Wang Yifei, Chen Nansheng
CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao 266200, China; College of Marine Science, University of Chinese Academy of Sciences, Beijing 100039, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao 266200, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China; Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada.
Mar Pollut Bull. 2024 Dec;209(Pt B):117180. doi: 10.1016/j.marpolbul.2024.117180. Epub 2024 Oct 31.
Recent studies demonstrated that the existence of high-levels intragenomic variations (IGVs) may lead to overinterpretation of species diversity and genetic diversity in metabarcoding analysis. In this study, IGVs of the V4 region of 18S rRNA gene (18S rDNA V4) in Phaeocystis globosa were ascertained through metabarcoding analysis results of 54 P. globosa strains. Each P. globosa strain harbored over 200 ASVs, in which one ASV was dominant with higher relative abundance than others. According to different dominant ASVs, 54 strains could be divided into two groups, suggesting the high genetic diversity of P. globosa. ASVs were shared in different strains, suggesting that IGVs were genuine existed, rather than sequencing errors. Metabarcoding analysis of field samples identified large numbers of IGVs. High levels of IGVs may be due to incomplete homogenization or existence of nonfunctional pseudogenes. An accurate understanding of IGVs is necessary for the correct interpretation of metabarcoding analysis results.
最近的研究表明，高水平的基因组内变异（IGVs）的存在可能导致在宏条形码分析中对物种多样性和遗传多样性的过度解读。在本研究中，通过对54株球形棕囊藻的宏条形码分析结果，确定了球形棕囊藻18S rRNA基因V4区域（18S rDNA V4）的IGVs。每株球形棕囊藻含有超过200个扩增子序列变异（ASVs），其中一个ASV占主导地位，相对丰度高于其他ASVs。根据不同的优势ASVs，54株菌株可分为两组，表明球形棕囊藻具有较高的遗传多样性。不同菌株中存在共享的ASVs，表明IGVs确实存在，而不是测序错误。对野外样本的宏条形码分析发现了大量的IGVs。高水平的IGVs可能是由于不完全均质化或无功能假基因的存在。准确理解IGVs对于正确解读宏条形码分析结果是必要的。
