An estimate of divergence time of parazoa and eumetazoa and that of cephalochordata and vertebrata by aldolase and triose phosphate isomerase clocks
An estimate of divergence time of parazoa and eumetazoa and that of cephalochordata and vertebrata by aldolase and triose phosphate isomerase clocks
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DOI：
10.1007/pl00006208
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发表时间：
1997-07-01
影响因子：
3.9
通讯作者：
Miyata, T
中科院分区：
文献类型：
--
作者：
Nikoh, N;Iwabe, N;Miyata, T
以前，我们认为包括醛缩酶和磷酸三糖异构酶(TPI)在内的四种蛋白质在覆盖整个动物门的很长一段时间内以几乎恒定的速度进化。根据3种不同的进化距离模型，对醛缩酶和TPI进化的恒定速率进行了重新检验，结果表明，无论是在不同的脊椎动物之间，还是在脊椎动物和节肢动物之间，甚至在动物和植物之间的比较中，这些酶的进化速率都基本保持不变，因此，这些酶可能是推断动物门的分化时间的有用的分子时钟，以了解副甲藻和真甲藻的分化时间，头足类和脊椎动物的分化时间，淡水海绵EPhydatia flviatilis的醛缩酶cDNA和文昌鱼的TPI cDNA已经被克隆和测序从淡水海绵中推导出的醛缩酶和TPI的氨基酸序列与已知序列的比较表明，Parazzo-Eumetazoa的分裂发生在大约9.4亿年前(Ma)，由两种蛋白质和三种模型的平均值确定，类似地，aldolase和TPI的时钟表明，脊椎动物和文昌鱼最后一次共享一个共同的祖先是在700 Ma左右，它们可能在后口动物和原口动物分化后不久就发生了分歧。
Previously we suggested that four proteins including aldolase and triose phosphate isomerase (TPI) evolved with approximately constant rates over long periods covering the whole animal phyla. The constant rates of aldolase and TPI evolution were reexamined based on three different models for estimating evolutionary distances, It was shown that the evolutionary rates remain essentially unchanged in comparisons not only between different classes of vertebrates but also between vertebrates and arthropods and even between animals and plants, irrespective of the models used, Thus these enzymes might be useful molecular clocks for inferring divergence times of animal phyla, To know the divergence time of Parazoa and Eumetazoa and that of Cephalochordata and Vertebrata, the aldolase cDNAs from Ephydatia fluviatilis, a freshwater sponge, and the TPI cDNAs from Ephydatia fluviatilis and Branchiostoma belcheri an amphioxus, have been cloned and sequenced, Comparisons of the deduced amino acid sequences of aldolase and TPI from the freshwater sponge with known sequences revealed that the Parazoa-Eumetazoa split occurred about 940 million years ago (Ma) as determined by the average of two proteins and three models, Similarly, the aldolase and TPI clocks suggest that vertebrates and amphioxus last shared a common ancestor around 700 Ma and they possibly diverged shortly after the divergence of deuterostomes and protostomes.