Partial base sequence analysis of Md alpha E7 gene and ali-esterase enzyme activities in field collected populations of house fly (Musca domestica L.) from Mediterranean and Aegean Regions of Turkey

Abstract

In housefly (Musca domestica L.) the product of alpha E7 gene, a member of the esterase cluster, probably plays a role in the detoxification of xenobiotic esters. In this study, the housefly samples were collected from farms and garbage disposal sites of 16 provinces in the Aegean and Mediterranean Regions of Turkey. After isolating the genomic DNA, Md alpha E7 gene was amplified, isolated and sequenced, from the beginning of exon 3 to the middle of exon 4. In addition to this, ali-esterase enzyme activities in these samples were assayed by using methylthiobutyrate as a substrate. In the Aegean Region, among the studied samples 46.8% of them have Gly(137)-Ser(251) combinations, diagnostic for malathion resistance, 21.8% of them have Asp(137)-Trp(251) combinations, characteristic diazinon resistance and 3.1% of them OP susceptible Gly(137)- Trp(251) combinations. In the Mediterranean Region, 59.3% of the samples have the specific diazinon resistance, 15.6% of them have the diagnostic malathion resistance, and 12.5% of them have the diagnostic sensitive combinations. A high level of the ali-esterase enzyme activity (142.7 +/- 4.3 nmol/min/mg) was detected for WHO strain. However, the enzyme activities for the other samples, having the malathion and diazinon resistance phenotypes, differed between the range of 31.4 +/- 3.5 nmol/min/mg to 136.8 +/- 36.8 nmol/min/mg. Our results indicate that the differences in frequency and distribution of the alleles in these two regions might be depending on the different insecticide usage strategies. The pest management strategies for these two regions must be evaluated again. (C) 2009 Elsevier Inc. All rights reserved.