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It has become increasingly clear that gut bacteria play vital roles in the development, nutrition, immunity, and overall fitness of their eukaryotic hosts. We conducted the present study to investigate the effects of gut microbiota disruption on the honey bee's immune responses to infection by the microsporidian parasite Nosema ceranae. Newly emerged adult workers were collected and divided into four groups: Group I-no treatment; Group II-inoculated with N. ceranae, Group III-antibiotic treatment, and Group IV-antibiotic treatment after inoculation with N. ceranae. Our study showed that Nosema infection did not cause obvious disruption of the gut bacterial community as there was no significant difference in the density and composition of gut bacteria between Group I and Group II. However, the elimination of gut bacteria by antibiotic (Groups III and IV) negatively impacted the functioning of the honey bees' immune system as evidenced by the expression of genes encoding antimicrobial peptides abaecin, defensin1, and hymenoptaecin that showed the following ranking: Group I > Group II > Group III > Group IV. In addition, significantly higher Nosema levels were observed in Group IV than in Group II, suggesting that eliminating gut bacteria weakened immune function and made honey bees more susceptible to Nosema infection. Based on Group IV having displayed the highest mortality rate among the four experimental groups indicates that antibiotic treatment in combination with stress, associated with Nosema infection, significantly and negatively impacts honey bee survival. The present study adds new evidence that antibiotic treatment not only leads to the complex problem of antibiotic resistance but can impact honey bee disease resistance. Further studies aimed at specific components of the gut bacterial community will provide new insights into the roles of specific bacteria and possibly new approaches to improving bee health.

Long QT syndromes (LQTS) are heritable diseases characterized by prolongation of the QT interval on an electrocardiogram, which often leads to syncope and sudden cardiac death. Here we report the generation of induced pluripotent stems (iPS) cells from two patients with LQTS type 3 carrying a different point mutation in a sodium channel Nav1.5 (p.V240M and p.R535Q) and functional characterization of cardiomyocytes (CM) derived from them. The iPS cells exhibited all characteristic properties of pluripotent stem cells, maintained the disease-specific mutation and readily differentiated to CM. The duration of action potentials at 50% and 90% repolarization was longer in LQTS-3 CM as compared to control CM but this difference did not reach statistical significance due to high variations among cells. Sodium current recordings demonstrated longer time to peak and longer time to 90% of inactivation of the Na(+) channel in the LQTS-3 CM. This hints at a defective Na(+) channel caused by deficiency in open-state inactivation of the Na(+) channel that is characteristic of LQTS-3. These analyses suggest that the effect of channel mutation in the diseased CM is demonstrated in vitro and that the iPS cell-derived CM can serve as a model system for studying the pathophysiology of LQTS-3, toxicity testing and design of novel therapeutics. However, further improvements in the model are still required to reduce cell-to-cell and cell line-to-cell line variability.

The incidence of nonalcoholic fatty liver disease (NAFLD) in postmenopausal women has increased significantly. Estrogen plays a very important role in NAFLD, but whether NAFLD in premenopausal women was caused by estrogen deficiency was unknown. Thus, it is of great clinical significance to explore the mechanism of NAFLD in premenopausal women. Gut microbiota and its metabolites short chain fatty acids (SCFA) have been shown to play important roles in the development of NAFLD. In this study, we investigated the impact of gut microbiota and SCFA in NAFLD patients and mice caused by estrogen deficiency. We showed that premenopause NAFLD patients had much lower estrogen levels. Estrogen deficient mice, due to ovariectomy (OVX), suffered more severe liver steatosis with an elevated body weight, abdominal fat weight, serum triglycerides and deterioration in hepatic steatosis. Altered gut microbiota composition and decreased butyrate content were found in NAFLD patients and in OVX mice. Furthermore, fecal microbiota transplantation (FMT) or supplementing with butyrate alleviated NAFLD in OVX mice. The production of antimicrobial peptides (AMP) Reg3ɣ, β-defensins and the expression of intestinal epithelial tight junction, including ZO-1 and Occluding-5, were decreased in the OVX mice compared to control mice. Upregulation of PPAR-ɣ and VLDLR, downregulation of PPAR-ɑ indicated that OVX mice suffered from abnormal lipid metabolism. These data indicate that changes in the gut microbiota and SCFA caused by estrogen reduction, together with a disorder in AMP production and lipid metabolism, promote NAFLD, thus provide SCFAs derived from microbiota as new therapeutic targets for the clinical prevention and treatment of NAFLD., Competing Interests: The authors have declared that no competing interests exist.

