Purification and characterization of NADH-dependent glutamate synthase from the silkworm fat body (Bombyx mori).

NADH-dependent glutamate synthase (Nadh-Gogat; EC 1.41.14) was purified 766-fold from the fat body of 5th instar larvae of the silkworm with a final specific activity of 13.

Complete nucleotide sequence of spheroidin gene of Anomala cuprea entomopoxvirus.

The complete nucleotide sequence of the spheroidin gene of Anomala cuprea entomopoxvirus (AcEPV) was determined. The sequence was compared with those of spheroidin genes of EPVs such as Melolontha melolontha EPV (MmEPV, Genus A), Choristoneura fumiferana EPV (CfEPV, Genus B) and Amsacta moorei EPV (AmEPV, Genus B). The gene harbored an open reading frame (ORF) of 2826 nt, with the same size as that of MmEPV belonging to the same genus, capable of coding for a polypeptide of 109.

Evidence for growth of strains of the plant epiphytic bacterium Erwinia herbicola and transconjugation among the bacterial strains in guts of the silkworm Bombyx mori.

Growth of plant epiphytic bacteria Erwinia herbicola and Pseudomonas syringae in guts of the silkworm, Bombyx mori, was studied. Fifth instar silkworm larvae were fed artificial diets supplemented with these bacteria for 6 to 12 h followed by uncontaminated diets. At 1, 3, and 6 days after feeding, bacteria were isolated from insect guts and feces.

Detection of variation of the R-domain structure of ice nucleation genes in Erwinia herbicola-group bacteria by PCR-RFLP analysis.

The structure of ice nucleation (IN) genes was compared among 20 strains of Erwinia herbicola-group bacterium of plant- and insect-origin including E. herbicola M1 (IceE) and E. ananas IN10 (inaA) that had been previously reported.

An insect picorna-like virus, Plautia stali intestine virus, has genes of capsid proteins in the 3' part of the genome.

The complete genome of an insect picorna-like virus, Plautia stali intestine virus (PSIV), was cloned and sequenced. The genome had 8797 nucleotides including two consecutive long open reading frames. The deduced amino acid sequence of the first open reading frame (nucleotides 571 to 6003) contained conserved sequence motifs for picornavirus RNA helicase, cysteine protease, and RNA-dependent RNA polymerase.

Purification and characterization of two insecticyanin-type proteins from the larval hemolymph of the Eri-silkworm, Samia cynthia ricini.

Two different biliverdin-binding proteins, designated BBP-I and BBP-II, were purified from the larval hemolymph of the Eri-silkworm, Samia cynthia ricini. These proteins were readily isolated from the hemolymph of fifth instar larvae using two chromatographic steps, hydrophobic interaction chromatography and ion exchange chromatography. Both BBPs were easily separated by Q-Sepharose HP column chromatography.

The spindles of an entomopoxvirus of coleoptera (Anomala cuprea) strongly enhance the infectivity of a nucleopolyhedrovirus in lepidoptera.

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Properties of a new picorna-like virus of the brown-winged green bug, plautia stali.

A picorna-like virus was isolated from the brown-winged green bug, Plautia stali. The virus was named Plautia stali intestine virus (PSIV) based on the multiplication site of the virus in the infected insects. PSIV is a spherical particle with a diameter of 30 nm.

Complete nucleotide sequence of the fusolin gene of an entomopoxvirus in the cupreous chafer, Anomala cuprea Hope (Coleoptera: Scarabaeidae).

The fusolin gene of Anomala cuprea entomopoxvirus (AcEPV) was cloned and sequenced. The sequence was compared with that of fusolin genes of EPVs from other insects such as Melolontha melolontha (MmEPV), Choristoneura biennis (CbEPV) and Heliothis armigera (HaEPV) previously reported. The gene harbored a single open reading frame (ORF) of 1119 nt capable of coding for a protein of 43.

Effect of the chemical modification of the arginyl residue in Bombyx mori silk fibroin on the attachment and growth of fibroblast cells.

