不同昆虫泛素延伸蛋白基因的生物信息学分析

采用生物信息学方法系统分析了甜菜夜蛾、菜粉蝶、烟夜蛾和黑腹果蝇泛素延伸蛋白(UBE)基因序列的遗传多样性、分子进化及其编码氨基酸序列的结构功能域和基序特点.结果显示,4种昆虫UBE基因序列的同源性较高(81.8%～99.7%),且遗传距离较近(0.003～0.199),均编码ubiquitin/L40 UBE.共检出8...     

家蚕微孢子虫转宿主果蝇的研究

1材料与方法 1．1材料与处理家蚕微孢子虫材料由西南大学蚕学与系统生物学研究所馈赠,野生型和突变型果蝇由重庆师范大学生物细胞生物学教研室提供。孢子经过percoll分离纯化后,采用细胞计数板取大约10^8个孢子虫,经0．2molKOH活化10min后,加入到预先配制好的5．0ml玉米粉培养基中。     

乌鸡黑色素对果蝇的紫外辐射保护作用

对黄体果蝇进行紫外辐射处理后,在含0.02或0.2mg/mL乌鸡黑色素的培养基中培养,通过测定果蝇寿命、繁殖力和SOD比活性来分析黑色素的紫外辐射保护作用。结果显示:果蝇在5min紫外辐射 0.2mg/mL黑色素组的下四分位(14.5±1.3)d、上四分位寿命(23.5±2.1)d以及平均寿命(15.7±7.1)d显著(P<0.05)高于5 min紫外辐射组(8.0±1.4)、(16.0±3.3)和(13.5±6.4)d。每对亲本果蝇在2min紫外辐射 0.2mg/mL黑色素组繁殖子代(50.0±11.4)只比2min紫外辐射组提高了156.4%(P<0.05)。另外,黑色素可能对辐射处理果蝇体内SOD比活性有保护作用,果蝇在5min紫外辐射 0.02mg/mL黑色素组和5min紫外辐射 0.2mg/mL黑色素组的SOD比活性((209.1±13.1)和(213.25±7.7)μmol/(mg.min))高于5min紫外辐射组((204.2±11.5)μmol/(mg.min)),但差异均不显著。本试验发现乌鸡黑色素能够延长辐射处理果蝇的寿命,提高繁殖力,对其SOD活性可能也具有保护作用。上述作用或许与黑色素清除自由基的特性有关,同时,2min紫外辐射 0.2mg/mL黑色素组高繁殖力的原因可能还与黑色素对果蝇生殖细胞的保护有关。     

海带多糖的抗衰老作用及其机理的研究

以果蝇(Drosophila melanogaster)作为试验动物,探讨了海带多糖(Laminaria japonicapolysaccharide,LJP)延缓衰老的作用及其机理。试验将未交配的果蝇雌雄分开并随机分成4组,每组100只,用含不同浓度海带多糖的培养基喂养,培养基中所含海带多糖的浓度分别为0(对照组)、0.25%、0.50%、1.00%。用果蝇寿命试验检测其抗衰老作用,分别使用邻苯三酚自氧化法、钼酸铵比色法、硫代巴比妥酸(TBA)法测定果蝇体内超氧化物岐化酶(SOD)、过氧化氢酶(CAT)活性及丙二醛(MDA)含量。利用统计学软件SAS v6.12对试验数据进行分析。结果表明:培养基中添加海带多糖能延长果蝇平均寿命,寿命延长的百分率与喂食果蝇的海带多糖浓度有一定的量效关系,培养基中海带多糖浓度为0.25%、0.50%、1.00%时,与对照组相比,雌果蝇寿命延长百分率分别为5.20%、6.20%、9.20%,雄果蝇寿命延长百分率分别为4.60%、5.00%、6.00%;饲喂海带多糖后果蝇体内的SOD、CAT活性提高,与对照组相比,海带多糖添加量为0.50%和1.00%时,雌性果蝇SOD、CAT活性提高量达到显著水平(P<0.05),MDA降低量达到显著水平(P<0.05);海带多糖添加量为1.00%时,雄性果蝇SOD与CAT活性提高量达到显著水平(P<0.05),MDA含量降低。提示提高生物体内抗氧化酶活力,降低衰老物质前体的含量可能是海带多糖抗衰老的途径之一。     

