Upstream open reading frame (uORF)-mediated translational inhibition is important in controlling key regulatory genes expression. However, understanding the underlying molecular mechanism of such uORF-mediated control system in vivo is challenging in the absence of an animal model. Therefore, we generated a zebrafish transgenic line, termed huORFZ, harboring a construct in which the uORF sequence from human CCAAT/enhancer-binding protein homologous protein gene (huORFchop) is added to the leader of GFP and is driven by a cytomegalovirus promoter. The translation of transgenic huORFchop-gfp mRNA was absolutely inhibited by the huORFchop cassette in huORFZ embryos during normal conditions, but the downstream GFP was only apparent when the huORFZ embryos were treated with endoplasmic reticulum (ER) stresses. Interestingly, the number and location of GFP-responsive embryonic cells were dependent on the developmental stage and type of ER stresses encountered. These results indicate that the translation of the huORFchop-tag downstream reporter gene is controlled in the huORFZ line. Moreover, using cell sorting and microarray analysis of huORFZ embryos, we identified such putative factors as Nrg/ErbB, PI3K and hsp90, which are involved in huORFchop-mediated translational control under heat-shock stress. Therefore, using the huORFZ embryos allows us to study the regulatory network involved in human uORFchop-mediated translational inhibition.

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The bacterium Yersinia entomophaga is pathogenic to a range of insect species, with death typically occurring within 2 to 5 days of ingestion. Per os challenge of larvae of the greater wax moth (Galleria mellonella) confirmed that Y. entomophaga was virulent when fed to larvae held at 25°C but was avirulent when fed to larvae maintained at 37°C. At 25°C, a dose of ϳ4 ؋ 10 7 CFU per larva of a Y. entomophaga toxin complex (Yen-TC) deletion derivative, the Y. entomophaga ⌬TC variant, resulted in 27% mortality. This low level of activity was restored to near-wild-type levels by augmentation of the diet with a sublethal dose of purified Yen-TC. Intrahemocoelic injection of ϳ3 Y. entomophaga or Y. entomophaga ⌬TC cells per larva gave a 4-day median lethal dose, with similar levels of mortality observed at both 25 and 37°C. Following intrahemocoelic injection of a Yen-TC YenA1 green fluorescent protein fusion strain into larvae maintained at 25°C, the bacteria did not fluoresce until the population density reached 2 ؋ 10 7 CFU ml ؊1 of hemolymph. The observed cells also took an irregular form. When the larvae were maintained at 37°C, the cells were small and the observed fluorescence was sporadic and weak, being more consistent at a population density of ϳ3 ؋ 10 9 CFU ml ؊1 of hemolymph. These findings provide further understanding of the pathobiology of Y. entomophaga in insects, showing that the bacterium gains direct access to the hemocoelic cavity, from where it rapidly multiplies to cause disease. The Gram-negative bacterium Yersinia entomophaga was isolated from the cadaver of a Costelytra zealandica (Coleoptera: Scarabaeidae) larva, and has proven consistently pathogenic by per os challenge to this host, as well as to a wide range of coleopteran, lepidopteran, and orthopteran species (1). A 6-day median lethal dose (LD 50 ) was determined as 2.9 ϫ 10 4 Y. entomophaga cells per C. zealandica larva. Following per os challenge with a bacterial dose of ϳ1 ϫ 10 7 Y. entomophaga cells per larva, the larvae typically vomited, expelled frass pellets, changed color from a healthy gray to amber and then a moribund brown, and exhibited reduced feeding activity. By 48 h postingestion, Y. entomophaga cells could be visualized within the hemocoelic cavity of the larvae, after which time death ensued (2).The main virulence determinant of Y. entomophaga is an insect-active toxin complex (TC) derivative termed "Yen-TC" (3). TCs were first identified in the genome of Photorhabdus luminescens (4) and have since been identified in other bacterial genera, including members of the genus Yersinia (5). Typically, TCs are comprised of three proteins, TC-A, TC-B, and TC-C, which combine to form the insect-active complex (6). Yen-TC is comprised of seven subunit proteins: two TC-A-like proteins (YenA1 and YenA2), a TC-B-like protein (YenB), two TC-C-like proteins (YenC1 and YenC2), and two chitinases (Chi1 and Chi2), which combine to form the insect-active TC. Recent structural analysis has revealed that both the Yen-TC and the P. lumine...