We prepared matrices of Bombyx mori silk fibroin (SF) with different degrees of modification of arginyl residues by reaction between 1,2-cyclohexanedione (CHD) and SF. Two kinds of SF, namely native SF (NSF), obtained from the silk gland of silkworm larvae, and regenerated SF (RSF), prepared from cocoons of the same silkworm, were used in this study because their amino acid compositions were slightly different from each other. The attachment and growth of mouse fibroblast (L-929) cells on the matrices of the NSF and RSF, in which half or almost all of the arginyl residues were modified (NSF50, RSF50, NSF100, and RSF100), were studied using a cell culture method.

Insecticyanin of Agrius convolvuli: purification and characterization of the biliverdin-binding protein from the larval hemolymph.

Blue biliprotein, insecticyanin (INS), has been purified from the hemolymph of the sweet potato hornworm, Agrius convolvuli. The protein was efficiently isolated from the hemolymph of fifth instar larvae using three successive column chromatographic techniques: hydrophobic interaction chromatography, ion exchange chromatography and gel-filtration. The purified INS showed a native molecular weight of approximately 59,000 by gel-filtration.

Synthesis of Both Enantiomers of 15-Hexadecanolide, a Sex Pheromone Component of the Stink Bug, Piezodorus hybneri.

Both enantiomers of 15-hexadecanolide, a sex pheromone component of the stink bug (Piezodorus hybneri), were synthesized by using the Yamaguchi or Mitsunobu macrolactonization reaction of (R)-15-hydroxyhexadecanoic acid prepared from ethyl (R)-β-hydroxybutyrate in 5 steps.

Overwintering status and cold hardiness of hypera punctata.

We investigated overwintering status and various characteristics related to cold hardiness in the clover leaf weevil, Hypera punctata. The larvae continue to feed and grow in winter. The proportion of late instar larvae in a field population increased gradually between December and the following March, and fourth (last) instar larvae were found in mid-February onward.

Endosymbionts of ticks and their relationship to Wolbachia spp. and tick-borne pathogens of humans and animals.

The presence, internal distribution, and phylogenetic position of endosymbiotic bacteria from four species of specific-pathogen-free ticks were studied. These included the hard ticks Ixodes scapularis (the black-legged tick), Rhipicephalus sanguineus (the brown dog tick), and Haemaphysalis longicornis and the African soft tick Ornithodoros moubata. PCR assays for bacteria, using two sets of general primers for eubacterial 16S and 23S rRNA genes (rDNAs) and seven sets of specific primers for wolbachial, rickettsial, or Francisella genes, indicated that I.

Tissue-specific and stage-specific expression of two silkworm ecdysone receptor isoforms -- ecdysteroid-dependent transcription in cultured anterior silk glands.

Previously, we isolated a cDNA clone for the ecdysone receptor B1 isoform of the silkworm, Bombyx mori (BmEcR-B1). Here we report the cloning of a cDNA that encodes the Bombyx ecdysone receptor A isoform (BmEcR-A) and mRNA expression of the two BmEcR isoforms during molting and metamorphosis. At larval-pupal transformation, mRNA expression of BmEcR-B1 was predominant in most tissues examined, including three larval tissues (midgut, epidermis, and fat body) and the wing imaginal disc.

Cloning and characterization of a mariner-like element in the silkworm, Bombyx mori.

We have identified a mariner-like element (MLE) in the genome of the silkworm, Bombyx mori. The cloned MLE, desiqnated as BmMLE, contained an ORF that was interrupted by insertions, stop codons, and frameshifts. The complete ORF sequence was estimated by sequencing the PCR products.

Detection and molecular analysis of plant- and insect-associated bacteria harboring aconitate isomerase involved in biosynthesis of trans-aconitic acid as antifeedant in brown planthoppers.

The activity of aconitate isomerase, which is involved in the biosynthesis of trans-aconitic acid as antifeedant in brown planthoppers, was detected in Pseudomonas fluorescens LRB3W1 and Pseudomonas putida MAFF301685 but not in Pseudomonas putida MAFF301684. The enzyme activity was induced in the presence of trans-aconitate, and therefore bacteria showing the enzyme activity were easily detected by their ability to grow on the minimal medium containing trans-aconitate as the sole carbon source (ACO agar medium). Experiments on growth of plant- or insect-associated bacteria on ACO agar medium showed that most of the Gram-negative bacteria displayed the aconitate isomerase activity unlike most of the Gram-positive bacteria isolated mainly from insects.

