Molecular analysis of acetylcholinesterase gene in field-collected populations of Musca domestica (Diptera: Muscidae) in Northwestern Iran.

Nowadays, pyrethroid (Py) insecticides are commonly used against household insect pests and housefly. The combination of Py and organophosphates (OP) are also utilized to combat these insects. The resistance status of Iranian housefly populations to them and carbamate (CB) insecticides is uncertain. This study investigates the presence of acetylcholinesterase (AChE) mutations related to the resistance of Musca domestica to OP and/or CB insecticides in Northwestern Iran. Nucleotides 1041-1776, based on their positions in the ACE gene of aabys strain, were amplified and sequenced in houseflies collected from West Azerbaijan, Gilan, and Ardebil Provinces, Iran. Among 12 single-nucleotide polymorphisms detected, 3 mismatches were found at nucleotides 1174 (T/A, G), 1473 (G/T, C), and 1668 (T/A), leading to amino acid substitutions in V260L, G342A/V, and F407Y positions with various combinations. Genotyping results showed that 85% of specimens had at least one of these substitutions. In addition, the Iranian housefly population was composed of 5 insensitive and sensitive alleles. For the first time, the current study reports the presence of V260L, G342A, G342V, and F407Y substitutions in M. domestica specimens collected from Northwestern Iran. The selection of multiple alleles in field populations might be due to the application of various pesticides/insecticides during extended periods in the region. These molecular levels signify the presence of control problems in the area and the need for developing effective control strategies for such populations.