Gsα的过表达和缺失对果蝇大脑形态发育的影响

Gsα作为G蛋白复合体的重要组成部分,通过直接调控cAMP-PKA等信号通路参与调控细胞的生命活动。文章通过构建Gsα过量表达及失活突变体,研究Gsα的过量表达及失活对果蝇神经细胞发育的影响。结果表明,在25℃培养条件下,Gsα的过量表达对果蝇幼虫具有致死性。但Gsα的过量表达及失活对果蝇神经细胞的细胞周期和细胞极性没有显著影响。     

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。     

黑腹果蝇紫眼卷翅遗传规律的研究

为研究本实验室在紫眼野生型黑腹果蝇中发现的卷翅突变体遗传规律和分子基础,通过观察紫眼卷翅与野生型、紫眼卷翅与红眼卷翅后代各性状的表现规律,设计14对引物检测了syt基因与Alp23B基因间DNA多态性。结果表明:1)在紫眼卷翅与野生型杂交的F1中,卷翅与野生型的比例为1∶1;2)紫眼卷翅与野生型杂交F1代卷翅个体自交的F2中,紫眼与红眼、卷翅与野生型正常翅2对性状符合孟德尔自由分离与组合定律;3)紫眼卷翅与红眼卷翅杂交的F1中,卷翅与野生型的比例为2∶1;4)2种卷翅品系中在syt与Alp23B之间的基因组区域存在1个多态位点;2种卷翅个体均为AB型,而野生型个体为无缺失的AA型;紫眼卷翅与红眼卷翅杂交F1中卷翅个体全为AB型。紫眼卷翅突变体为显性杂合子,平衡致死系;紫眼基因与卷翅基因不连锁;2个卷翅基因为等位基因,相互间不能互补,杂合状态下致死。     

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.     

10种杀虫剂对蓝莓重要害虫黑腹果蝇生物活性的测定

黑腹果蝇Drosophila melanogaster为皖南山区危害蓝莓的一种重要害虫。采用药膜接触法测定了10种杀虫剂对黑腹果蝇成虫的生物活性。供试药剂以乙基多杀菌素的杀虫活性最高,溴氰虫酰胺和核型多角体病毒的生物活性次之。乙基多杀菌素以15 mg·L~(-1)处理后24 h和48 h试虫的校正死亡率分别为91.8%和100.0%,处理后24和48 h的LC50分别为6.90和1.74 mg·L~(-1)。溴氰虫酰胺以40 mg·L~(-1)处理后72 h试虫的校正死亡率为93.7%。核型多角体病毒、甲氨基阿维菌素和苏云金杆菌按厂家推荐剂量处理后72 h对黑腹果蝇也表现出较好的生物活性。乙基多杀菌素和溴氰虫酰胺可作为防治蓝莓园黑腹果蝇的理想杀虫剂加以交替轮换施用。     

果蝇连锁交换率的测定

本研究应用测交原理，在果蝇特定突变种生活力测定的基础上，对果蝇紫眼（Ｐｒ）位点和残超（Ｖｇ）位点间的连锁交换率进行了测定。实验结果表明，在相斥相和相引相中，Ｐｒ和Ｖｇ两个基因位点之间的交换率分别为γＲ＝１２．４６％，γＣ＝１１．５９％，其平均值γ＝１２．０３％，是本实验室条件下紫眼和残翅基因位点间的交换率。这一研究结果是家畜连锁性状固定的育种进度研究中，果蝇模拟实验必须之参数。     

IPM program development for an invasive pest: coordination, outreach and evaluation

BACKGROUND: Spotted wing drosophila (SWD), Drosophila suzukii Matsumura, was found along the west coast of the United States, beginning in 2008 and 2009, infesting a wide variety of small and stone fruit crops. This pest is a serious economic threat, as noted in its native range (Asia), because it lays eggs within ripening fruit before harvest, leading to crop loss. The aim of this paper is to describe the process in order to create collaboration, communication routes and evaluation methods in response to a new invasive pest. RESULTS: Funding was secured and a program (SWD*IPM) was quickly developed to address social, economic and biological components. Communication routes were outlined, and a stakeholder advisory panel was established to guide program objectives. A central website was created to host up‐to‐date information. An online monitoring and mapping program for D. suzukii in Oregon fruit‐growing regions illustrated the range, distribution and seasonal abundance of the pest. In addition, a program for backyard fruit growers was initiated to examine citizen scientists' roles in managing D. suzukii infestations in the urban setting. A monitoring kit, laminated educational cards, dry fly mounts and quick‐time videos were some of the tools used to educate growers. First‐year challenges for dealing with a new pest are discussed. CONCLUSION: The discovery and subsequent response to an exotic pest is information intensive and requires a well‐planned, coordinated Extension and evaluation effort. Copyright © 2011 Society of Chemical Industry     

