Multiple mutations and overexpression of the MdaE7 carboxylesterase gene associated with male-linked malathion resistance in housefly, Musca domestica (Diptera: Muscidae)

Abstract

Two unique housefly strains, MSS and N-MRS, were selected and used to clarify mechanisms of sex-associated malathion resistance in the housefly, Musca domestica. Compared with the lab-susceptible CSS strain, susceptible females and resistant males were observed in the malathion-susceptible MSS strain, while the malathion-resistant near-isogenic line, N-MRS, achieved similar resistance level between genders. Significant synergistic effect of the esterase-inhibitor DEF on resistant houseflies pointed to the important involvement of esterase in this specific malathion resistance. Examination of the carboxylesterase gene MdαE7 in malathion resistant housefly populations found seven, non-synonymous SNP mutations (Ser250-Thr, Trp251-Ser, Met303-Ile, Leu354-Phe, Ser357-Leu, Trp378-Arg and Ser383-Thr), not found in susceptible houseflies, revealing a strong correlation between these mutations and the development of malathion resistance. Further genetic analysis conducted with bioassays by topical application and nucleotide polymorphism detection provided a first line of molecular evidence for a linkage between a male-determining factor and MdαE7 gene in the MSS and N-MRS males. This linkage results in a much higher level of malathion resistance for males than females in the MSS strain. Lastly, quantitative real-time PCR showed that MdαE7 was over expressed in the resistant strain due to the increased transcription level of mRNA rather than gene duplication.

Propoxur resistance associated with insensitivity of acetylcholinesterase (AChE) in the housefly, Musca domestica (Diptera: Muscidae)

“…Real-time quantitative PCR. Total RNA and genomic DNA were extracted from heads of PSS and N-PRS females to test the expression levels of mRNA and DNA of the Mdace gene by quantitative real-time PCR 43 . The reactions were performed on Applied Biosystems 7500 Real-time PCR system (Applied Biosystems, Foster City, CA, USA).…”

Evaluation of Resistance to Some Pyrethroid and Organophosphate Insecticides and Their Underlying Impact on the Activity of Esterases and Phosphatases in House Fly, <i>Musca domestica</i> (Diptera: Muscidae)

“…Moreover, binary combinations of organophosphate and synthetic pyrethroids are reported as more potent acetylcholinesterase inhibitors than organophosphate and carbamate mixtures [54]. Organophosphate resistance is mainly mediated by enhanced metabolic detoxification through quantitative changes in esterases [55]. Farooq & Fareed [40] studied biochemical parameters in M. domestica and found enzymatic modulation in the activity of glutathione S-transferases, total esterases, acetylcholinesterase, and acid and alkaline phosphates for each insecticide, which ultimately contributes to the development of resistance.…”

Functional analysis of a carboxylesterase gene involved in beta‐cypermethrin and phoxim resistance in Plutella xylostella (L.)

“…[8][9][10][11] Numerous studies have shown that mutation and overexpression of related genes are two major mechanisms for CarE-mediated insecticide resistance. CarE mutation-related insecticide resistance has been found in several species, 5 such as the Australian sheep blowfly Lucilia cuprina, 12,13 Musca domestica 14 and Aphis gossypii. 15 While insecticide resistance mediated by overexpression of CarE genes is more widely reported.…”