Characterization ofDicrocoelium chinensisfrom domestic yaks in Gansu and Sichuan provinces, China, using genetic markers in two mitochondrial genes

Abstract

Dicrocoelium chinensis is commonly known as the "lancet fluke" or "small liver fluke" which lives in the bile ducts and gall bladder of domestic and wild ruminants. In this study, we examined sequence variability in two mitochondrial (mt) genes, namely cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes, among D. chinensis isolated from domestic yaks in Gansu and Sichuan provinces, China. A portion of the cox1 (pcox1) and nad1 (pnad1) genes was amplified by PCR separately from the individual adult D. chinensis, and the amplicons were subjected to sequencing from both directions. The lengths of the sequences of pcox1 and pnad1 were 358 and 458 bp, respectively. The A+T contents of the sequences were 58.94-59.22% for pcox1 and 60.04-60.48% for pnad1, respectively. The intra-specific sequence variations within D. chinensis were 0-0.84% for pcox1 and 0-0.87% for pnad1. The inter-specific sequence differences among members of the examined trematodes were significantly higher, being 22.9-29.3% and 33.6-41.5% for pcox1 and pnad1, respectively. Phylogenetic analysis utilizing combined sequences of pcox1 and pnad1 using Bayesian inference revealed that all of the D. chinensis isolates grouped together with high statistical support. These findings demonstrated the existence of low intra-specific variation in mitochondrial DNA (mtDNA) sequences among the D. chinensis isolates from domestic yaks in China and had implications for studying the molecular epidemiology and population genetics of D. chinensis.

Genetic variability amongDicrocoelium dendriticumisolates from different regions in Shaanxi Province, China revealed by sequences of three mitochondrial genes

“…However, high inter-specific sequence differences were observed between D. dendriticum and some common trematodes (Figure 1), with 24.74 -29.40% for pcox1, 33.25 -49.40% for pnad1 and 29.07 -39.48% for pcytb. These results were consistent with the results of other helminthes in previous studies, including trematodes and cestodes (Li et al 2008;Liu et al 2012;Wang et al 2012Wang et al , 2013.…”

“…(Maurelli et al 2007;Otranto et al 2007;Wang et al 2012), which enhance difficulty for dicrocoeliosis control in animals (Rollinson et al 1986). Previous studies showed traditional morphological methods, mainly focused on recovering adults in the liver at necropsy or detecting eggs at coprological examination, are difficult to infer inter-species differences of Dicrocoelium spp.…”

Validation of deep amplicon sequencing of Dicrocoelium in small ruminants from Northern regions of Pakistan

“…dendriticum samples from various locations in Shaanxi Province, northern China [ 41 ]. In another study, the cox1 and nad1 fragments were used to reveal the intra-population genetic variations of D. chinensis from domestic yaks in Gansu and Sichuan Provinces, revealing lower intra-population genetic variations (1%), but higher inter-species differences (>10%) among common trematodes [ 42 ]. Phylogenetic comparison of published D .…”

Rapid Detection and Identification of Fasciola spp. and Dicrocoelium spp. Isolated from the Ruminant Livestock of Northwest Iran Using High-Resolution Melting Analysis (HRM)

“…Overall, the mitochondrial (mt) genomic materials are frequently used in the evolutionary relationships, phylogenetic and taxonomic levels of helminthes ( 40 – 43 ). In addition, mtDNA has been introduced as a useful molecular marker for accurate identification and differentiation, within and between species, of the flukes such as Dicrocoelium and Fasciola species ( 44 – 46 ).…”