文献类型： 外文期刊

作者： Li, Wen X. ¹ ; Fu, Pei P. ¹ ; Zhang, Dong ¹ ; Boyce, Kellyanne ⁴ ; Xi, Bing W. ⁵ ; Zou, Hong ¹ ; Li, Ming ¹ ; Wu, Shan G. ¹ ;

作者机构： 1.Chinese Acad Sci, Minist Agr, Key Lab Aquaculture Dis Control, Wuhan 430072, Hubei, Peoples R China

2.Chinese Acad Sci, State Key Lab Freshwater Ecol & Biotechnol, Inst Hydrobiol, Wuhan 430072, Hubei, Peoples R China

3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China

4.South Devon Coll Univ Ctr, Long Rd, Paignton TQ4 7EJ, England

5.Chinese Acad Fishery Sci, Freshwater Fisheries Res Ctr, Key Lab Freshwater Fisheries & Germplasm Resource, Minist Agr, Wuxi 214081, Peoples R China

关键词： Mitogenome; Eucestoda; Diphyllobothriidea; Digramma; Ligula

期刊名称：PARASITES & VECTORS （ 影响因子：3.876； 五年影响因子：3.959 ）

ISSN： 1756-3305

年卷期： 2018 年 11 卷

页码：

收录情况： SCI

摘要： Background: After observing differences in the number of reproductive complexes per proglottid within the genus Ligula, the genus Digramma was erected. However, the validity of Digramma has been previously questioned due to a low variability in the cox1, nad1 and ITS rDNA sequences between the two genera. We undertook a study to greatly increase the amount of sequence data available for resolution of this question by sequencing and characterizing the complete mitogenomes of Digramma interrupta and Ligula intestinalis. Results: The circular mtDNA molecules of Digramma interrupta and Ligula intestinalis are 13,685 bp and 13,621 bp in size, respectively, both comprising 12 PCGs, 22 tRNA genes, two rRNA genes, and two mNCRs. Both mitogenomes exhibit the same gene order and share 92.7% nucleotide identity, compared with 85.8-86.5% to the most closely related genus Dibothriocephalus. Each gene from D. interrupta and L. intestinalis is almost of the same size, and the sequence identity ranges from 87.5% (trnD) to 100% (trnH, trnQ and trnV). NCR2 sequences of D. interrupta and L. intestinalis are 249 bp and 183 bp in length, respectively, which contributes to the main difference in length between their complete mitogenomes. A sliding window analysis of the 12 PCGs and two rRNAs indicated nucleotide diversity to be higher in nad5, nad6, nad2, nad4 and cox3, whereas the most conserved genes were rrnL and rrnS. Lower sequence identity was also found in nad2, nad4, nad5, nad6 and cox3 genes between the two diphyllobothriids. Within the Diphyllobothriidae, phylogenetic analysis indicated Ligula and Digramma to be most closely related to one another, forming a sister group with Dibothriocephalus. Conclusions: Owing to higher nucleotide diversity, the genes nad2, nad4, nad5, nad6 and cox3 should be considered optimal candidates to use as molecular markers for population genetics and species identification between the two closely related species. The phylogenetic results in combination with the comparative analysis of the two mitogenomes, consistently support the congeneric status of L. intestinalis and D. interrupta.