蜕皮激素对家蚕卵黄蛋白合成积累及卵巢发育的影响

为探明蜕皮激素对家蚕三种卵黄蛋白合成、积累的调节作用,用不同剂量的蜕皮激素处理结扎后的雌蛹,应用火箭免疫电泳进行定量测定。结果注射不同剂量的蜕皮激素,均可加快卵巢的发行速度,尤以注射10μg蜕皮激素效果最佳,但更高剂量会导致蛹体死亡;注射不同剂量蜕皮激素后,血淋巴中V_g、30KP含量明显提高,卵巢内V_(tn)、ESP、30KP积累量增加,且剂量效应为:10μg>5μg>1μg。另外,还探讨了基端卵长度和卵巢发育的关系,影响血淋巴中V_g、30KP含量的因素等。     

柞蚕卵黄磷蛋白的鉴定、纯化及其在卵形成和胚胎发育中的变化

应用聚丙烯酰胺凝胶电泳、离子交换纤维素柱层析和薄层扫描等方法鉴定、纯化了柞蚕卵黄磷蛋白,并考察了该蛋白质在卵形成和胚胎发育期间的变化.结果表明:(1)发育卵巢和成熟卵内存在着一种卵黄磷蛋白(Vtn),其前体是雌蛹血淋巴内的卵黄原蛋白(Vg),该蛋白质具有雌特异性.(2)Chino等的方法也适用于以柞蚕卵为材料纯化Vtn,初步纯化的Vtn亚单位分子量是200KDa.(3)后蛹期,发育卵巢中可溶性总蛋白和Vtn的相对百分含量都迅速上升,至卵粒成熟期达最大值.(4)胚胎发育前期,卵可溶性总蛋白和Vtn的相对百分含量基本维持原水平;胚胎发育后期,二者都急剧地减少;孵化时卵可溶性总蛋白含量和Vtn的相对含量分别降至刚产下时的50%和10%以下.     

Mating pair combinations of insecticide-treated male and female Nilaparvata lugens Stål (Hemiptera: Delphacidae) planthoppers influence protein content in the male accessory glands (MAGs) and vitellin content in both fat bodies and ovaries of adult females

The brown planthopper, Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), is an insect pest in which offspring are produced by the mating of adult males with adult females. This species is a classic case in which pest resurgence is induced by insecticides. In the past, studies of resurgence mechanisms have focused on insecticide-induced stimulation of reproduction in adult females. To date, however, the role that males play in the resurgence mechanisms of N. lugens has not been investigated. The aim of the present study is to examine changes in protein levels in male accessory glands (MAGs) induced by the insecticides triazophos and deltamethrin and to determine their relationship with vitellin content in the fat bodies and ovaries of adult females in the context of mating pairs. Our results show that protein content in MAGs is significantly affected by male mating status, insecticide type, and insecticide concentration. Insecticide application induced increased protein levels in MAGs. A greater quantity of MAG products was transferred to females via mating. Thus, protein levels in MAGs significantly decreased after mating. Experimental matings indicate that vitellin content in both fat bodies and ovaries of adult females in mating pairs consisting of a treated male and an untreated female (♂_t × ♀_ck) is significantly greater than that of females in pairs consisting of an untreated male and an untreated female (♂_ck × ♀_ck). Under various concentrations of the two insecticides, vitellin levels are highest in mating pairs consisting of a treated male and a treated female (♂_t × ♀_t), followed by mating pairs consisting of an untreated male with a treated female (♂_ck × ♀_t). These findings demonstrate that (1) insecticides have an effect on males; (2) insecticide effect can be transferred to females; and (3) the reproductive effect of insecticides is strongest in mating pairs in which both the males and females are treated compared to pairs in which only one individual is treated. These findings provide valuable information about the role of males in pesticide-induced resurgence of N. lugens.     

