Development of an insect vector cell culture and RNA interference system to investigate the functional role of fijivirus replication protein.

An in vitro culture system of primary cells from white-backed planthopper, an insect vector of Southern rice black-streaked dwarf virus (SRBSDV), a fijivirus, was established to study replication of the virus. Viroplasms, putative sites of viral replication, contained the nonstructural viral protein P9-1, viral RNA, outer-capsid proteins, and viral particles in virus-infected cultured insect vector cells, as revealed by transmission electron and confocal microscopy. Formation of viroplasm-like structures in non-host insect cells upon expression of P9-1 suggested that the matrix of viroplasms observed in virus-infected cells was composed basically of P9-1. In cultured insect vector cells, knockdown of P9-1 expression due to RNA interference (RNAi) induced by synthesized double-stranded RNA (dsRNA) from the P9-1 gene strongly inhibited viroplasm formation and viral infection. RNAi induced by ingestion of dsRNA strongly abolished viroplasm formation, preventing efficient viral spread in the body of intact vector insects. All these results demonstrated that P9-1 was essential for viroplasm formation and viral replication. This system, combining insect vector cell culture and RNA interference, can further advance our understanding of the biological activities of fijivirus replication proteins.

MiR-142-5p promotes retinoblastoma cell proliferation, migration and invasion by targeting PTEN.

The study intends to probe the functions of miR-142-5p in retinoblastoma (RB) and the relationship between miR-142-5p and phosphatase and tensin homolog deleted on chromosome ten (PTEN). In our study, miR-142-5p and PTEN mRNA expression in RB tissue, serum of RB patients and RB cell lines were investigated by quantitative real-time polymerase chain reaction (qRT-PCR). The proliferation, migration, invasion and cell apoptosis were measured using MTT assay, BrdU assay, Transwell experiments and flow cytometry analysis, respectively. Binding sites between miR-142-5p and PTEN were predicted by the TargetScan database and were confirmed via qRT-PCR, western blot and dual-luciferase reporter gene assay. It was demonstrated that miR-142-5p expression was elevated in RB tissue, serum of RB patients and RB cell lines. MiR-142-5p overexpression remarkably promoted the proliferation, migration, invasion and inhibited the apoptosis of WERI-RB-1 cells while miR-142-5p knockdown induced opposite effects in Y79 cells. MiR-142-5p decreased PTEN expression in both mRNA and protein expression levels, and PTEN was identified as a target gene of miR-142-5p. Cotransfection of PTEN overexpression plasmids reversed the influences of miR-142-5p on RB cells. In conclusion, miR-142-5p enhances proliferation, migration and invasion of RB cell by targeting PTEN.

A novel green approach for fabricating visible, light sensitive nano-broccoli-like antimony trisulfide by marine Sb(v)-reducing bacteria: Revealing potential self-purification in coastal zones.

Antimony trisulfide (Sb2S3) is industrially important for processes ranging from a semiconductor dopant through batteries to a flame retardant. Approaches for fabricating Sb2S3 nanostructures or thin films are by chemical or physicochemical methods, while there have been no report focused on the biological synthesis of nano Sb2S3. In the present study, we fabricated nano-broccoli-like Sb2S3 using Sb(V) reducing bacteria. Thirty four marine and terrestrial strains are capable of fabricating Sb2S3 after 1-5 days of incubation in different selective media. The nano-broccoli-like bio-Sb2S3 was light sensitive between 400-550 nm, acting as a photo-catalyst with the bandgap energy of 1.84 eV. Moreover, kinetic and mechanism studies demonstrated that a k value of ∼0.27 h-1 with an R2 = 0.99. The bio-Sb2S3 supplemented system exhibited approximately 18.4 times higher photocatalytic activity for degrading methyl orange (MO) to SO42-, CO2 and H2O compared with that of control system, which had a k value of ∼0.015 h-1 (R2 = 0.99) under visible light. Bacterial community shift analyses showed that the addition of S or Fe species to the media significantly changed the bacterial communities driven by antimony stress. From this work it appears Clostridia, Bacilli and Gammaproteobacteria from marine sediment are potentially ideal candidates for fabricating bio-Sb2S3 due to their excellent electron transfer capability. Based on the above results, we propose a potential visible light bacterially catalyzed self-purification of both heavy metal and persistent organic contamination polluted coastal waters.

Sequence analysis and phylogeny of deer (Cervidae) MtDNA control regions.

The complete control regions of three Muntiacinae species of Cervidae (M. reevesi, M. muntjak and M. crinifrons) were located after their complete mtDNA genomes were sequenced. In addition the control region sequences of nine species of other three Cervidae subfamilies were obtained from the Genbank. Base compositions, genetic distances and percent similarities among these regions were calculated and the homologous sequences were compared. Based on their control region sequences, the molecular phylogenetic tree was constructed by Neighbor-Joining method and rooted using the mtDNA control region sequence of O. aries. Furthermore, the phylogenetic relationship among the twelve species was discussed. The lengths of their control regions ranged from 909 bp to 1 049 bp and A + T content is 62.06%. The sequence alignment revealed considerable variation in 363 nucleotide sites (about 34%). According to the phylogenetic tree, we suggest: (1) As a whole, the phylogenetic taxon of the twelve Cervidae species based on their control region sequences is consistent with that made by the NCBI; (2) A. alces, a species of Alces (subfamily: Odocoileinae) is most antique one among the twelve Cervidae species; (3) M. reevesi is more antique than M. muntjak and M. crinifrons; (4) H. inermis, belonging to the subfamily Hydropotinae, is merged into the branch which includes C. capreolus and C. pygargus, two species of Capreolus (subfamily: Odocoileinae).

[Sequence and organization of Muntiacus reevesi mitochondrial genome].

A shot-gun DNA sequence strategy was employed,in which the mitochondrial genome library of Muntiacus reevesi has been constructed to obtain the complete mitochondrial genome sequence. The Chinese Muntjac's mitochondrial genome, consisting of 16354 base pairs which encode genes for 13 proteins, 2 rRNAs, and 22 tRNAs, is similar to those mammals in both order and orientation. The sequence of rRNA gene, some of the protein-coding regions and tRNAs are highly homologous in mammals. Differences existing in the length and sequence of the D-loop regions account for the variations in mammals mitochondrial genomes.