东亚飞蝗山西两地理种群酯酶特性的比较研究

对东亚飞蝗山西临猗和永济2个地理种群的酯酶特性进行了比较研究。非变性聚丙烯酰胺凝胶电 泳图谱显示：以α-乙酸萘酯为底物染色,2个东亚飞蝗种群谱带差别不明显。但是,酯酶动力 学研究结果表明：以α-乙酸萘酯和α-丁酸萘酯为底物时,永济种群的酯酶活性分别是临猗 种群的1.81倍和1.20倍。永济种群酯酶活性的增高可能与非变性聚丙烯酰胺凝胶电泳图谱显 示出较临猗种群多出的酶带有关。体外酯酶抑制动力学研究表明：永济和临猗2种群所含酯酶大 都为B型酯酶,其含量分别为84.94%和91.47%。永济种群对对氧磷的耐受性要高于临猗种群 ,我们推测可能与2种群马拉硫磷使用背景不同有关。     

东亚飞蝗山西两地理种群酯酶特性的比较研究

对东亚飞蝗山西临猗和永济2个地理种群的酯酶特性进行了比较研究.非变性聚丙烯酰胺凝胶电泳图谱显示:以a-乙酸萘酯为底物染色,2个东亚飞蝗种群谱带差别不明显.但是,酯酶动力学研究结果表明:以a-乙酸萘酯和α-丁酸萘酯为底物时,永济种群的酯酶活性分别是临猗种群的1.81倍和1.20倍.永济种群酯酶活性的增高可能与非变性聚丙烯酰胺凝胶电泳图谱显示出较临猗种群多出的酶带有关.体外酯酶抑制动力学研究表明:永济和临猗2种群所含酯酶大都为B型酯酶,其含量分别为84.94%和91.47%.永济种群对对氧磷的耐受性要高于临猗种群,我们推测可能与2种群马拉硫磷使用背景不同有关.     

棉蚜抗氧化乐果品系及敏感品系羧酸酯酶性质的比较

在室内用氧化乐果逐代筛选的棉蚜抗性品系,相对于敏感品系的抗性倍数是17。用α-乙酸萘酯（α-NA）、α-丁酸萘酯（α-NB）、α-磷酸萘酯（α-NP）和β-磷酸萘酯（β-NP）作底物比较研究了氧化乐果抗性和敏感品系棉蚜Aphis gossypii羧酸酯酶的比活力、米氏常数（K_m）和最大反应速度V_max）等有关的动力学常数。以α-NA和α-NB作底物时,抗性品系棉蚜的比活力显著低于敏感品系的;以α-NP和β-NP作底物时,两个品系棉蚜的比活力、K_m和V_max没有明显差异。用α-NA、β-NA作底物染色做酯酶同工酶电泳,抗性品系棉蚜的酯酶同工酶染色比敏感品系棉蚜的浅。     

有机磷对抗拟除虫菊酯家蝇的毒力

测定敏感、抗溴氰菊酯(Del-R)、抗氯菊酯(2Cl-R)的家蝇品系对有机磷杀虫剂敌敌畏、辛硫磷及马拉硫磷的LD₅₀,α-乙酸萘酯（α-NA）酯酶动力学,酯酶的活性和酯酶的抑制作用。Del-R和2Cl-R的家蝇品系对三种有机磷杀虫剂的抗性倍数为0.966～7.190倍,均为低抗水平。三个家蝇品系的羧酸酯酶活性水平与抑制中浓度存在正相关性,说明羧酸酯酶在抗拟除虫菊酯家蝇对有机磷杀虫剂的抗性中起一定的作用。     