果蝇(Drosophila melanogaster)唾腺染色体的制备及染色体识别

果蝇(Drosophila melanogaster)唾腺染色体的制备与分析是果蝇细胞遗传研究的基本实验技术,也是非常流行的遗传学教学实验。国内绝大多数的实验教材介绍了这个实验的操作方法,但对于如何辨别染色体各条臂,并进而识别具体的带纹均未予以介绍。笔者详细介绍唾腺染色体的制备及拍摄、数码照片拼接方法;并着重介绍如何根据各条臂端粒端的形态特征,以及利用Lefevre的唾腺染色体照片图谱中指示的蓬突(puff)、缢缩及带纹组合特征识别染色体臂的方法,供研究和实验教学参考。     

Virtual screening identifies a novel piperazine-based insect juvenile hormone agonist

Juvenile hormone (JH) agonists constitute a subclass of insect growth regulators and play important roles in insect pest management. In this work, a multi-step virtual screening program was executed to find novel JH agonists. A database of 5 million purchasable compounds was sequentially processed with three computational filters: (i) shape and chemical similarity as compared to known JH-active compounds; (ii) molecular docking simulations against a Drosophila JH receptor, methoprene-tolerant; and (iii) free energy calculation of ligand–receptor binding using a modified MM/PBSA (molecular mechanics/Poisson–Boltzmann surface area) protocol. The 11 candidates that passed the three filters were evaluated in a luciferase reporter assay, leading to the identification of a hit compound that contains a piperazine ring system (EC₅₀=870 nM). This compound is structurally dissimilar to known JH agonists and synthetically easy to access; therefore, it is a promising starting point for further structure optimization.     

贵阳地区杨梅园黑腹果蝇的田间消长规律

为了摸清贵阳地区黑腹果蝇的发生规律,为其科学防控提供依据,2011年5—8月,采用诱杀剂诱集和采摘杨梅果实调查相结合的方法,对贵阳地区不同时期杨梅果园黑腹果蝇成虫和幼虫的发生规律进行了研究。结果表明:黑腹果蝇的发生数量和杨梅果实的成熟度密切相关,在杨梅成熟前期,黑腹果蝇成虫量处于低谷;当杨梅果实进入成熟采收期,成虫数量随之上升;随着成熟杨梅果实的陆续采收,大量的果蝇幼虫被带出园外,果园里果蝇成虫发生量随之趋于平缓;在采收后期,绝大多数杨梅均已成熟,果蝇的发生量随之上升,形成一个盛发高峰。     

引导学生有效分析遗传学综合性实验结果的探索与实践

以6#和2#果蝇的杂交为例,探讨了学生在实验过程中常出现的问题以及如何加强引导学生对实验结果的分析。认为分析"果蝇的综合杂交实验"的数据应从1对遗传因子分析到2对遗传因子分析,再到3对遗传因子分析;分析内容应包括性状的显隐判断、基因位置的确定、表现型比例和假设检验。同时,在实验的各个环节引导学生复习、巩固遗传学的基本原理。在实验的设计阶段让学生思考影响实验结果的因素。实践表明,学生对实验结果的分析不仅思路清晰、逻辑性增强,而且充分挖掘了实验数据所蕴含的信息,从而提高了遗传学实验教学质量。     

Effect of copper on the development,protein and esterase isozymes of Drosophila melanogaster

Copper is an important ingredient in fungicides, which are used for many economic plants. However, there is concern about the side‐effects of copper‐based fungicides due to their potential to affect beneficial mites. The purpose of the present paper was to investigate the effects of copper on the development of the fruit fly, Drosophila melanogaster. It was found that higher doses of copper significantly prolonged the developmental time of the fruit flies, especially during the larval stages. When 320 mg L^‐1 copper‐contaminated food was used, most of the larvae died when they were small and before the pupal stage. The protein contents and esterase isozymes extracted from the larvae changed according to the doses of copper. The small‐molecular‐weight protein bands gradually became weaker or were lost as the copper levels increased. However, low doses of copper stimulated a stronger expression of a few proteins. These results indicate that low doses of copper generally have no lethal effects on D. melanogaster because a specific group of genes, which encode specific proteins, are probably activated in order to withstand the onslaught of stressful conditions. At high doses of copper in food (e.g. 320 mg L^‐1), fly development and viability are significantly affected.