Potential Geographic Distribution Of Aedes Albopictus In China And The Effect Of Artificial Light At Night On The Characteristics Of Diapause

Objective:Use the niche model to predict the current and future suitable area of Aedes albopictus in our country.At the same time,by setting different light conditions,we experimentally studied the stagnation characteristics of different geographical strains of Aedes albopictus under the interference of artificial light at night(ALAN),explored the effect of artificial light at night(ALAN)on the stagnation of Aedes albopictus,and explored the molecular mechanism of artificial light at night on the stagnation process by second generation sequencing.This will provide a reference for novel vector control based on genetic or chemical interference with key traits of Aedes albopictus distribution trends.Methods:1.Potential distribution predicted for Ae.albopictus in China:We randomly screened 205 Ae.albopictus distribution points from 27 provincial administrative regions in China with known distribution of Ae.albopictus,and the environmental factors required for prediction were downloaded from Worldclim(https://www.worldclim.org/)with a spatial resolution of 2.5 min;the GARP model and Max Ent model were used for the prediction of Ae.albopictus fitness zone.The prediction results were imported into GIS to produce prediction maps,the ROC curve was used to evaluate the model prediction,and the knife cut method was used to screen the environmental factors.2.Diapause characteristics of Ae.albopictus under artificial light at night:Ae.albopictus from Guangzhou and Beijing were reared to F2 and F3 generations in the laboratory,and the F2 generation of Guangzhou strain and the F3 generation of Beijing strain were reared under the same temperature but different light conditions.We collected eggs at 11dpov,21dpov and 40dpov after blood feeding to compare the diapause and hatching rates of Ae.albopictus at different developmental time points under different light conditions in different geographical strains,as well as the life cycle of eggs laid under different light conditions in different geographical strains.The m RNA sequencing analysis was also performed on the parental female mosquitoes and the eggs at different developmental periods.Results:1.Prediction of suitable distribution of GARP for Ae.albopictus in China:According to the prediction results,the total area of Ae.albopictus in China is 5,453,100 km~2,mainly distributed in Yunnan,Guizhou,Guangxi,Hunan,Hubei,Jiangxi,Hainan,Guangzhou,Fujian and Zhejiang Province.The precipitation of driest month,isothermality,the mean temperature of coldest quarter and the mean temperature of driest quarter have important effects on the prediction of the distribution of Ae.albopictus.2.Prediction of suitable distribution of Max Ent for Ae.albopictus in China:According to the prediction results,the total area of Ae.albopictus in China is 5,420,900km~2,mainly in Guizhou,Guangxi,Hunan,Hubei,Jiangxi,Guangzhou,Fujian and Zhejiang Province.Annual mean temperature,the mean temperature of driest quarter and the precipitation of warmest quarter had high contribution to the distribution of Ae.albopictus.3.Model comparison:Prediction of suitable distribution of GARP is bigger than that of Max Ent.Two models have the same prediction accuracy,but in terms of ROC curve trends,the Max Ent model has higher sensitivity for the same AUC values.4.Effect of artificial light at night on the stagnation characteristics of Aedes albopictus:The diapause rates of Aedes albopictus in both Guangzhou and Beijing were lower than those in the ALAN group at 11,21 and 40 days after oviposition.The egg hatching rate of Aedes albopictus at 11,21 and 40days after oviposition under the artificial light at night was higher than that without artificial light.RNA-seq sequencing was used to sequence the transcriptomes of female mosquitoes in the two geographic strains with and without ALAN.Some signal and metabolic pathways related to diapause were found in the differential gene enrichment analysis,such as phototransduction-fly,Foxo signaling pathway,pyrimidine metabolism pathway.RNA-seq sequencing was used to sequence the transcriptomes of mid-and late-stage diapause eggs from two groups of geographic strains with and without ALAN,and the differential gene enrichment analysis revealed some signaling pathways and metabolic pathways related to diapause,such as glutathione metabolic pathway,longevity regulating pathway-multi species,and pyrimitine motabolism.Conclusion:1.Under the influence of the current climate change,the distribution of Aedes albopictus in our country has the tendency of extending to the northwest.Under the SSP126 climate scenario,the distribution of Aedes albopictus in China has the tendency of shrinking in the next 40 years,however,it will still expand to the northwest and northeast of China,and some high suitable areas in central and South China will still be the high suitable areas for Aedes albopictus in our country after 40 years.This information will provide important reference for the future monitoring and control of Aedes albopictus and its insect-borne infectious diseases in China.2.Artificial light at night(ALAN)inhibits Aedes albopictus diapause.In the short photoperiod induced diapause of Aedes albopictus in temperate strain Beijing and subtropical strain Guangzhou,the disturbance of ALAN reduced the egg diapause rate and increased the egg hatching rate of Aedes albopictus,and the disturbance of ALAN also shortened the life cycle of Aedes albopictus eggs after hatching.