The complete mitochondrial genomes of three parasitic nematodes of birds:a unique gene order and ins

• 作 者: 刘国华 Renfu Shao 李佳缘 周东辉 李虎 朱兴全
• 机 构: 中国农业科学院兰州兽医研究所家畜疫病病原生物学国家重点实验室甘肃省动物寄生虫病重点实验室,兰州 730046;湖南农业大学动物医学院,长沙410128
• 出 处: 中国畜牧兽医学会家畜寄生虫学分会第七次代表大会暨第十二次学术研讨会
• 发表日期: 2013年7期

　　Analyses ofmitochondrial (mt) genome sequences in recent years challenge the current working hypothesis of Nematoda phylogeny proposed from morphology,ecology and nuclear small subunit rRNA gene sequences,and raise the need to sequence additional mt genomes for a broad range of nematode lineages.We sequenced the complete mt genomes of three Ascaridia species,namely A.galli,A.columbae and Ascaridia sp.(GHL:2012),that infest chickens,pigeons and parrots,respectively.These three Ascaridia species have an identical arrangement ofmt genes to each other but differ substantially from other nematodes.Phylogenetic analyses of the mt genome sequences of the Ascaridia species,together with 62 other nematode species,support the monophylies of seven high:level taxa of the phylum Nematoda: 1) the subclass Dorylaimia; 2) the orders Rhabditida,Trichinellida and Mermithida; 3) the suborder Rhabditina; and 4) the infraorders Spiruromorpha and Oxyuridomorpha.Analyses ofmt genome sequences,however,reject the monophylies of the suborders Spirurina and Tylenchina,and the infraorders Rhabditomorpha,Panagrolaimomorpha and Tylenchomorpha.Monophyly of the infraorder Ascaridomorpha varies depending on the methods ofphylogenetic analysis.The Ascaridomorpha was more closely related to the infraorders Rhabditomorpha and Diplogasteromorpha (suborder Rhabditina) than they were to the other two infraorders of the Spirurina: Oxyuridorpha and Spiruromorpha.The closer relationship among Ascaridomorpha,Rhabditomorpha and Diplogasteromorpha was also supported by a shared common pattern ofmitochondrial gene arrangement.Analyses of mitochondrial genome sequences and gene arrangement has provided novel insights into the phylogenetic relationships among several maj or lineages of nematodes.Many lineages of nematodes,however,are underrepresented or not represented in these analyses.Expanding taxon sampling is necessary for future phylogenetic studies of nematodes with mt genome sequences.