Population structure of Haemonchus contortus from seven geographical regions in China, determined on the basis of microsatellite markers

Abstract

BackgroundStudying genetic variation within and among Haemonchus contortus populations can inform some aspects of this parasite’s population genetics and epidemiology. However, almost nothing is known about such variation in China.MethodsAdult males of H. contortus (n = 184) representing seven distinct populations in China were collected, and genetic variation within and among these populations was explored using eight distinct microsatellite markers.ResultsGenetic parameters, such as heterozygosity and inbreeding coefficient (F IS) indicated that all eight microsatellites were highly polymorphic. Various analyses (AMOVA, F ST, phylogenetic, structure, mantel test and population dynamics) revealed high within-population variation, low population genetic differentiation and high gene flow for H. contortus in China.ConclusionsThis study provides a first snapshot of the genetic substructuring of H. contortus populations in China using polymorphic markers, and might provide a starting point for assessing genetic changes over space and time during or following the implementation of particular treatment or control strategies, or changes as a consequence of environmental, management and climatic factors.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1864-z) contains supplementary material, which is available to authorized users.

A Whole Genome Re-Sequencing Based GWA Analysis Reveals Candidate Genes Associated with Ivermectin Resistance in Haemonchus contortus

“…The in-depth characterization of genetic diversity showed high level of within-population genetic diversity. This is consistent with recent estimates of genome-wide studies [40,43], and also with estimates that of the earlier studies [60][61][62][63][64]. Genetic diversity in parasites helps them to avoid eradication by the host immune system [65].…”

Evidence for the F200Y (TAC) mutation conferring benzimidazole resistance in a southern USA cattle population of Haemonchus placei spreading from a single emergence

“…If the gene flow is high, the F200Y (T A C), E198A (G C A) and F167Y (T A C) resistance mutations potentially spread in the regions under the influence of drug selection. These observations have also been recognized in H. contortus and H. placei studies (Ali et al, 2019b; Chaudhry et al, 2015a; Chaudhry et al, 2016b; Redman et al, 2015; Yin et al, 2016).…”

Does host socio-spatial behavior lead to a fine-scale spatial genetic structure in its associated parasites?

“…In addition, the sPCA uses allele frequencies as variables [47] and numerous alleles were identified in the five loci studied here (see Table 1), consequently increasing the statistical power to detect genetic structure, even though only a limited number of loci are involved. The relatively high null allele frequencies observed reflected the high genetic diversity reported in H. contortus worldwide and in the present study, in which the number of alleles by locus is even higher than the number observed in other populations (see e.g., [68,81]). Null alleles have frequently been reported in other studies on H. contortus (e.g., [12,13,46,68]) and more generally on parasitic nematodes (e.g., [38,73]).…”