Preliminary Analysis of Length and GC Content Variation in the Ribosomal First Internal Transcribed Spacer (ITS1) of Marine Animals
Preliminary Analysis of Length and GC Content Variation in the Ribosomal First Internal Transcribed Spacer (ITS1) of Marine Animals
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DOI：
10.1007/s10126-008-9153-2
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发表时间：
2009-06-01
影响因子：
3
通讯作者：
Takeyama, H.
中科院分区：
文献类型：
--
作者：
Chow, S.;Ueno, Y.;Takeyama, H.
比较了多种海洋动物核糖体第一内转录间隔区(ITS1)的长度和鸟嘌呤-胞嘧啶(GC)含量，并对其系统发育价值进行了研究。在599个种的773个个体中，仅有87个个体用通用的ITS1引物进行聚合酶链式反应未能扩增出ITS1序列。未发现任何物种的ITS1区小于100bp。总体而言，脊椎动物的ITS1序列较长(318~2318bp)，GC含量(56.8%~78%)高于无脊椎动物(分别为117~1613bp和35.8%~71.3%)。具体地说，胶状动物(Cnidaria和Ctenophora)的ITS1序列较短(118~422bp)，GC含量较低(35.8%~61.7%)。软体动物和甲壳类的ITS1长度分别为108~1,118和182~1,613个碱基。没有观察到长度与GC含量之间的普遍关系。我们的数据表明，ITS1在系统发育分析中的作用有限，因为在同一科的不同属之间，甚至在同属物种之间，往往不可能获得可信的序列比对。
Length and guanine-cytosine (GC) content of the ribosomal first internal transcribed spacer (ITS1) were compared across a wide variety of marine animal species, and its phylogenetic utility was investigated. From a total of 773 individuals representing 599 species, we only failed to amplify the ITS1 sequence from 87 individuals by polymerase chain reaction with universal ITS1 primers. No species was found to have an ITS1 region shorter than 100 bp. In general, the ITS1 sequences of vertebrates were longer (318 to 2,318 bp) and richer in GC content (56.8% to 78%) than those of invertebrates (117 to 1,613 bp and 35.8% to 71.3%, respectively). Specifically, gelatinous animals (Cnidaria and Ctenophora) were observed to have short ITS1 sequences (118 to 422 bp) with lower GC content (35.8% to 61.7%) than the other animal taxa. Mollusca and Crustacea were diverse groups with respect to ITS1 length, ranging from 108 to 1,118 and 182 to 1,613 bp, respectively. No universal relationship between length and GC content was observed. Our data indicated that ITS1 has a limited utility for phylogenetic analysis as obtaining confident sequence alignment was often impossible between different genera of the same family and even between congeneric species.