《自然》：海绵基因组草图绘制完成

2010/08/07 07:17:50

一个国际研究小组在8月5日出版的英国《自然》杂志上报告说，他们绘制出了海绵的基因组草图，并从中发现了许多有助于探索多细胞动物起源的信息。

这个由美国、德国、澳大利亚等国研究人员组成的小组报告说，他们完成了大堡礁海绵基因组测序草图，结果显示其中包含约1.8万个基因。海绵6亿多年前就出现在地球上，是已知最古老的多细胞动物，研究人员也在其基因组中找到了一些帮助单细胞动物进化为多细胞动物的关键基因，如指导细胞互相粘在一起的基因，以及使多个细胞能协调一致生长的基因。

虽然海绵结构简单，没有神经和肌肉等组织，研究人员还是在其基因组中发现了与高等动物体内指导神经与肌肉活动基因相似的基因。研究人员认为，海绵基因组的复杂程度说明进化成海绵的上一级动物比以前认为的更复杂，这将改变人们对多细胞动物起源的传统看法。

研究人员还在海绵基因组中找到了与细胞自杀有关的基因，这意味着这种原始多细胞动物有可能利用这一机制来对抗癌症等疾病。

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The Amphimedon queenslandica genome and the evolution of animal complexity

Mansi Srivastava, Oleg Simakov, Jarrod Chapman, Bryony Fahey, Marie E. A. Gauthier, Therese Mitros, Gemma S. Richards, Cecilia Conaco, Michael Dacre, Uffe Hellsten, Claire Larroux, Nicholas H. Putnam, Mario Stanke, Maja Adamska, Aaron Darling, Sandie M. Degnan, Todd H. Oakley, David C. Plachetzki, Yufeng Zhai, Marcin Adamski, Andrew Calcino, Scott F. Cummins, David M. Goodstein, Christina Harris, Daniel J. Jackson, Sally P. Leys, Shengqiang Shu, Ben J. Woodcroft, Michel Vervoort, Kenneth S. Kosik, Gerard Manning, Bernard M. Degnan & Daniel S. Rokhsar

Nature volume 466, pages 720–726 (05 August 2010) DOI: 10.1038/nature09201

Sponges are an ancient group of animals that diverged from other metazoans over 600 million years ago. Here we present the draft genome sequence of Amphimedon queenslandica, a demosponge from the Great Barrier Reef, and show that it is remarkably similar to other animal genomes in content, structure and organization. Comparative analysis enabled by the sequencing of the sponge genome reveals genomic events linked to the origin and early evolution of animals, including the appearance, expansion and diversification of pan-metazoan transcription factor, signalling pathway and structural genes. This diverse ‘toolkit’ of genes correlates with critical aspects of all metazoan body plans, and comprises cell cycle control and growth, development, somatic- and germ-cell specification, cell adhesion, innate immunity and allorecognition. Notably, many of the genes associated with the emergence of animals are also implicated in cancer, which arises from defects in basic processes associated with metazoan multicellularity.