Abstract: Objective To investigate the resistance of Rattus losea to the first-generation anticoagulant rodenticide in Xinhui district, Jiangmen, Guangdong province, China, and to elucidate the relationship between vitamin K epoxide reductase complex subunit 1 (VKORC1) gene mutation and rodenticide resistance. Methods The lethal feeding period test was used to determine the resistance of R. losea. The genomic DNAs of the rodents were extracted to clone the VKORC1 gene and screen out mutation and polymorphism sites. Meanwhile, the correlation between VKORC1 gene mutation and resistance was analyzed. Results The resistance rate of R. losea to the first-generation anticoagulant rodenticide was 27.03%, indicating the formation of a resistant population. The total length of the VKORC1 gene was 2 166 bp. A total of 12 mutation sites were detected and one of them was an insertion-deletion site. Exon 1 and exon 3 each had one mutation site, while intron 1 and intron 2 had six and four mutation sites, respectively. The exon 1 mutation resulted in an amino acid mutation at site 58 (Arg58Gly) and the exon 3 mutation was a synonymous mutation (Cys96Cys). A correlation analysis showed that there was no significant correlation between rodenticide resistance of R. losea and single nucleotide polymorphism site of the VKORC1 gene (P>0.05). Conclusion The site 58 amino acid mutation of the VKORC1 gene is not the main cause of rodenticide resistance in R. losea. The genetic mechanism of rodenticide resistance in R. losea may be related to other factors.

Key words: Rattus losea, Rodenticide resistance, Vitamin K epoxide reductase complex subunit 1 gene, Single nucleotide polymorphism site

摘要： 目的 测定广东省江门市新会区黄毛鼠对第一代抗凝血杀鼠剂的抗性发生状况，阐明维生素K环氧化物还原酶复合物亚单位1（VKORC1）基因变异与抗药性之间的关系。方法 采用致死期食毒法（LFP）检测黄毛鼠的抗性；提取鼠基因组DNA，克隆VKORC1基因，筛选突变和多态性位点，并分析VKORC1基因突变与抗性的相关性。结果 广东省江门市新会区黄毛鼠对第一代抗凝血杀鼠剂的抗性发生率为27.03%，已形成抗性种群；VKORC1基因全长为2 166 bp，共检测到12个变异位点，其中1个为插入缺失位点，外显子1和外显子3各存在1个变异位点，内含子1和内含子2分别存在6和4个变异位点，外显子1的突变导致VKORC1第58位氨基酸变异（Arg58Gly），外显子3的突变为同义突变（Cys96Cys），相关性分析显示，黄毛鼠的抗药性与VKORC1基因中单核苷酸多态性位点的相关性无统计学意义（P>0.05）。结论 VKORC1基因第58位氨基酸突变并不是导致黄毛鼠抗药性的主要原因，黄毛鼠抗性的遗传机制可能与其他因素有关。

关键词: 黄毛鼠, 抗药性, 维生素K环氧化物还原酶复合物亚单位1基因, 单核苷酸多态性位点