两个不同生态特征蝗区东亚飞蝗的两种代谢酶

黄骅和平山是中国河北省两个不同的蝗区,这两个蝗区的生态特征有很大的不同。黄骅位于河北平原,靠近渤海湾．属于滨海蝗区,蝗区植被以芦苇为主,是我国东亚飞蝗重点防治地区;平山位于河北和山西交界处,仍属于山区,蝗区位于岗南水库库区,属于滨湖蝗区,植被以稗草为主,并兼有玉米、豆类等农作物,为了保护岗南水库水质不受污染,该蝗区很少进行防治。对采自这两个蝗区东亚飞蝗的两种代谢酶：酯酶和谷胱甘肽S-转移酶进行了比较研究。用对氧磷、马拉氧磷、西维因及毒扁豆碱等4种抑制剂对这两个种群飞蝗的酯酶进行体外抑制实验,结果表明,这两个种群的大部分酯酶属于B-型。在雌性飞蝗中、用α-NA,αNB和β-NA3种酯酶底物测定酯酶活性,黄骅种群比平山种群的酯酶活性分别高1．63、1．66和1．70倍．雄性中则分别高1．12、1．41和1．27倍。对两个种群酯酶活性频率分布进行比较,黄骅种群中酯酶活性高的个体数远大于平山种群。两个种群酶活性的差异与马拉硫磷半致死剂量(LD50)的差异很相近,这提示酯酶活性的提高在东亚飞蝗对马拉硫磷的抗性中起一定的作用。酯酶活性频率分布显示出东亚飞蝗黄骅种群比平山种群具有较高的马拉硫磷抗性发展趋势．其抗性发展速度较平山种群快。然而,黄骅种群谷胱甘肽S-转移酶活性略低于平山种群,因此推测,谷胱甘肽S-转移酶活性与这两个东亚飞蝗种群对马拉硫磷的抗性无明显相关。     

不同寄主植物与棉蚜酯酶活性的关系

通过测定不同越冬寄主植物棉蚜Aphis gossypii种群α-乙酸萘酯（α-NA）酯酶的活力,结果表明：山东高密棉田棉蚜种群酯酶活力是北京花椒棉蚜酯酶活力的2.4倍,石榴、木槿上棉蚜酯酶活力是花椒棉蚜酯酶活力的1.3-1.5倍,不同寄主植物棉蚜α-NA酯酶和β-NA酯酶的频率分布表明：鼠李、花椒棉蚜的α-NA酯酶频率分布范围较集中,酯酶活力（每0.033头蚜虫的OD值）小于0.10时的频率分别为70%和62%,其个体累积率达50%时的酯酶活性（EF50）分别为0.08和0.085(每0.033头蚜虫的OD值）;石榴、木槿和棉苗上α-NA酯酶频率分别为25%、31%和45%,其EF50分别的0.154、0.1368和0.1138,酯酶活力明显比鼠李和花椒棉蚜高;高密棉蚜为4%,EF50为0.2113,频率分布范围较宽。β-NA酯酶的频率分布,鼠李、花椒、木槿和棉苗上棉蚜酯酶活力（每0.033头蚜虫的OD值）小于0.10时为52%-62%的个体,EF50分别为0.098、0.084、0.102和0.091,寄主之间差异不大,而石榴和高密棉蚜分别为23%和3%,EF50分别为0.135和0.2136,与其它4个寄主有明显差异。     

草甘膦对空心莲子草叶甲Agasicles hygrophila成虫3种代谢酶活性的影响

采用不同浓度的草甘膦0.41 g/L、0.82 g/L、1.23 g/L、1.64g/L、2.05 g/L分别以胃毒和触杀法处理空心莲子草叶甲Agasicles hygrophila成虫,测定其乙酰胆碱酯酶(AChE)、羧酸酯酶(CarE)和谷胱甘肽S-转移酶(GSTs)比活力.试验结果表明:两种处理,草甘膦对AChE活力均有不同程度的抑制作用;对CarE活力影响较为显著,在2.05 g/L浓度下,胃毒处理CarE对α-乙酸萘酯(α-NA)和β-乙酸萘酯(β-NA)水解能力分别是对照组的50%和57%,触杀处理CarE对α-乙酸萘酯(α-NA)和β-乙酸荼酯(β-NA)水解能力分别是对照组的53%和59%;胃毒处理埘酶活力影响大于触杀处理,草甘膦对GSTs的活力影响不明显.     

