Identification of differentially expressed genes in hepatopancreas of oriental river prawn, Macrobrachium nipponense exposed to environmental hypoxia

Hypoxia represents a major physiological challenge for prawn culture, and the hepatopancreas plays an important role in these processes. Here, we applied high-throughput sequencing technology to detect the gene expression profile of the hepatopancreas in Macrobrachium nipponense in response to hypoxia for 3 h and hypoxia for 24 h. Gene expression profiling identified 1925 genes that were significantly up- or down-regulated by dissolved oxygen availability. Functional categorization of the differentially expressed genes revealed that oxygen transport, electron transport chain, reactive oxygen species generation/scavenging, and immune response were the differentially regulated processes occurring during environmental hypoxia. Finally, quantitative real-time polymerase chain reaction using six genes independently verified the tag-mapped results. Immunohistochemistry analysis revealed, for the first time, hemocyanin protein expression as significant hypoxia-specific signature in prawns, which opens the way for in depth molecular studies of hypoxia exposure. The analysis of changes in hepatic gene expression in oriental river prawn provides a preliminary basis for a better understanding of the molecular response to hypoxia exposures.     

In vivo roles of the basic domain of dynactin p150 in microtubule plus-end tracking and dynein function

Microtubule (MT) plus-end-tracking proteins accumulate at MT plus ends for various cellular functions, but their targeting mechanisms are not fully understood (Akhmanova A and Steinmetz MO. Tracking the ends: a dynamic protein network controls the fate of microtubule tips. Nat Rev Mol Cell Biol 2008;9:309-322.). Here, we tested in the filamentous fungus Aspergillus nidulans the requirement for plus-end localization of dynactin p150, a protein essential for dynein function. Deletion of the N-terminal MT-binding region of p150 significantly diminishes the MT plus-end accumulation of both dynein heavy chain and p150, and causes a partial defect in nuclear distribution. Surprisingly, within the MT-binding region, the basic domain is more critical than the CAP-Gly (cytoskeleton-associated protein glycine-rich) domain for maintaining plus-end tracking of p150, as well as for the functions of dynein in nuclear distribution and early endosome movement. Our results show that the basic domain of A. nidulans p150 is important for p150-MT interaction both in vivo and in vitro, and the basic amino acids within this domain are crucial for the plus-end accumulation of p150 in the wild-type background and for the p150-MT interaction in the ΔkinA (kinesin-1) background. We suggest that the basic amino acids are required for the electrostatic interaction between p150 and MTs, which is important for kinesin-1-mediated plus-end targeting of dynactin and dynein in A. nidulans.     

Development of new IL28B genotyping method using Invader Plus assay

IL28B polymorphism is associated with the response to pegylated interferon-α with ribavirin (PEG-IFN-α/RBV) treatment in chronic hepatitis C patients. As a genotyping assay for IL28B single nucleotide polymorphisms (SNPs) in clinical practice, the Invader Plus assay was developed. The accuracy, intra-assay, inter-assay precision, and the limit of detection of the Invader Plus assay were evaluated. Two SNPs (rs8099917 and rs12979860) associated with IL28B were genotyped by the Invader Plus and TaqMan assay in 512 Japanese patients. In comparison with direct sequencing, the Invader Plus assay showed 99% accuracy in rs8099917 and 100% accuracy in rs12979860. Intra-assay and inter-assay precision were sufficient to use in clinical practice and the detection limit was 1ngDNA/assay. Genotyping by rs8099917 showed that 361 (71%), 144 (28%) and seven (1%) of the patients were major homozygous, heterozygous and minor homozygous types, respectively. Five of the 512 cases (1%) had haplotype differences, but none showed differences between the two genotyping methods. For patients with HCV genotype 1, the prevalence of responders in the major homozygous type was 83.3%, and that of non-responders in the minor heterozygous/homozygous type was 72.5%. A convenient IL28B genotyping method using the Invader Plus assay could be useful to predict the treatment outcome in clinical practice.     

The use of multiplexed MRM for the discovery of biomarkers to differentiate iron-deficiency anemia from anemia of inflammation

In this study we demonstrate the use of a multiplexed MRM-based assay to distinguish among normal (NL) and iron-metabolism disorder mouse models, particularly, iron-deficiency anemia (IDA), inflammation (INFL), and inflammation and anemia (INFL+IDA). Our initial panel of potential biomarkers was based on the analysis of 14 proteins expressed by candidate genes involved in iron transport and metabolism. Based on this study, we were able to identify a panel of 8 biomarker proteins: apolipoprotein A4 (APO4), transferrin, transferrin receptor 1, ceruloplasmin, haptoglobin, lactoferrin, hemopexin, and matrix metalloproteinase-8 (MMP8) that clearly distinguish among the normal and disease models. Within this set of proteins, transferrin showed the best individual classification accuracy over all samples (72%) and within the NL group (94%). Compared to the best single-protein biomarker, transferrin, the use of the composite 8-protein biomarker panel improved the classification accuracy from 94% to 100% in the NL group, from 50% to 72% in the INFL group, from 66% to 96% in the IDA group, and from 79% to 83% in the INFL+IDA group. Based on these findings, validation of the utility of this potentially important biomarker panel in human samples in an effort to differentiate IDA, inflammation, and combinations thereof, is now warranted. This article is part of a Special Section entitled: Understanding genome regulation and genetic diversity by mass spectrometry.     

