title: Intraspecific Variation in Mitogenomes of Five Crassostrea Species Provides Insight into Oyster Diversification and Speciation.
abstract: A large number of Crassostrea oysters are found in Asia-Pacific. While analyses of interspecific variation have helped to establish historical relationships among these species, studies on intraspecific variation are necessary to understand their recent evolutionary history and current forces driving population biology. We resequenced 18 and analyzed 31 mitogenomes of five Crassostrea species from China: Crassostrea gigas, Crassostrea angulata, Crassostrea sikamea, Crassostrea ariakensis, and Crassostrea hongkongensis. Our analysis finds abundant insertions, deletions, and single-nucleotide polymorphisms in all species. Intraspecific variation varies greatly among species with polymorphic sites ranging from 54 to 293 and nucleotide diversity ranging from 0.00106 to 0.00683. In all measurements, C. hongkongensis that has the narrowest geographic distribution exhibits the least sequence diversity; C. ariakensis that has the widest distribution shows the highest diversity, and species with intermediate distribution show intermediate levels of diversity. Low sequence diversity in C. hongkongensis may reflect recent bottlenecks that are probably exacerbated by human transplantation. High diversity in C. ariakensis is likely due to divergence of northern and southern China populations that have been separated without gene flow. The significant differences in mitogenome diversity suggest that the five sister species of Crassostrea have experienced different evolutionary forces since their divergence. The recent divergence of two C. ariakensis populations and the C. gigas/angulata species complex provides evidence for continued diversification and speciation of Crassostrea species along China's coast, which are shaped by unknown mechanisms in a north-south divide.
authors: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, Shanghai, 201306, China.|Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
authors: Jianfeng
authors: J
authors: Ren
authors: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
authors: Zhanhui
authors: Z
authors: Hou
authors: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.|Haskin Shellfish Research Laboratory, Department of Marine and Coastal Sciences, Rutgers University, 6959 Miller Avenue, Port Norris, NJ, 08349, USA.
authors: Haiyan
authors: H
authors: Wang
authors: Epigenomics and Computational Biology Lab, Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24060, USA.
authors: Ming-An
authors: MA
authors: Sun
authors: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China. liuxiao@qdio.ac.cn.
authors: Xiao
authors: X
authors: Liu
authors: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China. bliu@qdio.ac.cn.|Center of Systematic Genomics, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China. bliu@qdio.ac.cn.
authors: Bin
authors: B
authors: Liu
authors: Haskin Shellfish Research Laboratory, Department of Marine and Coastal Sciences, Rutgers University, 6959 Miller Avenue, Port Norris, NJ, 08349, USA. xguo@hsrl.rutgers.edu.
authors: Ximing
authors: X
authors: Guo
mesh_terms: D000818:Animals; D001483:Base Sequence; D002681:China; D049896:Crassostrea / Q000145:classification / Q000235:genetics*; D051456:Gene Flow; D049810:Genetic Speciation; D054629:Genome, Mitochondrial; D008928:Mitochondria / Q000235:genetics; D016254:Mutagenesis, Insertional; D010802:Phylogeny; D058974:Phylogeography; D020641:Polymorphism, Single Nucleotide; D060047:Reproductive Isolation; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion
keywords: Crassostrea oyster; Evolution; Mitogenome diversity; Phylogeography; Population genetics; Speciation