Phytohormones Related to Host Plant Manipulation by a Gall-Inducing Leafhopper

The maize orange leafhopper Cicadulina bipunctata (Hemiptera: Cicadellidae) induces galls characterized by growth stunting and severe swelling of leaf veins on various plants of Poaceae. Previous studies revealed that galls are induced not on feeding site but on distant, newly extended leaves during the feeding, and strongly suggested that some chemicals injected by the leafhopper affect at the leaf primordia. To approach the mechanism underlying gall induction by C. bipunctata, we examined physiological response of plants to feeding by the leafhopper. We performed high-throughput and comprehensive plant hormone analyses using LC-ESI-MS/MS. Galled maize leaves contained higher contents of abscisic acid (ABA) and trans-Zeatin (tZ) and lower contents of gibberellins (GA₁ and GA₄) than ungalled maize leaves. Leafhopper treatment significantly increased ABA and tZ contents and decreased GA₁ and GA₄ contents in extending leaves. After the removal of leafhoppers, contents of tZ and gibberellins in extending leaves soon became similar to the control values. ABA content was gradually decreased after the removal of leafhoppers. Such hormonal changes were not observed in leafhopper treatment on leaves of resistant maize variety. Water contents of galled leaves were significantly lower than control leaves, suggesting water stress of galled leaves and possible reason of the increase in ABA content. These results imply that ABA, tZ, and gibberellins are related to gall induction by the leafhopper on susceptible variety of maize.     

Hishot Display—A New Combinatorial Display for Obtaining Target-Recognizing Peptides

Display technologies are procedures used for isolating target-recognizing peptides without using immunized animals. In this study, we describe a new display method, named Hishot display, that uses Escherichia coli and an expression plasmid to isolate target-recognizing peptides. This display method is based on the formation, in bacteria, of complexes between a polyhistidine (His)-tagged peptide including random sequences and the peptide-encoding mRNA including an RNA aptamer against the His-tag. When this system was tested using a sequence encoding His-tagged green fluorescent protein that included an RNA aptamer against the His-tag, the collection of mRNA encoding the protein was dependent on the RNA aptamer. Using this display method and a synthetic library of surrogate single-chain variable fragments consisting of VpreB and Ig heavy-chain variable domains, it was possible to isolate clones that could specifically recognize a particular target (intelectin-1 or tumor necrosis factor-α). These clones were obtained as soluble proteins produced by E. coli, and the purified peptide clones recognizing intelectin-1 could be used as detectors for sandwich enzyme-linked immunosorbent assays. The Hishot display will be a useful method to add to the repertoire of display technologies.     

Synthesis of Certain Disaccharides Containing a α-or β- Rhamnopyranosidic Group and the Substrate Specificity of α-l-Rhamnosidase from Aspergillus niger

To investigate the substrate specificity of α-l-rhamnosidase from Aspergillus niger, the following seven substrates were synthesized: methyl 3-O-α-l-rhamnopyranosyl-α-d-mannopyranoside (1), methyl 3-O-α-l-rhamnopyranosyl-α-l-xylopyranoside (2), methyl 3-0-α-l-rhamnopyranosyl-α-l-rhamnopyranoside (3), methyl 4-0-α-l-rhamnopyranosyl-α-d-galactopyranoside (4), methyl 4-O-α-l-rhamnopyranosyl-α-d-mannopyranoside (5), methyl 4-0-α-l-rhamnopyra-nosyl-α-d-xylopyranoside (6), and 6-0-β-l-rhamnopyranosyl-d-mannopyranose (7). Compounds 1~6 were well-hydrolyzed by the crude enzyme, but 7 was unaffected.     

On the Acaciin

Synthesis of N-2,2,3,3-tetrafluoropropionyl-amino acids (abbreviated as tetrafluoropropionyl- or Tfp-amino acids) by the reaction of amino acids with tetrafluoropropionyl anhydride was described, Racemization was observed to occur to a considerable extent during the process of the introduction of this group. Optically active Tfp-amino acids were able to be prepared free from racemization by transesterification of methyl tetrafluoropropionate with amino acid tert-butyl esters, followed by treatment of the resulting Tfp-amino acid tert-butyl esters with trifluoroacetic acid. Some Tfp-dipeptide esters were prepared from the corresponding dipeptide tert-butyl esters in this way. This group was cleavable by mild alkaline hydrolysis or by reduction with sodium borohydrde as well as the Tfa-group.     

