Polyploidy has contributed to the evolution of eukaryotes, particularly flowering plants. The genomic consequences of polyploidy have been extensively studied, but the mechanisms for chromosome stability and diploidization in polyploids remain largely unknown. By using new cytogenetic tools to identify all of the homoeologous chromosomes, we conducted a cytological investigation of 50 resynthesized Brassica napus allopolyploids across generations S 0:1 to S 5:6 and in the S 10:11 generation. Changes in copy number of individual chromosomes were detected in the S 0:1 generation and increased in subsequent generations, despite the fact that the mean chromosome number among lines was approximately 38. The chromosome complement of individual plants (segregants) ranged from 36 to 42, with a bias toward the accumulation of extra chromosomes. Karyotype analysis of the S 10:11 generation detected aneuploidy and inter- and intragenomic rearrangements, chromosome breakage and fusion, rDNA changes, and loss of repeat sequences. Chromosome sets with extensive homoeology showed the greatest instability. Dosage balance requirements maintained chromosome numbers at or near the tetraploid level, and the loss and gain of chromosomes frequently involved homoeologous chromosome replacement and compensation. These data indicate that early generations of resynthesized B. napus involved aneuploidy and gross chromosomal rearrangements, and that dosage balance mechanisms enforced chromosome number stability. Seed yield and pollen viability were inversely correlated with increasing aneuploidy, and the greatest fertility was observed in two lines that were additive for parental chromosomes. These data on resynthesized B. napus and the correlation of fertility with additive karyotypes cast light on the origins and establishment of natural B. napus .
<p>A, 293T cells were co-transfected with HA-AR-V7 with or without Flag-KIF4A, shCHIP, and MYC-Ub for 2 days, and total cell lysates were immunoprecipitated with HA antibody and blotted with the indicated antibodies. B, 293T cells were co-transfected with eGFP-AR with or without Flag-KIF4A, shCHIP, and MYC-Ub for 2 days, and total cell lysates were immunoprecipitated with eGFP antibody and blotted with the indicated antibodies.</p>
BnAP2, an APETALA2 (AP2)-like gene, has been isolated from Brassica napus cultivar Zhongshuang 9. The cDNA of BnAP2, with 1, 299 bp in length, encoded a transcription factor comprising of 432 amino acid residues. Results from complementary experiment indicated that BnAP2 was completely capable of restoring the phenotype of Arabidopsis ap2-11 mutant. Together with the sequence and expression data, the complementation data suggested that BnAP2 encodes the ortholog of AtAP2. To address the transcriptional activation of BnAP2, we performed transactivation assays in yeast. Fusion protein of BnAP2 with GAL4 DNA binding domain strongly activated transcription in yeast, and the transactivating activity of BnAP2 was localized to the N-terminal 100 amino acids. To further study the function of BnAP2 involved in the phenotype of B. napus, we used a transgenic approach that involved targeted RNA interference (RNAi) repression induced by ihp-RNA. Floral various phenotype defectives and reduced female fertility were observed in B. napus BnAP2-RNAi lines. Loss of the function of BnAP2 gene also resulted in delayed sepal abscission and senescence with the ethylene-independent pathway. In the strong BnAP2-RNAi lines, seeds showed defects in shape, structure and development and larger size. Strong BnAP2-RNAi and wild-type seeds initially did not display a significant difference in morphology at 10 DAF, but the development of BnAP2-RNAi seeds was slower than that of wild type at 20 DAF, and further at 30 DAF, wild-type seeds were essentially at their final size, whereas BnAP2-RNAi seeds stopped growing and developing and gradually withered.
Objective
To investigate the effect and mechanism of liver cancer derived mesenchymal stem cell (LCMSC) on the invasion of liver cancer cells.
