Sheng Liu1,2, Youli Liu1,2, Jing He1,2, Zhihua Lin1,2, Qinggang Xue3,4. 1. Ninghai Institute of Mariculture Breeding and Seed Industry, Zhejiang Wanli University, Ningbo, 315100, China. 2. Zhejiang Key Laboratory of Aquatic Germplasm Resource, Zhejiang Wanli University, Ningbo, 315100, China. 3. Ninghai Institute of Mariculture Breeding and Seed Industry, Zhejiang Wanli University, Ningbo, 315100, China. qxue@zwu.edu.cn. 4. Zhejiang Key Laboratory of Aquatic Germplasm Resource, Zhejiang Wanli University, Ningbo, 315100, China. qxue@zwu.edu.cn.
Abstract
BACKGROUND: Crassostrea hongkongensis is an important mariculture shellfish with a relatively narrow distribution range. Recently, larger wild oysters were identified as C. hongkongensis from Sanmen bay in East China Sea. No natural distribution had been reported for this species here, and its origin remains unknown. METHODS AND RESULTS: We assembled the complete 18,617 bp circular mitochondrial genome of C. hongkongensis from Sanmen bay by next generation sequencing. It included 12 protein-coding genes, 23 tRNAs, and two rRNAs. The A/T content of the mitogenome was higher than its G/C content. Similar values and features were previously found for five other specimens of C. hongkongensis, and were comparable to those of other congeneric species. A phylogenetic analysis based on the 12 protein-coding genes and complete mitochondrial sequence indicated that the six specimens of C. hongkongensis formed a monophyletic group and shared a sister group relationship with C. ariakensis, C. nippona, C. sikamea, C. angulata, C. gigas, and C. iredalei, whereas specimens from the Sanmen bay area clustered later with the five other C. hongkongensis individuals, sharing a sub-clade. The newly sequenced mitogenome had more singleton sites than previously published C. hongkongensis mitogenomes. CONCLUSIONS: Crassostrea hongkongensis may be a native species, and the species' range extends further to the north than previously known. Our data may therefore contribute to a better understanding of the species diversity and conservation of Crassostrea oysters.
BACKGROUND: Crassostrea hongkongensis is an important mariculture shellfish with a relatively narrow distribution range. Recently, larger wild oysters were identified as C. hongkongensis from Sanmen bay in East China Sea. No natural distribution had been reported for this species here, and its origin remains unknown. METHODS AND RESULTS: We assembled the complete 18,617 bp circular mitochondrial genome of C. hongkongensis from Sanmen bay by next generation sequencing. It included 12 protein-coding genes, 23 tRNAs, and two rRNAs. The A/T content of the mitogenome was higher than its G/C content. Similar values and features were previously found for five other specimens of C. hongkongensis, and were comparable to those of other congeneric species. A phylogenetic analysis based on the 12 protein-coding genes and complete mitochondrial sequence indicated that the six specimens of C. hongkongensis formed a monophyletic group and shared a sister group relationship with C. ariakensis, C. nippona, C. sikamea, C. angulata, C. gigas, and C. iredalei, whereas specimens from the Sanmen bay area clustered later with the five other C. hongkongensis individuals, sharing a sub-clade. The newly sequenced mitogenome had more singleton sites than previously published C. hongkongensis mitogenomes. CONCLUSIONS: Crassostrea hongkongensis may be a native species, and the species' range extends further to the north than previously known. Our data may therefore contribute to a better understanding of the species diversity and conservation of Crassostrea oysters.
Authors: Anton Bankevich; Sergey Nurk; Dmitry Antipov; Alexey A Gurevich; Mikhail Dvorkin; Alexander S Kulikov; Valery M Lesin; Sergey I Nikolenko; Son Pham; Andrey D Prjibelski; Alexey V Pyshkin; Alexander V Sirotkin; Nikolay Vyahhi; Glenn Tesler; Max A Alekseyev; Pavel A Pevzner Journal: J Comput Biol Date: 2012-04-16 Impact factor: 1.479