北京地区家蝇对拟除虫菊酯的抗药性与α-乙酸萘酯(α-NA)酯酶的关系

 通过1988年以来对北京地区家蝇(Musca domestica L.)抗药性的研究表明,北京朝阳、回龙观、宣武、景陵地区的家蝇种群与海口种群LD_(50)比较,对溴氰菊酯的抗性为5.4—17.2倍,对二氯苯醚菊酯的抗性为2460—3080倍。不同抗性水平的家蝇种群中,α-NA确酶活性大于0.5(A600值(0.01头·15分))的个体频率与其溴氰菊酯和二氯苯醚菊酯的抗性程度具有显著相关(相关系数分别为0.94和0.98)。抗性程度较高的宣武种群平均酯酶活性为280μmol/(mg蛋白质·分),是海口敏感种群的10.5倍。海口种群α-NA酯酶的米氏常数值(Km)为4.49mol/L,分别是朝阳、回龙观、宣武种群的4.7、4.2和2.3倍,说明抗性种群α-NA酯酶对底物的亲合力高于相对敏感的海口种群。     

不同地区小菜蛾种群羧酸酯酶的毒理学性质研究

在1995～1997年对湖北武汉、河北张家口地区小菜蛾Plutella xylostella(L.)种群的抗药性进行了研究。结果表明对阿维菌素的抗性和台湾敏感种群相比,武汉种群抗性为4.3倍,张家口种群抗性为1.8倍;对马拉硫磷的抗性武汉和张家口种群分别为2.2和2.9倍;对氟铃脲的抗性分别为3.2和0.5倍;对溴氰菊酯的抗性分别为2.4和1.7倍。对羧酸酯酶(Care)的研究结果表明,三个种群幼虫CarE对a-乙酸萘酯或β-乙酸萘酯(a或β-NA)水解活性差异显著,但成虫Care活性没有明显差异。武汉和张家口种群幼虫CarE对a-NA和β-NA的亲和力没有明显差异,但是武汉种群幼虫Care对底物的亲和力高于张家口种群。敏感品系Care对a—NA的亲和力明显高于对β-NA,相差约3倍。不同类型的抑制剂对小菜蛾幼虫CarE的抑制能力不同。增效磷和对氧磷对敏感品系CarE水解a-NA具有明显的抑制作用,分别比对武汉种群Care的抑制作用大4.577倍(SVl)和2.576倍(对氧磷)。     

新疆棉铃虫对溴氰菊酯和硫丹 抗性的生化机理研究

通过生物测定和生化分析研究了新疆棉铃虫Helicoverpa armigera (Hübner)敏感种群和室内筛选获得的抗性种群对硫丹和溴氰菊酯的反应及其α-乙酸萘酯酶和乙酰胆碱酯酶的动态活性反应。结果表明,筛选后新疆棉铃虫对硫丹和溴氰菊酯产生的抗性倍数分别为13倍和66倍。两个抗性种群的α-乙酸萘酯酶和乙酰胆碱酯酶比活力均高于敏感种群。相应杀虫剂预处理后,α-乙酸萘酯酶酶活力受到抑制。抗性种群的α-乙酸萘酯酶对底物的亲和力高于敏感种群,但Vmax低于敏感种群。抗性种群的乙酰胆碱酯酶对底物的亲和力显著低于敏感种群,Vmax比敏感种群高。聚丙烯酰胺凝胶电泳显示,两个抗性种群都有一条特异性酶带,其迁移率相近,且均可被甲基对氧磷抑制。因此推测,α-乙酸萘酯酶参与了新疆棉铃虫对硫丹和溴氰菊酯的抗性,具有代谢和阻断作用;乙酰胆碱酯酶对抗性的产生也起到了重要作用。     

Toxicological and biochemical characterizations of malathion sensitivity in two field populations of Oxya chinensis （Orthoptera： Acridoidea）

