Comparative genomics reveal signatures of ecological specialization in the striped ambrosia beetle Trypodendron lineatum

The primary objective of this project was to sequence and analyze the genome of the striped ambrosia beetle, Trypodendron lineatum, to explore how its obligatory nutritional mutualism with a cultivated fungus and subsequent ecological specialization have influenced its genomic architecture. The RNA-seq libraries submitted here were critically utilized to provide transcriptomic evidence for the high-quality structural annotation of the genome assembly (GenBank Accession: [Insert GenBank Accession Number Here]). Comparative genomics, supported by this annotation, revealed that T. lineatum possesses a highly compact, streamlined genome, characterized by low repetitive DNA content and reduced transposable elements. The genome also shows lineage-specific gene family contractions in pathways related to plant digestion, detoxification (e.g., Cytochrome P450), and broad-spectrum immunity, supporting a model of genomic optimization driven by a stable, nutrient-rich fungal diet. Conversely, observed expansions in genes involved in genomic regulation and immune recognition suggest adaptive processes for tolerating the mutualistic symbiont. This dataset establishes T. lineatum as a crucial resource for understanding insect genome evolution under strong symbiotic and niche specialization pressures.

本研究的核心目标为对条纹食菌小蠹（Trypodendron lineatum）的基因组进行测序与分析，以揭示其与人工培育真菌的专性营养共生关系，以及后续的生态特化如何塑造了其基因组结构。本次提交的RNA测序（RNA-seq）文库被用于为该基因组组装的高质量结构注释提供关键转录组学证据（GenBank登录号：[此处插入GenBank登录号]）。依托该注释的比较基因组学分析显示，条纹食菌小蠹拥有高度紧凑、精简的基因组，其特征为低重复DNA含量与转座元件丰度降低。该基因组在植物消化、解毒（如细胞色素P450（Cytochrome P450））以及广谱免疫相关通路中，表现出谱系特异性的基因家族收缩，这支持了“稳定且营养丰富的真菌饮食驱动基因组优化”的演化模型。与之相对，基因组调控与免疫识别相关基因的扩增现象，则提示了其对共生伙伴的耐受适应性演化过程。本数据集确立了条纹食菌小蠹作为研究强共生与生态位特化压力下昆虫基因组演化的关键科研资源的地位。