Green tea polyphenol (-)-epigallocatechin-3-gallate prevents N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced dopaminergic neurodegeneration

In the present study we demonstrate neuroprotective property of green tea extract and (-)-epigallocatechin-3-gallate in N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mice model of Parkinson's disease. N-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine neurotoxin caused dopamine neuron loss in substantia nigra concomitant with a depletion in striatal dopamine and tyrosine hydroxylase protein levels. Pretreatment of mice with either green tea extract (0.5 and 1 mg/kg) or (-)-epigallocatechin-3-gallate (2 and 10 mg/kg) prevented these effects. In addition, the neurotoxin caused an elevation in striatal antioxidant enzymes superoxide dismutase (240%) and catalase (165%) activities, both effects being prevented by (-)-epigallocatechin-3-gallate. (-)-Epigallocatechin-3-gallate itself also increased the activities of both enzymes in the brain. The neuroprotective effects are not likely to be caused by inhibition of N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine conversion to its active metabolite 1-methyl-4-phenylpyridinium by monoamine oxidase-B, as both green tea and (-)-epigallocatechin-3-gallate are very poor inhibitors of this enzyme in vitro (770 microg/mL and 660 microM, respectively). Brain penetrating property of polyphenols, as well as their antioxidant and iron-chelating properties may make such compounds an important class of drugs to be developed for treatment of neurodegenerative diseases where oxidative stress has been implicated.     

Molecular phylogeny of fungus gnats (Diptera: Mycetophilidae) revisited: position of Manotinae,Metanepsiini, and other enigmatic taxa as inferred from multigene analysis

The phylogeny of selected genera from four subfamilies of fungus gnats (Diptera: Mycetophilidae) – Manotinae, Leiinae, Sciophilinae and Gnoristinae (including Metanepsiini) – is reconstructed based on the combined analysis of five mitochondrial (12S, 16S, COI, COII, cytB) and two nuclear (28S, ITS2) gene markers. Results of the different analyses all support Manotinae as a monophyletic group, with Leiinae as the sister group. Allactoneura DeMeijere is nested in the monophyletic and strongly supported clade of Leiinae. The tribe Metanepsiini is revealed as paraphyletic and the genera Metanepsia Edwards and Chalastonepsia Søli do not appear to be closely related. The genera Docosia Winnertz, Ectrepesthoneura Enderlein, Novakia Strobl and Syntemna Winnertz were placed with a group of genera included traditionally in the Gnoristinae. The monophyly of Dziedzickia Johannsen and Phthinia Winnertz is not supported. The genera of Sciophilinae (excluding Paratinia Mik but including Eudicrana Loew) form a monophyletic group in the Bayesian model.     

A genomic walking method for screening sequence length polymorphism

We adapted a recently developed nonrestrictional, nonligational genome walking method, Universal Fast Walking (UFW), for detection of length polymorphism in the proximal promoter region of genes. We demonstrate its efficacy at discovering naturally occurring transposition into heat‐shock genes of wild Drosophila and show that it surmounts limitations of simple polymerase chain reaction (PCR) approaches. We further present modifications to the standard UFW protocol and provide some guidelines to improve specificity. Although the resultant banding pattern of a standard UFW can be regarded as a DNA fingerprint, many amplicons result from false priming and not real polymorphisms. We describe ways to distinguish between UFW amplicons and false priming products in a high‐throughput assay.     

Polymorphism of PCR profiles and expression of alleles at the locus <Emphasis Type="Italic">Adh1</Emphasis> in agamospermous progeny of sugar beet <Emphasis Type="Italic">Beta vulgaris</Emphasis> L.

