Abstract

Homatula pycnolepis is a small-sized benthopelagic fish species in the family Nemacheilidae, superfamily Cobitidea. In this study, the entire mitogenome sequence of the H. pycnolepis has been sequenced by using sanger sequencing method. The circular mitochondrial genome was 16,570 bp in length and contained of 13 protein-coding genes, two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, an origin of light-strand replication (OL), and one displacement loop locus (D-loop). The overall base composition was 30.1% A, 26.4% T, 26.8% C, and 16.7% G with 56.6% AT content. Most genes were encoded on the heavy strand except for ND6 and eight tRNA genes. There were 11 regions of gene overlaps totaling 29 bp and 7 intergenic spacer regions totaling 37 bp. Its structure type was similar to the mitogenome of Cobitidea fishes. Phylogenetic analysis with 33 complete mitogenomes of Cobitidea and 2 Macrognathus fishes in the family of Mastacembelidae suggested that Homatula species clustered as one monophyletic clade and Homatula was closely related to Schistura. Mitogenome information from this study could be a useful basis for conservation and phylogenetics of this species.

摘要

碧萝mat（Homatula pycnolepis）是科纳比科（Namicheilidae）科（科比迪亚（Cobitidea）的超科）中的小型角鲨鱼类。在这项研究中，整个线粒体基因序列H. pycnolepis已使用Sanger测序方法进行了测序。环状线粒体基因组的长度为16,570 bp，包含13个蛋白质编码基因，两个核糖体RNA（rRNA）基因，22个转移RNA（tRNA）基因，轻链复制（OL）的起源和一个置换环基因座（D循环）。总体碱组成为30.1％A，26.4％T，26.8％C和16.7％G，AT含量为56.6％。除ND6和8个tRNA基因外，大多数基因都在重链上编码。有11个基因重叠区，共29 bp，7个基因间隔区，共37 bp。其结构类型类似于Cobitidea鱼类的有丝分裂基因组。系谱分析与33个完整的丝裂基因组和2个大嘴fish科的鱼类的巨有丝分裂基因组表明，Homatula物种聚集成一个单一的进化枝，而Homatula与Schistura密切相关。来自这项研究的线粒体信息可能是该物种保存和系统发育的有用基础。