Methods
The expressions of interleukin (IL)-6, IL-8 and chemotactic factors CXCL1, CXCL5 and CXCL12 mRNA in the bone marrow derived mesenchymal stem cell (BMSC) and LCMSC were detected by reverse transcription-polymerase chain reaction (RT-PCR). The expression of protein CXCL12 in the supernate of LCMSC was detected by enzyme-linked immunosorbent assy (ELISA) and Western blot. Different cells were co-cultured and divided into the HepG2+BMSC, HepG2+LCMSC and HepG2+LCMSC+siRNA-CXCL12 groups. The effect of CXCL12 on the invasion of liver cancer HepG2 cells were detected by Transwell migration assay. The experiment data were compared using one way analysis of variance and LSD-t test or t test.
Results
The expression of CXCL12 mRNA in LCMSC was 60.3±2.4, significantly higher than 13.8±1.8 in BMSC (t=15.68, P<0.05). The expression of protein CXCL12 in the supernate of LCMSC was (31.5±1.7) ng/L, significantly higher than (14.3±1.5) ng/L in BMSC (t=7.60, P<0.05). And the expression of protein CXCL12 was up-regulated. Transwell migration assay indicated that the quantity of membrane-invasion cells in the HepG2+LCMSC group was 110±12, significantly higher than 65±9 in the HepG2+BMSC group and 76±7 in the HepG2+LCMSC+siRNA-CXCL12 group (LSD-t=5.25, 4.86; P<0.05).
Conclusion
CXCL12 is highly expressed in LCMSC. LCMSC may enhance the invasion of HepG2 cells through up-regulating the expression of CXCL12. The invasion of liver cancer cells can be effectively weakend by silencing the CXCL12 gene with siRNA.
Key words:
Mesenchymal stem cells; Carcinoma, hepatocellular; Neoplasm invasiveness; Chemokine CXCL12
Integrated Modular Avionics (IMA) system has gradually been applied to the design of the aircraft avionics equipment, and configuration of IMA system is a key technique that makes such system flexible, yet controlled. In this paper, we focus on system configurations of IMA system based on the Arinc653 standard and present a method to classify these configurations. We divide IMA system configurations into two types, the necessary configurations and the configurations. The necessary configurations include core OS (operational system including kernel, BSP and some user defined codes) configuration, application configurations, mid-ware configuration, partition configurations, and the entire module configuration. While the optional configurations include shared data (a memory pool shared by different applications can be used to read or write, or exchange data) configurations, and shared I/O (input and output devices shared by core OS and applications) configurations. In general, there are three roles in developing an IMA system, platform provider, application developer and system integrator. It makes sense that every elements of an IMA system should be configured independently by this system configuration classified method, because of the isolation of different type configurations, and it will be easy to verify and validate the IMA system configuration in different development phases by different roles.
The epidermal growth factor receptor (EGFR) mutant of EGFRvIII is highly expressed in glioma cells, and the EGFRvIII-specific dendritic cell (DC)-induced tumor antigen-specific CD8+ cytotoxic T lymphocytes (CTLs) may hold promise in cancer immunotherapy. Interferon (IFN)-γ-inducible protein (IP)-10 (IP-10) is a potent inhibitor of angiogenesis and can recruit CXCR3+ T cells, including CD8+ T cells, which are important for the control of tumor growth. In this study, we assessed if the combination of IP10-EGFRvIIIscFv with DC-induced CTLs would improve the therapeutic antitumor efficacy. IP10-scFv was generated by linking the human IP-10 gene with the DNA fragment for anti-EGFRvIIIscFv with a (Gly4Ser)3 flexible linker, purified by affinity chromatography, and characterized for its anti-EGFRvIII immunoreactivity and chemotactic activity. DCs were isolated from human peripheral blood monocyte cells and pulsed with EGFRvIII-peptide, then co-cultured with autologous CD8+ T cells. BALB/c-nu mice were inoculated with human glioma U87-EGFRvIII cells in the brain and treated intracranially with IP10-scFv and/or intravenously with DC-induced CTLs for evaluating the therapeutic effect. Treatment with both IP10-scFv and EGFRvIII peptide-pulsed, DC-induced CTL synergistically inhibited the growth of glioma and prolonged the survival of tumor-bearing mice, which was accompanied by the inhibition of tumor angiogenesis and enhancement of cytotoxicity, thereby increasing the numbers of brain-infiltrating lymphocytes (BILs) and prolonging the residence time of CTLs in the tumor.
