Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan,
Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa 277-8564, Japan.
Zoolog Sci. 2021 Jun;38(3):267-272. doi: 10.2108/zs200167.
We present a complete mitochondrial genomic sequence for the tanaidacean (Richardson, 1899); this is the first complete mitogenome reported from the order Tanaidacea. The mitogenome is 13,988 bp long and contains 13 protein coding and two ribosomal RNA genes (as is typical for animal mitogenomes), and 21 of 22 transfer RNAs; we did not detect an isoleucine transfer RNA (trnI) gene. The gene order differed markedly from the hypothetical ground pattern for Pancrustacea; only four clusters (trnM + nad2; trnC + trnY + cox1 + trnL2 + cox2; trnD + atp8 + atp6 + cox3; trnH + nad4 + nad4l) ancestrally present were retained. In a malacostracan phylogenetic tree reconstructed from mitogenome data, basal relationships were marginally supported or incongruent with the traditional morphology-based classification and the latest phylogenetic reconstructions from large transcriptomic datasets. Relationships involving more recent divergences were better supported in our tree, suggesting that complete mitogenome sequences are more suitable for phylogenetic analyses within malacostracan orders, presumably including Tanaidacea.
我们呈现了一个完整的糠虾目（Richardson，1899）线粒体基因组序列；这是第一个来自糠虾目的完整线粒体基因组报告。线粒体基因组长 13988bp，包含 13 个蛋白质编码基因和两个核糖体 RNA 基因（如动物线粒体基因组的典型特征），以及 21 个转移 RNA 中的 22 个；我们没有检测到一个异亮氨酸转移 RNA（trnI）基因。基因顺序与假设的泛甲壳动物基础模式明显不同；只有四个簇（trnM + nad2；trnC + trnY + cox1 + trnL2 + cox2；trnD + atp8 + atp6 + cox3；trnH + nad4 + nad4l）保留了祖先的存在。在从线粒体基因组数据重建的软甲类系统发育树中，基础关系仅得到轻微支持或与传统的基于形态的分类和最新的基于大型转录组数据集的系统发育重建不一致。在我们的树中，最近分歧的关系得到了更好的支持，这表明完整的线粒体基因组序列更适合软甲类目中的系统发育分析，可能包括糠虾目。
