Abstract
The complete mitochondrial genome of hybrid grouper from Epinephelus awoara (♀) ×E. tukula (♂) was obtained by PCR amplification. The circular genome was 16,801 bp in length, consisting of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a control region (D-loop region). The overall base composition was as follows: A: 28.46%, T: 27.27%, C: 27.27%, G: 16.49%. The new results may provide valuable data for the genetic and taxonomic research on artificial hybrid grouper.
Keywords: Mitochondrial genome, Epinephelus awoara♀ × Epinephelus tukula♂
Epinephelus awoara and E. tukula are both to the subfamily Epinephelinae, family Serranidae and orders Perciformes. E. awoara lives in rocky areas as well as on sandy-mud bottoms, mainly distributed in Northwest Pacific: Korea, Japan, China and the like. It is not only a marine fish of high economic value but also an ornamental fish in some countries because of its gorgeous body color. E. tukula is mainly found in deep reef channels and seamounts, mainly distributed in Indo-West Pacific: Red Sea and East Africa to southern Japan, Australia, Paracel Islands in the South China Sea, with strong disease resistance and fast growth rate. For the past few years, hybridization was commonly used in fish breeding as it allowed for a combination of advantageous traits from different species (Cheng et al. 2019). And the newly hybrid grouper was obtained by artificial insemination from E. awoara (♀) × E. tukula (♂). This hybrid offspring has the advantages of low deformity rate and fast growth rate, and has potential economic value, but its genetic characteristics remain poorly understood (Li et al. 2019). Therefore, the complete mitochondrial genome of hybrid of E. awoara (♀) ×E. tukula (♂) was sequenced to provide useful information for the genetic and taxonomic research on artificial hybrid grouper.
In this study, the sample was collected at Laizhou Mingbo Aquatic Co., Ltd., Shandong province, China (372506.7300 N 1200015.1100E). The sample was numbered QJ2 and stored in a −80 °C refrigerator with accession number 20190705QJ before sequencing. Total DNA was extracted with standard phenol-chloroform methods (Sambrook et al. 1989). The complete mitochondrial genome of this sample (GenBank, MN879323) is 16,801bp in length which was sequenced by high-throughput sequencing technology (illumine HiSeq 2000, USA). It consisted of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a control region (D-loop region). Overall base composition of the complete mitochondrial DNA is A: 28.46%, T: 27.27%, C: 27.27%, G: 16.49%.
The phylogenetic tree was reconstructed based on the complete mitochondrial genome nucleotide sequences of the hybrid of E. awoara♀ × E. tukula♂ and 3 families, 12 genera, 29 species using the neighbor-joining (NJ) methods in MEGA 7. The mitochondrial genome sequences were aligned using Seqman and subsequently edited and trimmed. Numbers on each node are bootstrap values of 1000 replicates. As shown in Figure 1, the hybrid of E. awoara♀ × E. tukula♂ had a closer relationship with E. awoara (female parent) than the other species, which demonstrated that the mitochondrial genome DNA of the hybrid was also maternal inherited. In addition, the hybrid had close genetic distance with Carangoides equula of Carangidae family, while they were belong to deferent families. This results deserved further study.
Figure 1.
Phylogenetic tree based on mitochondrial genome nucleotide sequences of the hybrid of Epinephelus awoara♀ × Epinephelus tukula♂ and other 29 species using the NJ methods. Numbers on each node are bootstrap values of 1000 replicates.
Funding Statement
The work was funded by Key Research and Development Plan of Shandong Province [2019GHY112063], Superior Seed Project of Shandong Province [2019LZGC020], the Double-Hundred Talent Projectof Yantai city, Shandong Province, and Special Fund for Basic Scientific Research Business of Central Public Research Institutes [20603022019002; 2020XT06].
Disclosure statement
No potential conflict of interest was reported by the authors.
References
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