31 research outputs found

    Functional characterization of barley betaglucanless mutants demonstrates a unique role for CslF6 in (1,3;1,4)-β-D-glucan biosynthesis

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    (1,3;1,4)-β-D-glucans (mixed-linkage glucans) are found in tissues of members of the Poaceae (grasses), and are particularly high in barley (Hordeum vulgare) grains. The present study describes the isolation of three independent (1,3;1,4)-β-D-glucanless (betaglucanless; bgl) mutants of barley which completely lack (1,3;1,4)-β-D-glucan in all the tissues tested. The bgl phenotype cosegregates with the cellulose synthase like HvCslF6 gene on chromosome arm 7HL. Each of the bgl mutants has a single nucleotide substitution in the coding region of the HvCslF6 gene resulting in a change of a highly conserved amino acid residue of the HvCslF6 protein. Microsomal membranes isolated from developing endosperm of the bgl mutants lack detectable (1,3;1,4)-β-D-glucan synthase activity indicating that the HvCslF6 protein is inactive. This was confirmed by transient expression of the HvCslF6 cDNAs in Nicotiana benthamiana leaves. The wild-type HvCslF6 gene directed the synthesis of high levels of (1,3;1,4)-β-D-glucans, whereas the mutant HvCslF6 proteins completely lack the ability to synthesize (1,3;1,4)-β-D-glucans. The fine structure of the (1,3;1,4)-β-D-glucan produced in the tobacco leaf was also very different from that found in cereals having an extremely low DP3/DP4 ratio. These results demonstrate that, among the seven CslF and one CslH genes present in the barley genome, HvCslF6 has a unique role and is the key determinant controlling the biosynthesis of (1,3;1,4)-β-D-glucans. Natural allelic variation in the HvCslF6 gene was found predominantly within introns among 29 barley accessions studied. Genetic manipulation of the HvCslF6 gene could enable control of (1,3;1,4)-β-D-glucans in accordance with the purposes of use

    May Salivary Alpha-Amylase Level Be a Useful Tool for Assessment of the Severity of Schizophrenia and Evaluation of Therapy? A Case Report

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    Background. Previous studies suggested dysfunction of the autonomic nervous system (ANS) in schizophrenia patients, but the mechanism remains unclear. Recently, the measurement of salivary alpha-amylase (sAA) has been considered a useful tool for evaluating ANS, especially the sympathoadrenal medullary system. Furthermore, there was a report that patients with schizophrenia showed much higher sAA level than normal controls. Methods. We present the case of a 51-year-old female with catatonic schizophrenia. She needed the treatment of electroconvulsive therapy (ECT). We evaluated her sAA level and her psychiatric symptoms during the treatment. Results. Before ECT treatment, she showed high sAA level. Her sAA level decreased during the course of ECT, and this attenuation was accompanied by improvement of schizophrenic symptoms. Conclusion. We consider that measurement of the sAA level may be one of the useful biological markers for assessment of psychotic state and efficacy of treatment in patients with schizophrenia

    The active miniature inverted-repeat transposable element mPing posttranscriptionally produces new transcriptional variants in the rice genome

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    Posttranscriptional RNA processing inclusive of alternative splicing and alternative polyadenylation, as well as transcriptional regulation, plays important regulatory roles in eukaryotic gene expression. In eukaryotic genomes, transposable elements can alter gene expression at both transcriptional and posttranscriptional levels. Miniature Ping (mPing) is an active miniature inverted-repeat TE discovered in the rice genome, and its insertion renders adjacent genes stress inducible. In this study, we examined the effect of mPing insertion into coding sequences on RNA processing. The 3′ RACE (rapid amplification of cDNA ends) analysis of mutant alleles, each harboring an mPing insertion, revealed that mPing induced various alternative splicing events. Furthermore, it was found that mPing induced alternative polyadenylation within its sequence. In the mutant allele, the body region of mPing was heavily methylated, whereas the mPing-flanking regions were moderately methylated. These results indicate that mPing alters transcript structures posttranscriptionally via induction of alternative splicing that most likely depends on DNA methylation. Based on these results, we discuss the availability of mPing as an insertional mutagen in rice

    Serpentines as a capsule of the deep subsurface biosphere: Evidence from the Chamorro Seamount, Mariana forearc

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    Fibrogenesis and Carcinogenesis in Nonalcoholic Steatohepatitis (NASH): Involvement of Matrix Metalloproteinases (MMPs) and Tissue Inhibitors of Metalloproteinase (TIMPs)

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    Nonalcoholic steatohepatitis (NASH) is emerging worldwide because life-styles have changed to include much over-eating and less physical activity. The clinical and pathophysiological features of NASH are very different from those of HBV- and HCV-chronic liver diseases. The prognosis of NASH is worse among those with nonalcoholic fatty liver diseases (NAFLD), and some NASH patients show HCC with or without cirrhosis. In the present review we discuss fibrogenesis and the relationship between fibrosis and HCC occurrence in NASH to clarify the role of MMPs and TIMPs in both mechanisms. Previously we proposed MMP and TIMP expression in the multi-step occurrence of HCC from the literature based on viral-derived HCC. We introduce again these expressions during hepatocarcinogenesis and compare them to those in NASH-derived HCC, although the relationship with hepatic stem/progenitor cells (HPCs) invasion remains unknown. Signal transduction of MMPs and TIMPs is also discussed because it is valuable for the prevention and treatment of NASH and NASH-derived HCC
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