Chi Sylvia Ighem, Urbarova Ilona, Johansen Steinar D
Department of Medical Biology, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway.
Department of Medical Biology, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway; Genomics Group, Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway.
Gene. 2018 Apr 30;652:78-86. doi: 10.1016/j.gene.2018.01.067. Epub 2018 Jan 31.
The mitochondrial genomes of sea anemones are dynamic in structure. Invasion by genetic elements, such as self-catalytic group I introns or insertion-like sequences, contribute to sea anemone mitochondrial genome expansion and complexity. By using next generation sequencing we investigated the complete mtDNAs and corresponding transcriptomes of the temperate sea anemone Anemonia viridis and its closer tropical relative Anemonia majano. Two versions of fused homing endonuclease gene (HEG) organization were observed among the Actiniidae sea anemones; in-frame gene fusion and pseudo-gene fusion. We provided support for the pseudo-gene fusion organization in Anemonia species, resulting in a repressed HEG from the COI-884 group I intron. orfA, a putative protein-coding gene with insertion-like features, was present in both Anemonia species. Interestingly, orfA and COI expression were significantly up-regulated upon long-term environmental stress corresponding to low seawater pH conditions. This study provides new insights to the dynamics of sea anemone mitochondrial genome structure and function.
海葵的线粒体基因组在结构上具有动态性。遗传元件的入侵，如自我催化的I类内含子或插入样序列，导致了海葵线粒体基因组的扩展和复杂性增加。通过使用下一代测序技术，我们研究了温带海葵绿海葵（Anemonia viridis）及其亲缘关系较近的热带海葵壮丽海葵（Anemonia majano）的完整线粒体DNA和相应的转录组。在海葵科海葵中观察到了两种融合归巢内切酶基因（HEG）组织形式；框内基因融合和假基因融合。我们为海葵属物种中的假基因融合组织形式提供了支持，导致来自COI - 884 I类内含子的HEG受到抑制。orfA是一个具有插入样特征的假定蛋白质编码基因，在两种海葵物种中均存在。有趣的是，在对应于低海水pH条件的长期环境胁迫下，orfA和COI的表达显著上调。这项研究为海葵线粒体基因组结构和功能的动态变化提供了新的见解。