A modification of the ISSR amplification method based on using a combination of microsatellite and specific unique primer is proposed and tested. This modification simplifies the detected PCR profiles and allows the examination of DNA regions containing definite genes. Combinations of microsatellite primer Mic2 (5′-gacag-acaga-cagac-a-3′) and one of the primers specific to the Adh1 locus, which controls alcohol dehydrogenase (ADH1) in sugar beet, were employed in this work. The microsatellite primer was used in combination with the following specific primers: Adh1f (5′-agagt-gttgg-agagg-gtgtg-ac-3′) containing the binding site at the fourth exon of gene Adh1, or Adh1r (5′-act(ct)a-cagca-ag(ct)cc-(ct)ac(ct)g-ctcc-3′) that binds to the fifth exon of the same gene. In the agamospermous progeny of individual heterozygous diploid plants of sugar beet with the Adh1-F/Adh1-S genotype, polymorphism of PCR profiles obtained in plants of each of three phenotypic classes (FF, FS, and SS) was detected. Among plants of the progeny from an individual plant that represents the heterozygous phenotypic class FS, differences were revealed not only between the PCR profiles but also in the relative activity of allele isozymes of ADH1.     

Autosegregation of enzyme loci in agamospermous progenies of triploid plants of sugar beet (Beta vulgaris L.)

The ratios of the phenotypic classes of glucosephosphate isomerase (GP12) and malate dehydrogenase (MDH1 and MDH2) were studied in agamospermous progenies of triploid sugar beet plants. The ratio of the phenotypic classes of these enzymes corresponds to the calculations based on the assumption of polyteny of chromosomes carrying alleles of the enzyme loci accompanied by the loss of extra copies of the alleles in the first division of a cell entering embryogenesis. An increase in the gene dosage due to polyteny leads to the appearance in the progeny with a definite frequency of alleles that were absent in the original parental plant. The notions of meiotic autosegregation and mitotic autosegregation characteristic of meiotic and mitotic agamospermy are introduced, as well as the term locus polygenotype characterizing not only the allelic composition and the number of chromosomes, but also the number of chromatids carrying alleles of the marker locus in the cell before its entry into embryogenesis.     

The composition of the gut microbiota shapes the colon mucus barrier

Two C57BL/6 mice colonies maintained in two rooms of the same specific pathogen-free (SPF) facility were found to have different gut microbiota and a mucus phenotype that was specific for each colony. The thickness and growth of the colon mucus were similar in the two colonies. However, one colony had mucus that was impenetrable to bacteria or beads the size of bacteria—which is comparable to what we observed in free-living wild mice—whereas the other colony had an inner mucus layer penetrable to bacteria and beads. The different properties of the mucus depended on the microbiota, as they were transmissible by transfer of caecal microbiota to germ-free mice. Mice with an impenetrable mucus layer had increased amounts of Erysipelotrichi, whereas mice with a penetrable mucus layer had higher levels of Proteobacteria and TM7 bacteria in the distal colon mucus. Thus, our study shows that bacteria and their community structure affect mucus barrier properties in ways that can have implications for health and disease. It also highlights that genetically identical animals housed in the same facility can have rather distinct microbiotas and barrier structures.     

Expression of the enzyme-encoding genes under the influence of colchicine and triton X-100 in nongerminating seeds of sugarbeet (<Emphasis Type="Italic">Beta vulgaris</Emphasis> L.)

The expression of the enzyme-coding genes, controlling glucose-phosphate isomerase (GPI), malate dehydrogenase (MDH), and alcohol dehydrogenase (ADH), was examined in nongerminating seeds of sugarbeet after Triton X-100 (TX-100) and colchicine treatment. Two types of changes revealed included modification of the enzymatic loci expression (change of the isozyme electrophoretic mobility) and inactivation of standard profiles. In the MDH and GPI systems, these processes were found to be associated. Complete isozyme modification was accompanied with the disappearance of standard profiles. In the ADH system, the treatment with TX-100 and colchicine gave rise to two independent processes, including silencing of the Adh1 locus and the appearance of the ADH isozymes with abnormal electrophoretic mobility, which were probably the products of the Adh2 locus. It was suggested that the effect of TX-100 and colchicine on the expression of the enzyme-encoding genes examined depended on the intracellular localization of the encoded enzymes.