A new method of inference of ancestral nucleotide and amino acid sequences.
A new method of inference of ancestral nucleotide and amino acid sequences.
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发表时间：
1995-12
期刊：
影响因子：
3.3
通讯作者：
Ziheng Yang;Sudhir Kumar;M. Nei
中科院分区：
文献类型：
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作者：
Ziheng Yang;Sudhir Kumar;M. Nei
一种统计方法被开发用于重建已灭绝祖先的核苷酸或氨基酸序列，给定现存物种的进化史和序列。一个模型的核苷酸或氨基酸取代分析数据的当今序列，和参数的最大似然估计，如分支长度被用来比较后验概率的分配字符状态（核苷酸或氨基酸）的树的内部节点;具有最高的概率的分配是最好的重建在该网站。用似然法和简约法对6种哺乳动物的溶菌酶c序列进行了分析。新的基于似然的方法被发现是优于简约法的上级。在一个网站的所有内部节点的氨基酸重建的新方法是正确的概率计算为0.91，0.86，和0.73，分别为所有，变量，简约信息网站，而相应的概率为简约方法分别为0.84，0.76，和0.51，分别。通过似然分析，祖先序列中的氨基酸被正确重建的概率对于四个祖先序列而言范围从91.3%至98.7%。
A statistical method was developed for reconstructing the nucleotide or amino acid sequences of extinct ancestors, given the phylogeny and sequences of the extant species. A model of nucleotide or amino acid substitution was employed to analyze data of the present-day sequences, and maximum likelihood estimates of parameters such as branch lengths were used to compare the posterior probabilities of assignments of character states (nucleotides or amino acids) to interior nodes of the tree; the assignment having the highest probability was the best reconstruction at the site. The lysozyme c sequences of six mammals were analyzed by using the likelihood and parsimony methods. The new likelihood-based method was found to be superior to the parsimony method. The probability that the amino acids for all interior nodes at a site reconstructed by the new method are correct was calculated to be 0.91, 0.86, and 0.73 for all, variable, and parsimony-informative sites, respectively, whereas the corresponding probabilities for the parsimony method were 0.84, 0.76, and 0.51, respectively. The probability that an amino acid in an ancestral sequence is correctly reconstructed by the likelihood analysis ranged from 91.3 to 98.7% for the four ancestral sequences.