No abstract

Hematophagous female mosquitoes transmit numerous devastating human diseases, including malaria, dengue fever, Zika virus, and others. Because of their obligatory requirement of a vertebrate blood meal for reproduction, these mosquitoes need a lot of energy; therefore, understanding the molecular mechanisms linking metabolism and reproduction is of particular importance. Lipids are the major energy store providing the fuel required for host seeking and reproduction. They are essential components of the fat body, a metabolic tissue that is the insect analog of vertebrate liver and adipose tissue. In this study, we found that microRNA-277 (miR-277) plays an important role in regulating mosquito lipid metabolism. The genetic disruption of miR-277 using the CRISPR-Cas9 system led to failures in both lipid storage and ovary development. miR-277 mimic injection partially rescued these phenotypic manifestations. Examination of subcellular localization of FOXO protein via CRISPR-assisted, single-stranded oligodeoxynucleotide-mediated homology-directed repair revealed that insulin signaling is up-regulated in response to miR-277 depletion. In silico target prediction identified that insulin-like peptides 7 and 8 ( and ) are putative targets of miR-277; RNA immunoprecipitation and a luciferase reporter assay confirmed that and are direct targets of this miRNA. CRISPR-Cas9 depletion of and led to metabolic and reproductive defects. These depletions identified differential actions of ILP7 and ILP8 in lipid homeostasis and ovarian development. Thus, miR-277 plays a critical role in mosquito lipid metabolism and reproduction by targeting and , and serves as a monitor to control ILP7 and ILP8 mRNA levels.

Dual-biomarker-triggered fluorescent probes were developed for simultaneous detection of the two biomarkers H2S and hNQO1 in cancer cells.

A FRET-ICT dual-quenching probe with large off-on fluorescent response upon H2S treatment is reported. The probe can be used for bioimaging of endogenous H2S in living cells.