Investigation of the Function and Evolution of Vitamin K Epoxide Reductases

Vitamin K epoxide reductase complex subunit 1 (VKORC1) is an important enzyme in the vitamin K cycle, and the target of anticoagulant rodenticides. Polymorphisms identified in VKORC1 in Rattus norvegicus (brown rat) can cause anticoagulant resistance. Previous studies have shown several anticoagulant resistance polymorphisms that are found in the UK in brown rats, but the results are mainly derived from laboratory rat samples or frozen tissue samples collected between 1990-2000. The current status of anticoagulant rodenticide resistance in wild brown rat populations in the UK is therefore largely unknown. At present there has been no study of genetic resistance in Swedish rodents. In this study DNA sequencing of the VKORC1 gene of brown rats was done to assess the frequency and distribution of anticoagulant resistance polymorphisms in wild brown rats in the UK and Sweden.