Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, 1816 S. Oak St., Champaign, IL, 61820, USA.
INTERTRYP (Univ. Montpellier, CIRAD, IRD), Montpellier, France.
Parasit Vectors. 2023 Nov 22;16(1):434. doi: 10.1186/s13071-023-06037-z.
Estimating arbovirus transmission potential requires a mechanistic understanding of how environmental factors influence the expression of adult mosquito traits. While preimaginal exposure to environmental factors can have profound effects on adult traits, tracking and predicting these effects remains challenging.
Using Aedes albopictus and a structural equation modeling approach, we explored how larval nutrition and temperature jointly affect development rate and success, female body size, and whether these metrics capture carry-over effects on adult female longevity. Additionally, we investigated how larval diet and temperature affect the baseline expression of 10 immune genes.
We found that larval development success was primarily determined by diet, while temperature and diet both affected development rate and female body size. Under a low larval diet, pupal wet weight and wing length both declined with increasing temperature. In contrast, responses of the two morphometric measures to rearing temperature diverged when females were provided higher larval nutrition, with pupal wet weight increasing and wing length decreasing at higher temperatures. Our analyses also revealed opposing relationships between adult female lifespan and the two morphometric measures, with wing length having a positive association with longevity and pupal weight a negative association. Larval diet indirectly affected adult longevity, and the time to pupation was negatively correlated with longevity. The expression of eight immune genes from the toll, JAK-STAT and Imd pathways was enhanced in mosquitoes with higher nutrition.
Our results highlight deficiencies from using a single body size measure to capture carry-over effects on adult traits. Further studies of larval development rate under varying environmental conditions and its potential for tracking carry-over effects on vectorial capacity are warranted.
估算虫媒病毒传播潜力需要深入了解环境因素如何影响成蚊特征的表达。虽然胚胎期暴露于环境因素会对成蚊特征产生深远影响，但跟踪和预测这些影响仍然具有挑战性。
使用白纹伊蚊和结构方程模型方法，我们探讨了幼虫营养和温度如何共同影响发育速度和成功率、雌蚊体型，以及这些指标是否可以捕捉到对成年雌蚊寿命的滞后影响。此外，我们还研究了幼虫饮食和温度如何影响 10 个免疫基因的基础表达。
我们发现幼虫发育成功率主要取决于饮食，而温度和饮食都影响发育速度和雌蚊体型。在低幼虫饮食条件下，蛹湿重和翅长都随温度升高而下降。相比之下，当雌蚊提供较高的幼虫营养时，这两个形态计量指标对饲养温度的反应就会出现分歧，随着温度升高，蛹湿重增加而翅长减小。我们的分析还揭示了成年雌蚊寿命与这两个形态计量指标之间的相反关系，即翅长与寿命呈正相关，而蛹重与寿命呈负相关。幼虫饮食间接影响成年雌蚊的寿命，化蛹时间与寿命呈负相关。来自 toll、JAK-STAT 和 Imd 途径的 8 个免疫基因的表达在营养水平较高的蚊子中增强。
我们的结果强调了仅使用单一体型指标来捕捉对成年特征的滞后影响存在缺陷。进一步研究在不同环境条件下幼虫发育速度及其在追踪对媒介能力的滞后影响方面的潜力是必要的。
