果醋对高脂小鼠血脂和肝脏脂质过氧化的影响

本文目的在于研究果醋对高脂小鼠血脂和肝脏脂质过氧化的影响。长期饲喂高脂饲料造成小鼠高血脂和肝脏脂质过氧化模型,预防性给予果醋,测定血清中总胆固醇（TC）,甘油三酯（TG）,低密度脂蛋白胆固醇（LDL-C）和高密度脂蛋白胆固醇（HDL-C）的含量;测定肝脏中脂质过氧化终产物丙二醛（地A）的含量和超氧化物歧化酶（SOD）的活性。结果证明果醋可以明显降低高脂小鼠血清中TC,LDL含量和肝脏组织中MDA含量,提高肝脏组织SOD活性。     

Profiling of short RNAs during fleshy fruit development reveals stage-specific sRNAome expression patterns

Plants feature a particularly diverse population of short (s)RNAs, the central component of all RNA silencing pathways. Next generation sequencing techniques enable deeper insights into this complex and highly conserved mechanism and allow identification and quantification of sRNAs. We employed deep sequencing to monitor the sRNAome of developing tomato fruits covering the period between closed flowers and ripened fruits by profiling sRNAs at 10 time-points. It is known that microRNAs (miRNAs) play an important role in development but very little information is available about the majority of sRNAs that are not miRNAs. Here we show distinctive patterns of sRNA expression that often coincide with stages of the developmental process such as flowering, early and late fruit maturation. Moreover, thousands of non-miRNA sRNAs are differentially expressed during fruit development and ripening. Some of these differentially expressed sRNAs derived from transposons but many derive from protein coding genes or regions that show homology to protein coding genes, several of which are known to play a role in flower and fruit development. These findings raise the possibility of a regulative role of these sRNAs during fruit onset and maturation in a crop species. We also identified six new miRNAs and experimentally validated two target mRNAs. These two mRNAs are targeted by the same miRNA but do not belong to the same gene family, which is rare for plant miRNAs. Expression pattern and putative function of these targets indicate a possible role in glutamate accumulation, which contributes to establishing the taste of the fruit.     

家蝇蛹和果蝇蛹繁育的蝇蛹金小蜂对果蝇蛹的寄生比较

【目的】蝇蛹金小蜂Pachycrepoideus vindemmiae(Rondani)是杨梅园等果园果蝇类害虫蛹期常见寄生蜂种类,在对果蝇类害虫的生物防治上具有重要价值。本文旨在探讨使用家蝇蝇蛹为替代寄主繁育蝇蛹金小蜂的方法。【方法】探讨分别以家蝇蛹和果蝇蛹繁育的蝇蛹金小蜂对家蝇和果蝇蝇蛹的选择性,并比较了在两种寄主上繁育的蝇蛹金小蜂在大小、寿命、产卵期、后代产量和性比等方面的差异。【结果】结果表明与果蝇蛹相比,家蝇蛹明显较大,在家蝇蛹上发育的蝇蛹金小蜂后代个体也明显较大;家蝇蛹和果蝇蛹发育的寄生蜂雌蜂寿命为(13.4±4.11)和(3.94±2.49)d、产卵期分别为(11.4±4.11)和(3.13±2.42)d、单头雌蜂后代雌蜂数量分别为(34.31±31.83)和(7.88±3.58)头,在家蝇蛹上繁育的寄生蜂明显具有较长的寿命和产卵期、更多的雌雄蜂后代数量;在对家蝇蛹和果蝇蛹的选择上,繁育自家蝇和果蝇的蝇蛹金小蜂雌蜂选择频率的差异不大。【结论】利用家蝇蛹繁殖的蝇蛹金小蜂在寄生果蝇蛹时具有更大优势,在繁殖蝇蛹金小蜂控制杨梅园等果蝇的为害时,可以选择家蝇蛹作为替代寄主。     

β-oxidation enzymes and the carnitine-dependent oxidation of palmitate and palmitoyl CoA in mitochondria from avocado

