TBIS: A Web-Based Expert System for Identification of Tephritid Fruit Flies in China Based on DNA Barcode

International audienceTephritid fruit flies (Diptera: Tephritidae) include serious agricultural insect pests in the world. Besides causing severe damage to fruits and vegetables, this kind of pests could enter countries or regions with international trade easily. Strict trade quarantine measures are imposed in many countries or regions in order to prevent their introduction and spread. Thus accurate and rapid identification is regarded as an essential component of plant quarantine. Traditional expert systems for assistant identification of agricultural insect pests are based on their morphological characteristics. Compared with the morphological identification, however, molecular identification has more advantages especially for the identification of the immature samples which are intercepted more frequently. Among the molecular identification methods, DNA barcoding is very effective and has been selected by the taxonomists in recent 5 years. In view of the above, a network expert system based on the DNA barcode, Tephritid Barcode Identification System (TBIS) was developed with ASP.NET and C# to improve the molecular identification of fruit fly pests in China. The system was supported by Microsoft SQL server 2008 database. Three functions were provided such as molecular identification based on DNA barcode, information browse and inquiry. DNA sequence similarity alignment dynamic programming algorithm served as the inference mechanism. Molecular identification knowledge was obtained from the public database on the Internet and Plant Quarantine Laboratory of China Agricultural University, which contained about 400 COI sequences of nearly 150 species of fruit flies. Moreover, detailed information such as morphological description and pictures of adult, hosts, and geographical distribution are presented in this system. Mixed with molecular, morphological and distributional data, the system can be used as an identification tool both for quarantine technicians and for educational purposes in China

XRCC5 cooperates with p300 to promote cyclooxygenase-2 expression and tumor growth in colon cancers.

Cyclooxygenase (COX) is the rate-limiting enzyme in prostaglandins (PGs) biosynthesis. Previous studies indicate that COX-2, one of the isoforms of COX, is highly expressed in colon cancers and plays a key role in colon cancer carcinogenesis. Thus, searching for novel transcription factors regulating COX-2 expression will facilitate drug development for colon cancer. In this study, we identified XRCC5 as a binding protein of the COX-2 gene promoter in colon cancer cells with streptavidin-agarose pulldown assay and mass spectrometry analysis, and found that XRCC5 promoted colon cancer growth through modulation of COX-2 signaling. Knockdown of XRCC5 by siRNAs inhibited the growth of colon cancer cells in vitro and of tumor xenografts in a mouse model in vivo by suppressing COX-2 promoter activity and COX-2 protein expression. Conversely, overexpression of XRCC5 promoted the growth of colon cancer cells by activating COX-2 promoter and increasing COX-2 protein expression. Moreover, the role of p300 (a transcription co-activator) in acetylating XRCC5 to co-regulate COX-2 expression was also evaluated. Immunofluorescence assay and confocal microscopy showed that XRCC5 and p300 proteins were co-located in the nucleus of colon cancer cells. Co-immunoprecipitation assay also proved the interaction between XRCC5 and p300 in nuclear proteins of colon cancer cells. Cell viability assay indicated that the overexpression of wild-type p300, but not its histone acetyltransferase (HAT) domain deletion mutant, increased XRCC5 acetylation, thereby up-regulated COX-2 expression and promoted the growth of colon cancer cells. In contrast, suppression of p300 by a p300 HAT-specific inhibitor (C646) inhibited colon cancer cell growth by suppressing COX-2 expression. Taken together, our results demonstrated that XRCC5 promoted colon cancer growth by cooperating with p300 to regulate COX-2 expression, and suggested that the XRCC5/p300/COX-2 signaling pathway was a potential target in the treatment of colon cancers

Hydrogen embrittlement behavior of two mining chain steels by slow strain rate test

