Analysis of research status and trends on marine benthic dinoflagellate toxins: A bibliometric study based on web of science database and VOSviewer.

Marine benthic dinoflagellate toxins, potent bioactive compounds with wide-ranging presence in marine ecosystems, have surged in response to global climate change and human activities, prompting an urgent and imperative inquiry. This study conducts an in-depth review of contemporary research concerning these toxins, employing meticulous bibliometric analysis. Leveraging a dataset of 736 relevant literatures sourced from the Web of Science (spanning from 2000 to May 2023), our analysis delves comprehensively into the scientific discourse surrounding these toxic compounds. Employing tools such as VOSviewer, co-citation analysis, co-occurrence analysis, and cluster analysis, our study yields nuanced insights into the intricate characteristics and trajectories of the field. The co-citation analysis underscores the pivotal role played by benthic and epiphytic dinoflagellates like Ostreopsis and Gambierdiscus in shaping prevailing research trends. Our study identifies four distinct research directions, encompassing the domains of ecology, toxicology, toxin production, and taxonomy. Moreover, it traces the evolutionary journey of research stages, marking the transition from a focus on taxonomy to an emphasis on unraveling molecular mechanisms. The culmination of our comprehensive analysis yields three pertinent research recommendations: a call for widescale global studies, the advancement of rapid toxin monitoring techniques, and a deeper exploration of the factors influencing toxin synthesis and toxicity. These findings provide invaluable insights to researchers grappling with the complex realm of harmful algal blooms and substantially enrich the understanding of this pivotal and pressing field.

Chromosome-scale genome assembly and insights into the metabolome and gene regulation of leaf color transition in an important oak species, Quercus dentata.

Quercus dentata Thunb., a dominant forest tree species in northern China, has significant ecological and ornamental value due to its adaptability and beautiful autumn coloration, with color changes from green to yellow into red resulting from the autumnal shifts in leaf pigmentation. However, the key genes and molecular regulatory mechanisms for leaf color transition remain to be investigated. First, we presented a high-quality chromosome-scale assembly for Q. dentata. This 893.54 Mb sized genome (contig N50 = 4.21 Mb, scaffold N50 = 75.55 Mb; 2n = 24) harbors 31 584 protein-coding genes. Second, our metabolome analyses uncovered pelargonidin-3-O-glucoside, cyanidin-3-O-arabinoside, and cyanidin-3-O-glucoside as the main pigments involved in leaf color transition. Third, gene co-expression further identified the MYB-bHLH-WD40 (MBW) transcription activation complex as central to anthocyanin biosynthesis regulation. Notably, transcription factor (TF) QdNAC (QD08G038820) was highly co-expressed with this MBW complex and may regulate anthocyanin accumulation and chlorophyll degradation during leaf senescence through direct interaction with another TF, QdMYB (QD01G020890), as revealed by our further protein-protein and DNA-protein interaction assays. Our high-quality genome assembly, metabolome, and transcriptome resources further enrich Quercus genomics and will facilitate upcoming exploration of ornamental values and environmental adaptability in this important genus.

A Brassica miRNA Regulates Plant Growth and Immunity through Distinct Modes of Action.

In plants, high disease resistance often results in a reduction of yield. Therefore, breeding crops with balanced yield and disease resistance has become a major challenge. Recently, microRNA (miRNA)-mediated R gene turnover has been shown to be a protective mechanism used by plants to prevent autoimmunity in the absence of pathogens. However, whether these miRNAs play a role in plant growth and how miRNA-mediated R gene turnover responds to pathogen infection have rarely been explored. Here, we found that a Brassica miRNA, miR1885, targets both an immune receptor gene and a development-related gene for negative regulation through distinct modes of action. MiR1885 directly silences the TIR-NBS-LRR class of R gene BraTNL1 but represses the expression of the photosynthesis-related gene BraCP24 by targeting the Trans-Acting Silencing (TAS) gene BraTIR1 for trans-acting small interfering RNAs (tasiRNAs)-mediated silencing. We found that, under natural conditions, miR1885 was kept at low levels to maintain normal development and basal immunity but peaked during the floral transition to promote flowering. Interestingly, upon Turnip mosaic virus (TuMV) infection, miR1885-dependent trans-acting silencing of BraCP24 was enhanced to speed up the floral transition, whereas miR1885-mediated R gene turnover was overcome by TuMV-induced BraTNL1 expression, reflecting precise regulation of the arms race between plants and pathogens. Collectively, our results demonstrate that a single Brassica miRNA dynamically regulates both innate immunity and plant growth and responds to viral infection, revealing that Brassica plants have developed a sophisticated mechanism in modulating the interplay between growth, immunity, and pathogen infection.

[In vivo Cell CFSE Fluorescence Negative Staining for Detection of Super Paramagnetic Iron Oxide Nanoparticles Phagocytosed by Mouse Mononuclear Macrophage Leukemia Cells-RAW264.7].

OBJECTIVE: To explore the feasibility and fluorescence characteristics of CFSE negative staining for in vivo cell imaging of super paramagnetic iron oxide nanoparticles (SPIO) phagocytosed by mouse mononuclear macrophage leukemia cells-RAW264.7. METHODS: After labeled with SPIO, the RAW264.7 macrophages were stained with Prussian blue stain and CFSE fluorescence negative stain step by step. Furthermore, trypan blue staining was used to evaluate cell viability of cells which stained with CFSE. At last, laser scanning confocal microscope was used to measure SPIO in cells through CFSE fluorescence negative stain method. RESULTS: SPIO within RAW264.7 macrophages showed blue in Prussian's blue staining, while showed negative area in CFSE negative staining. Good consistencies between Prussian's blue staining and CFSE negative staining were observed. In addition, RAW264.7 macrophages showed high viability after SPIO/CFSE dual-labeled method, proved by typan stain. CONCLUSION: The CFSE fluorescence negative staining may be used for detecting SPIO that phagocytosed by RAW264.7 macrophages and it is showed good consistency that confirmed one another when compared to classic Prussian' blue staining.

