Omega-3 phospholipids from fish suppress hepatic steatosis by integrated inhibition of biosynthetic pathways in dietary obese mice

Non-alcoholic fatty liver disease (NAFLD) accompanies obesity and insulin resistance. Recent meta-analysis suggested omega-3 polyunsaturated fatty acids DHA and EPA to decrease liver fat in NAFLD patients. Anti-inflammatory, hypolipidemic, and insulin-sensitizing effects of DHA/EPA depend on their lipid form, with marine phospholipids showing better efficacy than fish oils. We characterized the mechanisms underlying beneficial effects of DHA/EPA phospholipids, alone or combined with an antidiabetic drug, on hepatosteatosis. C57BL/6N mice were fed for 7 weeks an obesogenic high-fat diet (cHF) or cHF-based interventions: (i) cHF supplemented with phosphatidylcholine-rich concentrate from herring (replacing 10% of dietary lipids; PC), (ii) cHF containing rosiglitazone (10 mg/kg diet; R), or (iii) PC + R. Metabolic analyses, hepatic gene expression and lipidome profiling were performed. Results showed that PC and PC + R prevented cHF-induced weight gain and glucose intolerance, while all interventions reduced abdominal fat and plasma triacylglycerols. PC and PC + R also lowered hepatic and plasma cholesterol and reduced hepatosteatosis. Microarray analysis revealed integrated down-regulation of hepatic lipogenic and cholesterol biosynthesis pathways by PC, while R-induced lipogenesis was fully counteracted in PC + R. Gene expression changes in PC and PC + R were associated with preferential enrichment of hepatic phosphatidylcholine and phosphatidylethanolamine fractions by DHA/EPA. The complex down-regulation of hepatic lipogenic and cholesterol biosynthesis genes and the antisteatotic effects were unique to DHA/EPA-containing phospholipids, since they were absent in mice fed soy-derived phosphatidylcholine. Thus, inhibition of lipid and cholesterol biosynthesis associated with potent antisteatotic effects in the liver in response to DHA/EPA-containing phospholipids support their use in NAFLD prevention and treatment.     

Listeria monocytogenes: diagnostic problems

The first isolation methods for the detection of Listeria spp. were generally based on the direct culture of samples on simple agar media, but isolation of the pathogenic Listeria monocytogenes was difficult. In time, new techniques were developed, based on a variety of selective and elective agents in isolation and enrichment media, which gained better and quicker results. Current reference methods allow the recovery of L. monocytogenes from a variety of foods with relative ease. However, more comparative studies are needed to select one horizontal method. It is suggested that the procedure of the International Organization for Standardization is a good base for such comparisons.     

A note on the effect of auditory stimulation on the behaviour and welfare of zoo-housed gorillas

Auditory stimulation has long been employed as a form of therapy for humans and animals housed in institutions. Its effect on one of our closest-living relatives, the gorilla, however, is largely unknown. This study explored the effect of auditory stimulation on the behaviour and welfare of six gorillas housed in Belfast Zoo. All animals were exposed to three conditions of auditory stimulation: a control (no auditory stimulation), an ecologically relevant condition (rainforest sounds) and an ecologically non-relevant condition (classical music). The gorillas’ behaviour was recorded in each condition using a scan-sampling technique. There was no significant effect of the auditory environment on the gorillas’ behaviour, although animals tended to show more behaviours suggestive of relaxation (i.e. resting, sitting) and fewer behaviours typically associated with stress (i.e. aggression, abnormal behaviour) during the ecologically relevant, and, in particular, the non-relevant, conditions than the control. Overall, findings suggest that certain types of auditory stimulation may hold some merit as a method of enrichment for zoo-housed gorillas, although more long-term work with a larger number of animals is needed before firm conclusions can be drawn.     

Isolation and characterization of microsatellite loci in the commercially important mudshrimp Austinogebia edulis (Upogebiidae) using PCR-based isolation of microsatellite arrays (PIMA)

Populations of mudshrimp, Austinogebia edulis, in the intertidal mud flat of western Taiwan have severely declined due to habitat destruction and overfishing in the past decades. Nine polymorphic microsatellite loci were isolated for this ecologically threatened species by using a polymerase chain reaction-based procedure. The number of alleles per locus ranged from five to 14 in 20 specimens from Central West Taiwan. Observed and expected heterozygosities ranged from 0 to 0.2500 (averaged at 0.0944) and 0.7333 to 0.9385 (averaged at 0.8524), respectively. There were significant departures from Hardy–Weinberg expectations. Significant LD was discovered in most loci. These primers may provide a tool for understanding population structure in A. edulis. Tzen-Yuh Chiang and Hung-Du Lin contributed to the study equally.     

