Transcriptional Responses of a Bicarbonate-Tolerant Monocot, Puccinellia tenuiflora, and a Related Bicarbonate-Sensitive Species, Poa annua, to NaHCO3 Stress

Puccinellia tenuiflora is an alkaline salt-tolerant monocot found in saline-alkali soil in China. To identify the genes which are determining the higher tolerance of P. tenuiflora compared to bicarbonate sensitive species, we examined the responses of P. tenuiflora and a related bicarbonate-sensitive Poeae plant, Poa annua, to two days of 20 mM NaHCO3 stress by RNA-seq analysis. We obtained 28 and 38 million reads for P. tenuiflora and P. annua, respectively. For each species, the reads of both unstressed and stressed samples were combined for de novo assembly of contigs. We obtained 77,329 contigs for P. tenuiflora and 115,335 contigs for P. annua. NaHCO3 stress resulted in greater than two-fold absolute expression value changes in 157 of the P. tenuiflora contigs and 1090 of P. annua contigs. Homologs of the genes involved in Fe acquisition, which are important for the survival of plants under alkaline stress, were up-regulated in P. tenuiflora and down-regulated in P. annua. The smaller number of the genes differentially regulated in P. tenuiflora suggests that the genes regulating bicarbonate tolerance are constitutively expressed in P. tenuiflora

The Effects of Brown Algae-Derived Monosaccharide L-Fucose on Lipid Metabolism in C57BL/6J Obese Mice

Obesity is a global public health problem and a risk factor for several metabolic disorders as well as cancer. In this study, we investigated the effects of L-fucose on lipid metabolism through chronic and acute in vivo experiments in mice. In the chronic test, mice were fed a high-calorie diet (HCD) containing 0.0001%, 0.001%, 0.01%, and 0.1% L-fucose for one month. The L-fucose supplementation inhibited body weight and visceral fat mass gain in HCD-fed mice. The results of the acute test showed that L-fucose increased the ratio of serum high molecular weight adiponectin and enhanced glucose and lipid catabolism. Furthermore, L-fucose also decreased the expression of adipogenic genes (peroxisome proliferator-activated receptor γ and cluster of differentiation 36). In conclusion, this study provides a new approach to combat obesity and the related diseases

Gene structure and cDNA sequence of 2-Cys peroxiredoxin in the harmful algal bloom species <i>Chattonella marina</i> and its gene transcription under different light intensities

<p>We investigated the gene structure and predicted amino acid sequence of the antioxidant enzyme 2-Cys peroxiredoxin (2-Cys Prx) in the raphidophyte <i>Chattonella marina</i>, which is a harmful algal bloom (HAB) species. The open reading frame of 2-Cys Prx was 585 bp long and encoded a protein consisting of 195 amino acids. The putative amino acid sequence contained two cysteine residues located at the 49th and 170th amino acid positions from the N-terminal methionine residue. The sequence also possessed 2-Cys Prx characteristic motifs, F (FFYPLDFTFVCPTEI) and EVCP. The position of the 2-Cys Prx gene relative to several others (<i>ycf</i>59 <i>– 2-CysPrx – rpl</i>35 <i>– rpl</i>20) was the same as that found in the chloroplast genome in the raphidophyte <i>Heterosigma akashiwo</i>. Upstream of the 2-Cys Prx gene, possible TATA and GGA motifs recognized by nuclear-encoded plastid RNA polymerase (NEP), and a possible -10 box and -35 box recognized by plastid-encoded plastid RNA polymerase (PEP) were observed. We measured the transcript levels of 2-Cys Prx in <i>C. marina</i> cells grown under three different light intensities (0, 100, 1000 µmol photons m^–2 s^–1, 14-h light/8-h dark photoperiod) by quantitative PCR. The 2-Cys Prx transcript level in cells grown under the highest light intensity on day 3 was threefold that on day 0 but two lower light intensities resulted in relatively stable transcription levels. The 2-Cys Prx transcript level was significantly positively related to the H₂O₂ concentration per cell and the H₂O₂ scavenging activity per cell. These results suggest that <i>C. marina</i> 2-Cys Prx functions in the chloroplast and its transcription could be regulated by both NEP and PEP. Moreover, the 2-Cys Prx transcript level might increase to remove excessive H₂O₂ produced under strong light conditions in order to maintain cell proliferation activity.</p

Purification and characterization of tributyltin-binding protein of tiger puffer, Takifugu rubripes

We successfully purified Trub.TBT-bpα, a tributyltin (TBT) binding protein (bp) of the tiger puffer, Takifugu rubripes. Tiger puffer was injected intraperitoneally with TBT (1.0 mg/kg body weight) and Trub.TBT-bpα was purified from serum by ammonium sulfate fractionation, gel filtration chromatography and polyacrylamide gel electrophoresis. Gel electrophoresis revealed that the Trub.TBT-bpα has a molecular mass of approximately 48.5 kDa and contains at least 40% N-glycan. The deduced 212 amino acid sequence of the protein showed the highest identity (41%, 212 amino acid overlap and E-value: 9e−42) with TBTbinding protein type 1 (TBT-bp1) of Paralichthys olivaceus (Japanese flounder). Analysis of the gene structure of Trub.TBT-bpα suggests that this protein belongs to the lipocalin superfamily, which may be important in the accumulation and elimination of TBT. Phylogenetic analysis suggests that functionalization of TBT-bps has occurred during evolution, and that the functions of this group of proteins might be important for fish survival.Published version is available for viewing only. (See "Related DOI")「関連URI」より出版社版の閲覧専用ページへリン

Transcriptome analysis of tetrodotoxin sensing and tetrodotoxin action in the central nervous system of tiger puffer Takifugu rubripes juveniles

To reveal the sensing of tetrodotoxin (TTX) by tiger puffer Takifugu rubripes juveniles and its action in the central nervous system (CNS), we conducted transcriptome analysis using next-generation sequencing for the olfactory system and brain of non-toxic cultured juveniles administered TTX. Sixty-seven million reads from the nasal region (olfactory epithelium and skin) and the brain of each of three individuals of the control, TTX-sensing and TTX-administered juveniles were assembled into 153,958 contigs. Mapping raw reads from each sample onto the nucleotide sequences of predicted transcripts in the T. rubripes genome (FUGU version 4) and the de novo assembled contigs to investigate their frequency of expression revealed that the expression of 21 and 81 known genes significantly changed in TTX-sensing and TTX-administered juveniles in comparison with control juveniles, respectively. These genes included those related to feeding regulation and a reward system, and indicated that TTX ingestion of T. rubripes juveniles is controlled in the feeding center in the brain, that T. rubripes may sense TTX as a reward, and that accumulated TTX directly acts on the central nervous system to adjust TTX ingestion