Inheritance of pyrethroid resistance and a sodium channel gene mutation in the cattle tick Boophilus microplus

Abstract

A substitution (Phe-->Ile) within the sodium channel gene sequence has been associated with pyrethroid resistance in Boophilus microplus. The aim of the present study was to analyze the inheritance of pyrethroid resistance and the mutant allele, on reciprocal crosses of a susceptible (SS) and a resistant (RR) strain. Bioassays and genotypes were determined to evaluate pyrethroid resistance. The resistance allele frequency of both parental strains were 100% and 2.27% for RR and SS, respectively. The reciprocal crosses show a predominance of the heterozygote genotype, in agreement with the significant decrease of the acaricide resistance to cypermethrin, deltamethrin, and flumethrin. However, the RS progeny showed a complete recessive survival (D (ML) = 0) for deltamethrin and flumethrin, suggesting a complete dominance of the susceptible allele and incomplete dominance for cypermethrin (D (ML) = 0.169). On the other hand, SR progeny showed a partially recessive survival for cypermethrin (D (ML) = 0.380), deltamethrin (D (ML) = 0.319), and flumethrin (D (ML) = 0.258), indicative of a partially dominant inheritance of the resistance. A possible maternal strain effect should be considered for practical purposes and prediction of acaricide resistance and further work needs to be done to elucidate the underlying inheritance of pyrethroid resistance and the sodium channel mutation in B. microplus.

Molecular survey of pyrethroid resistance mechanisms in Mexican field populations of Rhipicephalus (Boophilus) microplus

“…Despite the significant correlation between frequency of RR and RS and pyrethroid resistance (Fig. 3 ), there was one resistant strain (97.87% overall survival) showing 0.0% of RR and 92% of RS genotype frequency, recent studies have shown that the heterozygous condition show a susceptible genotype (Aguilar-Tipacamú et al 2008 ), therefore a heterozygous population must be susceptible. This may indicate that there is another esterase based resistance mechanisms non-detectable by the surrogate substrate alpha-Naphtyl acetate, that can act in unison with or independently of the kdr genotype to confer resistance since this strain (G-R49) showed only a medium level (3 U/L) of esterase activity.…”

Identification of pyrethroid resistance associated mutations in the para sodium channel of the two‐spotted spider mite Tetranychus urticae (Acari: Tetranychidae)

“…, 2005). The resistance in a B. microplus strain with the F1538I mutation displayed various levels of incomplete dominance to pyrethroids, although this was probably a maternal effect because of additional mechanism(s) involved in pyrethroid resistance (Aguilar‐Tipacamu et al. , 2008).…”

Strategies for the control of Rhipicephalus microplus ticks in a world of conventional acaricide and macrocyclic lactone resistance

“…Based on reciprocal crosses of a susceptible and a resistant R . microplus strain, Aguilar-Tipacamu et al ( 2008 ) evaluated the inheritance of SP resistance using the ‘effective dominance of survival method’ described by Bourguet et al ( 2000 ). The authors found that pyrethroid resistance (cypermethrin, flumethrin and deltamethrin) is inherited as a partially dominant trait when the R. microplus female is resistant.…”

“…Conversely, in R. microplus resistant to SP and OP, reversion to susceptibility is difficult because it has been demonstrated that resistance persist to OP and SP for several years (Rodriguez-Vivas et al 2005 , 2011 ). Additionally, Aguilar-Tipacamu et al ( 2008 ) demonstrated that the main mode of inheritance of SPs in R. microplus is by a partially dominant trait.…”