title: The complete maternally and paternally inherited mitochondrial genomes of the endangered freshwater mussel Solenaia carinatus (Bivalvia: Unionidae) and implications for Unionidae taxonomy.
abstract: Doubly uniparental inheritance (DUI) is an exception to the typical maternal inheritance of mitochondrial (mt) DNA in Metazoa, and found only in some bivalves. In species with DUI, there are two highly divergent gender-associated mt genomes: maternal (F) and paternal (M), which transmit independently and show different tissue localization. Solenaia carinatus is an endangered freshwater mussel species exclusive to Poyang Lake basin, China. Anthropogenic events in the watershed greatly threaten the survival of this species. Nevertheless, the taxonomy of S. carinatus based on shell morphology is confusing, and the subfamilial placement of the genus Solenaia remains unclear. In order to clarify the taxonomic status and discuss the phylogenetic implications of family Unionidae, the entire F and M mt genomes of S. carinatus were sequenced and compared with the mt genomes of diverse freshwater mussel species. The complete F and M mt genomes of S. carinatus are 16716 bp and 17102 bp in size, respectively. The F and M mt genomes of S. carinatus diverge by about 40% in nucleotide sequence and 48% in amino acid sequence. Compared to F counterparts, the M genome shows a more compact structure. Different gene arrangements are found in these two gender-associated mt genomes. Among these, the F genome cox2-rrnS gene order is considered to be a genome-level synapomorphy for female lineage of the subfamily Gonideinae. From maternal and paternal mtDNA perspectives, the phylogenetic analyses of Unionoida indicate that S. carinatus belongs to Gonideinae. The F and M clades in freshwater mussels are reciprocal monophyly. The phylogenetic trees advocate the classification of sampled Unionidae species into four subfamilies: Gonideinae, Ambleminae, Anodontinae, and Unioninae, which is supported by the morphological characteristics of glochidia.
authors.affiliation: Center for Watershed Ecology, Institute of Life Science, Nanchang University, Nanchang, P. R. China ; School of Life Sciences and Food Engineering, Nanchang University, Nanchang, P. R. China.
authors.forename: Xiao-Chen
authors.initials: XC
authors.lastname: Huang
authors.affiliation: Center for Watershed Ecology, Institute of Life Science, Nanchang University, Nanchang, P. R. China.
authors.forename: Jun
authors.initials: J
authors.lastname: Rong
authors.affiliation: School of Life Sciences and Food Engineering, Nanchang University, Nanchang, P. R. China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: School of Life Sciences and Food Engineering, Nanchang University, Nanchang, P. R. China.
authors.forename: Ming-Hua
authors.initials: MH
authors.lastname: Zhang
authors.affiliation: Center for Watershed Ecology, Institute of Life Science, Nanchang University, Nanchang, P. R. China ; School of Life Sciences and Food Engineering, Nanchang University, Nanchang, P. R. China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wan
authors.affiliation: School of Life Sciences and Food Engineering, Nanchang University, Nanchang, P. R. China.
authors.forename: Shan
authors.initials: S
authors.lastname: Ouyang
authors.affiliation: Center for Watershed Ecology, Institute of Life Science, Nanchang University, Nanchang, P. R. China ; School of Life Sciences and Food Engineering, Nanchang University, Nanchang, P. R. China.
authors.forename: Chun-Hua
authors.initials: CH
authors.lastname: Zhou
authors.affiliation: Center for Watershed Ecology, Institute of Life Science, Nanchang University, Nanchang, P. R. China ; School of Life Sciences and Food Engineering, Nanchang University, Nanchang, P. R. China.
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Wu
mesh_terms: D000818:Animals; D001482:Base Composition; D003062:Codon; D056727:Endangered Species; D005260:Female; D023061:Gene Order; D020459:Genes, rRNA; D014644:Genetic Variation; D054629:Genome, Mitochondrial; D040582:Inheritance Patterns; D008297:Male; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016366:Open Reading Frames; D010802:Phylogeny; D012343:RNA, Transfer; D049876:Unionidae / Q000145:classification / Q000235:genetics*
chemical_list: D003062:Codon; D012343:RNA, Transfer