The mitochondrial genome of Paraspadella gotoi is highly reduced and reveals that chaetognaths are a sister group to protostomes
The mitochondrial genome of Paraspadella gotoi is highly reduced and reveals that chaetognaths are a sister group to protostomes
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DOI：
10.1073/pnas.0400941101
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发表时间：
2004-07-20
影响因子：
11.1
通讯作者：
Boore, JL
中科院分区：
文献类型：
--
作者：
Helfenbein, KG;Fourcade, HM;Boore, JL
我们报告了完整的线粒体DNA序列从门毛颚动物（箭蠕虫）的成员。Paraspadella gotoi的mtDNA是非常不寻常的，缺失了23个在动物mtDNA中常见的基因，包括atp6，这是普遍存在的。它的14个基因不同寻常地排列成两组，每条链上一组。一组被许多非编码基因间核苷酸打断，而另一组被紧密包装，没有非编码核苷酸，导致推测有两个转录单位具有不同的表达模式。毛颚类在后生动物中的系统发育位置长期以来一直不确定，各种形态学分析和rRNA序列比较的结果相互矛盾或模棱两可。比较这里的氨基酸序列的编码蛋白质给一个单一的最简约的树，支持的立场，毛颚类作为姐妹的原口动物在这里研究。通过这种分析，人们可以更清楚地解释各种发育特征的进化模式，特别是关于胚孔的胚胎学命运。
We report the complete mtDNA sequence from a member of the phylum Chaetognatha (arrow worms). The Paraspadella gotoi mtDNA is highly unusual, missing 23 of the genes commonly found in animal mtDNAs, including atp6, which has otherwise been found universally to be present. Its 14 genes are unusually arranged into two groups, one on each strand. One group is punctuated by numerous noncoding intergenic nucleotides although the other group is tightly packed, having no noncoding nucleotides, leading to speculation that there are two transcription units with differing modes of expression. The phylogenetic position of the Chaetognatha within the Metazoa has long been uncertain, with conflicting or equivocal results from various morphological analyses and rRNA sequence comparisons. Comparisons here of amino acid sequences from mitochondrially encoded proteins give a single most parsimonious tree that supports a position of Chaetognatha as sister to the protostomes studied here. From this analysis, one can more clearly interpret the patterns of evolution of various developmental features, especially regarding the embryological fate of the blastopore.