Johansen Steinar Daae, Chi Sylvia I, Dubin Arseny, Jørgensen Tor Erik
Faculty of Biosciences and Aquaculture, Nord University, 8049 Bodø, Norway.
Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037 Tromsø, Norway.
Life (Basel). 2021 Apr 28;11(5):402. doi: 10.3390/life11050402.
A hallmark of sea anemone mitochondrial genomes (mitogenomes) is the presence of complex catalytic group I introns. Here, we report the complete mitogenome and corresponding transcriptome of the carpet sea anemone (family Stichodactylidae). The mitogenome is vertebrate-like in size, organization, and gene content. Two mitochondrial genes encoding NADH dehydrogenase subunit 5 (ND5) and cytochrome c oxidase subunit I (COI) are interrupted with complex group I introns, and one of the introns (ND5-717) harbors two conventional mitochondrial genes (ND1 and ND3) within its sequence. All the mitochondrial genes, including the group I introns, are expressed at the RNA level. Nonconventional and optional mitochondrial genes are present in the mitogenome of . One of these gene codes for a COI-884 intron homing endonuclease and is organized in-frame with the upstream COI exon. The insertion-like is expressed as RNA and translocated in the mitogenome as compared with other sea anemones. Phylogenetic analyses based on complete nucleotide and derived protein sequences indicate that is embedded within the family Actiniidae, a finding that challenges current taxonomy.
海葵线粒体基因组（有丝分裂基因组）的一个标志是存在复杂的催化I组内含子。在此，我们报告地毯海葵（刺胞海葵科）的完整有丝分裂基因组和相应的转录组。该有丝分裂基因组在大小、组织和基因含量方面类似于脊椎动物。两个编码NADH脱氢酶亚基5（ND5）和细胞色素c氧化酶亚基I（COI）的线粒体基因被复杂的I组内含子中断，其中一个内含子（ND5 - 717）在其序列中包含两个传统的线粒体基因（ND1和ND3）。所有线粒体基因，包括I组内含子，在RNA水平上均有表达。在该有丝分裂基因组中存在非常规和可选的线粒体基因。其中一个基因编码COI - 884内含子归巢内切酶，并与上游COI外显子框内排列。与其他海葵相比，插入样序列以RNA形式表达并定位于有丝分裂基因组中。基于完整核苷酸和推导蛋白质序列的系统发育分析表明，该海葵嵌套在海葵科内，这一发现对当前的分类学提出了挑战。
