Project description:Zika virus (ZIKV), a pathogen of global health concern, is transmitted to humans by Aedes mosquitoes. However, the molecular interactions between the vector and the virus remain largely unexplored. We demonstrated that ZIKV and dengue virus (DENV) have similar tropism and infection kinetics in two mosquito strains with different degrees of susceptibility to infection. Comparison of Aedes aegypti’s molecular responses to ZIKV and DENV infection indicated that around 40% of the mosquito’s infection-responsive transcriptome is virus-specific. Regulated genes also included key factors of the mosquito’s anti-viral immunity, pointing to the possible involvement of the Toll innate immune pathway. Comparison of ZIKV and DENV infection-responsive transcriptome data to those for yellow fever virus and West Nile virus identified 26 genes likely to play key roles in virus infection of Aedes mosquitoes. Through reverse genetic analyses, we showed that the Toll and the Jak/Stat innate immune pathways mediate increased resistance to ZIKV infection, and the virus use vATPase and inosine-5’-monophosphate dehydrogenase as mosquito’s host factors.
Project description:We examined the biogenesis of mRNA-derived endogenous short-interfering RNAs (endo-siRNAs) in the disease vector mosquito, Aedes aegypti. Under standard conditions, mRNA-derived endo-siRNAs were produced from the bidirectional transcription of tail-tail overlapping gene pairs. Upon infection with the alphavirus, Sindbis virus (SINV), another class of mRNA-derived endo-siRNAs was observed. Genes producing SINV-induced endo-siRNAs were not enriched for overlapping partners or nearby genes, but were enriched for transcripts with long 3'UTRs. Endo-siRNAs from this class derived uniformly from the entire length of the target transcript, and were found to regulate the transcript levels of the genes from which they were derived. Strand-specific qPCR experiments demonstrated that antisense strands of targeted mRNA genes were produced to exonic, but not intronic regions. Finally, small RNAs mapped to both sense and antisense strands of exon-exon junctions, suggesting double-stranded RNA precursors to SINV-induced endo-siRNAs may be synthesized from mature mRNA templates. These results suggest additional complexity in small RNA pathways and gene regulation in the presence of an infecting virus in disease vector mosquitoes. Examination of endo-siRNA production in Aedes aegypti mosquitoes
Project description:Aedes mosquitoes transmit pathogenic arthropod-borne (arbo) viruses, putting nearly half the world’s population at risk. Blocking virus replication in mosquitoes rather than in humans serves as a promising approach to prevent arbovirus transmission, which requires in-depth knowledge of mosquito immunity. By integrating multi-omics data, we identified that heat shock factor 1 (Hsf1) regulates eight small heat shock protein (sHsp) genes within one topological associated domain. This Hsf1-sHsp cascade acts as an early response against chikungunya virus (CHIKV) infection and shows pan-antiviral activity in three vector mosquitoes, Aedes aegypti, Aedes albopictus, and Anopheles gambiae. We then assessed the baseline expression of sHsp genes in different tissues of female Ae. aegypti using RNA-seq, and we observed a highly dynamic expression pattern of sHsp genes that varied dramatically across different tissues. Interestingly, sHsp genes were expressed at low levels in two main barrier tissues, the midgut and salivary glands, compared to other tissues such as the crop. Importantly, activation of Hsf1 led to a reduced CHIKV infection rate in adult Ae. aegypti mosquitoes, demonstrating Hsf1 as a promising target for the development of novel intervention strategies to limit arbovirus transmission by mosquitoes.
Project description:Oral susceptibility of Aedes aegypti mosquitoes to dengue viruses varies between different Aedes species and strains. However, the midgut-specific transcriptional profile that may produce this variation is presently obscure and was the subject of our investigation. The variation in active expression between dengue-2 susceptible (SUS) and refractory (REF) mosquitoes was investigated during the first critical 96 hours after infection Transcriptional profiles were mined from respective guts using the serial analysis of gene expression technique (SAGE) and libraries constructed from midguts obtained from mosquitoes that received a dengue-2 infected blood meal (DENV-2), a non infected blood meal (naive) or a 5% sucrose meal (SM). Here we report that variation between DENV-2 infected libraries versus respective naïve libraries revealed very few transcripts that were common and statistically significant in DENV-2 infected libraries. In addition, the expression profiles among libraries displayed up regulation of antisense transcripts especially in the SUS strain. A strong proclivity towards strain-specificity in differential expression was observed, which suggested an exclusive transcription that is likely up-regulated after DENV-2 infection
Project description:Oral susceptibility of Aedes aegypti mosquitoes to dengue viruses varies between different Aedes species and strains. However, the midgut-specific transcriptional profile that may produce this variation is presently obscure and was the subject of our investigation. The variation in active expression between dengue-2 susceptible (SUS) and refractory (REF) mosquitoes was investigated during the first critical 96 hours after infection Transcriptional profiles were mined from respective guts using the serial analysis of gene expression technique (SAGE) and libraries constructed from midguts obtained from mosquitoes that received a dengue-2 infected blood meal (DENV-2), a non infected blood meal (naive) or a 5% sucrose meal (SM). Here we report that variation between DENV-2 infected libraries versus respective naïve libraries revealed very few transcripts that were common and statistically significant in DENV-2 infected libraries. In addition, the expression profiles among libraries displayed up regulation of antisense transcripts especially in the SUS strain. A strong proclivity towards strain-specificity in differential expression was observed, which suggested an exclusive transcription that is likely up-regulated after DENV-2 infection Thirty Aedes aegypti female mosquitoes aged 4-5 days were transferred to 500 ml paper cups and offered a 5% sucrose meal (SM), a naïve blood meal or a dengue-2 (JAM 1409 strain) infectious blood meal, using standard artificial membrane feeders. Fully engorged females were isolated and maintained on a 5% sucrose solution ad libitum at 26oC and relative humidity till dissection
Project description:This analysis compare gene expression between 4 day old sugar fed female and male Aedes aegypti mosquitoes. Keywords: Aedes aegypti sex specific expression