http://informahealthcare.com/mdn ISSN: 1940-1736 (print), 1940-1744 (electronic) Mitochondrial DNA, Early Online: 1–2 ! 2014 Informa UK Ltd. DOI: 10.3109/19401736.2014.958705 MITOGENOME ANNOUNCEMENT The complete mitochondrial genome sequence of Platypharodon extremus (Cypriniformes: Cyprinidae) Chunhua Li 1,2 , Wen Xiong 1 , Yifeng Chen 1 , and Dekui He 1 1 Laboratory of Biological Invasion and Adaptive Evolution, Institute of Hydrobiology, Chinese Academy of Sciences, Wuchang District, Wuhan, Hubei Province, P.R. China and 2 University of Chinese Academy of Sciences, Beijing, P.R. China Abstract Platypharodon extremus Herzenstein, 1891 (Cyprinidae: Schizothoracinae), is a monotypic genus species only found in the Qinghai–Tibet plateau of China. Due to human disturbance and related environmental change since the 1950s, the population of P. extremus declined rapidly. As a result, it was listed in the China Red Data Book of Endangered Animal and the China’s Protected Species Priority List. There exist very limited researches done on P. extremus. The poor understanding of this species limits the effective protection on this species. Here, we determined the complete mitochondrial DNA sequence of P. extremus. The results show that the mitogenome is 16,651 bp in length, which includes 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and two non-coding regions: control region (D–loop) and origin of light-strand replication (OL). These baseline mitogenomic data provided by this study will facilitate the studies on P. extremus in genetics, developmental biology and conservation biology in the future. Keywords Endangered species, mitogenomic, Platypharodon extremus, Schizothoracinae History Received 13 August 2014 Accepted 23 August 2014 Published online 17 September 2014 Platypharodon extremus Herzenstein, 1891 (Cyprinidae: Schizothoracinae) is a monotypic genus species only found in the upper reaches of Yellow River at an altitude over 3000m (Chen & Cao, 2000). Basic biological characteristics of P. extremus like dietary specialization, growing slowly, and late sexual maturation, limit its recruitment capacity and population growth. Due to overfishing, water conservation project construc- tion, water pollution, and biological invasion since late 1950s (Yue, 1998), the population of P. extremus had declined rapidly. This species gradually retreated to headwaters with sparse resource in the Yellow River (Su et al., 2012; Yue & Chen, 1998). Although P. extremus had been listed in the China Red Data Book of Endangered Animal, Pisces (Yue & Chen, 1998) and the China’s Protected Species Priority List, there are extremely few researches focusing on P. extremus, the lack of knowledge on mitochondrial genome substantially hinders the stock evaluation and further conservation genetic studies for this endangered species. In this study, we designed 13 pairs of primers for polymerase chain reaction amplification based on original DNA sequences of cyprinid fish mitochondrial genomes, and by the way of assembling and alignment, we deposited the complete mitochondrial DNA sequence of P. extremus in GenBank database with accession number KM2886956. Overall, the length of P. extremus mitochondrial genome is 16,651 bp. The arrangement, composition and codon usage of genes were consistent with the most of teleost fish. The mitochondrial is consisted by 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and two non-coding regions: one control region (D–loop) and one origin of light-strand replication (OL) (Table 1). Except for a protein-coding gene (ND6) and eight tRNA (Gln, Ala, Asn, Cys, Tyr, Ser, Glu and Pro) genes, most of the genes are encoded on the heavy strand (H-strand). The overall nucleotide base composition is 28.66% for A, 27.35% for T, 25.94% for C, 18.05% for G, with a high A+ T content (56.01%), showing an obvious anti-G bias typical in teleost fishes (Tzeng et al., 1992). As shown in Table 1, of the initiation nucleotides in 13 protein- coding genes, except for COXI which starts with GTG, all others begin with the regular initiation codon TAG. In contrast, the termination codons of 13 protein-coding genes are varied. Two typical types of complete stop codons are shared by 10 protein- coding genes: TAG for four genes and TAA for six genes. The remaining three protein-coding genes COXII, ND4 and Cytb have incomplete stop codons: T (Table 1). There are 10 overlaps and 13 blank spaces exist in mitochondrial genome of P. extremus (Table 1). Four overlaps were found among the 13 protein-coding genes, as shown in ATP8-ATP6, ATP6-COXIII, ND-ND4L and ND5-ND6. The overlaps of the ATP genes appear to be common in most vertebrate mitochondrial genomes, with size ranging from 7 bp to 10 bp (Table 1). Only two overlaps are found among the 22 tRNA genes, i.e. tRNA Ile -tRNA Gln , tRNA Cys -tRNA Tyr . Correspondence: D. He, Laboratory of Biological Invasion and Adaptive Evolution, Institute of Hydrobiology, Chinese Academy of Sciences, No. 7 Donghu South Road, Wuchang District, Wuhan, Hubei Province 430072, P.R. China. Tel: +86 27 68780808. E-mail: hedekui@ihb.ac.cn Mitochondrial DNA Downloaded from informahealthcare.com by 111.11.202.162 on 09/20/14 For personal use only.