC content. Though, this bias is only strong in eusocial bees and Indian jumping ant, Harpegnathos saltator. Additionally, our GO analysis suggests that genes in high GC content regions tend to serve important roles in biological regulation processes of honey bee. DATA DESCRIPTION Genome assemblies of 21 hymenopteran insects and representatives of five other insect orders were segmented into GC compositional domains by IsoPlotter 2.4 (Elhaik and Graur 2013) (https://code.google.com/archive/p/isoplotter/). Data files provided per genome assembly are named according to the rule: [species name]_[assembly name]_GC_content_domains.txt Files are saved in tab-delimited text format with 5 columns: 1. Scaffold or Chromosome Accession 2. Domain Start Coordinate 3. Domain End Coordinate 4. Domain Percent GC 5. Is homogeneous# 研究摘要 真核基因组（eukaryotic genomes）的组成结构长期以来被证实具有非均匀性特征。分子进化生物学家已提出诸多理论与模型，用以刻画真核基因组的架构特征。西方蜜蜂（Apis mellifera）作为真社会性行为生物学与演化研究的模式生物，其基因组测序结果揭示了一系列异常的基因组组成特征，包括偏低且异质性显著的GC含量（GC content），以及基因倾向于富集于低GC区域的分布偏好。本研究旨在探究这些显著特征是否普遍存在于膜翅目真社会性昆虫类群中。 研究采用递归分割算法，对26个昆虫基因组进行分割并比较其组成结构域。结果显示，蜜蜂属（Apis）物种的基因组GC含量异质性最高，且GC含量呈双峰分布为蜜蜂属所独有。同时本研究发现，膜翅目昆虫的基因普遍倾向于定位于低GC区域，但该分布偏好仅在真社会性蜂类以及印度跳蚁（Harpegnathos saltator）中表现显著。此外，基因本体（Gene Ontology，GO）分析结果表明，西方蜜蜂基因组高GC区域内的基因往往在生物调控过程中发挥关键功能。 # 数据说明 本数据集包含21种膜翅目昆虫及5个其他昆虫纲代表类群的基因组组装序列，通过IsoPlotter 2.4（Elhaik and Graur 2013）（https://code.google.com/archive/p/isoplotter/）分割得到GC组成结构域。 每个基因组组装对应的数据文件命名遵循以下规则：[物种名]_[组装版本名]_GC_content_domains.txt。文件采用制表符分隔的纯文本格式，共包含5列信息： 1. 支架（Scaffold）或染色体登录号 2. 结构域起始坐标 3. 结构域终止坐标 4. 结构域GC百分比 5. 是否为均一结构域