Laboratory survival of Drosophila suzukii under simulated winter conditions of the Pacific Northwest and seasonal field trapping in five primary regions of small and stone fruit production in the United States

BACKGROUND: Drosophila suzukii was first found in Oregon in August 2009. The threat of this pest to regional small and stone fruit production industries led to investigations on its overwintering capabilities in fruit‐growing regions in the Pacific Northwest. Knowledge of its cold tolerance will help in the development of computer models to forecast seasonal population growth and decline. RESULTS: Of 1500 adults or pupae, 22 (1.4%) individuals survived the 84 day experimental chilling period. Most (86%) of the survivors were subjected to 10 °C temperature treatments. Survival decreased significantly at lower temperature treatments. Freezing temporarily increased the mortality rate but did not significantly affect overall mortality over the trial period. Flies that emerged from pupae are estimated to survive for up to 103–105 days at 10 °C and for shorter periods at lower temperatures. Field trapping in five fruit production areas has demonstrated overwintering survival in California and Oregon, but lower survival is predicted in Eastern Washington and Michigan. CONCLUSION: The experiments reported here indicate that long‐term survival of D. suzukii is unlikely at temperatures below 10 °C. Field data from five climatic regions indicated extended low initial D. suzukii field presence in 2010 in all regions except California, where field presence was recorded earlier. Copyright © 2011 Society of Chemical Industry     

果蝇凋亡抑制蛋白研究进展

介绍果蝇凋亡抑制蛋白的种类、结构特征、作用机制、生物学特性以及凋亡蛋白抑制剂最近的一些研究进展。     

Comparison of the activity of non‐steroidal ecdysone agonists between dipteran and lepidopteran insects,using cell‐based EcR reporter assays

BACKGROUND: Diacylhydrazine (DAH) analogues have been developed successfully as a new group of insect growth regulators, called ecdysone agonists or moulting accelerating compounds. These DAHs have been shown to manifest their toxicity via interaction with the ecdysone receptor (EcR) in susceptible insects, as does the natural insect moulting hormone 20‐hydroxyecdysone (20E). A notable feature is their high activity and specificity, particularly against lepidopteran insects, raising the question as to whether non‐lepidopteran‐specific analogues can be isolated. However, for the discovery of ecdysone agonists that target other important insect groups such as Diptera, efficient screening systems that are based on the activation of the EcR are needed. RESULTS: In this study, a dipteran‐specific reporter‐based screening system with transfected S2 cells of Drosophila melanogaster Meig. was developed in order to discover and evaluate compounds that have ecdysone agonistic or antagonistic activity. A library of non‐steroidal ecdysone agonists containing different mother structures with DAH and other related analogues such as acylaminoketone (AAK) and tetrahydroquinoline (THQ) was tested. None of the compounds tested was as active as 20E. This is in contrast to the very high activity of several DAH and AAK congeners in lepidopteran cells (Bombyx mori L.‐derived Bm5 cells). The latter agrees with a successful docking of a DAH, tebufenozide, in the binding pocket of the lepidopteran EcR (B. mori), while this was not the case with the dipteran EcR (D. melanogaster). Of note was the identification of two THQ compounds with activity in S2 but not in Bm5 cells. Although marked differences in activity exist with respect to the activation of EcR between dipterans and lepidopterans, there exists a positive correlation (R = 0.724) between the pLC₅₀ values in S2 and Bm5 cells. In addition, it was found through protein modelling that a second lobe was present in the ligand‐binding pocket of lepidopteran BmEcR but was lacking in the dipteran DmEcR protein, suggesting that this difference in structure of the binding pocket is a major factor for preferential activation of the lepidopteran over the dipteran receptors by DAH ligands. CONCLUSIONS: The present study confirmed the marked specificity of DAH and AAK analogues towards EcRs from lepidopteran insects. THQ compounds did not show this specificity, indicating that dipteran‐specific ecdysone‐agonist‐based insecticides based on the THQ mother structure can be developed. The differences in activity of ecdysone agonists in dipteran and lepidopteran ecdysone‐reporter‐based screening systems are discussed. Copyright © 2010 Society of Chemical Industry