CLOSE TETRAPOD RELATIONSHIPS OF THE COELACANTH LATIMERIA INDICATED BY HEMOGLOBIN SEQUENCES
CLOSE TETRAPOD RELATIONSHIPS OF THE COELACANTH LATIMERIA INDICATED BY HEMOGLOBIN SEQUENCES
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DOI：
10.1038/351394a0
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发表时间：
1991-05-30
期刊：
影响因子：
64.8
通讯作者：
FRICKE, H
中科院分区：
文献类型：
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作者：
GORR, T;KLEINSCHMIDT, T;FRICKE, H
四足动物的起源多年来一直争论不休。在传统系统学中，已灭绝的叶鳍硬骨鱼 (Rhipidistia) 被认为是四足动物 1 的最近亲。在现存鱼类中，腔棘鱼 Latimeria chalumnae (Actinistia) 2-4，它是 Crossopterygii (Actinistia 和 Rhipidistia) 的唯一近期代表，肺鱼 (Dipnoi) 5-8 和射线鳍鱼(Actinopterygii) 9、10 均被认为是四足动物的姐妹群。我们现在已经确定了腔棘鱼血红蛋白的α和β珠蛋白链的序列，并将它们与所有已知的硬骨鱼和软骨鱼以及蝌蚪和成年两栖动物的血红蛋白进行了比较。硬骨鱼的血红蛋白与幼鱼的血红蛋白比成年两栖动物的血红蛋白更接近。与其他鱼类相比，Latimeria 的 β 链与蝌蚪的 β 链更加接近（54%），而 Latimeria 的 α 链（45.4%），特别是硬骨鱼（49.2%），比肺鱼的 α 链更接近两栖幼体的 α 链（39.8%）。如果仅考虑同形序列匹配（那些在一种硬骨鱼和蝌蚪共享的派生位置，但不被任何其他硬骨鱼共享的位置），则两条 Latimeria 球蛋白链与蝌蚪阶段的同一性明显高于任何硬骨鱼。因此，Latimeria 血红蛋白的主要结构表明腔棘鱼是四足动物现存的最近亲。
THE origin of tetrapods has been debated for many years. In traditional systematics, the extinct lobe-finned bony fish (Rhipidistia) are regarded as the closest relatives of tetrapods 1. Among living fish, the coelacanth Latimeria chalumnae (Actinistia) 2-4, which is the only recent representative of the Crossopterygii (Actinistia and Rhipidistia), the lungfish (Dipnoi) 5-8 and ray-finned fish (Actinopterygii) 9, 10, have each been considered as sister-groups of the tetrapods. We have now determined the sequence of the alpha and beta-globin chains of coelacanth haemoglobin and compared them with all known haemoglobins of bony and cartilaginous fish as well as those of tadpoles and adult amphibians. Haemoglobins of bony fish match more closely those of larval than adult amphibians. The beta-chains of Latimeria match those of tadpoles more closely (54%) than do those of any other fish, whereas the alpha-chains of Latimeria (45.4%), and especially of teleosts (49.2%), are closer to those of larval amphibians than are those of lungfish (39.8%). If only synapomorphous sequence matches (those at derived positions shared by one bony fish and tadpoles but not by any other bony fish) are considered, both Latimeria globin chains have distinctly more identities with phase of tadpoles than do those of any bony fish. Thus the primary structure of Latimeria haemoglobin indicates that the coelacanth is the closest living relative of tetrapods.