Sex-based differences in fatty acid composition of adult walleye

Differences in reproductive strategies of male and female fishes are presumably accompanied by differences in nutrient allocation and predicted to lead to divergence in body composition between the sexes. We compared patterns of variation in fatty acid profiles of lipids extracted from ova, liver, muscle and visceral fat between mature male and female walleye (Sander vitreus) sampled from two wild spawning stocks. Fatty acid profiles differed significantly among body tissues in both males and females, with the strongest contrast between muscle and visceral fat. Significant differences in fatty acid composition between the sexes were found in liver, muscle and visceral fat tissues. Variation among sexes and populations was greater in liver than in the other tissues. Female livers had lower relative abundances of palmitic acid (PA, 16:0) and oleic acid (OA, 18:1(n-9)), and higher relative abundances of arachidonic acid (ARA, 20:4(n-6)), eicosapentaenoic acid (EPA, 20:5(n-3)) and docosahexaenoic acid (DHA, 22:6(n-3)) compared to male livers. In addition, female muscle had higher relative abundance of OA and lower relative abundance of DHA compared to male muscle. Our results illustrate the differential effects of reproductive demands on the biochemical composition of males and females and have implications for the analysis of fatty acid profiles in studies of wild fish populations.     

Effects of temperature,relative humidity and time on survival of pinewood nematodes in wood chips

The survival of two Canadian isolates of the pinewood nematode, Bursaphelenchus xylophilus, in coniferous wood chips under different temperatures, relative humidities and time intervals was investigated in vitro. The nature of the survival mechanism was examined and it was shown that the nematode's prolonged survival in the chips depended on its dispersal third larval stage. The possibility of PWN-infested wood chips spreading PWN-induced pine-wilt disease to forests is discussed.     

L-肉碱对普通小球藻Chlorella vulgaris种群增长和生化组成的影响

分别以0,5,50 mg/L的L-内碱(L-carnitine)处理淡水普通小球藻(Chlorella vulgaris),以SE为培养液,培养7 d,探究L-肉碱对淡水普通小球藻种群增长、总脂和可溶性蛋白质含量的影响.结果表明:不同质量浓度的L-肉碱在不同培养时期对普通小球藻种群增长影响显著(P<0.05);高浓度L...     

Effect of dietary fibre from cereal brans and legume seedcoats on serum lipids in rats

The present investigation was carried out to study the hypolipidemic effect of dietary fibre from cornbran and blackgram seedcoat in rats. Isoproteinous diet having one percent cholesterol and ten percent dietary fibre from cornbran and blackgram seedcoat was fed to four groups of albino rats for six weeks. With consumption of both the grain husks, total lipids, cholesterol and tryglycerides were lowered while HDL-cholesterol was found to be significantly increased. However, serum phospholipids were not affected significantly by grain husks. Cornbran was observed to be more hypolipidemic than blackgram seedcoat.     

饲喂益生菌Lactobacillus casei Zhang对高脂日粮大鼠肝脏脂质代谢的作用

【目的】研究不同剂量益生菌L. casei Zhang（2.0×1010 CFU/d、2.0×109 CFU/d和2.0×108 CFU/d）及其发酵乳饮料（2.0×108 CFU/mL/d）对高胆固醇血症大鼠肝脏脂质的治疗作用。【方法】采用高脂饲料诱导高脂血症,采用相应试剂盒测定肝脏总胆固醇水平（TC）和甘油三酯（TG）水平、粪便总胆汁酸水平与胆固醇水平以及血清载脂蛋白ApoAⅠ与ApoB水平。【结果】益生菌各剂量组和发酵饮料组与高脂模型组相比,肝脏总胆固醇水平（TC）和甘油三酯（TG）水平均显著降低(P＜0.05 或P＜0.01)。各试验组均可显著增加高血脂大鼠粪便总胆汁酸水平和血清载脂蛋白ApoAⅠ水平以及显著降低血清载脂蛋白ApoB水平(P＜0.01),但对粪便胆固醇水平影响不明显(P＞0.05)。【结论】益生菌L. casei Zhang主要通过增加总胆汁酸的排出和调节载脂蛋白水平来改善高血脂大鼠肝脏脂质水平。     

棉花突变体种子脂肪酸成分变化的诱导

油分在种子中的积累是生物合成的典型范例,其最终产物的多样性和多功能性,使得可通过遗传控制来有目的地提高种子的品质.种子油分含量的自然遗传倾向于低油分方向筛选.而目前,一系列新的育种目标逐渐拓展,以适应生物油脂化工的发展.另外,生物技术的不断创新也为食用及非食用油料作物突变体驯化甚至创造全新作物提供了便利.本研究分析了突变体种子的油分和脂肪含量及脂肪酸的构成,其中第11、7、2、9和5号突变体油分含量较高,这些突变体脂类含量增加了两倍.气相色谱分析表明,第11号突变体脂肪酸含量最高,其次为第7、2、9和5号突变体,在14种脂肪酸中,顺式亚油酸含量在各突变体中均为最高.     

