RESUMO
Wing dimorphism is regarded as an important phenotypic plasticity involved in the migration and reproduction of aphids. However, the signal transduction and regulatory mechanism of wing dimorphism in aphids are still unclear. Herein, the optimal environmental conditions were first explored for inducing winged offspring of green peach aphid, and the short photoperiod was the most important environmental cue to regulate wing dimorphism. Compared to 16 L:8 D photoperiod, the proportion of winged offspring increased to 90% under 8 L:16 D photoperiod. Subsequently, 5 differentially expressed microRNAs (miRNAs) in aphids treated with long and short photoperiods were identified using small RNA sequencing, and a novel miR-3040 was identified as a vital miRNA involved in photoperiod-mediated wing dimorphism. More specifically, the inhibition of miR-3040 expression could reduce the proportion of winged offspring induced by short photoperiod, whereas its activation increased the proportion of winged offspring under long photoperiod. Meanwhile, the expression level of miR-3040 in winged aphids was about 2.5 times that of wingless aphids, and the activation or inhibition of miR-3040 expression could cause wing deformity, revealing the dual-role regulator of miR-3040 in wing dimorphism and wing development. In summary, the current study identified the key environmental cue for wing dimorphism in green peach aphid, and the first to demonstrate the dual-role regulator of miR-3040 in photoperiod-mediated wing dimorphism and wing development.
RESUMO
Risk assessment is a critical part of risk management for contaminated sites. Howeverï¼ in the specific management practice of As-contaminated sitesï¼ it is difficult to obtain realistic health risks for contaminated sites based on the total amount of pollutants and determined values of the modelï¼ thus preventing the control requirements of later remediation to be met. An increasing number of studies have recently been conducting risk assessments by considering bioavailabilityï¼ modification parametersï¼ and combined probabilistic models. To improve the accuracy of risk assessment resultsï¼ taking a large As-contaminated site as a caseï¼ 432 sampling sites were set up and collected at different depths to analyze the level and distribution characteristics of As pollutionï¼ and probabilistic risk assessment was conducted with the modification of model parameters through literature research and Monte Carlo simulation. Thenï¼ the impact of traditional methods and probabilistic methods on health risk assessment was explored in comparison. The results indicated that ωï¼Asï¼ in the top soil of the study area ranged from 2.70-97.0 mg·kg-1ï¼ with a spatial variation coefficient of 0.61 and weaker spatial continuity. The carcinogenic risk and hazard index obtained by the traditional risk assessment method were 2.12E-4 and 8.36ï¼ respectivelyï¼ which obviously overestimated the actual risk level and were not conductive to the refined management of As-contaminated sites. Combined with modification of model parameters and probabilistic risk assessmentï¼ the non-carcinogenic risk for adults and children was found to be at an acceptable levelï¼ and the carcinogenic risk was reduced by nearly an order of magnitude compared to that in the conventional method. Considering the relative biological effectiveness ï¼RBAï¼ of Asï¼ the 95% quantile of the total carcinogenic risk was 1.24E-5ï¼ a reduction of up to 36.41% compared to the uncorrected corresponding risk value of 1.95E-5. The carcinogenic risk of soil As for adults and children in the study area exceeded acceptable risk levels 1E-6ï¼ with oral ingestion of soil being the primary route of exposure. In additionï¼ the results of the sensitivity analysis of the parameters showed that As concentrationï¼ daily oral ingestion rate of soilsï¼ and exposure duration of children had relatively larger effects for health risks. This work will provide a methodological and theoretical basis for achieving accurate risk assessment of As-contaminated sites and provide concepts for refined risk management.