Systematic characterisation and seed oil analysis in candidate plus trees of biodiesel plant, Pongamia pinnata

Candidate plus trees (CPTs) of Pongamia pinnata , a potential biodiesel plant occurring across 10 locations in North Guwahati, were identified based on morphological markers (vegetative and reproductive) using combined analysis over locations. Identified CPTs were then multiplied using seed propagation technique in a nursery bed. The performance of the candidate trees with respect to seed and pod traits, the two most important characters with regard to oil, were evaluated using CROPSTAT software for inferring potential genotypes that can be included in programmes aimed at genetic improvement of the species. Total oil content from the seeds of plus trees was also analysed using solvent extraction procedure at their boiling points. Hexane extraction yielded maximum oil content from seeds (33%) compared with petroleum ether (30%). When the seed to solvent ratio varied, no significant difference was noticed on the total oil yield for an individual tree, although the recovery of solvent and the time taken for oil extraction were significantly reduced at higher ratios of solvent used.     

A peptide containing residues 26-44 of tau protein impairs mitochondrial oxidative phosphorylation acting at the level of the adenine nucleotide translocator

Having confirmed that adenovirus-mediated overexpression of NH₂-tau fragment lacking the first 25 aminoacids evokes a potent neurotoxic effect, sustained by protracted stimulation of NMDA receptors, in primary neuronal cultures we investigated whether and how chemically synthesized NH₂-derived tau peptides, i.e. NH₂-26-44 and NH₂-1-25 fragments, affect mitochondrial function. We tested both fragments on each step of the processes leading to ATP synthesis via oxidative phosphorylation: i) electron flow via the respiratory chain from physiological substrates to oxygen with the activity of each individual complex of the respiratory chain investigated in some detail, ii) membrane potential generation arising from externally added succinate and iii) the activity of both the adenine nucleotide translocator and iv) ATP synthase. Oxidative phosphorylation is not affected by NH₂-1-25 tau fragment, but dramatically impaired by NH₂-26-44 tau fragment. Both cytochrome c oxidase and the adenine nucleotide translocator are targets of NH₂-26-44 tau fragment, but adenine nucleotide translocator is the unique mitochondrial target responsible for impairment of oxidative phosphorylation by the NH₂-26-44 tau fragment, which then exerts deleterious effects on cellular availability of ATP synthesized into mitochondria.     

Effects of acute and chronic nicotine on elevated plus maze in mice: involvement of calcium channels

The current experiments examined the anxiety-related effects of acute and repeated nicotine administration using the elevated plus maze test in mice. Nicotine (0.1 mg/kg s.c., 5 and 30 min after injection; 0.5 mg/kg, s.c., 5 min after injection) had an anxiogenic effect, shown by specific decreases in the percentage of time spent on the open arms and in the percentage of open arm entries. Tolerance developed to this anxiogenic action after 6 days of daily nicotine administration (0.1 mg/kg, s.c.). Five minutes after the seventh injection, an anxiolytic effect was observed, i.e., specific increases in the percentage of time spent on the open arms and in the percentage of open arm entries. L-type voltage-dependent calcium channel antagonists nimodipine (5 and 10 mg/kg, i.p.), flunarizine (5 and 10 mg/kg, i.p.), verapamil (5, 10, 20 mg/kg) and diltiazem (5, 10, 20 mg/kg, i.p.) were also injected prior to an acute low dose of nicotine or to each injection of chronic nicotine. Our results revealed that calcium channel blockers dose-dependently attenuated both an anxiogenic effect of nicotine as well as the development of tolerance to this effect. Our results suggest that neural calcium-dependent mechanisms are involved in the anxiety-related responses to acute and chronic nicotine injection that may ultimately lead to addiction and smoking relapse in human smokers.     

益气补肾方药对化疗荷瘤小鼠免疫功能的影响

目的　探讨益气补肾方药 (由金匮肾气方加味人参、黄芪组成 ,以下均称方药 ,TS)对环磷酰胺 (CY)处理的荷H2 2 瘤小鼠非特异免疫功能的影响。方法　用CY处理荷H2 2 瘤小鼠 ,建立免疫力低下动物模型。用乳酸脱氢酶 (LDH)释放法分别检测NK细胞、巨噬细胞 (M)的活性 ,用RT PCR法检测白细胞介素 12 (IL 12 )mRNA在脾脏细胞中的表达。结果　TS CY组小鼠吸光度A值为 1 332± 0 5 10 ,明显高于CY组小鼠 (P <0 0 1)。TS CY组小鼠A值为 1 12 9± 0 2 80 ,明显高于CY组小鼠 (P <0 0 1)。此方药能明显提高CY所致免疫力低下小鼠NK细胞、M的活性 ,增加IL 12在脾细胞中的表达。结论　该方药可以明显提高环磷酰胺所致免疫力低下荷瘤小鼠的非特异免疫功能。     

甘蓝型油菜芥酸含量的主基因＋多基因遗传

应用植物数量性状主基因＋多基因混合遗传模型对甘蓝型油菜无芥酸品种HSTC