赤狐线粒体全基因组及系统发育分析

测定了赤狐的线粒体基因组全序列，总长度为16 723 bp，碱基组成为：31.3% A、26.1% C、14.8% G、27.8% T。和大多数哺乳动物一样，赤狐的线粒体全基因组包含13个蛋白质编码基因、2个核糖体RNA基因、22个转运RNA基因和1个控制区。除ND3基因起始密码子为不常见的ATT外，赤狐与北极狐、狼、家犬、郊狼的线粒体蛋白质编码遵循相同模式。在控制区的保守序列区段1和2之间发现一段较长的富含AC的随机重复序列。为了验证赤狐与其他犬科动物的系统发育关系，利用12个重链蛋白质编码基因，分别通过邻接法和最大简约法构建了系统发育树。结果表明：赤狐与北极狐是姐妹群，它们在犬科中都属于赤狐型分支，而灰狼、家犬和郊狼则属于狼型分支，与现有的系统进化研究结果一致。

Complete Mitochondrial Genome of the Red Fox (Vuples vuples) and Phylogenetic Analysis with Other Canid Species

The whole mitochondrial genome sequence of red fox (Vuples vuples) was determined. It had a total length of 16 723 bp. As in most mammal mitochondrial genome, it contained 13 protein coding genes, two ribosome RNA genes, 22 transfer RNA genes and one control region. The base composition was 31.3% A, 26.1% C, 14.8% G and 27.8% T, respectively. The codon usage of red fox, arctic fox, gray wolf, domestic dog and coyote followed the same pattern except for an unusual ATT start codon, which initiates the NADH dehydrogenase subunit 3 gene in the red fox. A long tandem repeat rich in AC was found between conserved sequence block 1 and 2 in the control region. In order to confirm the phylogenetic relationships of red fox to other canids, phylogenetic trees were reconstructed by neighbor-joining and maximum parsimony methods using 12 concatenated heavy-strand protein-coding genes. The result indicated that arctic fox was the sister group of red fox and they both belong to the red fox-like clade in family Canidae, while gray wolf, domestic dog and coyote belong to wolf-like clade. The result was in accordance with existing phylogenetic results.