Hemichordate genomes and deuterostome origins.
Hemichordate genomes and deuterostome origins.
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DOI：
10.1038/nature16150
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发表时间：
2015-11-26
期刊：
影响因子：
64.8
通讯作者：
Gerhart J
中科院分区：
文献类型：
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作者：
Simakov O;Kawashima T;Marlétaz F;Jenkins J;Koyanagi R;Mitros T;Hisata K;Bredeson J;Shoguchi E;Gyoja F;Yue JX;Chen YC;Freeman RM Jr;Sasaki A;Hikosaka-Katayama T;Sato A;Fujie M;Baughman KW;Levine J;Gonzalez P;Cameron C;Fritzenwanker JH;Pani AM;Goto H;Kanda M;Arakaki N;Yamasaki S;Qu J;Cree A;Ding Y;Dinh HH;Dugan S;Holder M;Jhangiani SN;Kovar CL;Lee SL;Lewis LR;Morton D;Nazareth LV;Okwuonu G;Santibanez J;Chen R;Richards S;Muzny DM;Gillis A;Peshkin L;Wu M;Humphreys T;Su YH;Putnam NH;Schmutz J;Fujiyama A;Yu JK;Tagawa K;Worley KC;Gibbs RA;Kirschner MW;Lowe CJ;Satoh N;Rokhsar DS;Gerhart J
橡子蠕虫，也称为肠呼吸半索动物，是海洋无脊椎动物，与棘皮动物和脊索动物具有共同的特征。这三个门共同组成了后口动物。在这里，我们报告了两种橡实虫（Saccoglossus kowalevskii 和 Ptychodera flava）的基因组序列草案。通过将它们与不同的两侧对称动物基因组进行比较，我们确定了可能从最后一个共同的后口动物祖先继承的共同特征，然后探索从该祖先到半索动物、棘皮动物和脊索动物的进化轨迹。半索动物基因组与文昌鱼和其他两侧对称动物表现出广泛的保守同线性，以及作为保守基因调控元件候选者的深度保守的非编码序列。值得注意的是，半索动物拥有由四个有序转录因子基因组成的后口动物特异性基因组簇，其表达与咽“鳃”缝的发育有关，这是早期后口动物最重要的形态创新，并且可能是其滤食生活方式的核心。比较分析揭示了许多后口动物特有的基因新颖性，包括在后口动物和海洋微生物中发现的基因，但在其他动物中没有发现。这些基因的假定功能可以与滤食祖先的生理、代谢和发育特化相关。
Acorn worms, also known as enteropneust (literally, ‘gut-breathing’) hemichordates, are marine invertebrates that share features with echinoderms and chordates. Together, these three phyla comprise the deuterostomes. Here we report the draft genome sequences of two acorn worms, Saccoglossus kowalevskii and Ptychodera flava. By comparing them with diverse bilaterian genomes, we identify shared traits that were probably inherited from the last common deuterostome ancestor, and then explore evolutionary trajectories leading from this ancestor to hemichordates, echinoderms and chordates. The hemichordate genomes exhibit extensive conserved synteny with amphioxus and other bilaterians, and deeply conserved non-coding sequences that are candidates for conserved gene-regulatory elements. Notably, hemichordates possess a deuterostome-specific genomic cluster of four ordered transcription factor genes, the expression of which is associated with the development of pharyngeal ‘gill’ slits, the foremost morphological innovation of early deuterostomes, and is probably central to their filter-feeding lifestyle. Comparative analysis reveals numerous deuterostome-specific gene novelties, including genes found in deuterostomes and marine microbes, but not other animals. The putative functions of these genes can be linked to physiological, metabolic and developmental specializations of the filter-feeding ancestor.