十足目甲壳动物卵黄蛋白原的生化特性及生物合成

十足目在甲壳动物中种类最多,经济价值最大,分为枝鳃亚目(对虾类)和腹胚亚目(真虾、螯龙虾、蟹类)两大类。十足目种类卵黄蛋白原基因c DNA全长基本都在8 kb左右,编码2500~2600个氨基酸组成的多肽,具有高度保守性。然而这两类生物的卵黄发生机制却存在显著差异。人工育苗过程中,对虾类卵巢不易发育,通常需要切除眼柄促熟,而腹胚亚目种类容易成熟甚至需要控制早熟。对虾类的卵黄蛋白原由卵巢和肝胰腺共同合成,一般卵巢贡献更大。尤其在卵巢发育前期,卵巢合成卵黄蛋白原较肝胰腺显著旺盛,具有"卵巢内源基因表达型"的特征。在真虾等腹胚亚目种类中,卵巢虽然也参与合成卵黄蛋白原,但以肝胰腺为主,绝大多数种类肝胰腺的贡献率超过90%。本文探讨了两类甲壳动物在卵黄发生机制中的显著差异与其在人工控制条件下性腺发育的不同表现之间的相互关系。     

五种鱼类卵黄蛋白等电点特性分析

运用IFE-PAGE电泳技术,对施氏鲟(Acipenser schrencki Amur sturgeon)、小体鲟(Acipenser ruthenus Linnaeus)、西伯利亚鲟(Acipenser baeri Siberian sturgeon)、哲罗鲑(Huchotaimen Taimen)和虹鳟(Oncorhynchus mykissgo Lden rainbow trout)5种鱼类卵黄蛋白等电点的特性进行研究,建立了比较成熟的测定卵黄蛋白等电点的实验方法。5种鱼类卵黄蛋白等电聚焦电泳图谱都为3条带,表明5种鱼都是由3种卵黄蛋白组成,哲罗鲑和虹鳟卵黄蛋白都属于酸性类型,与鲟形目这3种鱼卵黄蛋白等电点差别较大。     

三疣梭子蟹卵黄蛋白的纯化和部分生化性质

通过电泳法检测到了三疣梭子蟹卵巢中的卵黄蛋白,采用EDTA-Mg2+沉淀法以及凝胶过滤(Sephadex-100)对该蛋白进行了纯化,并通过相关染色和光吸收法确定该蛋白为糖脂磷类胡萝卜素蛋白;梯度聚丙烯酰胺凝胶电泳以及SDS-聚丙烯酰胺凝胶电泳结果显示该蛋白的总分子量为362.5 ku,由分子量为102.3 ku、66.1 ku、38.9 ku三个亚基组成。     

Vaccine potential of a tick vitellin-degrading enzyme (VTDCE)

VTDCE (Vitelin-Degrading Cysteine Endopeptidase) is a peptidase with an active role in Rhipicephalus (Boophilus) microplus embryogenesis. VTDCE is found in the tick's eggs and was shown to be the most active protein in vitellin (VT) hydrolysis of the three peptidases already characterized in R. microplus eggs (Boophilus Yolk pro-cathepsin (BYC), Tick Heme Binding Aspartic Proteinase (THAP) and VTDCE). VTDCE activity was assessed in vitro using the natural substrate and a synthetic substrate (N-Cbz-Phe-Arg-MCA). The activity was inhibited by anti-VTDCE antibodies. In the present study, it was shown that VTDCE acts differently from BYC and THAP in VT hydrolysis and that the vaccination of bovines with VTDCE induces a partial protective immune response against R. microplus infestation. Immunized bovines challenged with R. microplus larvae presented an overall protection of 21%, and a reduction in the weight of fertile eggs of 17.6% was observed. The data obtained indicate that VTDCE seems to be important for tick physiology, and that it induces partial protective immune response when inoculated in bovines. This suggests that VTDCE can be useful to improve the protective capacity observed for other antigens.     

幼虫期营养对甜菜夜蛾生殖力及卵巢发育的影响

幼虫期营养是影响昆虫生长发育及种群动态的重要因素,笔者以周期性和突发性饥饿处理4、5龄甜菜夜蛾幼虫,结果表明,饥饿处理后蛹重下降,蛹期延长,羽化率和成虫交配率降低。以5龄幼虫的突发性饥饿影响最为显著,5龄幼虫饥饿处理36h时,产卵量仅为对照的56.8%。幼虫营养缺乏,可使产卵前期延长,卵期和雌蛾寿命明显缩短。5龄幼虫饥饿处理24h、36h,雌蛾卵巢管长度比对照分别缩短29.1%和36.1%,卵巢鲜重下降28.4%和30.9%。周期性饥饿处理只有5龄处理12h的影响较明显。突发性饥饿处理可引起卵巢内卵黄蛋白含量明显下降。在不同的营养条件下,雌蛾的产卵量与卵巢中的卵黄蛋白含量、产卵量与蛹重之间均呈明显的正相关。