BACKGROUND The invasive benthic round goby (Neogobius melanostomus) is the most successful temperate invasive fish and has spread in aquatic ecosystems on both sides of the Atlantic. Invasive species constitute powerful in situ experimental systems to study fast adaptation and directional selection on short ecological timescales and present promising case studies to understand factors involved the impressive ability of some species to colonize novel environments. We seize the unique opportunity presented by the round goby invasion to study genomic substrates potentially involved in colonization success. RESULTS We report a highly contiguous long-read-based genome and analyze gene families that we hypothesize to relate to the ability of these fish to deal with novel environments. The analyses provide novel insights from the large evolutionary scale to the small species-specific scale. We describe expansions in specific cytochrome P450 enzymes, a remarkably diverse innate immune system, an ancient duplication in red light vision accompanied by red skin fluorescence, evolutionary patterns of epigenetic regulators, and the presence of osmoregulatory genes that may have contributed to the round goby's capacity to invade cold and salty waters. A recurring theme across all analyzed gene families is gene expansions. CONCLUSIONS The expanded innate immune system of round goby may potentially contribute to its ability to colonize novel areas. Since other gene families also feature copy number expansions in the round goby, and since other Gobiidae also feature fascinating environmental adaptations and are excellent colonizers, further long-read genome approaches across the goby family may reveal whether gene copy number expansions are more generally related to the ability to conquer new habitats in Gobiidae or in fish.

中文翻译：

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虾虎鱼基因组提供了可能促进生物学入侵的机制的见解。

背景技术侵入性底栖圆虾虎鱼（Neogobius melanostomus）是最成功的温带侵入性鱼类，已在大西洋两岸的水生生态系统中传播。入侵物种构成了强大的原位实验系统，可在较短的生态时间尺度上研究快速适应和方向选择，并提出了有希望的案例研究，以了解涉及某些物种令人印象深刻的能力来殖民新环境的因素。我们抓住了虾虎鱼入侵带来的独特机会，以研究可能参与定殖成功的基因组底物。结果我们报告了一个高度连续的基于长读的基因组，并分析了我们推测与这些鱼应对新环境的能力有关的基因家族。这些分析提供了从大进化规模到小物种特定规模的新颖见解。我们描述了特定细胞色素P450酶的扩展，明显不同的先天免疫系统，在红光视野下古老的复制，伴随着红色皮肤荧光，表观遗传调控因子的进化模式以及渗透调节基因的存在，这些基因可能有助于轮虾的能力入侵寒冷和咸水。所有已分析基因家族中反复出现的主题是基因扩展。结论扩展的虾虎鱼先天免疫系统可能会潜在地促进其定殖新区域的能力。由于其他基因家族在虾虎鱼中也具有拷贝数扩展的功能，并且由于其他戈壁科动物也具有引人入胜的环境适应能力，并且是出色的定居者，