Composition and Distribution of Free Amino Acids in Flatpea (Lathyrus sylvestris L.) as Influenced by Water Deficit and Plant Age

Drought-stressed flatpea (Lathyrus sylvestris L.) plants from8 to 22 weeks old were analysed for nitrogen, soluble proteinand free amino acids. An increase in nitrogen and free aminoacid concentrations and a decrease in soluble protein levelwere observed in roots of plants up to 16 weeks old. The cumulativeconcentration of free amino acids increased with drought stress.Tissue concentrations of 2, 4-diaminobutyric acid (1.6–2.6%of the dry weight) were highest in leaves. Levels increasedsteadily, nearly doubling, in leaves and stems between weeks10 and 16. Levels in drought-stressed leaves were, on average,11.9% higher than those of controls. Estimated concentrationsof a mixture of 4-aminobutyric acid and an unknown amino acidwere highest in stems, increased in this tissue with age andtended to increase in stems and leaves and decrease in rootsin response to water deficit. Levels of the mixture of homoserineand another unidentified amino acid were not influenced by ageor water status of the plants. Root concentrations of asparagine,arginine, glutamine, aspartate, and another prominent, unidentifiedamino acid increased with plant age and reached a peak at thetime of flowering (14 to 18 weeks). Only the concentration ofthe unknown compound was elevated following drought stress.Concentrations of valine, isoleucine, leucine, phenylalanine,and methionine also increased during this period and were elevatedin drought-stressed plants. Proline levels increased with plantage and drought stress, but proline accounted for only about10% of the total free amino acids in the drought-stressed plants. Key words: 2, 4-Diaminobutyric acid, drought, flatpea     

厚壳贻贝whirlin类贝壳基质蛋白的重组表达与功能分析

贝壳历来是生物工程和材料学研究的重要对象。贝壳中的贝壳基质蛋白质在贝壳的形成与发育过程中具有重要的调控作用。Whirlin类蛋白质(Whirlin-like protein,WLP)是一种从厚壳贻贝(Mytilus coruscus)中鉴定的新型贝壳基质蛋白质。序列分析结果显示,该蛋白质含有PDZ(postsynaptic density/Discs large/Zonula occludens)结构域,而该结构域对贝壳生物矿化的影响目前尚无报道。为深入了解WLP在贝壳形成中对碳酸钙晶体的影响,在序列分析基础上,采用密码子优化结合原核重组表达,获得其重组表达产物后,开展了重组WLP对碳酸钙晶体形貌及晶型的影响研究,结晶速度抑制以及碳酸钙晶体结合分析。分析结果表明,重组WLP能诱导文石型碳酸钙晶体的形貌和方解石型碳酸钙晶体的晶型发生改变;同时重组WLP对碳酸钙晶体具有结合作用,且能抑制碳酸钙晶体的结晶速度。上述结果表明,WLP对贝壳的形成及发育具有重要影响,并可能在贝壳肌棱柱层的形成中发挥了重要作用。     

中国黑缘蝽属新种记述(半翅目:缘蝽科)

中国黑缘蝽属(Hygia Uhler)为缘蝽科缘蝽亚科中较大的属,体均为黑色,常具黄色或褐黄色斑。截止到目前已记载19种,现由近年来采集的标本中又发现7新种,分属于两个亚属:黑缘蝽亚属Hygia Uhler及沟缘蝽亚属Colpura Bergroth,现描述如下。文内所用量度单位均为毫米。模式标本除注明者外,均存放南开大学生物系。     

利他林对戊巴比妥钠深麻醉家兔呼吸的兴奋效应及机制

在125只呼吸受戊巴比妥钠抑制并切断双侧颈迷走神经的家兔,分析了利他林(MP)呼吸效应的中枢部位及可能的递质。静脉注射 MP(2mg/kg)引起呼气时程显著缩短和呼吸频率显著增加。去除颈动脉体不影响 MP 兴奋呼吸的效应。将浸有2%MP 溶液的滤纸(2×2mm~2)贴敷在第四脑室底闩附近,或微量注射2%MP 2μl 到延髓 NTS 区,均可引起上述效应,但 NA区、NPBM 区和皮层体感运动区则无效。第四脑室或 NTS 区微量注射酚妥拉明均可阻断 MP兴奋呼吸的效应,但第四脑室注射心得安却不能阻断。结果提示,MP 可能作用于 NTS 区,在肾上腺素能α受体的参与下,受戊巴比妥钠抑制的家兔发生呼吸频率增快的效应。     

