Current progress in DNA barcoding and future implications for entomology

DNA barcoding is a technique for identifying organisms based on a short, standardized fragment of genomic DNA. The standardized sequence region is called a DNA barcode because it is like a barcode tag for each taxon. Since the proposition of this concept and the launch of a large project named the Barcode of Life, this simple technique has attracted attention from taxonomists, ecologists, conservation biologists, agriculturists, plant‐quarantine officers and others, and the number of studies using the DNA barcode has rapidly increased. The extreme diversity of insects and their economical, epidemiological and agricultural importance have made this group a major target of DNA barcoding. However, there is some controversy about the utility of DNA barcoding. In this review, we present an overview of DNA barcoding and its application to entomology. We also introduce current advances and future implications of this promising technique.     

l-Lysine production in continuous culture of an l-lysine hyperproducing mutant of Corynebacterium glutamicum

Summary l-Lysine production was studied in and volumetric productivity were 105 g/l and 5.6 g/l per hour, respectively. The latter corresponded to a 2.5-fold higher value than that of a fed-batch culture. Higher agitation or use of oxygen-enriched air was critical for high productivity. This indicates that oxygen supply greatly affects l-lysine productivity in continuous culture.     

Inhibition of repulsive guidance molecule-a protects dopaminergic neurons in a mouse model of Parkinson’s disease

Repulsive guidance molecule-a (RGMa), a glycosylphosphatidylinositol-anchored membrane protein, has diverse functions in axon guidance, cell patterning, and cell survival. Inhibition of RGMa attenuates pathological dysfunction in animal models of central nervous system (CNS) diseases including spinal cord injury, multiple sclerosis, and neuromyelitis optica. Here, we examined whether antibody-based inhibition of RGMa had therapeutic effects in a mouse model of Parkinson’s disease (PD). We treated mice with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and found increased RGMa expression in the substantia nigra (SN). Intraventricular, as well as intravenous, administration of anti-RGMa antibodies reduced the loss of tyrosine hydroxylase (TH)-positive neurons and accumulation of Iba1-positive microglia/macrophages in the SN of MPTP-treated mice. Selective expression of RGMa in TH-positive neurons in the SN-induced neuronal loss/degeneration and inflammation, resulting in a progressive movement disorder. The pathogenic effects of RGMa overexpression were attenuated by treatment with minocycline, which inhibits microglia and macrophage activation. Increased RGMa expression upregulated pro-inflammatory cytokine expression in microglia. Our observations suggest that the upregulation of RGMa is associated with the PD pathology; furthermore, inhibitory RGMa antibodies are a potential therapeutic option.Subject terms: Cell death in the nervous system, Parkinson''s disease     

Vasopressin Modulates Membrane Properties of Taste Cells Isolated from Bullfrogs

The effect of arginine vasopressin (AVP) on the membrane propertieswas analyzed in isolated bullfrog taste cells using a perforatedwhole-cell patch-clamp technique. AVP (100 nM) induced threekinds of responses in rod-type taste cells: appearance of inwardcurrent, inhibition of voltage ramp-induced outward currentand enhancement of the outward current. The Ca²⁺-ionophore ionomycin(3 µM) also induced inward current in taste cells. A membrane-permeablecAMP analog, 8-CPT-cAMP (0.3 mM) inhibited voltage ramp-inducedoutward current in some rod cells, but enhanced the currentin other rod cells. The results suggest that AVP may increaseeither intracellular Ca²⁺ level or cAMP level in taste cells,modulating the membrane excitability. Chem. Senses 21: 739–745,1996.     

A Simple Method of Staining Juxtaglomerular Granules in the Rat Kidney for High Resolution Light Microscopy

A simple method for the demonstration of juxtaglomerular granules in Epon embedded semithin (0.5-1 μm) sections has been developed as follows: sections are prepared as for routine electron microscopy except that before dehydration, the tissues are immersed in 0.5% uranyl acetate in Veronal acetate buffer (pH 5.0) overnight at room temperature. After sectioning on an ultramicro-tome, the semithin sections are briefly stained with toluidine blue-pyronin Y. After staining, the section is rinsed in running tap water and then air dried. Under a light microscope with a 40 × or a 100 × objective, the juxtaglomerular granules appear as deep purple particles and are thus easily separated from the bluish cytoplasm of the juxtaglomerular cells. Cellular organelles in other cells of the kidney were also clearly stained and their fine structure distinguishable.     

Preparative separation of amino acid enantiomers as N-TFA,O-isopropyl derivatives by continuous countercurrent gas-liquid chromatography

Preparative separation of derivatives of amino acid enantiomers was carried out by a countercurrent gas–liquid chromatography (CCGLC) with chiral liquid phases, N-stearoyl-L -valine tert-butylamide and/or N-stearoyl-L -leucine tert-butylamide. In order to make effective use of these phases and also to lower the viscosity, Apiezon C was added as diluent. Through a repeated operation of a temperature gradient, purities more than 99% of leucine and α-amino butyric acid derivatives were proved to be obtained. © 1993 Wiley-Liss, Inc.     

The Effects of Benzyladenine on the Accumulation of Messenger RNAs That Encode the Large and Small Subunits of Ribulose-l,5-bisphosphate Carboxylase/oxygenase and Light-Harvesting Chlorophyll a/b Protein in Excised Cucumber Cotyledons

Benzyladenine promoted rapid accumulation of mRNAs that encodedthe small subunit of ribulose-l,5-bisphosphate carboxylase/oxygenase(RuBisCO) and light-harvesting chlorophyll a/b protein in etiolatedcucumber cotyledons, but only after prior incubation of thecotyledons in water. However, benzyladenine hardly affectedthe level of mRNA for the large subunit of RuBisCO. ¹ Present address: Shonan Junior College, Yokosuka, Kanagawa238, Japan (Received September 3, 1990; Accepted March 4, 1991)     

Taste thresholds of Japanese dental students to phenylthiocarbamide

Recognition taste thresholds for phenylthiocarbamide (PTC),a specific bitter substance, in Japanese dental students weremeasured with 372 males of 20–36 years old and 55 femalesof 20–34 years old. The mean PTC threshold in male studentswas 2.7 x 10^–5 M for tasters and 8.9 x 10^–3 M fornon-tasters. The mean threshold in female students was 2.5 x10^–5 M for tasters and 6.5 x 10^–3 M for the non-tasters.The percentage of non-tasters in a total of 427 male and femalestudents was 5.4%. There was no significant difference in non-tasterdistributions between students from the western districts ofJapan and from other districts.