農業部-水產試驗所全球資訊網農業部-水產試驗所全球資訊網

本研究利用Long PCR及primer walking的方式將達氏深水尾魟完整粒線體DNA完成定序，並分析基因排序與組成。達氏深水尾魟完整粒線體DNA全長17514個鹼基對，共由37個基因所組成，包含2個核糖核酸基因 (rns、rnl)、13個蛋白質基因 (atp6、atp8、cox1-3、cob、nad1-6、nad4L) 及22個傳遞者核酸基因 (tRNA)，與其他脊椎動物相似。達氏深水尾魟與其他7種軟骨魚類的完整粒線體基因組的排序上並無明顯不同，但是達氏深水尾魟其介於tRNA^Pro 和 tRNA^Phe之間的主要非編碼區，又稱D-loop，是目前已知的軟骨魚序列中最長的，共 1830個鹼基對。而這段序列包含了兩段47個鹼基對的重複性片段，以及兩段具有保守性特徵的片段。建構其親緣關係樹後發現，達氏深水魟在演化上是與六鰓魟科為姊妹群，並且屬於燕魟亞目的基群。

The 17514-nucleotide mitochondrial DNA (mtDNA) sequence of the deepwater stingray (Plesiobatis daviesi) was determined using long PCR and primer walking methods. The deepwater stingray genome contains 37 genes, including 2 ribosomal RNAs, 22 transfer RNAs (tRNAs), and 13 protein-coding genes, which are similar to other vertebrates. A comparison of the deepwater stingray mtDNA sequence with that of seven completely sequenced chondrichthyan mtDNAs revealed an identical gene order. However, the major noncoding region of the deepwater stingray genome, a D-loop sequence between the tRNA^Pro and tRNA^Phe, is the longest (1830 bp) among all known available sequences of chondrichthyan species. The components of D-loop sequences are two major copies of 47-bp tandem repeats and two characteristic conserved sequence blocks in this region. Phylogenetic analyses suggest that the deepwater stingray belongs to the basal group of Myliobatoidei that forms a sister group with Hexatrygonidae.