昆虫共生细菌研究进展

昆虫体内定殖着大量微生物,经过漫长协同进化,昆虫与这些微生物构建了共生体系,这些昆虫共生微生物参与整个生态过程,对于生态系统中物质转化与交换、能量流动与利用、信息传递与调控等均发挥着重要作用。昆虫共生细菌具有丰富的物种多样性;昆虫与其共生细菌之间通过化学机制、生理机制、生态学机制和遗传学机制构建复杂的共生体系;昆虫为细菌提供稳定的生境并共享特定的代谢途径,共生细菌则协助宿主营养代谢,提供食物中缺乏的养分,促进昆虫生长和繁殖;通过分泌抗菌肽、毒素等,细菌能增强昆虫对寄生物的防御能力和抗病性,并通过调节昆虫对非生物因子的抗逆性和耐药性,扩大昆虫的生态位。昆虫共生细菌在农林牧渔业可持续安全生产与医药研发等领域具有应用潜力和广阔的发展前景。     

昆虫抗冻蛋白基因的克隆与表达研究进展

产生抗冻蛋白(antifreeze protein,AFP)是许多昆虫抵御寒冷的一种重要机制。昆虫抗冻蛋白基因的克隆和表达是研究抗冻蛋白活性和功能的主要途径。文章归纳GenBank所登录的昆虫抗冻蛋白基因及其特点,总结昆虫抗冻蛋白基因的天然表达和基因工程表达方面尚未明确或需要克服的一些问题。目前在GenBank注册的昆虫抗冻蛋白基因约100个,集中于9种昆虫隶属鞘翅目3个科和鳞翅目1个科。昆虫抗冻蛋白基因具有多拷贝和多同种型(isoforms)的特点。昆虫抗冻蛋白的天然表达具有物种间和同种型间的多样性。基因工程表达昆虫抗冻蛋白需要克服表达量低活性不高的问题。对昆虫抗冻蛋白表达规律的研究有助于全面认识其功能。     

Approaches to radioiodination of insect neuropeptides

High quality radioiodinated neuropeptides are essential to radioimmunoassays (RIA) and receptor binding assays. Approaches of direct and indirect labeling of neuropeptides with 125Iodine (125I) are compared. An HPLC equipped with an in-line gamma detector and UV absorbance detector was used to evaluate selected labeling methods and products. Treatment of [Y(1)]-adipokinetic hormone-I ([Y(1)]-AKH-I) with chloramine-T caused oxidative damage, whereas enzymatic labeling with lactoperoxidase in the presence of H(2)O(2) produced a good yield of intact, apparently monoiodinated peptide. Labeling of the FMRFamide-related peptide (YGGFMRFa), with chloramine-T apparently formed the methionine sulfoxide, which subsequently could be reduced with dithiothreitol. Products of high specific activity typically are achievable.     

产甲烷古菌研究进展

产甲烷古菌是一类严格厌氧的古菌,只能利用简单的化合物进行产甲烷生长。产甲烷古菌在地球生命起源和进化、全球气候变化、碳生物地球化学循环和农业废弃物资源化利用等领域,都起着至关重要的作用。系统了解产甲烷古菌的生物学特征,将有助于在这些基础和应用领域的研究工作。本文主要从生理生化特征、代谢途径、能量储存和系统分类等方面介绍产甲烷古菌的研究进展。     

昆虫漆酶的研究进展

从昆虫漆酶的种类、分布、序列信息、研究方法以及体内功能等方面对昆虫漆酶的研究现状进行综述,并提出昆虫漆酶有望应用于木质素降解和害虫防治等领域。     

Interactions of selected insect neuropeptides with synthetic lipids.

Interactions of the insect neuropeptide proctolin (Arg-Tyr-Leu-Pro-Thr), its [beta-cyclohexyl-(4-O-methyl)2]-L-alanine analog, and the leucopyrokinin [2-8]-fragment (Thr-Ser-Phe-Thr-Pro-Arg-Leu-NH2), with synthetic phospholipids (DPPC, DMPE, DMPG) were studied using the microcalorimetric method. Most pronounced changes of the lipid thermotropic behavior were observed with DMPG/leucopyrokinin [2-8]-fragment mixtures. Proctolin itself was less active with all the lipids studied. The results obtained suggest that the studied peptides interact with the head group region of lipid bilayer.