Key Lab of Integrated Pest Management of Shandong Province, College of Agronomy and Plant Protection, Qingdao Agricultural University, Qingdao, China.
Department of Evolutionary Biology, University of Siena, Siena, Italy.
PLoS One. 2014 Jun 25;9(6):e100558. doi: 10.1371/journal.pone.0100558. eCollection 2014.
The complete 16,043 bp mitochondrial genome (mitogenome) of Bactrocera minax (Diptera: Tephritidae) has been sequenced. The genome encodes 37 genes usually found in insect mitogenomes. The mitogenome information for B. minax was compared to the homologous sequences of Bactrocera oleae, Bactrocera tryoni, Bactrocera philippinensis, Bactrocera carambolae, Bactrocera papayae, Bactrocera dorsalis, Bactrocera correcta, Bactrocera cucurbitae and Ceratitis capitata. The analysis indicated the structure and organization are typical of, and similar to, the nine closely related species mentioned above, although it contains the lowest genome-wide A+T content (67.3%). Four short intergenic spacers with a high degree of conservation among the nine tephritid species mentioned above and B. minax were observed, which also have clear counterparts in the control regions (CRs). Correlation analysis among these ten tephritid species revealed close positive correlation between the A+T content of zero-fold degenerate sites (P0FD), the ratio of nucleotide substitution frequency at P0FD sites to all degenerate sites (zero-fold degenerate sites, two-fold degenerate sites and four-fold degenerate sites) and amino acid sequence distance (ASD) were found. Further, significant positive correlation was observed between the A+T content of four-fold degenerate sites (P4FD) and the ratio of nucleotide substitution frequency at P4FD sites to all degenerate sites; however, we found significant negative correlation between ASD and the A+T content of P4FD, and the ratio of nucleotide substitution frequency at P4FD sites to all degenerate sites. A higher nucleotide substitution frequency at non-synonymous sites compared to synonymous sites was observed in nad4, the first time that has been observed in an insect mitogenome. A poly(T) stretch at the 5' end of the CR followed by a [TA(A)]n-like stretch was also found. In addition, a highly conserved G+A-rich sequence block was observed in front of the poly(T) stretch among the ten tephritid species and two tandem repeats were present in the CR.
已成功对 16043bp 的烟实蝇（双翅目：实蝇科）线粒体基因组（mitogenome）进行了测序。基因组共编码 37 个通常存在于昆虫线粒体基因组中的基因。烟实蝇的线粒体基因组信息与地中海实蝇、桔小实蝇、瓜实蝇、番石榴实蝇、番木瓜实蝇、瓜实蝇、南亚果实蝇、南瓜实蝇和黑腹果蝇的同源序列进行了比较。分析表明，其结构和组织与上述 9 种密切相关的物种相似，尽管其基因组具有最低的全基因组 A+T 含量（67.3%）。在所研究的 9 种实蝇和烟实蝇中观察到 4 个具有高度保守性的短基因间隔区（IGS），这些间隔区在控制区（CR）中也有明显的对应物。对这 10 种实蝇的相关性分析表明，零倍简并位点（P0FD）的 A+T 含量、P0FD 位点与所有简并位点（零倍简并位点、两倍简并位点和四倍简并位点）的核苷酸替换频率比以及氨基酸序列距离（ASD）之间呈密切正相关。此外，还发现四倍简并位点（P4FD）的 A+T 含量与 P4FD 位点与所有简并位点的核苷酸替换频率比之间呈显著正相关，而 ASD 与 P4FD 的 A+T 含量以及 P4FD 位点与所有简并位点的核苷酸替换频率比之间呈显著负相关。与同义位点相比，在 nad4 中观察到非同义位点的核苷酸替换频率更高，这是首次在昆虫线粒体基因组中观察到。还在 CR 的 5'端发现了一个由（TA(A)）n 样序列组成的聚（T）延伸段。此外，在所研究的 10 种实蝇和两种串联重复序列中，在聚（T）延伸段前发现了一个高度保守的富含 G+A 的序列块。