PREMISE OF THE STUDY Previous phylogenetic studies employing molecular markers have yielded various insights into the evolutionary history across Brassicales, but many relationships between families remain poorly supported or unresolved. A recent phylotranscriptomic approach utilizing 1155 nuclear markers obtained robust estimates for relationships among 14 of 17 families. Here we report a complete family‐level phylogeny estimated using the plastid genome. METHODS We conducted phylogenetic analyses on a concatenated data set comprising 44,926 bp from 72 plastid genes for species distributed across all 17 families. Our analysis includes three additional families, Tovariaceae, Salvadoraceae, and Setchellanthaceae, that were omitted in the previous phylotranscriptomic study. KEY RESULTS Our phylogenetic analyses obtained fully resolved and strongly supported estimates for all nodes across Brassicales. Importantly, these findings are congruent with the topology reported in the phylotranscriptomic study. This consistency suggests that future studies could utilize plastid genomes as markers for resolving relationships within some notoriously difficult clades across Brassicales. We used this new phylogenetic framework to verify the placement of the At‐α event near the origin of Brassicaceae, with median date estimates of 31.8 to 42.8 million years ago and restrict the At‐β event to one of two nodes with median date estimates between 85 to 92.2 million years ago. These events ultimately gave rise to novel chemical defenses and are associated with subsequent shifts in net diversification rates. CONCLUSIONS We anticipate that these findings will aid future comparative evolutionary studies across Brassicales, including selecting candidates for whole‐genome sequencing projects.
Objective
To investigate the inhibiting effect and its mechanism of β-hydroxybutyrate dehydrogenase 2 (BDH2) gene on the proliferation of liver cancer cells.
Methods
The lentiviral vectors expressing BDH2 were constructed. The liver cancer cell line HepG2-BDH2 stably expressing BDH2 (experimental group) and the control cell line HepG2-Vector (control group) were established. The expression levels of BDH2 mRNA in two groups were detected by RT-PCR. The proliferation of liver cancer cells in two groups was detected by CCK-8 assay. The colony formation ability of cells was observed in two groups by colony formation assay. The expression of BDH2 protein and apoptosis-associated protein Bcl-2 was detected by Western blot. The experimental data were compared using t test.
Results
In experimental group, the expression level of BDH2 mRNA was (2.20±0.10)×10-3, which was significantly higher than (0.20±0.01)×10-3 in control group (t=34.95, P<0.05). In experimental group, the A450 values at 3, 4, 5, 6 and 7 d after cell culture were 0.55±0.20, 0.73±0.02, 1.26±0.12, 1.62±0.14 and 2.19±0.12, which were significantly lower than 0.70±0.06, 1.13±0.08, 1.77±0.15, 2.45±0.12 and 3.02±0.15 in control group (t=-5.19, -11.34, -5.96, -10.35, -9.54; P<0.05), respectively. The cell proliferation curve showed that the proliferation of cells in experimental group was significantly weaker than that in control group. Colony formation assay indicated that the number of cell clones in experimental group was 184±7, which was significantly less than 429±15 in control group (t=-25.84, P<0.05). Compared with control group, the expression levels of BDH2 and cleaved caspase-3 protein in experimental group were up-regulated significantly, whereas the expression level of Bcl-2 protein was down-regulated significantly.
Conclusions
BDH2 gene can inhibit the proliferation of liver cancer cells probably through promoting the apoptosis of liver cancer cells via Bcl-2 signaling pathway.
Key words:
Carcinoma, hepatocellular; Cell proliferation; Apoptosis; BDH2 gene; Bcl-2
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