Jian Xian-Yi, Jiang Yu-Ting, Wang Miao, Jia Nan, Cai Tong, Xing Dan, Li Chun-Xiao, Zhao Tong-Yan, Guo Xiao-Xia, Wu Jia-Hong
The Key and Characteristic Laboratory of Modern Pathogen Biology, School of Basic Medical Sciences, Guizhou Medical University, Guiyang, China.
State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
Front Microbiol. 2023 Jan 4;13:1075362. doi: 10.3389/fmicb.2022.1075362. eCollection 2022.
Numerous studies on the mosquito life cycle and transmission efficacy were performed under constant temperatures. Mosquito in wild, however, is not exposed to constant temperature but is faced with temperature variation on a daily basis.
In the present study, the mosquito life cycle and Zika virus transmission efficiency were conducted at daily fluctuating temperatures and constant temperatures. was infected with the Zika virus orally. The oviposition and survival of the infected mosquitoes and hatching rate, the growth cycle of larvae at each stage, and the infection rate (IR) of the progeny mosquitoes were performed at two constant temperatures (23°C and 31°C) and a daily temperature range (DTR, 23-31°C).
It showed that the biological parameters of mosquitoes under DTR conditions were significantly different from that under constant temperatures. Mosquitoes in DTR survived longer, laid more eggs (mean number: 36.5 vs. 24.2), and had a higher hatching rate (72.3% vs. 46.5%) but a lower pupation rate (37.9% vs. 81.1%) and emergence rate (72.7% vs. 91.7%) than that in the high-temperature group (constant 31°C). When compared to the low-temperature group (constant 23°C), larvae mosquitoes in DTR developed faster (median days: 9 vs. 23.5) and adult mosquitoes carried higher Zika viral RNA load (median log RNA copies/μl: 5.28 vs. 3.86). However, the temperature or temperature pattern has no effect on transovarial transmission.
Those results indicated that there are significant differences between mosquito development and reproductive cycles under fluctuating and constant temperature conditions, and fluctuating temperature is more favorable for mosquitos' survival and reproduction. The data would support mapping and predicting the distribution of mosquitoes in the future and establishing an early warning system for Zika virus epidemics.
众多关于蚊子生命周期和传播效率的研究是在恒温条件下进行的。然而，野外的蚊子并非处于恒温环境，而是每天都面临温度变化。
在本研究中，在每日波动温度和恒温条件下进行蚊子生命周期和寨卡病毒传播效率的研究。蚊子经口感染寨卡病毒。在两个恒定温度（23°C和31°C）以及一个每日温度范围（DTR，23 - 31°C）下，对受感染蚊子的产卵、存活及孵化率、各阶段幼虫的生长周期以及子代蚊子的感染率（IR）进行了研究。
结果表明，在DTR条件下蚊子的生物学参数与恒温条件下有显著差异。与高温组（恒定31°C）相比，处于DTR条件下的蚊子存活时间更长，产卵更多（平均数量：36.5对24.2），孵化率更高（72.3%对46.5%），但化蛹率（37.9%对81.1%）和羽化率（72.7%对91.7%）更低。与低温组（恒定23°C）相比，处于DTR条件下的幼虫发育更快（中位天数：9对23.5），成年蚊子携带的寨卡病毒RNA载量更高（中位对数RNA拷贝数/微升：5.28对3.86）。然而，温度或温度模式对经卵传播没有影响。
这些结果表明，在波动温度和恒温条件下蚊子的发育和繁殖周期存在显著差异，波动温度更有利于蚊子的生存和繁殖。这些数据将有助于未来绘制和预测蚊子的分布，并建立寨卡病毒流行的预警系统。
