Cellulase genes are very important for plant-parasitic nematodes to move and feed within their host plants. The pine wood nematode, Bursaphelenchus xylophilus, causes destructive damage by killing pine trees. In this study, by employing dsRNA interference technology, knockdown of a cellulase gene (Bx-eng-1) of B. xylophilus was achieved and the biological effects of RNAi on the nematode were observed. The result showed that, after 24 h soaking, dsRNA of the Bx-eng-1 gene was effectively delivered into the nematode causing a post-transcriptional gene silencing and decrease in cellulase activity. Moreover, the number of F1 generation offspring was reduced significantly when the dsRNA-treated nematodes were cultured on fungal mats. We consider that cellulase is important to B. xylophilus because it not only hydrolyses cellulose of plant cell wall for its parasitism and penetration in host plants, but also influences its feeding, development and propagation on fungal mats.

A Gram-positive, non-motile, spherical, red-pigmented and facultatively anaerobic bacterium, designated strain I-0 T , was isolated from a sand sample of the Gobi desert in Xinjiang Autonomous Region, China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that this isolate represents a novel member of the genus Deinococcus, with low sequence similarities (,94 %) to recognized Deinococcus species. The major cellular fatty acids were C 16 : 1 v7c and C 16 : 0 . Its polar lipid profile contained several unidentified glycolipids, phosphoglycolipids, phospholipids, pigments and an aminophospholipid. The peptidoglycan type was Orn-Gly 2 (A3b) and the predominant respiratory quinone was MK-8. The DNA G+C content was 65.4 mol%. DNA-DNA relatedness between strain I-0 T and Deinococcus radiodurans ACCC 10492 T was 37 %. The strain was shown to be extremely resistant to gamma radiation (.15 kGy) and UV light (.600 J m "2 ). On the basis of the phylogenetic, chemotaxonomic and phenotypic data presented, strain I-0 T represents a novel species of the genus Deinococcus, for which the name Deinococcus gobiensis sp. nov. is proposed. The type strain is I-0 T (5DSM 21396 T 5CGMCC 1.7299 T ).The genus Deinococcus, which was described by Brooks & Murray (1981) ) and desiccation (years) is a distinctive characteristic of this genus (Makarova et al., 2007). This resistance has been attributed to a highly proficient DNA repair system, and it seems likely that radiation resistance evolved as a consequence of chronic exposure to non-radioactive forms of DNA damage, such as desiccation (Makarova et al., 2001).In the course of the study of stress-resistant bacteria from arid environments, a novel Deinococcus isolate was obtained from the upper sand layers of the Gobi desert, Xinjiang, China, where bacteria are exposed to cycles of high and low temperatures and to prolonged desiccation. In this paper, we report on the taxonomic characterization of this radiation-resistant, red-coloured strain, designated I-0 T , which was obtained from a mixed sand sample. After exposure of the sample to 10 kGy gamma radiation from a 60 Co source (CAIC), it was enriched in 50 ml TGY medium (1.0 % peptone, 0.5 % yeast extract, 0.1 % glucose) at 30 u C with shaking at 200 r.p.m. for up to 5 days, followed by isolation of surviving red-colony-forming bacteria on TGY agar plates (TGY medium with 1.5 % agar).Morphology of cells grown for 24-48 h on TGY agar was examined by zoom stereo microscopy (model SZX7; Olympus), light microscopy (model BX-51; Olympus), scanning electron microscopy (model S-570; Hitachi) and transmission electron microscopy (model H-7500; Hitachi). Gram staining was carried out using the modified 3These authors contributed equally to this work.The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain I-0 T is EU427464.Micrographs of colonies and cells of strain I-0 T , a 16S rRNA gene sequence-based maximum-parsimony tree, the fatty acid profile of strain I-0 T and a table of 16S rRNA gene sequence s...

T cell immunity, such as CD4 and/or CD8 T cell responses, plays a vital role in controlling the virus infection and pathological damage. Several studies have reported SARS-CoV-2 proteins could serve as ideal vaccine candidates against SARS-CoV-2 infection by activating the T cell responses. In the current study, based on the SARS-CoV-2 sequence and distribution of host human leukocyte antigen (HLA), we predicted the possible epitopes for the vaccine against SARS-CoV-2 infections. Firstly, the current study retrieved the SARS-CoV-2 S and N protein sequences from the NCBI Database. Then, using the Immune Epitope Database Analysis Resource, we predicted the CTL epitopes of the SARS-CoV-2 S and N proteins according to worldwide frequency distributions of HLA-A, -B, and -C alleles (>1%). Our results predicted 90 and 106 epitopes of N and S proteins, respectively. Epitope cluster analysis showed 16 and 34 respective clusters of SARS-CoV-2 N and S proteins, which covered 95.91% and 96.14% of the global population, respectively. After epitope conservancy analysis, 8 N protein epitopes and 6 S protein epitopes showed conservancy within two SARS-CoV-2 types. Of these 14 epitopes, 13 could cover SARS coronavirus and Bat SARS-like coronavirus. The remaining epitope (KWPWYIWLGF 1211-1220 ) could cover MERS coronavirus. Finally, the 14-epitope combination could vaccinate 89.60% of all individuals worldwide. Our results propose single or combined CTL epitopes predicted in the current study as candidates for vaccines to effectively control SARS-CoV-2 infection and development.