昆虫气味认知的嗅觉神经结构及分子机制

大多数昆虫主要通过气味认知感知外界环境的变化,维持生命活动。探究昆虫气味认知的嗅觉系统神经结构及分子机制,对于完善气味认知神经生物学理论及利用其原理进行仿生学研究等有重要的科学意义。近年,关于昆虫气味认知科学研究有了很大的进展。本文从昆虫神经生物学的视角详细综述了近年关于昆虫气味认知的嗅觉神经结构、分子机制及气味信号的神经传导途径等方面的基本理论及最新研究成果。综述结果显示:昆虫对气味的认知是通过嗅觉神经系统的触角感器、触角叶(AL)、蕈形体(MB)等脑内多层信号处理神经结构来实现的。当外界气味分子进入触角感器内后,由感器内特定的气味识别蛋白(OBP)将气味分子运载到达嗅觉感受神经元(ORN)树突膜上的受体位点,气味分子与表达特定气味的受体(OR)结合产生电信号,并以动作电位的形式通过ORN的轴突传到脑内的触角叶。在触角叶经过嗅觉纤维球对气味信息选择性加工处理,再由投射神经元(PNs)将初步的识别和分类的气味信息传到蕈形体和外侧角(LH)等神经中枢,实现对气味的识别和认知。虽然,近年昆虫气味认知神经生物学的研究有了很大的进步,但是,我们认为目前的研究成果还不能完全阐明昆虫气味认知的神经机制,还有很多问题,例如,触角叶上众多的嗅觉纤维球是如何对嗅觉感受神经元传入的气味信息进行编码处理的?等有待进一步深入研究。为了搞清这些疑难问题,我们认为需要提高现有的实验技术水平,加强电生理学和分子神经生物学相结合的实验研究,从分子水平探究气味认知的神经机制可能是未来研究的热点。     

四个不同种属动物肢体Ⅱ导联心电图比较

目的对比格犬、恒河猴、日本大耳白兔、树鼩四个不同种属实验动物的ECG-II进行分析比较,归纳其ECG-II的特点,旨在为上述动物在安评中的运用提供参考。方法选择成年比格犬、恒河猴、日本大耳白和树鼩,分别对其在清醒状态下的ECG-II进行描记和分析,并对ECG-II各项指标进行测量分析。结果与结论不同种属动物均为窦性心律,在波型方面基本一致,未出现特异性改变,但不同动物在QRS波群和T波形态上具有一定差异;各指标测定结果显示,日本大耳白兔P波、T波振幅和树鼩心率分别小于和快于其他种属动物。     

Untargeted metabolomic profiling of accessory sex gland fluid from Morada Nova rams

The present study was conducted to characterize the metabolome of accessory gland fluid (AGF) of locally adapted Morada Nova rams, raised in the Brazilian Northeast. AGF was collected by an artificial vagina from five vasectomized rams. Metabolites were identified by gas chromatography‐mass spectrometry (GC/MS) and high‐performance liquid chromatography‐mass spectrometry (LC/MS), with the support of Human Metabolome Database, PubChem, LIPID Metabolites, Pathways Strategy databases, and MetaboAnalyst platforms. There were 182 and 190 metabolites detected by GC/MS and LC/MS, respectively, with an overlap of one molecule. Lipids and lipid‐like molecules were the most abundant class of metabolites in the ram AGF (127 compounds), followed by amino acids, peptides, and analogs(103 metabolites). Considering all GC/MS and LC/MS, fructose, glycerol, citric acid, d ‐mannitol, d ‐glucose, and l ‐(+)‐lactic acid were the most abundant single metabolites present in the ram AGF. Meaningful pathways associated with AGF metabolites included glycine, serine and threonine metabolism; pantothenate and CoA biosynthesis; galactose metabolism; glutamate metabolism and phenylalanine metabolism, and so forth. In conclusion, the combined use of LC/MS and GC/MS was essential for getting a holistic view of the compounds embedded in the ram AGF. Chemical analysis of the accessory sex gland secretion is relevant for understanding sperm function and fertilization.     

Pindamoraria boraceiae, a new genus and species of freshwater Canthocamptidae (Copepoda, Harpacticoida) from Brazil

Members of a new genus and species of harpacticoid copepod crustacean appeared in samples from semi-terrestrial (moist arboreal mosses, wet soil) and aquatic (bromeliad tanks, Sphagnum moss, rock pools, stream) habitats in a remnant of the Atlantic Forest in south-eastern Brazil. The new taxon, for which we propose the name Pindamoraria boraceiae sp. nov. , is distinguished by a unique combination of characters, in particular the segmentation and setation pattern of legs 1–4 in both sexes, the structure of leg 5 in the female, and the strongly modified claw of the maxilliped in the male. It most resembles the canthocamptid genera Moraria , Pseudomoraria , Morariopsis and Paramorariopsis . Both previous records of species of Moraria from South America refer to members of Antarctobiotus , which is not considered a member of the Moraria group: Moraria (Kuehneltiella) neotropica Löffler has previously been transferred to Antarctobiotus ; and we propose herein the transfer of Moraria kummeroworum Ebert & Noodt to Antarctobiotus as well. In the New World, the genus Moraria extends only as far south as Honduras; and Pseudomoraria , Morariopsis and Paramorariopsis are Old World genera. The new species from Brazil is therefore the only member of the Moraria group known from South America.  © 2003 The Linnean Society of London, Zoological Journal of the Linnean Society , 2003, 139, 81–92.     

