Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia & Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Spain.
Department of Environmental Science and Policy, Università degli Studi di Milano (UniMi), Milan, Italy.
Genome Biol Evol. 2022 May 3;14(5). doi: 10.1093/gbe/evac067.
The Balearic shearwater (Puffinus mauretanicus) is the most threatened seabird in Europe and a member of the most speciose group of pelagic seabirds, the order Procellariiformes, which exhibit extreme adaptations to a pelagic lifestyle. The fossil record suggests that human colonisation of the Balearic Islands resulted in a sharp decrease of the Balearic shearwater population size. Currently, populations of the species continue to be decimated mainly due to predation by introduced mammals and bycatch in longline fisheries, with some studies predicting its extinction by 2070. Here, using a combination of short and long reads, we generate the first high-quality reference genome for the Balearic shearwater, with a completeness amongst the highest across available avian species. We used this reference genome to study critical aspects relevant to the conservation status of the species and to gain insights into the adaptation to a pelagic lifestyle of the order Procellariiformes. We detected relatively high levels of genome-wide heterozygosity in the Balearic shearwater despite its reduced population size. However, the reconstruction of its historical demography uncovered an abrupt population decline potentially linked to a reduction of the neritic zone during the Penultimate Glacial Period (∼194-135 ka). Comparative genomics analyses uncover a set of candidate genes that may have played an important role into the adaptation to a pelagic lifestyle of Procellariiformes, including those for the enhancement of fishing capabilities, night vision, and the development of natriuresis. The reference genome obtained will be the crucial in the future development of genetic tools in conservation efforts for this Critically Endangered species.
巴利阿里群岛剪水鹱（Puffinus mauretanicus）是欧洲受威胁最严重的海鸟，也是数量最多的远洋海鸟——管鼻类的成员之一，它们对远洋生活方式表现出了极端的适应性。化石记录表明，人类对巴利阿里群岛的殖民导致了巴利阿里群岛剪水鹱数量的急剧减少。目前，该物种的数量仍在继续减少，主要原因是引入的哺乳动物捕食和延绳钓渔业的兼捕，一些研究预测该物种将在 2070 年灭绝。在这里，我们使用短读长和长读长的组合，生成了巴利阿里群岛剪水鹱的第一个高质量参考基因组，其完整性在现有的鸟类物种中是最高的之一。我们使用这个参考基因组研究了与物种保护状况相关的关键方面，并深入了解了管鼻类对远洋生活方式的适应。尽管巴利阿里群岛剪水鹱的种群规模较小，但我们检测到了相对较高水平的全基因组杂合度。然而，对其历史种群动态的重建揭示了一个突然的种群下降，这可能与末次冰期期间（约 194-135 千年前）滨海区的减少有关。比较基因组学分析揭示了一组候选基因，这些基因可能在管鼻类对远洋生活方式的适应中发挥了重要作用，包括增强捕鱼能力、夜视和发展利钠排泄的基因。获得的参考基因组将在未来为保护这种极度濒危物种的遗传工具的开发中发挥关键作用。
