Habitat degradation impacts black howler monkey (Alouatta pigra) gastrointestinal microbiomes

The gastrointestinal (GI) microbiome contributes significantly to host nutrition and health. However, relationships involving GI microbes, their hosts and host macrohabitats remain to be established. Here, we define clear patterns of variation in the GI microbiomes of six groups of Mexican black howler monkeys (Alouatta pigra) occupying a gradation of habitats including a continuous evergreen rainforest, an evergreen rainforest fragment, a continuous semi-deciduous forest and captivity. High throughput microbial 16S ribosomal RNA gene sequencing indicated that diversity, richness and composition of howler GI microbiomes varied with host habitat in relation to diet. Howlers occupying suboptimal habitats consumed less diverse diets and correspondingly had less diverse gut microbiomes. Quantitative real-time PCR also revealed a reduction in the number of genes related to butyrate production and hydrogen metabolism in the microbiomes of howlers occupying suboptimal habitats, which may impact host health.     

Inhibition of eukaryotic cell-free protein synthesis by thionins from wheat endosperm

Thionins are polypeptide toxins of about 5000 molecular weight, present in the endosperms of many Gramineae, which modify membrane permeability and inhibit macromolecular synthesis in cultured mammalian cells. Evidence is presented that they inhibit in vitro protein synthesis at micromolar concentrations in cell-free systems derived from wheat germ or from rabbit reticulocytes. Inhibition seems to occur by direct binding of mRNA by the toxin, as judged by the ability of thionins to mediate retention of RNA in nitrocellulose filters and by the dependence of inhibitory concentrations on the amount of exogenous RNA added to the wheat-germ translation system. Commercial preparations of wheat-germ have been found to include some endosperm contamination (up to 15%), which may result in at least partially inhibitory concentrations of the toxin in the cell-free extracts.     

Signal peptide homology between the sweet protein thaumatin II and unrelated cereal alpha-amylase/trypsin inhibitors

A cDNA clone (pUP-23) corresponding to a member of a protein family that includes inhibitors of trypsin and of heterologous alpha-amylases has been selected from a library derived from developing barley endosperm and its sequence has been determined. A stretch of 95 nucleotides that included the signal peptide and the first 8 residues of the mature protein was found to be homologous to an exactly equivalent region of the nucleotide sequence encoding the sweet protein thaumatin II. Evolutionary implications of this finding are discussed.     

A major barley allergen associated with baker's asthma disease is a glycosylated monomeric inhibitor of insect α-amylase: cDNA cloning and chromosomal location of the gene

A 14.5 kDa barley endosperm protein that is a major allergen in baker's asthma disease, as previously shown by both in vitro (IgE binding) and in vivo tests, has been identified as a glycosylated monomeric member of the multigene family of inhibitors of -amylase/trypsin from cereals. A cDNA encoding this allergen (renamed BMAI-1) has been isolated and characterized. The deduced sequence for the mature protein, which is 132 residues long, is identical in its N-terminal end to the 20 amino acid partial sequence previously determined from the purified allergen, and fully confirms that it is a member of the multigene family of cereal inhibitors. Southern-blot analysis of wheat/barley addition lines using the insert in the BMAI-1 cDNA clone as a probe, has led to the location of the allergen gene (Iam1) in barley chromosome 2, while another related member of this protein family, the barley dimeric -amylase inhibitor BDAI-1 gene (Iad1) has been located in chromosome 6. Iam1 is the first member of this inhibitor family in cereals to be assigned to chromosome group 2, thus extending the dispersion of genes in the family to five out of the seven homology groups of chromosomes in wheat and barley (chromosome 2, 3, 4, 6 and 7).     

The promoter of barley trypsin-inhibitor BTI-CMe,discriminates between wheat and barley endosperm protoplasts in transient expression assays

Several promoter fragments from the barley gene coding for trypsin inhibitor, BTI-CMe, have been fused to the -glucuronidase (GUS) reporter gene and these chimeric constructs used for transient expression in protoplasts. Transfection of developing endosperm protoplasts from barley (cv Bomi) show a maximum GUS expression of about 50% of that driven by the cauliflower mosaic virus 35S promoter, while in wheat endosperm protoplasts expression is less than 10%. No significant expression is found in transfected leaf protoplasts from barley, wheat or tobacco (<2% of the 35S control). All the information required for endosperm and barley specificity is present in the 343 bp proximal to the translation initiation site.Abbreviations MS Murashige and Skoog medium - PEG polyethyleneglycol - GUS -glucuronidase - MU methylumbelliferone - MUG 4-methylumbelliferyl--D glucuronide - pp protoplasts     

Inhibitory effects of some esters of 2- and 3-substituted alkoxyphenylcarbamic acids on photosynthetic characteristics

The inhibitory effect of 23N-alkyl-4-piperidylesters (alkyl = ethyl-butyl) (APEA) and 8N-ethyl-2-pyrrolidinylmethylesters (EPMEA) of 2- and 3-substituted alkoxyphenylcarbamic acids (alkoxy = butoxy-heptyloxy-) on photosynthetic Hill reaction activity of spinach chloroplasts and on chlorophyll (Chl) synthesis in green algaeChlorella vulgaris was investigated. Inhibitory activities of these compounds were strongly connected with the lipophilicity of the whole molecule. A lower inhibitory activity of 2-alkoxy-substituted derivatives in relation to the corresponding 3-substituted ones was confirmed. Electron spin resonance (ESR) spectra of spinach chloroplasts demonstrated that the studied compounds affected the structure of photosystem (PS) 2 with the release of Mn²⁺ ions into interior of thylakoid membranes.     

Transgenic Expression of Trypsin Inhibitor CMe from Barley in Indica and Japonica Rice,Confers Resistance to the Rice Weevil Sitophilus Oryzae

Indica and japonica rice (Oryza sativa L.) plants were transformed by particle bombardment with the Itr1 gene encoding the barley trypsin inhibitor BTI-CMe, under the control of its own promoter that confers endosperm specificity, and the maize ubiquitin promoter. From 38 independent transgenic lines of indica (breeding line IR58) and 15 of the japonica (cv Senia) selected, 22 and 11, respectively, expressed the barley inhibitor at detectable levels. The transgene was correctly translated as indicated by western blot analysis with a level of expression in R₃ seeds up to 0.31% (IR58) and 0.43% (Senia) of the total extracted protein. The functional integrity of BTI-CMe was confirmed by trypsin activity assays in liquid media and by activity staining gels, performed with seed extracts. The significant reduction of the survival rate of the rice weevil (Sitophilus oryzae, Coleoptera: Curculionidae) reared on homozygous transgenic indica and japonica rice seeds expressing the BTI-CMe, compared to non-transformed controls, and the decrease in the trypsin-like activity of insect crude midgut extracts, confirmed the utility of this proteinase inhibitor gene for the control of important storage pests.