Sea cucumber species are abundant (>1400 species) and widely distributed globally. mtDNA sequencing is frequently used to identify the phylogenetic and evolutionary relationships among species. However, there are no reports on the mitochondrial genome of Phyllophorus liuwutiensis. Here, we performed mtDNA sequencing of P. liuwutiensis to examine its phylogenetic relationships with other echinoderms. Its mitochondrial genome (15 969 bp) contains 37 coding genes, including 13 protein‐coding genes, 22 tRNA genes and 2 rRNA genes. Except for one protein‐coding gene (nad6) and five tRNA genes encoded on the negative strand, all other genes were encoded on the positive strand. The mitochondrial bases of P. liuwutiensis were composed of 29.55% T, 22.16% C, 35.64% A and 12.64% G. The putative control region was 703 bp in length. Seven overlapping regions (1–10 bp) were found. The noncoding region between the genes ranged from 1 to 130 bp in length. One putative control region has been found in the P. liuwutiensis mitogenome. All of the tRNA genes were predicted to fold into a cloverleaf structure. In addition, we compared the gene arrangements of six echinoderms, revealing that the gene order of P. liuwutiensis was a new arrangement.

中文翻译：

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柳五叶海参（棘皮动物：海参科：海参科）的完整线粒体基因组与其他海参的比较。

海参种类丰富（>1400 种），在全球范围内广泛分布。mtDNA 测序经常用于识别物种之间的系统发育和进化关系。然而，尚无关于柳乌梯叶蕨线粒体基因组的报道。在这里，我们对P. liuwutiensis进行了 mtDNA 测序，以检查其与其他棘皮动物的系统发育关系。其线粒体基因组（15 969 bp）包含37个编码基因，其中蛋白质编码基因13个，tRNA基因22个，rRNA基因2个。除了一个蛋白质编码基因（nad6）和五个在负链上编码的tRNA基因外，所有其他基因都在正链上编码。六武田松的线粒体碱基由 29.55% T、22.16% C、35.64% A 和 12.64% G 组成。推定的控制区长度为 703 bp。发现了七个重叠区域（1-10 bp）。基因之间的非编码区长度从 1 到 130 bp 不等。在P. liuwutiensis 有丝分裂基因组中发现了一个推定的控制区域。预测所有 tRNA 基因都会折叠成三叶草结构。此外，我们比较了六种棘皮动物的基因排列，揭示了六武体棘皮动物的基因排列是一个新的排列。