Stem cells are highly resistant to viral infection compared to their differentiated progeny; however, the mechanism is mysterious. Here, we analyzed gene expression in mammalian stem cells and cells at various stages of differentiation. We find that, conserved across species, stem cells express a subset of genes previously classified as interferon (IFN) stimulated genes (ISGs) but that expression is intrinsic, as stem cells are refractory to interferon. This intrinsic ISG expression varies in a cell-type-specific manner, and many ISGs decrease upon differentiation, at which time cells become IFN responsive, allowing induction of a broad spectrum of ISGs by IFN signaling. Importantly, we show that intrinsically expressed ISGs protect stem cells against viral infection. We demonstrate the in vivo importance of intrinsic ISG expression for protecting stem cells and their differentiation potential during viral infection. These findings have intriguing implications for understanding stem cell biology and the evolution of pathogen resistance.

Alternaria alternata produces more than 60 secondary metabolites, among which alternariol (AOH) and alternariol-9-methyl ether (AME) are important mycotoxins. Whereas the toxicology of these two polyketide-based compounds has been studied, nothing is known about the genetics of their biosynthesis. One of the postulated core enzymes in the biosynthesis of AOH and AME is polyketide synthase (PKS). In a draft genome sequence of A. alternata we identified 10 putative PKS-encoding genes. The timing of the expression of two PKS genes, pksJ and pksH , correlated with the production of AOH and AME. The PksJ and PksH proteins are predicted to be 2222 and 2821 amino acids in length, respectively. They are both iterative type I reducing polyketide synthases. PksJ harbors a peroxisomal targeting sequence at the C-terminus, suggesting that the biosynthesis occurs at least partly in these organelles. In the vicinity of pksJ we found a transcriptional regulator, altR , involved in pksJ induction and a putative methyl transferase, possibly responsible for AME formation. Downregulation of pksJ and altR caused a large decrease of alternariol formation, suggesting that PksJ is the polyketide synthase required for the postulated Claisen condensations during the biosynthesis. No other enzymes appeared to be required. PksH downregulation affected pksJ expression and thus caused an indirect effect on AOH production.

Induction of vast transcriptional programs is a central event of innate host responses to viral infections. Here we report a transcriptional program with potent antiviral activity, driven by E74-like ETS transcription factor 1 (ELF1). Using microscopy to quantify viral infection over time, we found that ELF1 inhibits eight diverse RNA and DNA viruses after multi-cycle replication. Elf1 deficiency results in enhanced susceptibility to influenza A virus infections in mice. ELF1 does not feed-forward to induce interferons, and ELF1’s antiviral effect is not abolished by the absence of STAT1 or by inhibition of JAK phosphorylation. Accordingly, comparative expression analyses by RNA-seq revealed that the ELF1 transcriptional program is distinct from interferon signatures. Thus, ELF1 provides an additional layer of the innate host response, independent from the action of type I interferons.

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Aim:The present study was carried out to compare the associated role of micro minerals and hormones in repeat breeding animals with the normal crossbred cows.Materials and Methods:Blood samples were collected from 10 normal cycling and 10 repeat breeding crossbred cows of Ramakrishna Mission Ashram, Narendrapur to study the plasma mineral profile and hormonal activities.Results:Zn was found to be highly significant (p<0.01) between the two groups. Follicle stimulating hormone (FSH) and progesterone showed significant (p<0.05) difference in repeat breeding animal from the normal cyclic animal, whereas no significant differences were observed in Ca, P, Cu, Se, Co, luteinizing hormone and estradiol level.Conclusion:It may conclude that repeat breeding condition of crossbred cows in farm condition is mainly due to the low level of progesterone, FSH and zinc.

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An improved analytical device capable of performing simultaneous immunofiltration-based immunoassay on 30 samples in the presence of reference standards has been developed. The device consists of a rectangular membrane with 36 antibody spotted zones, one end of which was attached to a semirigid polyethylene card. A piece of wetted filter paper between the membrane and the polyethylene card absorbs the added reagent. The assay is a competitive one using T-2 toxin-horseradish peroxidase (T-2 toxin-HRP) as the labeled analyte and 4-chloro-1 naphthol (4CN) as the substrate. Signal amplification was done by the Super-CARD signal amplification method. Semiquantitative results were obtained by visual comparison of the color intensity of a sample spot with those of reference standards. Densitometric analysis was used for quantitation. The method allows rapid and easy determination of T-2 toxin in wheat and poultry feed with detection limits of 12.5 and 25 microg x kg(-)(1), respectively, with accuracy and precision. Matrix interference was eliminated by appropriate dilution of sample extracts with assay buffer. The detection sensitivity in ELISA was 10-fold higher than that in the membrane-based method. Noninfected samples were spiked with T-2 toxin at several concentrations and analyzed by the present method and rapid ELISA. Mean recoveries by both methods were between 80 and 108%. The correlation between the two methods was excellent (R(2) = 0.99).

A strategy for rapid in situ elimination of interfering substances that are present in extracts of food samples during assay is described in this article. The novel feature of this method is that the sample purification is carried out as a part of the assay, and a separate sample cleanup step is not required. The assay procedure involves the sequential addition of standard or sample, cleaning solutions, and aflatoxin B1-horseradish peroxidase conjugate (AFB1-HRP) over antibody-spotted zones of a membrane, and 3,3'-diaminobenzidine was used as the substrate for visualization. We have determined that trifluoroacetic acid and propionic acids at concentrations of 100 mM are highly effective for cleaning groundnut, wheat, corn, and poultry feed samples and that NaHCO3 (100 mM) is successful in cleaning processed soybean. In all cases, subsequent washing was performed with phosphate-buffered saline solution to facilitate the removal of traces of adhering interfering substances. A batch of 12 samples can be analyzed within 8 min either by visual comparison of the color intensity (inversely related to the analyte concentration) of a sample spot with those of reference standards or, more precisely, by densitometry. The method was tested for the analysis of AFB1 in groundnut, wheat, corn, processed soybean, chili, and poultry feed. The detection limit obtained was 5 microg/kg, except for chili, where it was 10 microg/kg. The average recoveries from different noninfected food samples spiked with AFB1 at concentrations of 5 to 100 microg/kg were between 99 and 105%. The values obtained for infected corn and groundnut samples correlated well with the estimates obtained by high-pressure liquid chromatography. The absence of a sample extraction step reduces the cost and labor involved in the assay. The method may be potentially applicable to the assay of other mycotoxins and environmental pollutants.