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喙头蜥基因组揭示羊膜进化的古老特征
2020-08-06 19:08

2020年8月5日出版的《自然》杂志在线发表了新西兰奥塔哥大学Neil J. Gemmell团队的最新成果,他们利用喙头蜥基因组揭示了羊膜进化的古老特征。

研究人员分析了喙头蜥约5 Gb的基因组,这是迄今已组装的最大的脊椎动物基因组之一。通过对该基因组的分析以及与其他脊椎动物基因组的比较,研究人员揭示了喙头蜥的独特性。系统发育分析表明,大约在2.5亿年前,喙头蜥谱系与蛇和蜥蜴谱系开始分离。该谱系还显示出中等程度的分子进化速率,并带有标志性进化实例。该基因组序列分析可识别蛋白质、非蛋白质编码RNA家族和重复元件的扩展,其中后者具有爬虫类和哺乳动物特征的混合。

喙头蜥基因组测序为四足动物的深入比较分析以及喙头蜥的生物学和保护提供了宝贵的资源。该研究还提供了与基因组测序相关的技术挑战和对文化责任的重要见解。

据了解,喙头蜥(斑点楔齿蜥)是爬行动物类喙头目唯一现存的物种,曾经分布于冈瓦纳区,是新西兰特有的标志性物种。作为与现已灭绝爬行动物(恐龙、现代爬行动物、鸟类和哺乳动物从中进化而来)的关键链接,喙头蜥为理解羊膜动物的祖先提供了重要证据。

附:英文原文

Title: The tuatara genome reveals ancient features of amniote evolution

Author: Neil J. Gemmell, Kim Rutherford, Stefan Prost, Marc Tollis, David Winter, J. Robert Macey, David L. Adelson, Alexander Suh, Terry Bertozzi, Jos H. Grau, Chris Organ, Paul P. Gardner, Matthieu Muffato, Mateus Patricio, Konstantinos Billis, Fergal J. Martin, Paul Flicek, Bent Petersen, Lin Kang, Pawel Michalak, Thomas R. Buckley, Melissa Wilson, Yuanyuan Cheng, Hilary Miller, Ryan K. Schott, Melissa D. Jordan, Richard D. Newcomb, Jos Ignacio Arroyo, Nicole Valenzuela, Tim A. Hore, Jaime Renart, Valentina Peona, Claire R. Peart, Vera M. Warmuth, Lu Zeng, R. Daniel Kortschak, Joy M. Raison, Valeria Velsquez Zapata, Zhiqiang Wu, Didac Santesmasses, Marco Mariotti, Roderic Guig, Shawn M. Rupp, Victoria G. Twort, Nicolas Dussex, Helen Taylor, Hideaki Abe, Donna M. Bond, James M. Paterson, Daniel G. Mulcahy, Vanessa L. Gonzalez, Charles G. Barbieri, Dustin P. DeMeo, Stephan Pabinger, Tracey Van Stijn, Shannon Clarke, Oliver Ryder, Scott V. Edwards, Steven L. Salzberg, Lindsay Anderson, Nicola Nelson, Clive Stone

Issue&Volume: 2020-08-05

Abstract: The tuatara (Sphenodon punctatus)—the only living member of the reptilian order Rhynchocephalia (Sphenodontia), once widespread across Gondwana1,2—is an iconic species that is endemic to New Zealand2,3. A key link to the now-extinct stem reptiles (from which dinosaurs, modern reptiles, birds and mammals evolved), the tuatara provides key insights into the ancestral amniotes2,4. Here we analyse the genome of the tuatara, which—at approximately 5 Gb—is among the largest of the vertebrate genomes yet assembled. Our analyses of this genome, along with comparisons with other vertebrate genomes, reinforce the uniqueness of the tuatara. Phylogenetic analyses indicate that the tuatara lineage diverged from that of snakes and lizards around 250 million years ago. This lineage also shows moderate rates of molecular evolution, with instances of punctuated evolution. Our genome sequence analysis identifies expansions of proteins, non-protein-coding RNA families and repeat elements, the latter of which show an amalgam of reptilian and mammalian features. The sequencing of the tuatara genome provides a valuable resource for deep comparative analyses of tetrapods, as well as for tuatara biology and conservation. Our study also provides important insights into both the technical challenges and the cultural obligations that are associated with genome sequencing.

DOI: 10.1038/s41586-020-2561-9

Source: https://www.nature.com/articles/s41586-020-2561-9

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:69.504
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html


本期文章:《自然》:Online/在线发表

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