Bioinformatics and Genome Biology Laboratory, Universidade Católica de Brasília, Brasília, Brazil.
Mol Biol Rep. 2012 Mar;39(3):2767-72. doi: 10.1007/s11033-011-1034-5. Epub 2011 Jun 17.
Here we report the complete sequence of mitochondrial genomes for two sister taxa of freshwater teleosts, the recently derived Yarra pigmy perch Nannoperca obscura and the southern pigmy perch Nannoperca australis. These represent the first complete mitochondrial genomes for Percichthyidae (Perciformes), a family mostly distributed in Australia. The de novo genome assembly of 316,430 pyrosequencing reads from 454 libraries has produced the entire mitochondria for N. obscura and a nearly complete version for N. australis. The mtDNA genome from the latter was completed through the design of one primer set and standard Sanger sequencing for genome finishing, followed by the hybrid assembly of reads with MIRA software using N. obscura sequence as reference genome. The complete mitogenomes of N. obscura and N. australis are 16,496 and 16,494 bp in size, respectively. Both genomes contain 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes and a control region. Several characteristics of mitochondria typically found in teleost fishes were detected, such as: (i) most genes found in the heavy strand, with the exception of ND6 and eight tRNA genes; (ii) avoidance of G as the third base of codons; (iii) presence of gene overlapping; (iv) percentage of bases usage. We found only eight indels and 197 nucleotide substitutions between these Nannoperca mitogenomes, consistent with a previous hypothesis of recent speciation. The data reported here provide a resource for comparative analysis of recent evolution of mitochondrial genomes.
我们在此报道了两种淡水鱼类近缘种——雅拉矮鲈(Nannoperca obscura)和南方矮鲈(Nannoperca australis)的完整线粒体基因组序列。这两种鱼类隶属于鲈形目(Perciformes)的脂鲤科(Percichthyidae),该科鱼类主要分布于澳大利亚。通过对 454 个文库的 316,430 条焦磷酸测序reads 进行从头组装,得到了 N. obscura 的完整线粒体基因组序列,以及 N. australis 的近乎完整线粒体基因组序列。后者的线粒体基因组序列通过设计一对引物,并对基因组进行 Sanger 测序完成,随后使用 MIRA 软件,以 N. obscura 的序列为参考基因组,对reads 进行混合组装。N. obscura 和 N. australis 的线粒体基因组大小分别为 16,496 和 16,494 bp。这两个基因组均包含 13 个蛋白编码基因、2 个核糖体 RNA 基因、22 个转移 RNA 基因和一个控制区。检测到了一些在硬骨鱼类中常见的线粒体特征,如:(i)大多数基因位于重链上,除了 ND6 和 8 个 tRNA 基因;(ii)避免第三位碱基为 G;(iii)存在基因重叠;(iv)碱基使用百分比。我们在这两个 Nannoperca 线粒体基因组之间仅发现了 8 个插入缺失和 197 个核苷酸替换,这与最近的物种形成假说一致。本研究报告的数据为比较分析线粒体基因组的近期进化提供了资源。