Trichoptera (caddisflies) play an essential role in freshwater ecosystems; for instance, larvae process organic material from the water and are food for a variety of predators. Knowledge on the genomic diversity of caddisflies can facilitate comparative and phylogenetic studies thereby allowing scientists to better understand the evolutionary history of caddisflies. Although Trichoptera are the most diverse aquatic insect order, they remain poorly represented in terms of genomic resources. To date, all long-read based genomes have been sequenced from individuals in the retreat-making suborder, Annulipalpia, leaving ∼275 Ma of evolution without high-quality genomic resources. Here, we report the first long-read based de novo genome assemblies of two tube case-making Trichoptera from the suborder Integripalpia, Agrypnia vestita Walker and Hesperophylax magnus Banks. We find that these tube case-making caddisflies have genome sizes that are at least 3-fold larger than those of currently sequenced annulipalpian genomes and that this pattern is at least partly driven by major expansion of repetitive elements. In H. magnus, long interspersed nuclear elements alone exceed the entire genome size of some annulipalpian counterparts suggesting that caddisflies have high potential as a model for understanding genome size evolution in diverse insect lineages.

中文翻译：

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Agrypnia vestita Walker 和 Hesperophylax magnus Banks 的基因组组装和注释草案揭示了管状制盒石蝇（昆虫纲：毛翅目）中的大量重复元素扩展

毛翅目（石蛾）在淡水生态系统中发挥着重要作用；例如，幼虫从水中加工有机物质，是各种捕食者的食物。关于石蝇基因组多样性的知识可以促进比较和系统发育研究，从而使科学家能够更好地了解石蝇的进化历史。尽管毛翅目是最多样化的水生昆虫目，但它们在基因组资源方面的代表性仍然很低。迄今为止，所有基于长读长的基因组都已从撤退亚目 Annulipalpia 中的个体中测序，留下 275 Ma 的进化没有高质量的基因组资源。在这里，我们报告了来自 Integripalpia 亚目的两个管壳毛翅目的第一个基于长读长的从头基因组组装，Agrypnia vestita Walker 和 Hesperophylax magnus Banks。我们发现，这些管壳制作的石蛾的基因组大小至少比目前测序的年长类动物基因组大 3 倍，并且这种模式至少部分是由重复元素的主要扩展驱动的。在 H. magnus 中，仅长散布的核元素就超过了一些环距动物对应物的整个基因组大小，这表明石蝇作为了解不同昆虫谱系中基因组大小进化的模型具有很高的潜力。