DRD1-Pol V-dependent self-silencing of an exogenous silencer restricts the non-cell autonomous silencing of an endogenous target gene.

In plants, the exogenous transgene transcribing inverted-repeat (exo-IR) sequences produces double-stranded RNAs that are processed by DCL4. The 21-nt small interfering RNAs generated function as mobile signals to trigger non-cell autonomous silencing of target endogenes in the neighboring 10-15 cells. The potential involvement of nuclear silencing pathway components in signal spreading or sensing in target cells is not clear. Here, we demonstrate that the exo-IR silencer (exo-Pdsi) is negatively autoregulated through methylation spreading, which acts in cis to reinforce the self-silencing of the silencer. Mutations affecting nuclear proteins DRD1 and Pol V (NRPE1 or NRPD2) relieved exo-Pdsi self-silencing, resulting in higher levels of Pdsi transcripts, which increased the non-cell autonomous silencing of endo-PDS. Our results suggest that in an experimental silencing pathway, methylation spreading on a silencer transgene may not have a direct endogenous plant counterpart when the protein-encoding gene is the target. DRD1-Pol V-dependent de novo methylation, by acting in cis to reinforce self-silencing of exo-IR, may play a role in restraining the inappropriate silencing of active protein-coding genes in plants.

Enhancing therapy of B16F10 melanoma efficacy through tumor vaccine expressing GPI-anchored IL-21 and secreting GM-CSF in mouse model.

In the present study, we developed the tumor vaccine expressing IL-21 in the GPI-anchored form together with secreting GM-CSFs and investigated its antitumor efficacy in C57BL/6 mouse model. The fusion genes containing IL-21 and the GPI anchor signal sequence were acquired by overlaping PCR, inserted into the downstream of two multi-clone sites in recombinant plasmid pRSC/GM-CSFs to form pRSC/IL-21-gpi-GM-CSFs that was transfected into the B16F10 cells. The tumor cell vaccine B16F10/IL-21-gpi-GM-CSFs was identified by reverse transcription PCR, IFA and FCM, respectively. The results showed that the pRSC/IL-21-gpi-GM-CSFs had no cell cycle and proliferative state impact on the B16F10 cells after transfected, and that the tumor vaccine B16F10/IL-21-gpi-GM-CSFs increased the cytotoxicities of NK cells and CD8(+)CTL, enhanced the level of serum IFN-gamma, augmented therapy of tumor effect and prolonged survival time in the tumor-bearing mice immunized with the tumor vaccine B16F10/IL-21-gpi-GM-CSFs. The data that we presented here provided a rationale and practical platform for clinical testing of enhancing cell therapy of B16F10 melanoma efficacy by modified tumor vaccine expressing GPI-anchored IL-21 and secreting GM-CSF.

Antitumor efficacy induced by human ovarian cancer cells secreting IL-21 alone or combination with GM-CSF cytokines in nude mice model.

The ovarian cancer cells (SKOV3) secreting IL-21 alone or combination with GM-CSF cytokines was developed and its antitumor effect was evaluated in the nude mice. The gene of IL-21 was amplified from plasmid pRSC-IL-21 by PCR, cloned into the plasmid pRSC-GM-CSF, and the plasmid pRSC-GM-CSF-IL21 was constructed. The plasmids of pRSC-GM-CSF, pRSC-IL21, pRSC-GM-CSF-IL21 and pRSC were respectively transfected into the SKOV3 cells and antitumor efficacy induced by the SKOV3 cells secreting IL-21 or combination with GM-CSF was evaluated by surveying the tumor growth and the nude mice's survival. The results indicated that the secreted IL-21 and GM-CSF were functional because the culture supernatant of SKOV3 cells transfected with the plasmid pRSC-GM-CSF-IL21 enhanced NK cytotoxicity in vitro. The expressions of MIC A/B, NKG2D and ICAM-1 molecules on the SKOV3 cells were up-regulated. The level of IFN-gamma and TNF-alpha, the NK cytotoxicity and the antitumor efficacy were significantly increased in the null mice inoculated with the SKOV3 cells secreting both IL-21 and GM-CSF in comparison with the nude mice inoculated with the other different SKOV3 cells. We concluded that the SKOV3 cells genetically engineered to secrete biologically active IL-21 and GM-CSF elicited antitumor immunity effectively through enhancing NK cytotoxicity, promoting the expressions of MIC A/B , ICAM-1 and NKG2D molecules as well as elevating level of IFN-gamma and TNF-alpha in the nude mice model.

Characterization of conserved and novel microRNAs and their targets, including a TuMV-induced TIR-NBS-LRR class R gene-derived novel miRNA in Brassica.

Nine conserved miRNA families and three potential novel miRNAs in Brassica rapa were identified from a small RNA library. The expression patterns of some conserved miRNAs had different tissue specificity in Brassica and Arabidopsis. One of the three potential miRNAs, named bra-miR1885, was verified as a true functional miRNA. It could be induced specifically by Turnip mosaic virus (TuMV) infection, and target TIR-NBS-LRR class disease-resistant transcripts for cleavage. Based on the hypothesis for de novo generation of new miRNA genes and the sequence similarity between bra-MIR1885 precursor loci and target transcript sequences, we suggest that bra-MIR1885 is a new miRNA gene that originated through inverted duplication events from TIR-NBS-LRR class disease-resistant protein-coding gene sequences, which became bra-miR1885 targets.