We evaluate comparative toxicity of malathion in the two populations of the grasshopper Oxya chinensis, collected from Daixian and Fanshi of Shanxi province, China. General esterases and acetylcholinesterase （ACHE） from the two populations were characterized and compared. LD50 of the Daixian population （7.58 μg/g body weight） was 2.02-fold higher than that of the Fanshi population （3.75μg/g body weight）. General esterase-specific activities in the Daixian population were 1.91,130 and 1.85-fold higher than those in the Fanshi population, when α-NA, α-NB and β-NA were used as a substrate, respectively. Kinetic studies of general esterase showed that Vmax values of general esterases hydrolyzing α-NA,α-NB and β-NA in the Daixian population were 2.15-, 1.12-, and 1.47-fold, respectively, higher than those in the Fanshi population. The AChE activity of the Fanshi population was 1.54-fold higher than that of the Daixian population. Kinetic analysis of AChE showed that significant differences were presented between the two populations in the Km values; and the Vmax value in the Fanshi population was higher than that in the Daixian population. Inhibition studies of AChE indicated that AChE from the Daixian population was 2.56-, 2.80-, and 2.29-fold less sensitive to inhibition by paraoxon, chlorpyrifos-oxon, and demeton-S-methyl, respectively, than that from the Fanshi population. These biochemical characterizations of general esterases and AChE were consistent with malathion bioassay in the two populations. It is inferred that the reduced sensitivity of altered AChE and increased general esterase activities play an important role in the differences of insusceptibility of Oxya chinensis to malathion between the two populations.     

Characterization of the esterase isozymes of Ips typographus (coleoptera,scolytidae)

Four esterase isozymes hydrolyzing α-naphthyl acetate (α-NA) were detected screening whole body homogenates of larvae and adults of Ips typographus by electrophoresis. Two of the four isozymes (isozymes 3 and 4) were not detected by α-NA staining in the pupal stage, but topical application of juvenile hormone III (JH III) on the pupa induced these isozymes. The JH esterase (JHE) activity on the gel was associated with the proteins of isozyme 2. The compounds OTFP, PTFP, and DFP inhibited this catalytic activity of isozyme 2 on the gel at low concentrations, whereas the proteins of isozyme 3 and 4 were affected only at higher concentrations. A quantitative developmental study was performed to characterize which of the esterases hydrolyzed JH III, using a putative surrogate substrate for JH (HEXTAT) and α-NA. The I₅₀ of several esterase inhibitors and the JH metabolites were also defined. All findings supported the results that a protein associated with isozyme 2 is catabolizing JH and that isozymes 3 and 4 are the main contributors to the general esterase activity on α-NA. The JHE from Tenebrio molitor was purified by affinity chromatography. Although the recovery was low, an analytical isoelectric focusing gel showed that the JHE activity of the purified enzyme. T. molitor cochromatographed at the same pl as the JHE activity of I. typographus. Arch. Insect Biochem. Physiol. 34:203–221, 1997. © 1997 Wiley-Liss, Inc.     

Role of juvenile hormone metabolism during embryogenesis of the house cricket,Acheta domesticus

The duration of embryogenesis was 9.5 days for house crickets, Acheta domesticus (L.), reared at 35°C. The major route of juvenile hormone (JH) metabolism was ester hydrolysis. The level of α-naphthyl acetate (α-NA) esterase activity per mg wet weight remained relatively constant throughout embryogenesis and was similar to that of eggs dissected from the oviducts. JH esterase activity per mg wet weight was highest in the dissected and day-1 eggs, declined to one-third of this peak activity by day 5, and then remained unchanged through hatching. Two populations of esterases (130,000 and > 200,000 in molecular weight) which metabolized JH and α-NA were resolved in day-1 eggs by gel filtration chromatography. Specific JH esterase appeared by day 4 with a molecular weight of 200,000. Correlative evidence is presented from other insect species that supports a functional role for JH metabolism during embryo development.     

不同地区致倦库蚊种群相关酯酶 基因的特征分析

分别从广州、沙市、武汉近郊采集到致倦库蚊Culex pipiens quinquefasciatus,对单只蚊虫进行淀粉凝胶电泳和Southern杂交方法的分析结果表明：3个实验种群中均分布有与抗性有关的高活性酯酶β1¹,酯酶α2/β2分布于广州实验种群中;广泛分布于地中海地区尖音库蚊Culex pipiens种群中的酯酶α4/β4、α5/β5在以上3个种群中均不存在。但是,在3个实验种群中均发现存在有一对新的高活性酯酶α8/β8,其电泳迁移率和限制性酶切片段均与目前已报道的几种高活性酯酶不同。含这两对新酯酶的蚊虫将应进一步从种群中纯化,纯合蚊虫新品系做分子特征的研究。     

Characterization and the developmental role of plasma juvenile hormone esterase in the adult cabbage looper,Trichoplusia ni

