Fig. 4.

Allele frequencies of isotype 1 β-tubulin locus SNPs in field populations of T. circumcincta. Red colour indicates F167Y (TAC), green indicates E198L (TTA) and blue indicates F200Y (TAC) and purple indicates susceptible alleles. Fig. 4A: dots represent the resistance allele frequencies for each sampling time-point. The data shows the three farms with date of sample collection on the X-axis and the Y-axis representing the allele frequencies. Fig. 4B: the pie charts show the overall prevalence of the isotype 1 β-tubulin locus SNPs in ewes and lambs on each farm. The prevalence of SNPs and combinations of SNPs at farm level are shown in the table below the figure. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)