Variation in the life history pattern of Tetranychus urticae (Acari: Tetranychidae) after selection for dispersal

The spider mite Tetranychus urticae shows variation in its dispersal capacity (i.e., the leaf quality at which a female decides to disperse). We were able to artificially select mites that had either a high or a low dispersal capacity, indicating that this trait was genetically controlled. We then compared correlated responses to this selection. Mites with a genetically high dispersal capacity (‘HD’ strains) had a higher diapause incidence and a lower performance compared to mites with a low dispersal capacity (‘LD’ strains). A possible effect of random genetic drift during the selection was negligible. Our results suggest that differential dispersal capacity is associated with contrasting life history patterns as a result of natural selection. This revised version was published online in July 2006 with corrections to the Cover Date.     

Xenoestrogenic short ethoxy chain nonylphenol is oxidized by a flavoprotein alcohol dehydrogenase from <Emphasis Type="Italic">Ensifer</Emphasis> sp. strain AS08

The ethoxy chains of short ethoxy chain nonylphenol (NPEO_av2.0, containing average 2.0 ethoxy units) were dehydrogenated by cell-free extracts from Ensifer sp. strain AS08 grown on a basal medium supplemented with NPEO_av2.0. The reaction was coupled with the reduction in 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide and phenazine methosulfate. The enzyme (NPEO_av2.0 dehydrogenase; NPEO-DH) was purified to homogeneity with a yield of 20% and a 56-fold increase in specific activity. The molecular mass of the native enzyme was 120 kDa, consisting of two identical monomer units (60 kDa). The gene encoding NPEO-DH was cloned, which consisted of 1,659 bp, corresponding to a protein of 553 amino acid residues. The deduced amino acid sequence agreed with the N-terminal amino acid sequence of the purified NPEO-DH. The presence of a flavin adenine dinucleotide (FAD)-binding motif and glucose–methanol–choline (GMC) oxidoreductase signature motifs strongly suggested that the enzyme belongs to the GMC oxidoreductase family. The protein exhibited homology (40–45% identity) with several polyethylene glycol dehydrogenases (PEG-DHs) of this family, but the identity was lower than those (approximately 58%) among known PEG-DHs. The substrate-binding domain was more hydrophobic compared with those of glucose oxidase and PEG-DHs. The recombinant protein had the same molecular mass as the purified NPEO-DH and dehydrogenated PEG400-2000, NPEO_av2.0 and its components, and NPEOav10, but only slight or no activity was found using diethylene glycol, triethylene glycol, and PEG200. English edition: The paper was edited by a native speaker through American Journal Experts ().     

Carbohydrate-recognition domains of galectin-9 are involved in intermolecular interaction with galectin-9 itself and other members of the galectin family

Galectin-9 (Gal-9) is a tandem-repeat-type member of the galectin family associated with diverse biological processes, such as apoptosis, cell aggregation, and eosinophil chemoattraction. Although the detailed sugar-binding specificity of Gal-9 has been elucidated, molecular mechanisms that underlie these functions remain to be investigated. During the course of our binding study by affinity chromatography and surface plasmon resonance (SPR) analysis, we found that human Gal-9 interacts with immobilized Gal-9 in the protein-protein interaction mode. Interestingly, this intermolecular interaction strongly depended on the activity of the carbohydrate recognition domain (CRD), because the addition of potent saccharide inhibitors abolished the binding. The presence of multimers was also confirmed by Ferguson plot analysis of result of polyacrylamide gel electrophoresis and matrix-assisted laser-desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). Moreover, this intermolecular interaction was observed between Gal-9 and other galectin members, such as Gal-3 and Gal-8, but not Gal-1. Because such properties have not been reported yet, they may explain an unidentified mechanism underlying the diverse functions of Gal-9.     

Occurrence of Potential Brassinosteroid Precursor Steroids in Seeds of Wheat and Foxtail Millet

Triticum aestivum L.) and foxtail millet (Setaria italica Beauv.) were found by GC-MS to contain, in addition to bulk sterols, 4-en-3-one steroids including 24-ethylcholesta-4,24(28)Z- dien-3-one (a new steroid), 24-methylcholest-4-en-3-one, 24-ethylcholesta-4,22E-dien-3-one and 24-ethylcholest-4-en-3-one, as well as 5α-steroidal 3-one compounds including 24-methyl-5α-cholestan-3-one, 24-ethyl-5α-cholestan-3-one and 24-ethyl 5α-cholest-22E-en-3-one (in S. italica only). Analysis of free sterol and steryl ester fractions indicated that campestanol and sitostanol were present at high levels in both seeds. These results suggest that the seeds of T. aestivum and S. italica synthesize campestanol from campesterol via 24-methylcholest-4-en-3-one and 24-methyl-5α-cholestan-3-one as has already been demonstrated in Arabidopsis thaliana L., and also produce sitostanol from sitosterol via 24-ethylcholest-4-en-3-one and 24-ethyl-5α-chotestan-3-one. Biosynthetic relationships of campestanol and sitostanol with C₂₈ and C₂₉ brassinosteroids are discussed. Received 4 September 1998/ Accepted in revised form 26 November 1998     

Isolation and characterization of sex chromosome rearrangements generating male muscle dystrophy and female abnormal oogenesis in the silkworm, Bombyx mori