Quantum dots (QDs) are an increasingly important class of nanoparticle, but little ecotoxicological data for QDs has been published to date. The effects of mercaptosuccinic acid (MSA)-capped QDs (QDs-MSA) and equivalent concentrations of cadmium (Cd) from cadmium chloride on growth and reproduction of the nematode Caenorhabditis elegans (Rhabditidae) were assessed in laboratory experiments. Growth from larvae to adults of C. elegans was unaffected by exposure to 1 µM fluorescent QDs-MSA, but adults produced more embryos and laid them prematurely. Furthermore, C. elegans exposed to QDs-MSA (1 µM) showed a high percentage of embryo mortality (19.2 ± 0.5, p < 0.001, percentage ± standard deviation) compared with unexposed nematodes (11.6 ± 0.4). An egg-laying defect phenotype was also observed at high frequency in response to 1 µM QDs-MSA exposure (38.3 ± 3.6%, p < 0.01; control 10.0 ± 2.2%). This resulted in a reduced mean life span (20.5 ± 1.1 d, p < 0.05) compared with the control (24.6 ± 1.0 d). Cadmium also caused reduced life span in C. elegans, but a low incidence of egg-laying defects was observed, suggesting that Cd and QDs-MSA affected C. elegans by different mechanisms. Furthermore, egg-laying defects caused by QDs-MSA responded to the addition of the anticonvulsant ethosuximide and to a lesser extent to the neurotransmitter serotonin, suggesting that QDs-MSA might have disrupted motor neurons during the reproduction process.

D-amino acid oxidase (DAO) has been reported to be associated with schizophrenia. This study aimed to search for genetic variants associated with this gene. The genomic regions of all exons, highly conserved regions of introns, and promoters of this gene were sequenced. Potentially meaningful single-nucleotide polymorphisms (SNPs) obtained from direct sequencing were selected for genotyping in 600 controls and 912 patients with schizophrenia and in a replicated sample consisting of 388 patients with schizophrenia. Genetic associations were examined using single-locus and haplotype association analyses. In single-locus analyses, the frequency of the C allele of a novel SNP rs55944529 located at intron 8 was found to be significantly higher in the original large patient sample (p = 0.016). This allele was associated with a higher level of DAO mRNA expression in the Epstein-Barr virus-transformed lymphocytes. The haplotype distribution of a haplotype block composed of rs11114083-rs2070586-rs2070587-rs55944529 across intron 1 and intron 8 was significantly different between the patients and controls and the haplotype frequencies of AAGC were significantly higher in patients, in both the original (corrected p < 0.0001) and replicated samples (corrected p = 0.0003). The CGTC haplotype was specifically associated with the subgroup with deficits in sustained attention and executive function and the AAGC haplotype was associated with the subgroup without such deficits. The DAO gene was a susceptibility gene for schizophrenia and the genomic region between intron 1 and intron 8 may harbor functional genetic variants, which may influence the mRNA expression of DAO and neurocognitive functions in schizophrenia.

SummaryReduction of the potent greenhouse gas nitrous oxide (N2O) occurs in soil environments by the action of denitrifying bacteria possessing nitrous oxide reductase (N2 OR), a dimeric copper (Cu)‐dependent enzyme producing environmentally benign dinitrogen (N2). We examined the effects of increasing Cu concentrations on the transcription and activity of nitrite reductase (NIR), nitric oxide reductase (NOR) and N2 OR in Pseudomonas stutzeri grown anaerobically in solution over a 10‐day period. Gas samples were taken on a daily basis and after 6 days, bacterial RNA was recovered to determine the expression of nirS, norB and nosZ encoding NIR, NOR and N2 OR respectively. Results revealed that 0.05 mM Cu caused maximum conversion of N2O to N2 via bacterial reduction of N2O. As soluble Cu generally makes up less than 0.001% of total soil Cu, extrapolation of 0.05 mg l−l soluble Cu would require soils to have a total concentration of Cu in the range of, 150–200 μg g−1 to maximize the proportion of N2O reduced to N2. Given that many intensively farmed agricultural soils are deficient in Cu in terms of plant nutrition, providing a sufficient concentration of biologically accessible Cu could provide a potentially useful microbial‐based strategy of reducing agricultural N2O emissions.

The protective effects of Houttuynia cordata aqueous extract (HCAE) in mice consuming a high saturated fat diet (HFD) were examined. HCAE, at 0.5, 1, or 2%, was supplied in drinking water for 8 weeks. HCAE was rich in phenolic acids and flavonoids. HCAE intake at 1 and 2% decreased body weight, epididymal fat, insulin resistance, triglyceride and total cholesterol contents in plasma and liver from HFD-treated mice (p < 0.05). HFD enhanced hepatic activity of malic enzyme, fatty acid synthase (FAS) and 3-hydroxy-3-methylglutaryl coenzyme A reductase; and augmented the hepatic level of saturated fatty acids (p < 0.05). HCAE intake at 2% reduced malic enzyme and FAS activities, and lowered saturated fatty acids content in liver (p < 0.05). HCAE suppressed HFD induced oxidative and inflammatory stress in the heart and liver via reducing the malondialdehyde level, retaining glutathione content and glutathione peroxidase activity, decreasing tumor necrosis factor-alpha, interleukin (IL)-1beta and IL-6 production (p < 0.05). These results support that Houttuynia cordata is a potent food against HFD induced obesity, and oxidative and inflammatory injury.

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