Secondary structure of mitochondrial 12S rRNA among fish and its phylogenetic applications.
Secondary structure of mitochondrial 12S rRNA among fish and its phylogenetic applications.
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鱼类线粒体12S rRNA的二级结构及其系统发育应用。
DOI：
10.1093/oxfordjournals.molbev.a004066
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发表时间：
2002
影响因子：
10.7
通讯作者：
Sin‐Che Lee
中科院分区：
文献类型：
--
作者：
Hurng‐Yi Wang;Sin‐Che Lee
利用23种虾虎鱼和9种其他鱼类的完整12 S核糖体RNA（rRNA）序列建立了鱼类12 S rRNA的核心二级结构模型。在43个被确认的茎中，有41个至少得到了脊椎动物中一些补偿性证据的支持。茎中的核苷酸替换率低于环中的核苷酸替换率。这可能会产生较少的系统发育信息的茎时，最近分歧的类群进行比较。补偿取代的分析表明，共变异的百分比为68%，和权重因子的系统发育分析，以占突变的依赖性应该是0.66。不同的茎环加权方案应用于系统发育关系的分析的Gobioidei表明，降低权重配对区域，因为不独立，不能改善目前的系统发育分析。在哺乳动物对应物中也观察到环区的偏向性核苷酸组成（腺嘌呤% [A%] >胸腺嘧啶% [T%]，胞嘧啶% [C%] >鸟嘌呤% [G%]）。环区A和C的过量可能是由于mtDNA复制的不对称机制，导致C和A自发脱氨。这个过程也可能是负责转换颠换偏置和模式的核苷酸取代的茎和环。
The complete 12S ribosomal RNA(rRNA) sequences from 23 gobioid species and nine diverse assortments of other fish species were employed to establish a core secondary structure model for fish 12S rRNA. Of the 43 stems recognized, 41 were supported by at least some compensatory evidence among vertebrates. The rates of nucleotide substitution were lower in stems than in loops. This may produce less phylogenetic information in stems when recently diverged taxa are compared. An analysis of compensatory substitution shows that the percentage of covariation is 68%, and the weighting factor for phylogenetic analyses to account for the dependence of mutations should be 0.66. Different stem-loop weighting schemes applied to the analyses of phylogenetic relationships of the Gobioidei indicate that down-weighting paired regions because of nonindependence could not improve the present phylogenetic analysis. A biased nucleotide composition (adenine% [A%] > thymine% [T%], cytosine% [C%] > guanine% [G%]) in the loop regions was also observed in the mammalian counterpart. The excess of A and C in the loop regions may be because of the asymmetric mechanism of mtDNA replication, which leads to the spontaneous deamination of C and A. This process may also be responsible for a transition-transversion bias and the patterns of nucleotide substitutions in both stems and loops.
影响因子：
14.9
作者：
GUTELL, RR
通讯作者：
GUTELL, RR