OBJECTIVETo screen the molecules binding dengue II virus expressed in Aedes albopictus C6/36 cells and characterize their biological functions.

METHODSAedes albopictus C6/36 cells were infected with dengue II virus, and the virus were collected and purified. The total and membrane proteins of C6/36 cells were extracted and analyzed using 12% SDS-polyacrylamide gel (PAGE). After electrophoresis, the proteins were transferred to a nitrocellulose membrane, and virus overlay protein-binding assay (VOPBA) was carried out using an anti-dengue virus 1-4 monoclonal antibody.

RESULTSTwo specific bands of 67 000 and 30 000 occurred after VOPBA of the proteins from the cells incubated with the virus, while the negative control group did not show these specific bands.

CONCLUSIONTwo putative dengue virus receptor molecules of 67 000 and 30000 have been obtained from C6/36 cells using VOPBA, and their functional identification is in progress.

Aedes ; cytology ; virology ; Animals ; Cells, Cultured ; Dengue Virus ; isolation & purification ; Membrane Proteins ; Receptors, Virus ; isolation & purification ; metabolism ; Virus Attachment

Mosquitoes secrete saliva that contains biological substances, including anticoagulants that counteract a host's hemostatic response and prevent blood clotting during blood feeding. This study aimed to detect heparin, an anticoagulant in Aedes togoi using an immunohistochemical detection method, in the salivary canal, salivary gland, and midgut of male and female mosquitoes. Comparisons showed that female mosquitoes contained higher concentrations of heparin than male mosquitoes. On average, the level of heparin was higher in blood-fed female mosquitoes than in non-blood-fed female mosquitoes. Heparin concentrations were higher in the midgut than in the salivary gland. This indicates presence of heparin in tissues of A. togoi.
Aedes/*metabolism ; Animals ; Anticoagulants/*isolation & purification ; Blood Coagulation/physiology ; Female ; Gastrointestinal Tract/*metabolism ; Heparin/*isolation & purification ; Male ; Salivary Ducts/metabolism ; Salivary Glands/*metabolism

Several virus families have been shown to encode microRNAs (miRNAs), which have roles in the infection and replication of viruses in host cells. These virus-encoded miRNAs are identified in double-stranded DNA virus (dsDNA virus) and in several RNA virus families, but not in single-stranded DNA virus (ssDNA virus). We used a bioinformatics approach based on VMir, miRNAFold and MaturePred software to predict virus-encoded miRNA-like small RNAs from the genome of a ssDNA virus: Aedes aegypti densovirus (AaeDV). Northern blotting and stem-loop reverse transcription-polymerase chain reaction (RT-PCR) were used to detect predicted small RNAs. A miRNA-like small RNA termed "AaeDVMD" was identified by stem-loop RT-PCR from predicted candidates. This is the first report demonstrating that a ssDNA virus can encode miRNA-like small RNAs. These data will aid further exploration of the interaction between the AaeDV and its mosquito host.
Aedes ; virology ; Animals ; Base Sequence ; Computational Biology ; Densovirinae ; chemistry ; genetics ; metabolism ; MicroRNAs ; chemistry ; genetics ; metabolism ; Molecular Sequence Data ; RNA, Viral ; chemistry ; genetics ; metabolism

OBJECTIVETo assess the larvicidal and irritant activities of the hexane extracts of leaves of Citrus sinensis (C. sinensis) against the early fourth instars and female adults of Aedes aegypti (Ae. aegypti).

METHODSThe larvicidal potential of the prepared leaf extract was evaluated against early fourth instar larvae of Ae. aegypti using WHO protocol. The mortality counts were made after 24 h and LC50 and LC90 values were calculated. The efficacy of extract as mosquito irritant was assessed by contact irritancy assays. Extract-impregnated paper was placed on a glass plate over which a perspex funnel with a hole on the top was kept inverted. Single female adult, 3-day old unfed/blood-fed, was released inside the funnel. After 3 min of acclimatization time, the time taken for the first take-off and total number of flights undertaken during 15 min were scored.

RESULTSThe citrus leaf extracts from hexane possessed moderate larvicidal efficiency against dengue vector. The bioassays resulted in an LC50 and LC90 value of 446.84 and 1 370.96 ppm, respectively after 24 h of exposure. However, the extracts were proved to be remarkable irritant against adults Ae. aegypti, more pronounced effects being observed on blood-fed females than unfed females. The extract-impregnated paper was thus proved to be 7-11 times more irritable as compared with the control paper.

CONCLUSIONSThe hexane extracts from C. sinensis leaves are proved to be reasonably larvicidal but remarkably irritant against dengue vector. Further studies are needed to identify the possible role of extract as adulticide, oviposition deterrent and ovicidal agent. The isolation of active ingredient from the extract could help in formulating strategies for mosquito control.

Aedes ; drug effects ; Animals ; Citrus sinensis ; metabolism ; Dengue ; transmission ; Disease Vectors ; Female ; Insecticides ; pharmacology ; Larva ; drug effects ; Mosquito Control ; methods ; Plant Extracts ; pharmacology ; Plant Leaves ; metabolism