珠江三角洲地区黄毛鼠抗药性的发生趋势及其Vkorc1基因多态性

为阐明珠江三角洲地区黄毛鼠Rattus losea对第1代抗凝血灭鼠剂的抗性发生趋势及其遗传机制，以杀鼠灵为标准药物，采用致死期食毒法对2017—2021年在广东省江门市捕获的165只黄毛鼠进行生理抗性检测，并测定每只试鼠的维生素K环氧化物还原酶复合物亚单位1(vitamin K epoxide reductase complex subunit 1,Vkorc1)的编码基因序列，分析其突变情况。结果显示，江门市黄毛鼠对第1代抗凝血灭鼠剂杀鼠灵的抗性率为27.03%～50.00%，在黄毛鼠Vkorc1基因中检测到6个不同的突变位点，包括2个错义突变位点Arg58Gly及Tyr139Cys和4个沉默突变位点Ala41Ala、Cys96Cys、Arg98Arg及Ala143Ala，突变率分别为87.27%、0.61%、1.21%、0.61%、1.21%和0.61%，其中Ala143Ala是在黄毛鼠中新发现的沉默突变位点。表明珠江三角洲地区黄毛鼠已对第1代抗凝血灭鼠剂产生了群体抗性并呈上升趋势，第58位的精氨酸突变成甘氨酸(Arg58Gly)是黄毛鼠抗性基因Vkorc1的主要突变位点。

Occurrence trend of rodenticide resistance and Vkorc1 gene polymorphism in lesser ricefield rat Rattus losea in the Pearl River Delta

To elucidate the occurrence trend of the resistance of lesser ricefield rat Rattus losea in the Pearl River Delta to the first-generation anticoagulant rodenticide and its genetic mechanism, by using warfarin as the standard drug, the physiological resistance of 165 R. losea captured in Jiangmen City, Guangdong Province from 2017 to 2021 was detected using the lethal feeding period method. In addition, the gene sequence of vitamin K epoxide reductase complex subunit 1 (Vkorc1) was determined for each rat tested, and the mutation status of Vkorc1 gene was analyzed. The results showed that the resistance rate of R. losea in Jiangmen City to the first-generation anticoagulant rodenticide ranged from 27.03% to 50.00%. Six different mutation sites were detected in the Vkorc1 gene of R. losea, including two missense mutations, Arg58Gly and Tyr139Cys, and four silent mutations, Ala41Ala, Cys96Cys, Arg98Arg, and Ala143Ala, with a mutation rate of 87.27%, 0.61%, 1.21%, 0.61%, 1.21% and 0.61%, respectively. Among them, Ala143Ala was a newly discovered silent mutation in R. losea. These results indicated that R. losea in the Pearl River Delta has developed population resistance to the first-generation anticoagulant rodenticide with an increasing trend. The arginine at position 58 mutated to glycine (Arg58Gly) was the main mutation site of the resistance gene Vkorc1 in R. losea.