Two mining chain steels 23MnNiMoCr5-4 and 0.3C0.2Si0.3Mn4.2(Cr+Ni+Mo) with tensile strengths of 1200 MPa and 1250 MPa, respectively, were employed to investigate their hydrogen embrittlement behaviors by slow strain rate tests combined with thermal desorption analyses. It is shown that at initial stage the fracture stress decreases linearly as the hydrogen content increases, and the turning points occur at hydrogen content of 1.2 wppm for 0.3C0.2Si0.3Mn4.2(Cr+Ni+Mo) and 0.26 wppm for 23MnNiMoCr5-4. The fractured surface observation suggests that the ratio of intergranular fracture area to quasi-cleavage area increases dramatically at the turning points. The maximum hydrogen contents resulting from the corrosive HCl solutions with pHs of 2 are approximately 0.6 wppm 0.3C0.2Si0.3Mn4.2(Cr+Ni+Mo) and 0.11 wppm for 23MnNiMoCr5-4, corresponding to the activation energies for hydrogen desorption are 21.57 kJ/mol and 14.53 kJ/mol, respectively

XRCC5 interacting with p300 to co-regulate COX-2 expression in colon cancer cells.

<p>(A) Immunofluorescence and confocal microscopy of XRCC5 and p300 in RKO and LoVo cells. XRCC5 is stained by TRITC-conjugated secondary antibodies (red), p300 is stained by FITC-conjugated secondary antibodies (green), and nuclei are stained with DAPI (blue). (B) Co-immunoprecipitation assay of p300 and XRCC5 in RKO, LoVo and SW480 cells.Left: Immunoprecipitation assay (IP) of p300 and XRCC5. Right: Western blot (WB) of XRCC5 and p300. (C) Bottom: The design of the flag-tagged plasmids with different domains of p300. Left: The interaction between XRCC5 and the different domains of p300 detected by immunoprecipitation assay and Western blot. (D)Western blot of XRCC5 with the nuclear extractsimmunoprecipitated by an anti-acetylation antibody in RKO, LoVo and SW480 cells. (E) Western blot of XRCC5 with the nuclear extracts immunoprecipitated by an anti-acetylation antibody in LoVo cells. (F) Western blot of XRCC5 and COX-2 in LoVo cells. (G) MTS cell viability assay in LoVo cells (Left) and RKO cells (Right). Cells treated with liposome negative control is used for data alignment. Data are presented as the meanen.D. (*<i>P</i><0.05). lacZ represents negative control vector, p300WT represents wild type p300 overexpression, Δp300 represents histone acetyltransferase (HAT) domain deletion mutant p300, C646 represents p300 HAT inhibitor C646, and siXRCC5 represents knockdown of XRCC5 with siRNAs.</p

XRCC5 regulating colon cancer cell proliferation <i>in vitro</i>.

<p>(A) MTS cell viability assay of LoVo cells. Cells treated with BPS negative control are used for data alignment. Data are presented as the meaen.D. (*<i>P</i><0.05). (B) MTS cell viability assay of RKO cells. Cells treated with PBS negative control are used for data alignment. Data are presented as the meannt.D. (*<i>P</i><0.05). (C) Morphology observation of LoVo cells. (D) Colony formation assay of LoVo cells. Si1, Si2 and Si3 represent three sequences of siRNAs of XRCC5, Sictr represents negative control siRNA of XRCC5, PBS represents PBS negative control, XRCC5 represents overexpression of XRCC5, and LacZ represents negative control vector.</p

XRCC5 regulating COX-2 promoter activation and protein expression in colon cancer cells.

<p>(A) Left: Western blot of XRCC5 and COX-2 in LoVo cells. Right: Western blot of XRCC5 and COX-2 in RKO cells. (B) Luciferase reporter assay of the activity of COX-2 promoter in LoVo cells. Protein weight is used to adjust relative luciferase activity (RLU), and cells treated with BPS negative control are also used for data alignment. Data in the figure are presented as the meanmoter i<i>P</i><0.05). (C) Luciferase reporter assay of the activity of COX-2 promoter in RKO cells. Protein weight is used to adjust relative luciferase activity (RLU). Data are presented as the meanve pro<i>P</i><0.05).(D) MTS cell viability assay of RKO cells. Cells treated with LacZ is used for data alignment. Data are presented as the mean±SD. (*<i>P</i><0.05). Si1, Si2 and Si3 represent three sequences of siRNAs of XRCC5, Sictr represents negative control siRNA of XRCC5, LacZ represents negative vector control, LPS represents lipopolysaccharides, PBS represents PBS negative control, XRCC5 represents overexpression of XRCC5, and CB represents celecoxib.</p