Seasonal plasticity in growth and development of the speckled wood butterfly, Pararge aegeria (Satyrinae)

Regulation of growth and development by photoperiod was studied in a population of the speckled wood butterfly, Purarge aegeria L. (Lepidoptera: Satyrinae), from southern Sweden. Individuals were reared in a range of photoperiodic regimes (9L. to 22L) and temperatures (13°C to 21° C). Plasticity was found for important life-history traits- generation time, growth rate and final weight and seasonal regulation of development in response to photoperiod was found to occur at two levels. Purarge aegeria hibernates as a third instar larva or in the pupal stage, cantering one of four major developmental pathways in response to photoperiod: (1) direct development in both the larval and pupal stages, (2) pupal winter diapause with or (3) without a preceding larval summer diapause, or (4) larval winter diapause. In addition to this high-level regulation of individual development, larval growth rate and pupal development rate also appear to be finally regulated by photoperiod within each major pathway. As photoperiods decreased from 22 h to 17 h at 17° C, growth rate among directly developing larvae increased progressively, as was the case for larva? developing according to a univoltine life cycle from 17 h to 14 h. At two photoperiods, 13 h and 16 h (corresponding to shifts between major pathways), both larval and pupal development were extremely variable with the fastest individuals developing directly and the slowest developing with a diapause. This indicates a gradual nature of diapause itself, suggesting that the two level may not he fundamentally different.     

消炎痛对大鼠肝线粒体微粒体^45Ca摄取及膜流动性的影响

我们曾报道消炎痛预处理在大鼠能引起明显的肝保护作用,为了进一步探讨消炎痛肝保护作用的机制,本工作观察了它对大鼠肝线粒体、微粒体钙调节作用及膜流动性的影响。结果表明,经消炎痛整体预处理的大鼠肝线粒体和微粒体的钙摄取及膜流动性均明显增加,但是,将消炎痛直接加入由正常大鼠分离的线粒体或微粒体中,则反而使膜的流动性降低。这些变化可能与消炎痛的肝保护作用有关。     

在原代培养的大鼠肝细胞观察消炎痛的细胞保护作用

我们曾观察到消炎痛预处理能明显减轻四氯化碳和半乳糖胺对大鼠的肝损伤作用,本工作采用原代培养的大鼠肝细胞进一步观察了这一现象。结果表明,经消炎痛整体处理后分离的大鼠肝细胞,在原代培养的条件下,对四氯化碳的损伤仍然具有明显的抵抗作用,表现为细胞内酶的漏出少于对照组。正常大鼠离体肝细胞在原代培养条件下用消炎痛处理,在相当大的剂量和相当长的时间范围内未出现明显的抗损伤作用。结果提示:消炎痛整体处理可使肝细胞本身获得抗损伤的能力,而这种抗损伤能力的产生可能有赖于肝细胞外其它因素的参与。     

艾菲属吸虫一新种（复殖目：鳞肉科）

艾菲属(Aephnidiogenes)吸虫在我国为首次报道,文中记述了采自海南岛一种胡椒鲷(Plectorhynchus pictus)体内的海南艾菲吸虫,新种(Aephnidiogenes hainanensis sp. nov.),对其形态特征进行了描述,并与相近种作了比较。虫体11.641—17.425mm,卵巢为不规则三角形,卵子66—69×33—45μm。     

压脚痛阈测定法的改进和应用

本文介绍一种改进的压脚测痛法。采用电机驱动替代用手挤压橡皮球完成升压过程;通过一个自动的电路切断结构判定抽脚反应,较目视更加客观;用读数保持电路记录压力变化,较直接读取刻度值更加准确,可靠。这些优点,业经电针和吗啡镇痛实验验证。