Rice stripe virus (RSV) transmitted by the small brown planthopper causes severe rice yield losses in Asian countries. Although viral nuclear entry promotes viral replication in host cells, whether this phenomenon occurs in vector cells remains unknown. Therefore, in this study, we systematically evaluated the presence and roles of RSV in the nuclei of vector insect cells. We observed that the nucleocapsid protein (NP) and viral genomic RNAs were partially transported into vector cell nuclei by utilizing the importin α nuclear transport system. When blocking NP nuclear localization, cytoplasmic RSV accumulation significantly increased. In the vector cell nuclei, NP bound the transcription factor YY1 and affected its positive regulation to FAIM. Subsequently, decreased FAIM expression triggered an antiviral caspase-dependent apoptotic reaction. Our results reveal that viral nuclear entry induces completely different immune effects in vector and host cells, providing new insights into the balance between viral load and the immunity pressure in vector insects.
Animals ; Cell Nucleus ; Hemiptera/metabolism* ; Insect Vectors/genetics* ; Insecta ; Nucleocapsid Proteins/metabolism* ; Oryza ; Plant Diseases ; Tenuivirus/metabolism* ; Virus Replication

Pathogens like bacteria and protozoa, which affect human and animal health worldwide, can be transmitted by vectors like ticks. To investigate the epidemiology and genetic diversity of bacteria and protozoans carried by ticks in Chengmai county of Hainan province, China, 285 adult hard ticks belonging to two species [
Anaplasmataceae/isolation & purification* ; Animals ; Chaperonin 60/genetics* ; China ; Citrate (si)-Synthase/genetics* ; Coccidia/isolation & purification* ; Coxiellaceae/isolation & purification* ; Insect Vectors/microbiology* ; Islands ; Ixodidae/microbiology* ; Phylogeny ; Piroplasmia/isolation & purification* ; RNA, Ribosomal, 16S/genetics* ; RNA, Ribosomal, 18S/genetics*

Larvae of Bradysia agrestis, an insect vector that transports plant pathogens, were sampled from geographically isolated regions in Korea to identify their cutaneous fungal and bacterial flora. Sampled areas were chosen within the distribution range of B. agrestis; each site was more than 91 km apart to ensure geographical segregation. We isolated 76 microbial (fungi and bacteria) strains (site 1, 29; site 2, 29; site 3, 18 strains) that were identified on the basis of morphological differences. Species identification was molecularly confirmed by determination of universal fungal internal transcribed spacer and bacterial 16S rRNA gene sequences in comparison to sequences in the EzTaxon database and the NCBI GenBank database, and their phylogenetic relationships were determined. The fungal isolates belonged to 2 phyla, 5 classes, and 7 genera; bacterial species belonged to 23 genera and 32 species. Microbial diversity differed significantly among the geographical groups with respect to Margalef's richness (3.9, 3.6, and 4.5), Menhinick's index (2.65, 2.46, and 3.30), Simpson's index (0.06, 0.12, and 0.01), and Shannon's index (2.50, 2.17, and 2.58). Although the microbial genera distribution or diversity values clearly varied among geographical groups, common genera were identified in all groups, including the fungal genus Cladosporium, and the bacterial genera Bacillus and Rhodococcus. According to classic principles of co-evolutionary relationship, these genera might have a closer association with their host insect vector B. agrestis than other genera identified. Some cutaneous bacterial genera (e.g., Pseudomonas) displaying weak interdependency with insect vectors may be hazardous to agricultural environments via mechanical transmission via B. agrestis. This study provides comprehensive information regarding the cutaneous microflora of B. agrestis, which can help in the control of such pests for crop management.
Bacillus ; Biodiversity ; Cladosporium ; Databases, Nucleic Acid ; Genes, rRNA ; Insect Vectors* ; Insects* ; Korea ; Larva ; Plants* ; Rhodococcus

We wished to sequence the full-length genomes of the DHL10M110 strain of the Akabane virus (AKV) isolated from mosquitoes in Yunnan Province, China, in 2010. We also wished to analyze the characteristics of these complete nucleotide sequences. The complete genomic sequence of the DHL10M110 strain from Yunnan Province was obtained by reverse transcription-polymerase chain reaction and direct sequencing. We found that the length of the L, M and S gene nucleotide sequences of the DHL10M110 strain were 6 869-bp, 4 309-bp and 856-bp, respectively, including the open reading frame (ORF) nucleotide sequences of 6 756-bp (L), 4 206-bp (M) and 702-bp (S), encoding 2252, 1402 and 234 amino-acid polyproteins, respectively. Phylogenetic analyses based on L-fragment ORF showed that the DHL10M110 strain had a close relationship with the OBE-1 strain of the AKV from Japan and AKVS-7/SKR/2010 strain of the AKV from South Korea. Phylogenetic analyses based on M- and S-fragment ORF showed that the DHL10M110 strain had a close relationship with the epidemic strains of the AKV from Japan, South Korea and Taiwan, but that the DHL10M110 strain had a lone evolutionary branch. In terms of nucleotide (amino acid) homology, the similarity of L-, M- and S-fragment ORFs of the DHL10M110 strain to the OBE-1 strain from Japan was 92.6% (98%), 88.5% (94%) and 96.4% (99.1%), respectively. When comparing the DHL10M110 strain with the OBE-1 strain, we noted 45, 84, and 2 different sites in the amino acids of L, M and S fragments, respectively. Homology and phylogenetic analyses also suggested that the DHL10M110 strain had a distant relationship with the epidemic strains of the AKV from Kenya and Australia. Also, we confirmed by complete genomic sequence analyses that the DHL10M110 strain was clade-Asia of the AKV. However, differences between the DHL10M110 strain compared with strains from Japan and South Korea were also noted. These results suggest that the DHL10M110 strain harbored relatively stable genetic characteristics and distinct regional features. This is the first time that full-length genomic sequences of the DHL10M110 strain of the AKV in mainland China have been obtained.
Amino Acid Sequence ; Animals ; Base Sequence ; Bunyaviridae Infections ; transmission ; virology ; China ; Culicidae ; virology ; Female ; Genome, Viral ; Humans ; Insect Vectors ; virology ; Male ; Molecular Sequence Data ; Open Reading Frames ; Orthobunyavirus ; classification ; genetics ; isolation & purification ; Phylogeny ; Sequence Alignment ; Viral Proteins ; chemistry ; genetics

