The Bombyx mori sex pheromone biosynthetic pathway is not mediated by cAMP

In most moths, sex pheromone production is regulated by pheromone biosynthesis-activating neuropeptide (PBAN). How the extracellular PBAN signal is turned into a biological response has been the focus of numerous studies. In the classical scheme of signal transduction, activated G proteins relay the extracellular signal to downstream effector molecules such as calcium channels and adenylyl cyclase. The role of calcium in PBAN signaling has been clearly demonstrated, but the possible involvement of cAMP is not as straightforward. While cAMP has been shown to be necessary for PBAN signaling in most heliothine species, there has been no definitive demonstration of its role in Bombyx mori. To address this question, we used degenerate RT-PCR to clone two Gs subunits, designated P50Gs1 and P50Gs2, from B. mori pheromone gland (PG) cDNAs. The two Gs proteins were expressed in all tissues examined and were not up-regulated in accordance with adult eclosion. Even though two bands corresponding to the approximate molecular weights of P50Gs1 and P50Gs2 were detected in PG homogenates, the Gs antagonist, NF449, had no effect on sex pheromone production. Furthermore, no changes in the intracellular cAMP levels were detected following PBAN stimulation.     

Effects of phylogeny,leaf traits,and the altitudinal distribution of host plants on herbivore assemblages on congeneric Acer species

Historical, niche-based, and stochastic processes have been proposed as the mechanisms that drive community assembly. In plant–herbivore systems, these processes can correspond to phylogeny, leaf traits, and the distribution of host plants, respectively. Although patterns of herbivore assemblages among plant species have been repeatedly examined, the effects of these factors among co-occurring congeneric host plant species have rarely been studied. Our aim was to reveal the process of community assembly for herbivores by investigating the effects of phylogeny, leaf traits, and the altitudinal distribution of closely related host plants of the genus Acer. We sampled leaf functional traits for 30 Acer species in Japan. Using a newly constructed phylogeny, we determined that three of the six measured leaf traits (leaf thickness, C/N ratio, and condensed tannin content) showed a phylogenetic signal. In a field study, we sampled herbivore communities on 14 Acer species within an elevation gradient and examined relationships between herbivore assemblages and host plants. We found that herbivore assemblages were significantly correlated with phylogeny, leaf traits, phylogenetic signals, and the altitudinal distribution of host plants. Our results indicate that the interaction between historical and current ecological processes shapes herbivore community assemblages.     

Function of the Herpes Simplex Virus 1 Small Capsid Protein VP26 Is Regulated by Phosphorylation at a Specific Site

Replacement of the herpes simplex virus 1 small capsid protein VP26 phosphorylation site Thr-111 with alanine reduced viral replication and neurovirulence to levels observed with the VP26 null mutation. This mutation reduced VP26 expression and mislocalized VP26 and its binding partner, the major capsid protein VP5, in the nucleus. VP5 mislocalization was also observed with the VP26 null mutation. Thus, we postulate that phosphorylation of VP26 at Thr-111 regulates VP26 function in vitro and in vivo.     

Degradation of Mono-chlorinated Dibenzo-p-Dioxins by Janibacter sp. Strain YA Isolated from River Sediment

Strain YA was newly isolated from an enrichment culture of river sediment and was identified as Janibacter sp. It was able to utilize dibenzofuran as the sole source of carbon and energy. Strain YA degraded > 90% of 1-chloro-dibenzo-p-dioxin (1-CDD) and > 80% of 2-chloro-dibenzo-p-dioxin in 18 hours with each initial concentration at 40 mg/L. A novel metabolite, 2-chloro-2′,6-dihydroxydiphenylether, was observed in 1-CDD degradation. From the metabolites detected by gas chromatography–mass spectrometry, strain YA was supposed to have at least two types of oxidation pathways in 1-CDD degradation.     