Juvenile hormone (JH) esterase was characterized from the plasma of adult females of the cabbage looper, Trichoplusia ni, and compared with that present in 4th and 5th instar larvae. Ester hydrolysis was the principal route of JH metabolism. Gel filtration of plasma resolved a single peak of JH esterase which was distinct from that of the α-naphthyl acetate (α-NA) esterase activity. The JH esterase apparent molecular weight was 62,000 in prepupae and virgin, female adults and 69,000 in 2-day-old 4th instar larvae. Broad range isoelectric focusing of plasma of prepupae and adults resolved a major peak of activity at pH 5.5 with a minor peak of activity at pH 6.1 and in 4th instar larvae at pH 5.45 and 5.8, respectively. By this method JH esterase was resolved from the α-NA esterase activity. The plasma of prepupae and adults metabolized JH I at about twice the rate of JH III. JH esterase activity from adult plasma was more stable than the α-NA esterase activity. Adult JH esterase activity was insensitive to inhibition by O,O-diisopropyl phosphorofluoridate in contrast to that of the α-NA esterase activity. Mated females oviposited 8 times more eggs than virgin females to 10 days after emergence. The total haemolymph protein content of virgin females remained high throughout the period of study whereas mated females showed a significant decline beginning on day 4. JH esterase activity remained unchanged in virgins whereas it declined drastically in mated females. The α-NA esterase activity declined to low levels shortly after emergence in both groups. JH and α-NA esterase activity was not affected by the application of the juvenoid, (RS)-methoprene. The present study provides evidence of a functional role for JH esterase in JH metabolism and reproduction in adult T. ni. JH esterases in the adult were identical to that of prepupae by the methods described above.     

USING FILTER PAPER TEST FOR DETECTING INHIBITORY FREQUENCY OF ORGANOPHOSPHATE TO ESTERASES IN COTTON APHIDS, APHIS GOSSYPII (GLOVER)

Abstract The individual esterase activity which is measured by filter paper test (FPT) method may determine the resistance of cotton aphids Aphis gossypii (Glover) against organophosphorus (OP) insecticides. For testing accurately resistant level caused by different insecticides, we applied FPT method for measuring inhibitory action of methyl-parathion, monocrotophos and omethoate to α-NA esterase of individual cotton aphids, and compared the inhibitory frequencies of these three insecticides to susceptible population (BCA) and resistant population (GCA). Results showed that their inhibitory frequencies of the susceptible population were evidently higher than that of the resistant population. The inhibitory rate of α-NA esterase in F1 generation individual cotton aphids by monocrotophos was low when the cotton aphid population had been treated in advance with monocrotophos, but it got to 75%-90% when the cotton aphid population had been untreated in advance with monocrotophos. Besides, the differences in esterase activity were not obvious between them. In same region when cotton aphids were treated with insecticides the inhibitory frequency of esterases in individual by the insecticides was lower than counterparts in individual cotton aphids which were not treated with insecticides. All these demonstrated that inhibitory frequency of α-NA esterase in individual cotton aphids by OP insecticides could be used as a technique of forecasting pest resistance.     

The occurrence of an adult reproductive diapause in the univoltine life cycle of the beech leaf mining weevil,Rhynchaenus fagi L.

Summary

Juvenile hormone (JH) and α-naphthyl acetate (α-NA) esterase activity was measured on a daily basis during embryogenesis of the house cricket, Acheta domesticus. In eggs dissected from the lateral oviducts and embryos through blastokinesis, there were elevated levels of nonspecific JH esterase activity. The JH esterase activity could not be resolved from the α-NA esterase activity by gel filtration chromatography and the metabolism of both substrates was inhibited equally by 0,0-diisopropyl phosphorofluoridate (DFP). From blastokinesis through egg hatch, the JH esterase activity was maintained at relatively low levels and was resolved from the α-NA esterase activity by gel filtration. The α-NA esterase activity was inhibited by DFP while the JH esterase activity was relatively unaffected. Low JH titers in eggs must be maintained through blastokinesis for normal development. Elevated JH esterase activity in eggs during this period appears to have a functional role in the metabolism of maternal JH in the egg.