Since Zika virus (ZIKV) has firstly been isolated in 1947, Uganda, outbreaks of Zika fever have been reported in many areas such as in Africa, Southeast Asia and America. Imported cases in China also have been reported. Zika virus belongs to the family Flaviviridae, genus Flavivirus, and include Africa subtype and Asia subtype. It is a mosquito-borne virus primarily transmitted by Aedes aegypti mosquitoes. Sexual transmission, Blood transmission and mother-to-fetus transmission were also reported. Zika virus can go though blood-brain barrier and infect central nervous system. Symptoms are generally mild and self-limited, but recent evidence suggests a possible association between maternal Zika virus infection and adverse fetal outcomes, such as congenital microcephaly, as well as a possible association with Guillain-Barré syndrome. Laboratorial Diagnosis includes nucleic acid detection, Serological test, and isolation of virus. Currently, no vaccine or medication exists to prevent or treat Zika virus infection. Preventive measures against Zika virus infection should be taken through prevention of mosquito bites and surveillance in epidemic area.
Aedes ; physiology ; virology ; Animals ; Humans ; Insect Vectors ; physiology ; virology ; Zika Virus ; genetics ; physiology ; Zika Virus Infection ; transmission ; virology

OBJECTIVEAssessment of the bacterium L. sphaericus as a dual-action candidate for biological control of mosquito-borne diseases and bioremediation of toxic metals.

METHODSLarvae of the mosquito, C. quinquefasciatus, were first evaluated for metal tolerance and then exposed to 5 ppm cadmium, chromium, arsenic, and lead in assays together with seven strains of L. sphaericus. A probit regression analysis was used to estimate the LC(50) of Cd, Cr, As, and Pb to C. quinquefasciatus. An analysis of covariance and multifactorial ANOVA examined the metal biosorption and larvicidal properties of the seven strains of L. sphaericus.

RESULTSWe found that L. sphaericus adsorbed the toxic metal ions and was toxic against mosquito larvae. The L. sphaericus strain III(3)7 resulted in a larvae mortality of over 80% for all the tested metals. This strain also exhibited the capacity to adsorb 76% of arsenic, 32% of lead, 25% of chromium, and 7% of cadmium.

CONCLUSIONThis study found combined metal adsorption and larval toxicity associated with three strains of L. sphaericus [III(3)7, OT4b.31, and CBAM5]. This suggests that a combination of these strains shows strong dual potential for biological control of mosquitos in heavy metal-contaminated areas and remediate the heavy metal contamination as well.

Animals ; Bacillaceae ; physiology ; Culicidae ; microbiology ; Host-Pathogen Interactions ; Insect Vectors ; Larva ; microbiology ; Metals, Heavy ; metabolism ; toxicity ; Water Pollutants, Chemical ; metabolism ; toxicity