长江中下游黄鳝遗传多样性的微卫星分析

为了解我国长江中下游地区野生黄鳝(Monopterus albus)的种质资源现状,利用黄鳝微卫星分子标记分析我国长江中下游4个黄鳝野生群体(湖北群体、安徽群体、江苏群体和浙江群体)的遗传多样性水平.通过磁珠富集法获得50个黄鳝徽卫星序列,设计并合成了30对微卫星引物,经筛选得到8对多态性稳定的引物,均为高度多态位点.每对引物扩增得到等位基因数12 -26,平均等位基因数17.4个群体的平均多态信息含量分别为0.804、0.864、0.824和0.736,平均等位基因数分别为9.13、11.00、9.00和7.25,平均期望杂合度分别为0.865、0.918、0.882和0.813,表明4个黄鳝群体遗传多样性丰富,其中安徽群体遗传多样性水平最高,浙江群体相对较低.4个群体间遗传分化指数(FsT)为0.031 2-0.096 5,6.28％的遗传变异存在于群体间,表明4个群体间存在一定的遗传分化.聚类分析显示,浙江群体与安徽群体先聚在一起,再与江苏群体聚为一支,湖北群体单独聚为一支.     

Examining ubiquitinated peptide enrichment efficiency through an epitope labeled protein

Ubiquitination is a dynamic process that is responsible for regulation of cellular responses to stimuli in a number of biological systems. Previous efforts to study this post-translational modification have focused on protein enrichment; however, recent research utilizes the presence of the di-glycine (Gly-Gly) remnants following trypsin digestion to immuno-enrich ubiquitinated peptides. Monoclonal antibodies developed to the cleaved ubiquitin modification epitope, (tert-butoxycarbonyl) glycylglycine (Boc-Gly-Gly-NHS)¹, are used to identify the Gly-Gly signature. Here, we have successfully generated the Boc-Gly-Gly-NHS modification and showed that when conjugated to a lysine containing protein, such as lysozyme, it can be applied as a standard protein to examine ubiquitinated peptide enrichment within a complex background.     

Elevated CO2 effects on canopy and soil water flux parameters measured using a large chamber in crops grown with free-air CO2 enrichment

An arable crop rotation (winter barley-sugar beet-winter wheat) was exposed to elevated atmospheric CO(2) concentrations ([CO(2) ]) using a FACE facility (Free-Air CO(2) Enrichment) during two rotation periods. The atmospheric [CO(2) ] of the treatment plots was elevated to 550 ppm during daylight hours (T>5°C). Canopy transpiration (E(C) ) and conductance (G(C) ) were measured at selected intervals (>10% of total growing season) using a dynamic CO(2) /H(2) O chamber measuring system. Plant available soil water content (gravimetry and TDR probes) and canopy microclimate conditions were recorded in parallel. Averaged across both growing seasons, elevated [CO(2) ] reduced E(C) by 9%, 18% and 12%, and G(C) by 9%, 17% and 12% in barley, sugar beet and wheat, respectively. Both global radiation (Rg) and vapour pressure deficit (VPD) were the main driving forces of E(C) , whereas G(C) was mostly related to Rg. The responses of E(C) and especially G(C) to [CO(2) ] enrichment were insensitive to weather conditions and leaf area index. However, differences in LAI between plots counteracted the [CO(2) ] impact on E(C) and thus, at least in part, explained the variability of seasonal [CO(2) ] responses between crops and years. As a consequence of lower transpirational canopy water loss, [CO(2) ] enrichment increased plant available soil water content in the course of the season by ca. 15 mm. This was true for all crops and years. Lower transpirational cooling due to a [CO(2) ]-induced reduction of E(C) increased canopy surface and air temperature by up to 2 °C and 0.5 °C, respectively. This is the first study to address effects of FACE on both water fluxes at canopy scale and water status of a European crop rotation.     

微卫星标记在分子生态学中的应用及其位点的分离策略

微卫星DNA作为一种优良的遗传标记在分子生态学领域得到了广泛应用,本文综述了其在分子种群生物学、分子环境遗传学、分子适应等研究领域中的应用情况.微卫星位点的获得是开展各项研究的前提,传统的构建微卫星文库再杂交筛选的方法工作量大、效率低,因而在实践过程中又产生了富集文库法、PIMA法、FIASCO法等新的分离策略.本文对几种微卫星位点分离技术进行介绍并对其进行分析比较,为分子生态学研究过程中微卫星位点筛选方法的选择提供参考.     

深黄被孢霉发酵生产γ-亚麻酸的研究

以深黄被孢霉AS 3.3410(Mortierella isabellina AS 3.3410)的变异株M_6为出发菌株,γ—亚麻酸含量210mg/L,经紫外线和微波处理得到变异株M_(6-22),摇瓶发酵γ-亚麻酸含量1181mg/L,200升发酵罐发酵γ-亚麻酸含量达到1350mg/L。对200升罐发酵的后提取工艺进行了研究,以乙醇和正己烷分步抽提效果最好。脲素包合法的实验结果表明,在70～75℃、3h的条件下可以使γ-亚麻酸由7.2％浓缩到72％。