四季鹅抱窝期间血浆某些代谢产物浓度的变化

四季鹅抱窝期间血浆葡萄糖浓度显著低于醒抱后恢复期水平,而血浆游离脂肪酸浓度高出四倍;并且两者呈强直线负相关。血浆总脂水平抱窝期显著高于醒抱后恢复期。结果提示:四季鹅在其抱窝期间,由于采食抑制,主要依靠消耗体内脂肪储备来满足其能量需要。     

Altered Fatty Acid Profile of Polar Lipids in Maize Seedlings in Response to Excess Copper

A wide range of cellular responses occur when plants are exposed to heavy metal stress, including changes in the membrane fatty acid composition. In this study, we examined the effect of excess copper (100 μm ) on the degree of unsaturation [double bond index (DBI) of 18‐C fatty acids] and the polar lipid profiles in maize (Zea mays L.). The level of unsaturation of total fatty acids decreased from 1.42 to 1.28 in maize roots. However, copper‐induced compositional changes of polar fatty acid composition show a general trend of increasing DBI. These responses suggest that individual 18‐C fatty acid classes may have specific roles in maintaining optimal membrane function, enabling plant growth under copper stress. The results also reveal key changes including marked decrease in total root phospholipid levels and consistent increase in the steryl lipid/phospholipid (SL/PL) ratio, as well as a decrease in monogalactosyldiacylglycerol/digalactosyldiacylglycerol (MGDG/DGDG) ratio, reflecting alteration of membrane permeability and fluidity. In shoots, the DBI obtained from phosphatidylcholine (PC), sulphoquinovosyldiacylglycerol (SQDG) and monogalactosyldiacylglycerol (MGDG) was increased. In contrast, these indices were decreased in phosphatidylinositol (PI) and phosphatidylglycerol (PG). However, the PI, PC, PG, MGDG and DGDG contents in shoots were significantly decreased, suggesting alterations in the photosynthetic membranes.     

枇杷种子脱水敏感性的初步研究

枇杷（EriobotryajaponicaL.）种子成熟采收时含水量高达58.7％，其中子叶含水量为55.3％，胚轴的含水量为73.2％。新鲜种子的发芽率和活力指数分别为90％和0.81。轻度脱水能较大幅度地提高发芽率和活力指数。但随着脱水程度的不断加深，子叶和胚轴的超氧物歧化酶（SOD）活性下降，丙二醛（MDA）含量和种子浸泡液的电导率增加，种子活力迅速降低。当子叶和胚轴的含水量分别降至35.5％和28.0％时，种子发芽力完全丧失。枇杷种子脱水敏感的一个重要原因就是在脱水劣变过程中，发生了膜脂过氧化作用，从而使膜脂含量下降，膜结构和功能受损，最终导至种子活力丧失。     

Influence of medium‐chain triglycerides on consumption and weight gain in rats: a systematic review

The use of medium‐chain triglycerides (MCTs) has been studied for years in an attempt to elucidate their effects in food intake and body weight in animals. The aim of this study was to determine whether there is evidence that the use of MCT reduces consumption and body weight gain in rats, a species chosen as it has been widely used as an animal model in different surveys. A search of scientific work was performed in November 2011 on two bases: ‘Web of Science’ and ‘PubMed’. The terms sample size and homogeneity, randomisation, food consumption and weight gain, body composition, enzyme activity and hormonal activity in rats were used as selection criteria. Thirteen papers were selected after the refinement of the research. Twelve studies measured weight gain and among these, seven detected a decrease in weight gain and five found no differences. Twelve papers also measured food intake and among these, four detected a decrease in consumption, one detected an increase and seven found no differences. Based on established criteria for the ranking of scientific papers, it is concluded that there is strong evidence that MCTs can effectively reduce the consumption and subsequent weight gain of animals. However, in the long term, there may not be differences in results depending on the phenotypic adaptation of animals to a new metabolic condition.