Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China.
Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, 1 Wenhai Road, Aoshanwei Town, Qingdao 266237, China.
Int J Mol Sci. 2020 May 17;21(10):3545. doi: 10.3390/ijms21103545.
The Indo-Pacific nassariids (genus ) possesses the highest diversity within the family Nassariidae. However, the previous shell or radula-based classification of is quite confusing due to the homoplasy of certain morphological characteristics. The toxin accumulators and are widely distributed in the subtidal regions of the Indo-Pacific Ocean. In spite of their biological significance, the phylogenetic positions of . and . are still undetermined. In the present study, the complete mitochondrial genomes of . and . were sequenced. The present mitochondrial genomes were 15,296 and 15,337 bp in length, respectively, showing negative AT skews and positive GC skews as well as a bias of AT rich on the heavy strand. They contained 13 protein coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and several noncoding regions, and their gene order was identical to most caenogastropods. Based on the nucleotide sequences combining 13 protein coding genes and two rRNA genes, a well-supported phylogeny of was reconstructed, and several morphological synapomorphies were observed corresponding to the phylogenetic framework. In addition, the sister group relationship between and the remaining toxin-accumulated nassariids was determined, suggesting that the phylogeny might be related to their diet. The divergence time estimation analysis revealed a correlation between speciation events of nassariids and glacial cycles during the Pliocene-Pleistocene epoch.
印度洋-太平洋芋螺科（属）在芋螺科中拥有最高的多样性。然而，由于某些形态特征的趋同，以前基于壳或齿舌的分类对 属非常混乱。毒素积累者 和 广泛分布在印度洋-太平洋的潮间带地区。尽管它们具有重要的生物学意义，但 、 和 的系统发育位置仍未确定。在本研究中，对 和 的完整线粒体基因组进行了测序。目前的线粒体基因组分别长 15296 和 15337bp，表现出负的 AT 偏斜和正的 GC 偏斜，以及重链上富含 AT 的偏斜。它们包含 13 个蛋白编码基因、22 个转移 RNA 基因、两个核糖体 RNA 基因和几个非编码区，其基因顺序与大多数腹足纲动物相同。基于结合了 13 个蛋白编码基因和两个 rRNA 基因的核苷酸序列，重建了 的系统发育，观察到了几个与系统发育框架相对应的形态共衍征。此外，确定了 和其余毒素积累芋螺之间的姐妹群关系，这表明系统发育可能与它们的饮食有关。分化时间估计分析表明，芋螺科的物种形成事件与上新世-更新世时期的冰川周期之间存在相关性。