Two sites for the β-oxidation of fatty acids in avocado (Persea americana L.) mesocarp exist. One site is the microbody, the other the mitochondrion. It is apparent that the mitochondrial membrane barrier, which remains intact after sucrose density gradient centrifugation, prevents rapid access of acyl CoA substrates to matrix β-oxidation sites. Thus, intact mitochondria showed little β-oxidation enzyme activity. Rupturing of the mitochondrial membrane allowed rapid access of the acyl CoA substrates to matrix sites. Consequently, in ruptured mitochondria, high O₂-oxidation enzyme activities were measured. O₂ uptake studies further distinguished the two organellar sites of β-oxidation. During palmitoyl CoA oxidation, O₂ uptake was reduced by catalase and increased by KCN in the microbodies, whilst mitochondrial O₂ uptake was unaffected by catalase and reduced by KCN. This reflected the differing fates of FADH₂, produced during the first β-oxidation step, in the two organelles. In addition, only the mitochondrial β-oxidation of fatty acids was carnitine-dependent.     

Competitive Superiority of Early Acting Species: A Case Study of Opiine Fruit Fly Parasitoids

Koinobiont parasitoids that attack an early host stage may have an advantage in suppressing competing parasitoids that attack later stages of the same host. We examined the competitive interaction between the two most important parasitoids of tephritid fruit flies in Hawaii, Fopius arisanus (Sonan), and Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae). The former species attacks host eggs while the latter attacks host larvae, and both species emerge as adults from the host puparia. F. arisanus physiologically suppressed egg development of D. longicaudata. Over 90% of D. longicaudata eggs died in the presence of F. arisanus larvae within host larvae of either the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) or the oriental fruit fly, Bactrocera dorsalis (Hendel). D. longicaudata appeared not to discriminate against hosts previously parasitized by F. arisanus. The mechanism that F. arisanus uses to eliminate D. longicaudata is similar to that which it employs to eliminate five other larval fruit fly parasitoids so far reported in Hawaii. This suggests that there is a broad competitive superiority of the early acting species in fruit fly parasitoids. We discuss the implication of this in relation to future biological control introductions against tephritid fruit flies.     

我国新分离乙型脑炎病毒株毒力特征研究

将分离自不同年代的17株乙脑毒株在小鼠脑内传代,然后将病毒在BHK21细胞单层上观察不同毒株的空斑形成大小形态,小鼠脑内和皮下途径接种观察病毒的毒力,结果显示不同毒株在BHK21细胞上形成的噬斑大小不尽相同,减毒株形成的噬斑最小。所有毒株对小鼠的脑内毒力都很强,病毒滴度高达lg8.0/mL以上,毒株间无明显差异。毒株对9～11g小日龄小鼠的皮下毒力有一定差异但不明显,但对14～16g较大日龄小鼠则差别明显。PFU/LD50的对数值差异除一株(M47株)为8.44外,其余各株差别在3.94～0.45间。本研究结果证明自然界乙脑毒株存在明显的神经外毒力差异,毒力差异与分离年代和病毒基因型无关,但从人体分离到的毒株毒力表现较强。     

Ecology of the fruit spotting bug, Amblypelta lutescens lutescens Distant (Hemiptera: Coreidae) in cashew plantations, with particular reference to the potential for its biological control

Abstract  The fruit spotting bug, Amblypelta lutescens lutescens, is one of the principal insect pests of cashews in Australia. Its population dynamics were studied using field observations and long-term monitoring to find suitable management methods. Observations of bugs reared in netting bags showed a sequence of change in bug-damage symptoms after 12 h and up to 3 d. Field observations revealed that adults preferred to feed and rest on the shady side of the tree. The number of bugs observed accounted for only 17–35% of the total variability in the number of damaged shoots, suggesting that the number of flushing shoots (leaf, flower or young nuts) with fresh damage symptoms was a more reliable parameter for determining the presence and level of activity of bugs than was a direct estimate of the number of bugs. The green tree ant, Oecophylla smaragdina (F), was the most important factor regulating bug populations. When predation was excluded as a factor, the number of flushing shoots and maximum temperature accounted for 80% of the total variability in the bug damage. Green tree ants should be considered as an important biological control agent for fruit spotting bug, and monitoring should be commenced when cashew trees start to flush (using damaged shoots as indicator).     

秦光油桃果实生长曲线和落果波相的观察

以北京8号桃作对照,对秦光油桃果实生长发育和落果进行了系统观察,结果表明秦光油桃果实生长曲线与桃一样,也可分为3个时期。不同的是秦光油桃硬核期果实仍继续生长,果实生长不呈典型的“双S”曲线。秦光油桃硬核期落果较重,这可能与其在硬核期继续生长有关。