In deletion-mapping of W-specific RAPD (W-RAPD) markers and putative female determinant gene (Fem), we used X-ray irradiation to break the translocation-carrying W chromosome (W ^Ze ). We succeeded in obtaining a fragment of the W ^Ze chromosome designated as Ze ^W, having 3 of 12 W-RAPD markers (W-Bonsai, W-Yukemuri-S, W-Yukemuri-L). Inheritance of the Ze ^W fragment by males indicates that it does not include the Fem gene. On the basis of these results, we determined the relative positions of W-Yukemuri-S and W-Yukemuri-L, and we narrowed down the region where Fem gene is located. In addition to the Ze ^W fragment, the Z chromosome was also broken into a large fragment (Z₁) having the + ^sch (1-21.5) and a small fragment (Z₂) having the + ^od (1-49.6). Moreover, a new chromosomal fragment (Ze ^WZ₂) was generated by a fusion event between the Ze ^W and the Z₂ fragments. We analyzed the genetic behavior of the Z₁ fragment and the Ze ^WZ₂ fragment during male (Z/Z₁ Ze ^WZ₂) and female (Z₁ Ze ^WZ₂/W) meiosis using phenotypic markers. It was observed that the Z₁ fragment and the Z or the W chromosomes separate without fail. On the other hand, non-disjunction between the Ze ^WZ₂ fragment and the Z chromosome and also between the Ze ^WZ₂ fragment and the W chromosome occurred. Furthermore, the females (2A: Z/Ze ^WZ₂/W) and males (2A: Z/Z₁) resulting from non-disjunction between the Ze ^WZ₂ fragment and the W chromosome had phenotypic defects: namely, females exhibited abnormal oogenesis and males were flapless due to abnormal indirect flight muscle structure. These results suggest that Z₂ region of the Z chromosome contains dose-sensitive gene(s), which are involved in oogenesis and indirect flight muscle development.     

Single crystals of bovine heart cytochrome c oxidase at fully oxidized resting, fully reduced and CO-bound fully reduced states are isomorphous with each other.

Fully reduced and CO-bound fully reduced forms of cytochrome c oxidase from beef heart muscle were crystallized in the presence of sodium ascorbate under N2 or CO atmosphere. Hexagonal bipyramidal and tetragonal crystals were obtained for both forms depending on buffer species. The hexagonal bipyramidal crystals, as large as 0.6 mm in the largest dimension, diffracted X-rays at 7 A resolution, showing an identical space group and cell dimension, P6(2) or P6(4) and a = b = 209 A, c = 283 A, respectively. These parameters coincide with those for crystals of the fully oxidized resting enzyme. This result suggests that a large conformational change, like a subunit arrangement, is not induced by the redox change and/or binding of CO (and possibly O2) to heme a3.     

Effects of a New Calcium Channel Blocker, KB-2796, on Protein Synthesis of the CA1 Pyramidal Cell and Delayed Neuronal Death Following Transient Forebrain Ischemia

The effects of a new calcium channel blocker, 1-[bis(4-fluorophenyl)methyl]-4-(2,3,4-trimethoxybenzyl)-piperazine dihydrochloride (KB-2796), on delayed neuronal death (DND) in the hippocampus were examined in gerbils in comparison with those of pentobarbital and flunarizine. The neuronal density in the hippocampal CA1 subfield was counted on the seventh day of recirculation following 5 min of bilateral carotid occlusion, and protein biosynthesis in the brain was also determined at 1, 2, 4, 24, and 72 h following occlusion. The drugs were intraperitoneally administered after recirculation. KB-2796 (10 mg/kg) significantly prevented DND in the CA1 subfield. Pentobarbital (40 mg/kg), but not flunarizine (3 and 10 mg/kg), inhibited DND. Protein synthetic activity in the CA1 subfield was reduced by ischemia and the reduction was not restored even at 72 h after recirculation. KB-2796 did not ameliorate the reduction of protein synthesis in the CA1 subfield by 24 h after recirculation, but in one of three animals restoration of protein synthesis was observed at 72 h of recirculation. Pentobarbital also restored the reduced protein synthesis in two of three animals at 72 h. These results suggest that calcium influx into neurons participates in the pathogenesis of DND, and also that KB-2796 might prevent both morphological and functional cell damage in CA1 neurons induced by transient ischemia.     

C-reactive protein-induced upregulation of extracellular matrix metalloproteinase inducer in macrophages: inhibitory effect of fluvastatin

OBJECTIVE: Extracellular matrix metalloproteinase inducer (EMMPRIN) and matrix metalloproteinase (MMP)-9 were reported to be expressed at the macrophage-rich area in human coronary atherosclerotic plaque. We examined whether C-reactive protein (CRP) activates macrophages to express EMMPRIN and MMP-9 in vitro and whether statins inhibit it. METHODS AND RESULTS: Rat peritoneal macrophages were collected by peritoneal lavage, and were incubated in the presence or absence of CRP. CRP at 5 microg/ml increased the gene expression of EMMPRIN relative to GAPDH, measured by RT-PCR, by 1.67+/-0.07 fold at 24 h and by 1.85+/-0.49 fold at 48 h (both p<0.05). The gene expression of MMP-9 in the presence of CRP at 5 microg/ml was followed by 1.36+/-0.11 fold increase at 24 h and by 3.95+/-0.81 fold at 48 h (both p<0.05). CRP at 5 microg/ml for 48 h increased by 6 fold MMP-9 activity, measured by zymography, without affecting tissue inhibitor of metalloproteinases-1. Boiled CRP at 5 mug/ml for 48 h unaffected MMP-9 activity. Fluvastatin blocked the CRP-induced increases in EMMPRIN and MMP-9 expression and activity. Diphenylene iodonium, an inhibitor of NADPH oxidase, had a similar effect on MMP-9 activity. Fluvastatin suppressed the CRP-induced increases in 8-epi-prostaglandin F(2alpha) levels in the condition media. CONCLUSIONS: CRP is an activator for macrophages to enhance EMMPRIN and MMP-9 expression. Fluvastatin inhibits them presumably through its antioxidant effect.