Biology subjects

Khorramnejad, A.

Publications and source records attributed to Khorramnejad, A..

3 recordsLinked to original sources

bioRxiv2024

Prolonged thermal stress enhances mosquito tolerance to viral infection

How and to what extent mosquito-virus interaction is influenced by climate change is a complex question of ecological and epidemiological relevance. We worked at the intersection between thermal biology and vector immunology and studied shifts in tolerance and resistance to the cell fusing agent virus (CFAV), a prominent component of the mosquito virome know to contribute to shaping mosquito vector competence, in warm-acclimated and warm-evolved Aedes albopictus mosquitoes. We show that the length of the thermal challenge influences the outcome of the infection with warm-evolved mosquitoes being more tolerant to CFAV infection, while warm-acclimated mosquitoes being more resistant and suffering from extensive fitness costs. These results highlight the importance of considering fluctuations in vector immunity in relation to the length of a thermal challenge to understand natural variation in vector response to viruses and frame realistic transmission models.

immunology↗

bioRxiv2024

Reproductive resource allocation correlates with successful global invasion of a mosquito species

The understanding of traits favoring biological invasions has been considered an essential step to predict which species would become successful invaders. Classical approaches test for differences between invasive vs. not invasive species and emphasize reproduction as a critical phenotype for successful establishment of an invasive species. However, cross-species comparisons underestimate intraspecies differences, which may be relevant in invasive species with highly genetically diverse populations. Here we capitalize on the well-characterized invasion history of the arboviral vector Aedes albopictus, which resulted in genetically-distinct native, old and invasive populations, and compared the reproductive capacity (fertility and fecundity), development (timing of egg development, oviposition patterns and egg hatching) and physiology (blood digestion and nutrient movement during oogenesis) across populations. We observed that invasive mosquitoes optimize their nutrient investment during development and oogenesis, which leads to increased egg production with respect to native and long adapted laboratory mosquitoes. This higher fecundity results from a delay in oogenesis and is accompanied by higher fertility. We further tested inheritance of reproductive traits via reciprocal crosses, which showed a higher fertility and fecundity in hybrids with respect to parental strains and a potential contribution of males to the reproductive success of invasive mosquitoes. Our results provide evidence that resource allocation during development and oogenesis influences the reproductive capacity of Ae. albopictus and manifests in population differences that correlate with their invasion success. Significance StatementIn addition to being an essential process to ensure the survival of a species, reproduction is a key determinant for a species invasion success because it facilitates a species ability to establish in a new area. Reproduction is a complex phenotype that relies on intricate and timely interactions between genetic and physiological factors. Here we combined molecular, biochemical, and genetic approaches to show that efficient allocation of energetic resources during development and oogenesis fosters the reproductive output of Ae. albopictus mosquitoes and manifests as variation in the reproductive capacity of its geographic populations. These results are critical for predicting the invasion success of this species and tailoring effective control strategies.

evolutionary biology↗

bioRxiv2023

Population-specific responses to developmental temperature in the arboviral vector : implications for climate change

The increase of environmental temperature due to current global warming is not only favoring the expansion of the distribution range of many insect species, but it is also changing their phenology. Insect phenology is tightly linked to developmental timing, which is regulated by environmental temperatures. However, the degree to which effects of developmental temperatures extend across developmental stages and their inter-stage relationships have not been thoroughly quantified in mosquitoes. Here, we used the mosquito Aedes albopictus, which is an aggressive invasive species and an arboviral vector to study how developmental temperature influences fitness across developmental stages, thermal traits, energy reserves, transcriptome, and Wolbachia prevalence in populations from either temperate or tropical regions. We show that hatchability, larval and pupal viability, and developmental speed are strongly influenced by temperature and these effects extend to wing length, body mass, longevity, content of water, protein and lipids in adults, in a population-specific manner. On the contrary, neither adult thermal preference nor heat resistance significantly change with temperature. Development at 18{degrees}C revealed to be a limiting factor for the proliferation of Wolbachia in adults and transcriptome analysis showed enrichment for functions linked to stress responses (i.e. cuticle proteins and chitin, cytochrome p450, and heat shock proteins) in mosquitoes reared at both 18{degrees}C and 32{degrees}C. Our data showed an overall reduced vector fitness performance when mosquitoes were reared at 32{degrees}C, and the absence of isomorphy in the relationship between developmental stages and temperature in the temperate population. Altogether these results have important implications for reliable model projections of the invasion potentials of Ae. albopictus and its epidemiological impact.

ecology↗