Cyanobacterial blooms are a worldwide environmental problem and frequently occur in eutrophic lakes. Organophosphorus mineralization regulated by microbial alkaline phosphatase provides available nutrients for bloom regeneration. To uncover the dynamics of bacterial alkaline phosphatase activity and microbial backgrounds in relation to organophosphorus mineralization during the decomposition process of cyanobacterial blooms, the response of alkaline phosphatase PhoX-producing bacteria were explored using a 23-day mesocosm experiment with three varying densities of Microcystis biomass from eutrophic Lake Taihu. Our study found large amounts of soluble reactive phosphorus and dissolved organophosphorus were released into the lake water during the decomposition process. Bacterial alkaline phosphatase activity showed the peak values during days 5~7 in groups with different chlorophyll-a densities, and then all decreased dramatically to their initial experimental levels during the last stage of decomposition. Bacterial phoX abundances in the three experimental groups increased significantly along with the decomposition process, positively related to the dissolved organic carbon and organophosphorus released by the Microcystis blooms. The genotypes similar to the phoX genes of Alphaproteobacteria were dominant in all groups, whereas the genotypes most similar to the phoX genes of Betaproteobacteria and Cyanobacteria were also abundant in the low density (~15 μg L-1 chlorophyll-a) group. At the end of the decomposition process, the number of genotypes most similar to the phoX of Betaproteobacteria and Cyanobacteria increased in the medium (~150 μg L-1 chlorophyll-a) and high (~1500 μg L-1 chlorophyll-a) density groups. The released organophosphorus and increased bacterial phoX abundance after decomposition of Microcystis aggregates could potentially provide sufficient nutrients and biological conditions for algal proliferation and are probably related to the regeneration of Microcystis blooms in eutrophic lakes.

Recombinant protein therapeutics have become important components of the modern medicine. Majority of them are produced with mammalian cells that are cultured either through adherent culturing, in which cells are cultured on substrates, or suspension culturing, in which cells are suspended and cultured in agitated cell culture medium in a culture vessel. The adherent cell culturing method is limited by its low yield. In suspension culturing, cells need extensive genetic manipulation to grow as single cells at high density, which is time- and labor-consuming. Here, we report a new method, which utilizes a thermoreversible hydrogel as the scaffold for culturing protein-expressing cells. The hydrogel scaffolds not only provide 3D spaces for the cells, but also act as physical barriers to prevent excessive cellular agglomeration and protect cells from the hydrodynamic stresses. As a result, cells can grow at high viability, high growth rate, and extremely high yield even without genetic manipulations. The cell yield in the hydrogels is around 20 times of the suspension culturing. In addition, the protein productivity per cell per day in the hydrogel is higher than the adherent culturing method. This new method is simple, scalable and defined. It will be of great value for both the research laboratories and pharmaceutical industry for producing proteins.

Recent advances demonstrate that epigenome changes can also cause phenotypic diversity and can be heritable across generations, indicating that they may play an important role in evolutionary processes. In this study, we analyzed the chromosomal distribution of several histone modifications in five elite maize cultivars (B73, Mo17, Chang7-2, Zheng58, ZD958) and their two wild relatives (Zea mays L. ssp. parviglumis and Zea nicaraguensis) using a three-dimensional (3D) epigenome karyotyping approach by combining immunostaining and 3D reconstruction with deconvolution techniques. The distribution of these histone modifications along chromosomes demonstrated that the histone modification patterns are conserved at the chromosomal level and have not changed significantly following domestication. The comparison of histone modification patterns between metaphase chromosomes and interphase nuclei showed that some of the histone modifications were retained as the cell progressed from interphase into metaphase, although remodelling existed. This study will increase comprehension of the function of epigenetic modifications in the structure and evolution of the maize genome.

Aptamers are short RNA or DNA oligonucleotides which can bind with different targets. Typically, they are selected from a large number of random DNA sequence libraries. The main strategy to obtain aptamers is systematic evolution of ligands by exponential enrichment (SELEX). Low efficiency is one of the limitations for conventional PCR amplification of random DNA sequence library in aptamer selection because of relative low products and high by-products formation efficiency. Here, we developed emulsion PCR for aptamer selection. With this method, the by-products formation decreased tremendously to an undetectable level, while the products formation increased significantly. Our results indicated that by-products in conventional PCR amplification were from primer-product and product-product hybridization. In emulsion PCR, we can completely avoid the product-product hybridization and avoid the most of primer-product hybridization if the conditions were optimized. In addition, it also showed that the molecule ratio of template to compartment was crucial to by-product formation efficiency in emulsion PCR amplification. Furthermore, the concentration of the Taq DNA polymerase in the emulsion PCR mixture had a significant impact on product formation efficiency. So, the results of our study indicated that emulsion PCR could improve the efficiency of SELEX.