Unique antioxidant effects of herbal leaf tea and stem tea from Moringa oleifera L. especially on superoxide anion radical generation systems

ABSTRACT

This study aimed to investigate the unique antioxidative effects of Japanese moringa products, herbal leaf tea and stem tea, using established free radical assays, focusing on superoxide anion (O₂^?) radical generation systems. Hot-water extracts from moringa teas resulted in different but lower scavenging activities than Trolox in four synthetic free radical models. Interestingly, these extracts further showed higher O₂^? radical scavenging effects than Trolox in the phenazine methosulfate-NADH-nitroblue tetrazolium and xanthine oxidase assay systems. Incubating human neutrophils in the presence of these tea extracts rather than Trolox effectively suppressed cellular O₂^? radical generation. Among the eight known phenolic constituents of moringa leaves, caffeic acid and chlorogenic acid may be responsible for the O₂^–specific radical scavenging capacity stronger than that of Trolox. These results suggest that moringa herbal teas are a good source of natural antioxidants for preventing O₂^? radical-mediated disorders.

Abbreviations: O₂^?: superoxide anion; ROS: reactive oxygen species; H₂O₂: hydrogen peroxide; XOD: xanthine oxidase; DPPH: 1,1-diphenyl-2-picrylhydrazyl; ABTS⁺: 2,2′-azinobis(2-ethylbenzothiazoline-6-sulfonic acid) cation; CPZ⁺: chlorpromazine cation; PMS: phenazine methosulfate; NBT: nitroblue tetrazolium; PMA: phorbol 12-myristate 13-acetate     

Mapping mammalian replication domains using the ion torrent semiconductor sequencing platform

ABSTRACT

Here, we show that semiconductor-based sequencing technology can be used to map mammalian replication domains, chromosomal units with similar DNA replication timing. Replicating DNA purified from mammalian cells was successfully sequenced by the Ion Torrent platform. The resultant replication domain map of mouse embryonic stem cells is comparable to those obtained by the conventional microarray-based method.     

The development of circadian rhythm of human body temperature

Abstract

Daily periodic changes of body temperature were examined in 138 subjects ranging in age between 5 days and 44 years. Whereas the circadian rhythm of human body temperature was not discerned in newborn babies, body temperatures were higher during daytime than during nighttime in infants over one month. Temperature rhythm similar to that of adults, with respect to phase, was observed in the age groups of ten to eleven months and over, earlier than previously reported. The amplitude in circadian oscillation was, however, significantly larger in children between 7 months and 7 years of age than in adults. Thus, it is concluded that the adult type of circadian rhythm of human body temperature is fully established with respect to phase and amplitude after 7 years of age.     

Mitochondrial respiration of complex II is not lower than that of complex I in mouse skeletal muscle

Skeletal muscle (SKM) requires a large amount of energy, which is produced mainly by mitochondria, for their daily functioning. Of the several mitochondrial complexes, it has been reported that the dysfunction of complex II is associated with several diseases, including myopathy. However, the degree to which complex II contributes to ATP production by mitochondria remains unknown. As complex II is not included in supercomplexes, which are formed to produce ATP efficiently, we hypothesized that complex II-linked respiration was lower than that of complex I. In addition, differences in the characteristics of complex I and II activity suggest that different factors might regulate their function. The isolated mitochondria from gastrocnemius muscle was used for mitochondrial respiration measurement and immunoblotting in male C57BL/6J mice. Student paired t-tests were performed to compare means between two groups. A univariate linear regression model was used to determine the correlation between mitochondrial respiration and proteins. Contrary to our hypothesis, complex II-linked respiration was not significantly less than complex I-linked respiration in SKM mitochondria (complex I vs complex II, 3402 vs 2840 pmol/[s × mg]). Complex I-linked respiration correlated with the amount of complex I incorporated in supercomplexes (r = 0.727, p < 0.05), but not with the total amount of complex I subunits. In contrast, complex II-linked respiration correlated with the total amount of complex II (r = 0.883, p < 0.05), but not with the amount of each complex II subunit. We conclude that both complex I and II play important roles in mitochondrial respiration and that the assembly of both supercomplexes and complex II is essential for the normal functioning of complex I and II in mouse SKM mitochondria.