关键词: Lucilia sericata, CYTB, geographic isolation, genetic diversity, forensic medicine, death location

Abstract: 【Aim】 To sequence the mitochondrial cytochrome b (CYTB) gene of populations of the green bottle fly, Lucilia sericata from different localities in China, to investigate the effect of geographical isolation on the genetic diversity of L. sericata inChinaand to assess its application in forensic medicine for speculating death location. 【Methods】 The mitochondrial cytochrome b gene of 55 individuals of L. sericata collected in 2016 from 11 localities inChinawas amplified by PCR and sequenced. Then we used a variety of biological software for data analysis, including MEGA 6.0 for the analysis of genetic diversity, phylogeny and genetic distance, Primer 5 for cluster analysis, WinArl35 for genetic differentiation analysis, DnaSP 5.0 for haplotype statistical analysis and SPSS for data reduction. In 2017, two of the 11 localities (Qitaihe and Chuxiong) were selected using random sampling, and more L. sericata flies from the two localities were captured to verify the SNP locus of regional features. 【Results】 A total of 55 CYTB sequences (GenBank accession no.: MG696659-696663; MG734397-734446) of L. sericata were obtained with 19 mutation sites. The overall nucleotide polymorphism (Pi) was 0.00205, and the average genetic distance within the group was 0.00178. The main-coordinate clustering analysis showed that all the samples clustered into three clusters. The fixation index (Fst) values in six groups were statistically significant among the populations, ranging from 0.056 to 0.350. There was a high correlation between cumulative genetic distance and cumulative latitude. A total of 11 regional private SNP loci and 14 private haplotypes were found in all the samples. In the SNP verification experiment, there were no new SNP loci in Chuxiong samples, and three new SNP loci in Qitaihe samples, including two regional private SNP loci.【Conclusion】 Geographic isolation has an impact on the genetic diversity of mitochondrial cytochrome b gene of L. sericata in China, and this effect may be helpful to speculate death location in forensic medicine.

Key words: 丝光绿蝇')">丝光绿蝇, CYTB, 地理隔离')">地理隔离, 遗传多样性')">遗传多样性, 法医学')">法医学, 死亡地点')">死亡地点