2个油菜CMS系统的酯酶和过氧化物酶同工酶分析

以甘蓝型油菜细胞质雄性不育系(CMS)Polima A及其保持系Polima B、陕2A及其保持系陕2B 4个材料初花期的叶片、叶柄以及花蕾组织为材料,采用聚丙烯酰胺垂直板凝胶电泳比较它们在酯酶(EST)和过氧化物酶(POD)同工酶酶谱的差异.结果表明,甘蓝型油菜不育系与其对应保持系的叶片、叶柄的EST同工酶谱均无明显差异,但两系花蕾的EST同工酶谱有一定的差异;Polima A与陕2A对应器官的EST同工酶谱均表现出明显差异.不育系与其对应保持系的叶片、叶柄的POD同工酶谱差异不明显,而两系花蕾的POD同工酶谱有明显的差异;两个不育系之间的POD同工酶谱明显不同.花蕾的EST和POD同工酶的条带数目明显多于相应材料的叶片和叶柄,且EST同工酶的条带数目明显多于相应的POD同工酶.因此,甘蓝型油菜CMS系统Polima A和陕2A有着不同的遗传背景.     

Mutation in the RGD motif decreases the esterase activity of <Emphasis Type="Italic">Xcc_est</Emphasis>

Five truncated constructs of Xcc_est GDSL esterase from Xanthomonas campestris were heterologously expressed and purified. The truncated constructs with a RGD motif had higher specific activities than those without the motif. The specific activity of wild-type Xcc_est was 32.5 ± 2.7 U/mg, while the RGD mutant was 12.5 ± 4.9 U/mg. Moreover, we expressed mature forms of the Xcc_est protein and the RGD mutant as inclusion bodies and, after refolding, there was no significant difference between the two constructs in specific activity. These results suggest that the RGD motif affects the esterase-domain folding in vivo during the translocation process. Jianjun Wang and Yanping Cao are contributed equally to this work.     

The SGNH-hydrolase of Streptomyces coelicolor has (aryl)esterase and a true lipase activity

The Streptomyces coelicolor A3(2) gene SCI11.14c was overexpressed and purified as a His-tagged protein from heterologous host, Streptomyces lividans. The purification procedure resulted in 34.1-fold increase in specific activity with an overall yield of 21.4%. Biochemical and physical properties of the purified enzyme were investigated and it was shown that it possesses (aryl)esterase and a true lipase activity. The enzyme was able to hydrolyze p-nitrophenyl-, α- and β-naphthyl esters and poly(oxyethylene) sorbitan monoesters (Tween 20–80). It showed pronounced activity towards p-nitrophenyl and α- and β-naphthyl esters of C₁₂–C₁₆. Higher activity was observed with α-naphthyl esters. The enzyme hydrolyzed triolein (specific activity: 91.9 U/mg) and a wide range of oils with a preference for those having higher content of linoleic or oleic acid (C18:2; C18:1, cis). The active-site serine specific inhibitor 3,4-dichloroisocoumarin (DCI) strongly inhibited the enzyme, while tetrahydrofurane and 1,4-dioxane significantly increased (2- and 4- fold, respectively) hydrolytic activity of lipase towards p-nitrophenyl caprylate. The enzyme exhibited relatively high temperature optimum (55 °C) and thermal stability. CD analysis revealed predominance of α-helical structure (54% α-helix, 21% β-sheet) and a T_m value at 66 °C.     

利用菌体酯酶同工酶和可溶性蛋白SDS—PAGE鉴定链霉菌融合子

利用酯酶同工酶技术鉴定链霉菌融合子证实,融合子SP-7和SR-T19的酯酶同工酶谱表现为介于双亲的中间型,并互不相同。此外,融合子SR-7还出现1条双亲所没有的决要酶带。表明融合子在融合过程中发生了真正的遗传重组,而不是亲本遗传物质的简单加合。菌体可溶性蛋白SDS－PAGE显示,融合子SR-7和SR-T19与双亲具有总体上的相似性,且可分辨的谱带数目和强度都超过了双亲,同时相互之间又有明显的不同,支持了这2个融合子均是双亲重组的后代。     

Population genetics of insecticide resistance in the mosquito Culex pipiens

Thirty years of control of the mosquito Culex pipiens using organophosphate insecticides (OP) has selected for OP-resistance alleles on a world-wide scale. As reviewed here, studies at the levels of gene and population allow identification of the main forces driving this process of adaptation. Three loci are involved in OP-resistance in C. pipiens. For two of these, adaptive mutations were found to be rare events, such that the ubiquitous distribution of certain resistance alleles could only be explained as deriving from a single origin by mutation followed by extensive migration. Population structure analyses confirmed that long-distance migration is frequent. Thus, different resistance alleles could accumulate and compete within populations soon after their origin by mutation. The different selection pressures acting on these alleles, i.e. their selective advantage in the presence of OP and their disadvantage (resistance cost) in absence of OP, were also analysed. Substantial differences in resistance cost among alleles present within the Mediterranean area were discovered. Long-term surveys of Mediterranean populations confirmed the pivotal importance of resistance cost in shaping the evolution of this adaptive polymorphism. Some hypotheses on the functional links between the nature of the initial mutation events and the subsequent evolution of polymorphism are discussed.     

