Virologica Sinica - Influenza is one of the major respiratory diseases in humans. Macau is a tourist city with high density of population and special population mobility. The study on the... 相似文献
Sweetness is one of the key factors determining peach fruit quality. To better understand the molecular basis of gibberellic acid (GA) and 1-naphthaleneacetic acid (NAA) interference with sugar biosynthesis, a middle-late maturing commercial cultivar, ‘Jinxiu’ yellow peach fruit, was treated with three different concentrations of GA4+7 and four of NAA. Fruit weight, firmness, total soluble solids, different sugar contents and the expression level of sugar-related genes were evaluated. The results showed that maximum increase in cv. ‘Jinxiu’ peach fruit size and sucrose content was with 1.25 mM GA4+7, compared to control fruits and the other treatments during the ripening stages. The sucrose-phosphate synthase gene (PpSPS2) which had a high level of expression and positive correlation with sucrose content was significantly regulated by 1.25 mM GA4+7 in the final ripening stages. 0.5 mM NAA treatments significantly reduced the sucrose content and fruit size. Ninety percent of the fruits were deformed or dropped from the trees with treatments of 1 mM NAA and 2 mM NAA in the early development period. The crosstalk of different phytohormones and the related genes will be further investigated to get an insight into the inherent association between hormone control and sugar accumulation.
Joint analysis of microbiome and metabolomic data represents an imperative objective as the field moves beyond basic microbiome association studies and turns towards mechanistic and translational investigations. We present a censored Gaussian graphical model framework, where the metabolomic data are treated as continuous and the microbiome data as censored at zero, to identify direct interactions (defined as conditional dependence relationships) between microbial species and metabolites. Simulated examples show that our method metaMint performs favorably compared to the existing ones. metaMint also provides interpretable microbe-metabolite interactions when applied to a bacterial vaginosis data set. R implementation of metaMint is available on GitHub.
The development of clustered regularly interspaced palindromic repeats (CRISPR)-associated protein (Cas) variants with a broader recognition scope is critical for further improvement of CRISPR/Cas systems. The original Cas9 protein from Streptococcus canis (ScCas9) can recognize simple NNG-protospacer adjacent motif (PAM) targets, and therefore possesses a broader range relative to current CRISPR/Cas systems, but its editing efficiency is low in plants. Evolved ScCas9+ and ScCas9++ variants have been shown to possess higher editing efficiencies in human cells, but their activities in plants are currently unknown. Here, we utilized codon-optimized ScCas9, ScCas9+ and ScCas9++ and a nickase variant ScCas9n++ to systematically investigate genome cleavage activity and cytidine base editing efficiency in rice (Oryza sativa L.). This analysis revealed that ScCas9++ has higher editing efficiency than ScCas9 and ScCas9+ in rice. Furthermore, we fused the evolved cytidine deaminase PmCDA1 with ScCas9n++ to generate a new evoBE4max-type cytidine base editor, termed PevoCDA1-ScCas9n++. This base editor achieved stable and efficient multiplex-site base editing at NNG-PAM sites with wider editing windows (C−1–C17) and without target sequence context preference. Multiplex-site base editing of the rice genes OsWx (three targets) and OsEui1 (two targets) achieved simultaneous editing and produced new rice germplasm. Taken together, these results demonstrate that ScCas9++ represents a crucial new tool for improving plant editing. 相似文献
Four new nanaomycins ( 1 – 4 ), together with two known compounds, nanaomycin αA ( 5 ) and nanaomycin βA ( 6 ) were isolated from a fermentation broth of Streptomyces hebeiensis derived from lichen. The structures of the new nanaomycins 1 – 4 were established using comprehensive NMR spectroscopic data analysis as well as UV, IR, and MS data. The antimicrobial activities of 1 – 6 were evaluated against Gram‐positive bacteria and fungus. Compounds 5 and 6 showed antimicrobial activities against the test microorganisms, while 1 – 4 were inactive at 100 μg/ml. 相似文献
Masting is defined as the intermittent highly variable production of seed in a plant population. According to reproductive modes, that is, sexual and asexual reproduction, masting species can be separated into three groups, that is, (1) species, for example, bamboo, flower only once before they die; (2) species, for example, Fagus, reproduce sexually; and (3) species, for example, Stipa tenacissima, reproduce both sexually and asexually. Several theories have been proposed to explore the underlying mechanisms of masting. However, to our knowledge, no theory has been found to explain the mechanism of masting species that reproduce both sexually and asexually. Here we refine the Resource Budget Model by considering a trade‐off between sexual and asexual reproduction. Besides the depletion efficient (i.e., the ratio of the cost of seed setting and the cost of flowering), other factors, such as the annual remaining resource (i.e., the rest of the resource from the photosynthetic activity after allocating to growth and maintenance), the trade‐off between sexual and asexual reproduction, and the reproductive thresholds, also affect masting. Moreover, two potential reproductive strategies are found to explain the mechanisms: (1) When the annual remaining resource is relatively low, plants reproduce asexually and a part of the resource is accumulated as the cost of asexual reproduction is less than the annual remaining resource. Plants flower and set fruits once the accumulated resource exceeds the threshold of sexual reproduction; (2) when the annual remaining resource is relatively high, and the accumulated resource surpasses the threshold of sexual reproduction, masting occurs. Remarkably, under certain depletion efficient, more investigation in sexual reproduction will lead plants to reproduce periodically. Additionally, plants investigate less resource to reproduce periodically when depletion efficient keeps increasing as plants can reproduce efficiently. Overall, our study provides new insights into the interpretation of masting, especially for species that reproduce both sexually and asexually. 相似文献
Although recent evidence has shown that hepatocyte senescence plays a crucial role in the pathogenesis and development of non-alcoholic fatty liver disease (NAFLD), the mechanism is still not clear. The purpose of this study was to investigate the signal transduction pathways involved in the senescence of hepatocyte, in order to provide a potential strategy for blocking the process of NAFLD. The results confirmed that hepatocyte senescence occurred in HFD-fed Golden hamsters and PA-treated LO2 cells as manifested by increased levels of senescence marker SA-β-gal, p16 and p21, heterochromatin marker H3K9me3, DNA damage marker γ-H2AX and decreased activity of telomerase. Further studies demonstrated that iron overload could promote the senescence of hepatocyte, whereas the overexpression of Yes-associated protein (YAP) could blunt iron overload and alleviate the senescence of hepatocyte. Of importance, depression of lncRNA MAYA (MAYA) reduced iron overload and cellular senescence via promotion of YAP in PA-treated hepatocytes. These effects were further supported by in vivo experiments. In conclusion, these data suggested that inhibition of MAYA could up-regulate YAP, which might repress hepatocyte senescence through modulating iron overload. In addition, these findings provided a promising option for heading off the development of NAFLD by abrogating hepatocyte senescence. 相似文献