To evaluate the prevalence of mosquito-borne viruses in Manshi and Ruili (Yunnan Province, China), we collected 2 149 mosquitoes (17 species) in August 2010. Virus isolation was undertaken by the cul- ture of baby hamster kidney cells (BHK-21 cells). Two virus-like isolates were obtained: DHL10M117 was isolated from collected in Mangshi; DHL10M110 was obtained from Anopheles vagus collected in Rui- li. Both isolates caused cytopathic effects,illness and death in suckling mice inoculated with these isolates via the intracerebral route. Two positive amplicons, 702-bp from the S segment and 456-bp from the M segment,were obtained using reverse transcription-polymerase chain reaction using primers specific for the Akabane virus (AKV). Phylogenetic analysis suggested that these two virus stains had a distant relation- ship with AKVs from Kenya and Australia,but were genetically close to those from Japan,South Korea, and Taiwan. However,they were separate from other Asian strains and grouped into a small branch. The highest nucleotide and amino-acid sequence identity of the S segment was found with the CY-77 strain from Taiwan (96.6% and 99.6% for DHL10M117 and 96.7% and 100% for DHL10M110,respectively). Com- parison of the M segment showed they shared the highest amino acid identity with CY-77 (99.6% and 100%, respectively), whereas the highest nucleotide identity was found with the Iriki strain from Japan (99.6% and 100%, respectively). Compared with the MP496 strain from Kenya,they displayed lower lev- els of sequence homology, at 69.7% and 70.0% for nucleotide sequences of the two loci,and 91. 0% for a- mino acids. Our results identified that DHL10M117 and DHL10M110 were strains of AKV,and provided molecular biological evidence for the existence of AKV in Yunnan Province. These AKV strains that are circulating in Yunnan Province share a close genetic relationship with strains from the rest of Asia. Culex tritaeniorhynchus and Anopheles vagus may serve as transmission vectors.
Amino Acid Sequence ; Animals ; Anopheles ; virology ; Base Sequence ; Bunyaviridae Infections ; virology ; China ; Cricetinae ; Female ; Humans ; Insect Vectors ; virology ; Male ; Mice ; Orthobunyavirus ; classification ; genetics ; isolation & purification ; physiology ; Phylogeny ; Sequence Homology ; Viral Proteins ; chemistry ; genetics

microRNAs (miRNAs) are an extensive class of -22-nucleotide (nt) endogenous noncoding RNAs regulating life activities ofmetazoans through binding to 3'-untranslated regions (3'-UTRs) of their target genes. This work aimed to identify yan gene in the silkworm, reveal its expression profile and confirm if it is one target of bmo-miR-7 and, as such, have potential for contributing to better understanding of the molecular mechanisms involved in the metamorphosis of silkworm. Based on homolog searching and PCR amplification, we cloned the coding sequence (CDS) of Bmyan, which encodes 476 amino acid residues and contains SAM-PNT and ETs domains. Quantitative PCR (q-PCR), RT-PCR and microarray data revealed high expression of Bmyan in the head, body wall and ovary of day-3 fifth instar larval silkworm, low or no expression in other tissues. It was lowly expressed in the early larval stages, but highly expressed from late spinning to day 4 pupa. The 3'-UTR of Bmyan was obtained by rapid-amplification of cDNA ends (3'RACE) and predicted to contain two potential recognition sites of bmo-miR-7. The luciferase reporter vector containing the 3'-UTR of Bmyan was constructed and co-transfected into BmE cell line with the mimic of bmo-miR-7 and the decreased relative activity of luciferase showed that Bmyan is one target of bmo-miR-7. This work helps further functional analysis of bmo-miR-7 and Bmyan in the silkworm.
3' Untranslated Regions ; Animals ; Bombyx ; genetics ; Cell Line ; Cloning, Molecular ; Female ; Genetic Vectors ; Insect Proteins ; genetics ; Larva ; Metamorphosis, Biological ; MicroRNAs ; genetics ; Pupa

To improve the expression of heterologous genes using baculovirus expression system, we constructed a novel shuttle vector based on the Bm-Bacmid. In the Bm-Bacmid, partial sequences of Chitinase and Cystein Protease were replaced with a tandem cassette of Cm and egfp through homologous recombination. Bombyx mori bidensovirus (BmBDV) ns1 under the control of polyhedrin promoter was inserted into the modified Bm-bacmid by transposition. For comparison, BmBDV ns1 under the control of polyhedrin promoter was also cloned in the wild type Bm-bacmid. The resulting Bm-bacmids were transfected into the cultured BmN cells to prepare recombinant virus to infect silkworms for expression of BmBDV ns1. Total proteins of hemocyte from infected silkworms were subjected to Western blotting and ELISA analysis. The yield of BmBDV NS1 1 with the modified vector was three times as much as that with the unmodified vector. The method to improve the yield of BmBDV NS1 in silkworms will facilitate the function and three-dimensional structure study of BmBDV NS1.
Animals ; Baculoviridae ; Bombyx ; virology ; Cell Line ; Chitinases ; Cysteine Proteases ; Genetic Vectors ; Insect Viruses ; Promoter Regions, Genetic ; Transfection

Biting midges belonging to the genus Culicoides (Diptera: Ceratopogonidae) were collected by Mosquito Magnet(R) and black light traps at 5 sites on Jeju-do, Republic of Korea (Korea), from May-November 2013 to determine species diversity and seasonal distribution. A total of 4,267 specimens were collected, of which 99.9% were female. The most common species was Culicoides tainanus (91.8%), followed by C. lungchiensis (7.2%) and C. punctatus (0.6%), while the remaining 4 species accounted for <0.5% of all Culicoides spp. that were collected. High numbers of C. tainanus were collected in May, followed by decreasing numbers through August, and then increasing numbers through November when surveillance was terminated. Peak numbers of C. lungchiensis were collected during September, with low numbers collected from May-August and October-November. The presence of C. lungchiensis in Korea was confirmed by morphological and molecular analyses.
Animals ; *Biodiversity ; Ceratopogonidae/classification/*growth & development ; Female ; Insect Vectors/classification/*growth & development ; Male ; Phylogeny ; Republic of Korea ; Seasons