对家鸡血清酯酶发育调控的初步研究

采用垂直平板聚丙烯酰胺凝胶电泳方法跟踪测定了 １０ 羽优黄 ３８０ 商品蛋鸡血清酯酶的遗传表现型,结果表明：血清酯酶（ Ｅｓ１）的遗传表达具有明显的发育阶段差异性,开产前均为有带类型,并表现出遗传多态现象,开产后 Ｅｓ１ 酶带消失,表现为无活性 Ｏ 型⒚对 Ｉ Ｓ Ａ Ｂ３８０ 父母代 Ｃ Ｄ 母鸡的扩大抽样测定结果验证了上述的结论⒚由此我们推测,母鸡产蛋期 Ｅｓ１ 区无活性“ Ｏ 型”可能是基因表达在不同发育阶段调控（抑制）的结果,因此不存在“ Ｅｓ１基因座位上决定 Ｏ 型的等位基因 Ｅｓ１ｏ ⒚ Ｅｓ１ 基因在开产前处于转录活跃状态,开产后基因转录就被抑制,以维持产蛋期母鸡体内所需较高的血脂水平⒚母鸡血清酯酶表达发育遗传学规律可能广泛存在于家禽各种群体之中⒚如果该推测成立的话,家鸡酯酶的生物合成就可能成为研究禽类基因表达和调控的理想模型⒚     

Variability of Storage Proteins and Esterase Isozymes in Vicia Sativa Subspecies

The relationships among 20 samples belonging to 6 subspecies of Vicia sativa based on the variability of seed storage proteins and esterase isozyme electrophoretic patterns was discussed in relation to variation in their morphology and chromosome characters. Electrophoretic protein profiles of different accessions of the same subspecies showed identical (e.g. macrocarpa and cordata) or similar (e.g. amphicarpa) patterns, confirming the stablity of seed storage proteins within these subspecies. However, considerable variation of protein patterns were observed within accessions of both nigra and sativa subspecies, which could be correlated to different geographical origins. Esterase pattern revealed a sharp distinction for each subspecies according to the number and loci of allelic bands. The dendrogram delimited the subspecies incisa and sativa as two separate groups, while the other subspecies were grouped together in another group.     

外源ABA对低温胁迫水稻幼苗酯酶同工酶的影响

研究外源ＡＢＡ对低温胁迫的水稻幼苗酯酶同工酶的影响。结果表明,水稻幼苗经７℃－１０℃低温处理６ｄ,长势明显不降,与其相应的酯酶同工酶也发生变化。外施ＡＢＡ提高了水稻幼苗的抗寒能力,同样在酯酶同工酶酶谱上也有相应改变。     

淡色库蚊 (Culex pipiens pallens Coquillett)的抗性酯酶表现型及其在杀虫剂压力下的变化趋势(英文)

对来自杭州、临海和金华三个城市的淡色库蚊种群进行了抗性酯酶表现型频率分布的测定和分析 ,同时对三个种群进行双硫磷、敌百虫、毒死蜱和马拉硫磷等四种有机磷杀虫剂的抗性品系筛选 ,逐代测定和分析各种群在不同杀虫剂压力下 ,其抗性酯酶表现型频率分布的变化。结果表明 ,三个自然种群中都存在酯酶B1 、B2 纯合表现型及酯酶B1 /B2 杂合表现型 ,其中酯酶B1 纯合表现型占优势。各自然种群中的抗性酯酶表现型频率分布有差异。经过杀虫剂的逐代筛选 ,各种群相对于某一杀虫剂的压力 ,表现出选择较为单一的抗性酯酶表现型的趋势 :双硫磷有利于酯酶B1 纯合表现型的选择 ,敌百虫和毒死蜱有利于酯酶B2 纯合表现型的选择 ,马拉硫磷则似乎有利于酯酶B1 纯合表现型和酯酶B1 /B2 杂合表现型的选择 ,但酯酶B1 纯合表现型相对于B1 /B2 杂合表现型来说 ,对马拉硫磷抗性更强一些。根据研究结果 ,就蚊虫的抗性酯酶基因对不同杀虫剂的选择优势及相应的蚊媒控制策略进行了讨论。