Using stable isotope analysis to study the diet of Gilchristella aestuaria larvae: preliminary insights into the foodwebs of six South African estuaries

South African estuarine systems are becoming increasingly altered by anthropogenic and environmental factors, but the consequences of such changes for these systems are still not fully understood. The most common approach for evaluating the ecological status of aquatic systems is studying their associated foodwebs. Due to their high abundance and important ecological role, the larvae of estuarine round herring Gilchristella aestuaria (Gilchrist, 1913) are key candidates for examining the foodweb structure and function of southern African estuaries. The foodwebs and trophic interactions of G. aestuaria larvae in six estuaries in South Africa were compared using larvae sampled in November 2013 and analysed using δ¹³C and δ¹⁵N and Bayesian isotopic mixing models. The main prey type for G. aestuaria larvae in all estuaries was zooplankton. We found a high similarity among the Kariega, Gamtoos, Great Fish and Sundays estuaries in terms of consumers and potential sources for both δ¹³C and δ¹⁵N signatures. Significant differences were found in δ¹³C values among marine-dominated estuaries, such as the Kromme Estuary, and the more freshwater-dominated systems. In addition, in the Kromme Estuary particulate organic matter was very important in the diet of G. aestuaria larvae. Our results suggest that both food availability and physical environmental parameters strongly affect the diet and condition of G. aestuaria and, consequently, the entire foodweb in the system.     

γ-聚谷氨酸基因工程研究进展与展望

γ-聚谷氨酸(γ-PGA)是一种天然高分子可降解、环境友好型的新型阴离子聚合物。目前发现多种芽孢杆菌、古细菌和一种真核生物均可合成γ-PGA。根据其合成是否需要外加谷氨酸分为谷氨酸依赖性和谷氨酸非依赖型。γ-PGA的合成基因分为结合型的cap系和游离型的pgs系,其表达产物组成的γ-PGA合成酶复合体调节着γ-PGA的合成和转运。由于γ-PGA具有水溶性好、保湿性好、吸水性好、良好的生物兼容性和生物可降解性、可食用、对环境无污染等优点,在医药、农业、食品、环境、化妆品等领域具有广泛的应用前景。主要对γ-PGA的结构特点、微生物合成、相关基因、合成机理、应用、诱变处理进行综述。以期通过物理和化学等技术的诱变,获得γ-PGA的高产菌株,为提高γ-PGA产量提供依据。     

Construction and evaluation of multisite recombinatorial (Gateway) cloning vectors for Gram-positive bacteria

Background  

The Gateway recombinatorial cloning system allows easy and rapid joining of DNA fragments. Here we report the construction and evaluation of three different Gram-positive vectors that can be used with the Multisite Gateway cloning system to rapidly produce new gene arrangements in plasmid constructs for use in a variety of Gram-positive bacteria.     

Ag85ADNA疫苗对荷瘤鼠Th1细胞免疫功能的影响

为了探讨肌肉注射Ag85A DNA疫苗能否在肿瘤宿主,一个低细胞免疫应答的机体内激发Th1型细胞免疫应答,将6~8周龄BALB/c雌性小鼠随机分成实验组(Ag85A-V1Jns.tPA组),空质粒组(V1Jns.tPA组)和生理盐水组3组,将生长旺盛的Meth-A细胞接种于各组小鼠右侧背部皮下,每只小鼠2×105个细胞,1d后于小鼠大腿肌肉内分别注射100μL Ag85A-V1Jns.tPA(1 g/L),V1Jns.tPA(1 g/L)或生理盐水。每10 d 1次,共3次,于末次注射后第8 d,无菌取脾,分离细胞进行培养。检测NK细胞活性以及脾细胞培养上清中IFN-γ含量。结果显示:实验组平均NK细胞杀伤率以及脾细胞培养上清中IFN-γ含量较空质粒组和生理盐水组均显著增高,而空质粒组和生理盐水组之间未见有意义的变化。提示肌肉注射Ag85A DNA疫苗可以提高Meth-A纤维肉瘤荷瘤小鼠Th1细胞免疫功能。     

人-禽双价流感新型DNA疫苗构建及免疫保护实验研究

流感病毒是威胁人类和动物健康的重要病原. 研究表明, 流感大流行株的形成与人流感和禽流感毒株基因重配密切相关. 因此在目前流感流行趋势下, 在人流感和禽流感疫苗开发中考虑对人流感和禽流感流行亚型进行共预防具有重要意义. 本研究针对人-禽多价流感疫苗进行了尝试, 构建了共表达H5亚型HA和H3亚型主要抗原区HA1的DNA疫苗pVAX1-H5/H3, 并进行了小鼠免疫攻毒研究. 结果表明, 攻毒前pVAX1-H5/H3有效诱导小鼠产生了针对 H5HA和H3HA1的体液抗体和细胞免疫应答. 当采用H5亚型和H3亚型流感病毒攻击时, pVAX1-H5/H3实验组小鼠对病毒攻击产生了抵抗作用, 显示了更快的体重回复及肺部病毒清除速度. 在H3亚型流感保护方面, pVAX1-H5/H3作用显著优于单表达H3HA1的pVAX1-H3. 结果证实, 共表达双亚型HA策略可对相关流感病毒攻击产生保护, 不同HA间未发现免疫干扰现象, 同时存在潜在的增益效果. 本研究为人-禽多价流感疫苗的研发奠定了基础.