背景:三带囊库蚊在中国分布广泛,从南面的海南岛到北面的黑龙江,覆盖热带,亚热带,和温带气候区。三带库蚊携带19种虫媒病毒。它是日本脑炎病毒(JEV)的主要载体,严重威胁人类健康。了解环境因素对三带库蚊的影响可以为其种群结构或隔离模式提供重要的见解。目前尚不清楚。
结果:总计,在552个扩增序列中检测到138个COI单倍型,单倍型多样性(Hd)值从温带(0.534)增加到热带(0.979)。单倍型系统发育分析表明,单倍型分为两个高支持进化分支。温带种群主要分布在进化分支II中,显示出与热带/亚热带种群的遗传隔离,群体之间的基因流动较少。HNQH(琼海)和HNHK(海口)人群的中性检测结果均为阴性(P<0.05),表明种群中存在许多低频突变,并且种群可能处于扩展过程中。此外,Wolbachia感染仅在SDJN(济宁)中检测到(2.24%),所有Wolbachia基因型都属于超群B。为了了解环境因素对蚊媒病毒的影响,我们在山东省三个生态环境中检测了三带钩状库蚊的感染情况。我们发现,与灌溉渠地区相比,莲池中的三带囊库蚊的JEV感染发生率明显更高。在这项研究中,JEV的总感染率为15.27/1000,提示目前山东省发生乙型脑炎的风险.
结论:热带和亚热带三带囊库蚊种群具有较高的遗传多样性,这些气候条件为三带囊库蚊的建立和扩展提供了巨大的优势。在不同的生态条件下,三带囊库蚊野生种群的JEV感染率存在差异。我们的结果表明遗传分化的复杂相互作用,人口结构,和环境因素在塑造三带囊库蚊动力学中的作用。Wolbachia在野生种群中的低患病率可能反映了最近在三带囊库蚊中存在Wolbachia入侵。
BACKGROUND: Culex tritaeniorhynchus is widely distributed in
China, from Hainan Island in the south to Heilongjiang in the north, covering tropical, subtropical, and temperate climate zones. Culex tritaeniorhynchus carries 19 types of arboviruses. It is the main vector of the Japanese encephalitis virus (JEV), posing a serious threat to human health. Understanding the effects of environmental factors on Culex tritaeniorhynchus can provide important insights into its population structure or isolation patterns, which is currently unclear.
RESULTS: In total, 138 COI haplotypes were detected in the 552 amplified sequences, and the haplotype diversity (Hd) value increased from temperate (0.534) to tropical (0.979) regions. The haplotype phylogeny analysis revealed that the haplotypes were divided into two high-support evolutionary branches. Temperate populations were predominantly distributed in evolutionary branch II, showing some genetic isolation from tropical/subtropical populations and less gene flow between groups. The neutral test results of HNQH (Qionghai) and HNHK(Haikou) populations were negative (P < 0.05), indicating many low-frequency mutations in the populations and that the populations might be in the process of expansion. Moreover,
Wolbachia infection was detected only in SDJN (Jining) (2.24%), and all
Wolbachia genotypes belonged to supergroup B. To understand the influence of environmental factors on mosquito-borne viruses, we examined the prevalence of Culex tritaeniorhynchus infection in three ecological environments in Shandong Province. We discovered that the incidence of JEV infection was notably greater in Culex tritaeniorhynchus from lotus ponds compared to those from irrigation canal regions. In this study, the overall JEV infection rate was 15.27 per 1000, suggesting the current risk of Japanese encephalitis outbreaks in Shandong Province.
CONCLUSIONS: Tropical and subtropical populations of Culex tritaeniorhynchus showed higher genetic diversity and those climatic conditions provide great advantages for the establishment and expansion of Culex tritaeniorhynchus. There are differences in JEV infection rates in wild populations of Culex tritaeniorhynchus under different ecological conditions. Our results suggest a complex interplay of genetic differentiation, population structure, and environmental factors in shaping the dynamics of Culex tritaeniorhynchus. The low prevalence of
Wolbachia in wild populations may reflect the recent presence of
Wolbachia invasion in Culex tritaeniorhynchus.