MtgA Deletion-Triggered Cell Enlargement of Escherichia coli for Enhanced Intracellular Polyester Accumulation

Bacterial polyester polyhydroxyalkanoates (PHAs) have been produced in engineered Escherichia coli, which turned into an efficient and versatile platform by applying metabolic and enzyme engineering approaches. The present study aimed at drawing out the latent potential of this organism using genome-wide mutagenesis. To meet this goal, a transposon-based mutagenesis was carried out on E. coli, which was transformed to produce poly(lactate-co-3-hydroxybutyrate) from glucose. A high-throughput screening of polymer-accumulating cells on Nile red-containing plates isolated one mutant that produced 1.8-fold higher quantity of polymer without severe disadvantages in the cell growth and monomer composition of the polymer. The transposon was inserted into the locus within the gene encoding MtgA that takes part, as a non-lethal component, in the formation of the peptidoglycan backbone. Accordingly, the mtgA-deleted strain E. coli JW3175, which was a derivate of superior PHA-producing strain BW25113, was examined for polymer production, and exhibited an enhanced accumulation of the polymer (7.0 g/l) compared to the control (5.2 g/l). Interestingly, an enlargement in cell width associated with polymer accumulation was observed in this strain, resulting in a 1.6-fold greater polymer accumulation per cell compared to the control. This result suggests that the increase in volumetric capacity for accumulating intracellular material contributed to the enhanced polymer production. The mtgA deletion should be combined with conventional engineering approaches, and thus, is a promising strategy for improved production of intracellularly accumulated biopolymers.     

bop5 Mutations reveal new roles for the IC138 phosphoprotein in the regulation of flagellar motility and asymmetric waveforms

I1 dynein, or dynein f, is a highly conserved inner arm isoform that plays a key role in the regulation of flagellar motility. To understand how the IC138 IC/LC subcomplex modulates I1 activity, we characterized the molecular lesions and motility phenotypes of several bop5 alleles. bop5-3, bop5-4, and bop5-5 are null alleles, whereas bop5-6 is an intron mutation that reduces IC138 expression. I1 dynein assembles into the axoneme, but the IC138 IC/LC subcomplex is missing. bop5 strains, like other I1 mutants, swim forward with reduced swimming velocities and display an impaired reversal response during photoshock. Unlike mutants lacking the entire I1 dynein, however, bop5 strains exhibit normal phototaxis. bop5 defects are rescued by transformation with the wild-type IC138 gene. Analysis of flagellar waveforms reveals that loss of the IC138 subcomplex reduces shear amplitude, sliding velocities, and the speed of bend propagation in vivo, consistent with the reduction in microtubule sliding velocities observed in vitro. The results indicate that the IC138 IC/LC subcomplex is necessary to generate an efficient waveform for optimal motility, but it is not essential for phototaxis. These findings have significant implications for the mechanisms by which IC/LC complexes regulate dynein motor activity independent of effects on cargo binding or complex stability.     

Staphylococcus aureus requires cardiolipin for survival under conditions of high salinity

Background  

The ability of staphylococci to grow in a wide range of salt concentrations is well documented. In this study, we aimed to clarify the role of cardiolipin (CL) in the adaptation of Staphylococcus aureus to high salinity.     

Isolation and characterization of human trophoblast side-population (SP) cells in primary villous cytotrophoblasts and HTR-8/SVneo cell line

Recently, numerous studies have identified that immature cell populations including stem cells and progenitor cells can be found among "side-population" (SP) cells. Although SP cells isolated from some adult tissues have been reported elsewhere, isolation and characterization of human trophoblast SP remained to be reported. In this study, HTR-8/SVneo cells and human primary villous cytotrophoblasts (vCTBs) were stained with Hoechst 33342 and SP and non-SP (NSP) fractions were isolated using a cell sorter. A small population of SP cells was identified in HTR-8/SVneo cells and in vCTBs. SP cells expressed several vCTB-specific markers and failed to express syncytiotrophoblast (STB) or extravillous cytotrophopblast (EVT)-specific differentiation markers. SP cells formed colonies and proliferated on mouse embryonic fibroblast (MEF) feeder cells or in MEF conditioned medium supplemented with heparin/FGF2, and they also showed long-term repopulating property. SP cells could differentiate into both STB and EVT cell lineages and expressed several differentiation markers. Microarray analysis revealed that IL7R and IL1R2 were exclusively expressed in SP cells and not in NSP cells. vCTB cells sorted as positive for both IL7R and IL1R2 failed to express trophoblast differentiation markers and spontaneously differentiated into both STB and EVT in basal medium. These features shown by the SP cells suggested that IL7R and IL1R2 are available as markers to detect the SP cells and that vCTB progenitor cells and trophoblast stem cells were involved in the SP cell population.