Geographic variation in critical photoperiod for diapause induction and its temperature dependence in Hyphantria cunea Drury (Lepidoptera: Arctiidae).

The fall webworm, Hyphantria cunea Drury (Lepidoptera: Arctiidae), was introduced from North America to Japan half a century ago. The critical photoperiod for diapause induction and its temperature dependence, as defined by the difference in the critical photoperiod between 20 and 25°C, were investigated in order to understand the mechanisms behind a shift from bi- to trivoltine life cycles. The critical photoperiod for diapause induction was shorter in the southern trivoltine populations than in the northern bivoltine populations, and this was more marked at 25°C than at 20°C.

An allatostatic factor and juvenile hormone synthesis by corpora allata in Locusta migratoria.

The hemolymph juvenile hormone (JH) titer in sexually immature female adults of Locusta migratoria (Ibaraki strain, Japan) was lower than in sexually mature females; nevertheless, JH synthetic activity by the corpora allata (CA) in vitro was considerably higher in immature females than in sexually mature females ([Okuda et al., 1996]). We carried out experiments to explain this contradiction.

Site of secretion and properties of endogenous endo-beta-1,4-glucanase components from Reticulitermes speratus (Kolbe), a Japanese subterranean termite.

Two endo-beta-1,4-glucanase components (YEG1 and YEG2) of the endogenous cellulase from the Japanese subterranean termite, Reticulitermes speratus, were purified to homogeneity using gel filtration and hydroxylapatite chromatography, and their enzymatic properties were investigated. Using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), YEG1 and YEG2 had M(r) of 42 kDa and 41 kDa, respectively. Both components had an optimal pH of 6.

Glycine in Digestive Juice: a Strategy of Herbivorous Insects Against Chemical Defense of Host Plants.

A large amount of free glycine was found in the digestive juice of several Lepidoptera larvae and appears to be secreted. The amount of glycine differs greatly among species and seems to correlate with the host plant. Several species of Lepidoptera from different famileis which feed on the privet tree, Ligustrum obtusifolium, show extremely large amounts of free glycine.

In vitro phagocytosis of Escherichia coli and release of lipopolysaccharide by adhering hemocytes of the silkworm, Bombyx mori.

A primary culture containing adhering hemocytes mainly granular cells from the silkworm, Bombyx mori, was used to investigate in vitro phagocytosis of Escherichia coli. Phagocytosis was confirmed to occur in this system by microscopic observation. Lipopolysaccharide (LPS) concentration in the culture medium was measured by a Limulus test and a higher LPS concentration was detected in phagocytosis-occurred samples than in control samples, which omitted either E.

Synthesis of poly(ethylene glycol)-silk fibroin conjugates and surface interaction between L-929 cells and the conjugates.

Poly(ethylene glycol) (PEG)-silk fibroin (SF) conjugates (PEG2-SF) were prepared by the chemical modification of solubilized SF with 2,4-bis[O-methoxypoly(ethylene glycol)]-6-chloro-s-triazine (actPEG2) in borate buffer at 37 degrees C. The IR spectra and DSC curves of PEG2-SF and SF suggested the introduction of PEG into SF by the modification and the beta-sheet structure of both SF and PEG2-SF induced by the treatment with methanol aqueous solutions. The content of the PEG component in PEG2-SF was evaluated to be 67% by weight from the melting enthalpy change of PEG observed on the DSC thermogram of PEG2-SF.

Preferential codon usage and two types of repetitive motifs in the fibroin gene of the Chinese oak silkworm, Antheraea pernyi.

In this paper we describe the peculiar structures and preferential codon usage found in wild silkworm fibroin genes. We determined a 1350 bp nucleotide sequence from the Chinese oak silkworm, Antheraea pernyi. The deduced amino acid sequence was partitioned into thirteen polyalanine-containing repetitive motifs, which was one of the characteristics of Antheraea fibroins.

Absolute Configurations of Some Hydroxy-fatty Acids Produced by the Insect Genus Laccifer.

The absolute configurations of some hydroxy-fatty acids were examined by the modified Mosher's method proposed by Ohtani et al. The absolute configurations of the major components were determined from NMR data of their ΜΤΡΑ esters and 2-ΝΜΑ esters. The application of Mosher's method for the anti-glycol is discussed.