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Figure 2 | Parasites & Vectors

Figure 2

From: Multiple mutations in the para-sodium channel gene are associated with pyrethroid resistance in Rhipicephalus microplus from the United States and Mexico

Figure 2

Multi-locus genotype (MLG) proportions of 13 U.S. field collections of Rhipicephalus microplus with corresponding larval packet discriminating dose (DD) resistance data. The bar for each field collection shows the total proportion of individuals with two resistance SNPs from any of three SNP loci (see Table 2); each color-coded portion represents the frequency of specific MLGs (no instances of MLG 5 or 6 occur in these 13 collections). Not shown are the proportion of individuals with a single resistance SNP (which occur in Hardy-Weinberg proportions) and those with fully susceptible MLGs. We note that no ticks were found to carry three or more resistance SNPs. The lines represent larval packet DD survivorship (%) at two permethrin AI concentrations (0.125% and 0.250%). The proportion of MLGs that carry any two resistance SNPs is highly correlated with larval packet DD survival at permethrin concentrations of 0.125% AI (r = 0.73, p = 0.0065) and 0.250% AI (r = 0.81, p = 0.0013). Collections Rm34 and Rm64 displayed a small number of resistant phenotypes in the larval packet DD assays, but neither collection had individuals with two resistance SNPs. Both had a small number of individuals with a single resistance SNP (1/42 ticks in Rm34 and 4/4 ticks in Rm64).

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