岩豆凝集素的圆二色性与生物学活性关系的研究

岩豆凝集素（ＭＤＬ）的远紫外圆二色性谱（ＣＤ谱）显示２１６－２１７ｎｍ处的单一负峰。此时ＭＤＬ分子含有１６．２％的α螺旋,４６．３％的β折叠和３７．５％的无规卷曲。ｐＨ９．０时负峰红移至２２０ｎｍ,且在２１７－２２２ｎｍ处的峰值几乎相同;在２０－４０℃范围内,ＣＤ谱的变化甚微;６０℃时谱峰蓝移;在８０℃或１００℃时,２１２ｎｍ处出现一大负峰。１ｍｏｌ／Ｌ或２ｍｏｌ／Ｌ脲时,ＭＤＬ的ＣＤ谱已发生明显变化,二级结构单元也有变化,凝集兔红细胞的活性也随之减弱;随脲浓度的增加,ＭＤＬ的谱峰蓝移,最终在２１２ｎｍ处出现大负峰。当胍浓度为０．７５ｍｏｌ／Ｌ时,ＭＤＬ的ＣＤ谱即有明显变化和活性丧失;胍浓度继续增加,ＣＤ谱逐渐成为特征的无规卷曲的谱形。在ｐＨ９．０、温度超过８０℃、脲或胍浓度分别高于２ｍｏｌ／Ｌ和０．７５ｍｏｌ／Ｌ时,ＭＤＬ的ＣＤ谱发生显著变化的同时,其凝集兔红细胞的生物学活性全部丧失,分子的二级结构单元也发生很大改变。     

广西HBsAg阳性母亲的胎儿肝、肾细胞中乙肝病毒DNA存在状态的研究

采用核酸分子杂交Ｓｏｕｔｈｅｒｎ印迹法,以３２Ｐ标记的ＨＢＶＤＮＡ为探针,检测ＨＢｓＡｇ阳性母亲引产的４０例胎儿的肝、肾组织。结果有２例胎肝和１例胎肾细胞ＤＮＡ出现大于３．２ｋｂ的杂交带,表明ＨＢＶＤＮＡ已处于整合状态。胎肾细胞基因组中查出ＨＢＶＤＮＡ整合为首次报道。     

黄花棘豆的喹诺里西定生物碱

豆科棘豆属有毒植物含多种有毒生物碱,有关棘豆属中生物碱成分的研究,早在1929年Couch由兰伯氏棘豆(Oxytropis lambertii DC.)中分离到一种多羟基化的含氮有机化合物,这是最早报道由棘豆属植物中分离出的生物碱成分,由于当时条件限制未能确定其结构。1982年美国农业部西部研究中心的植物化学家Molyneux从绢毛棘豆(Oxytropis sericea)中分离到苦马豆碱(swainsonine)等吲哚里西定生物碱(indolizidinealkaloids);1989年沈阳药学院于荣敏等由小花棘豆(Oxytropis glabra DC.)中分离出多种喹诺里西定生物碱。喹诺里西定生物碱具有多种生理活性,对试验动物中枢神经系统产生抑制,呼吸抑制或兴奋,致幻、流产和致畸等作用。本文报道由黄花棘豆(Oxytropis ochrocephala Bunge)中测得4种喹诺里西定生物碱。     

柬埔寨白蝶兰，中国兰科一新记录种

报道中国兰科白蝶兰属一新记录种——柬埔寨白蝶兰Pecteilis cambodiana (Gagnep.) Aver.,描述其特征并提供了彩色图片。凭证标本保存于福建农林大学林学院树木标本室(FJFC)。     

Site and mechanism of behavioral tolerance to cocaine: A study of dopamine release in Wistar-Kyoto and spontaneously hypertensive rats

Wistar-Kyoto and spontaneously hypertensive rats received i.v. infusions of cocaine hydrochloride (60 mg/kg per day) for 3, 7, and 14 days, or saline for 7 days. Acute cocaine challenge (40 mg/kg, s.c.) was given to treated and control rats 24 hr after the termination of each infusion period. There were no strain differences in brain levels of cocaine during cocaine infusion, nor after cocaine challenges. There were no strain differences in resting levels of [³H]dopamine release. Release of [³H]dopamine decreased in nuclei accumbens of 7- and 14-day cocaine-infused animals. Release of [³H]dopamine was maximal in both brain regions 2 hr after acute cocaine challenge. After 14 days of cocaine infusion, cocaine challenge in both strains reduced [³H]dopamine release in the nucleus accumbens, but not in the striatum; the reduction being greater in Wistar-Kyoto rats. The behavioral tolerance which accompanies similar cocaine infusion regimens may be related to striatal tolerance to cocaine-induced dopamine release.     

应激时大鼠血,脑,心血管,肾上腺血管紧张素Ⅱ含量的变化

本实验观察了三种应激情况下,大鼠血浆,下丘脑,延髓,心肌,血管及肾上腺组织血管紧张素Ⅱ（ＡⅡ）含量,以及血浆皮质酮含量的。应激方式分为急性应激（冷水游泳,断肢创伤）与慢性应激（寒冷环境刺激）。结果表明：急性应激动物血中ＡⅡ剧烈增高,游泳组达对照值的９００％,创伤组增至３９０％,慢性寒冷组增至１３４％;而组织ＡⅡ除肾上腺外,则以慢性寒冷组增加最明显,游泳组次之,创伤组无明显变化。血浆皮质酮各组均显著     

土壤理化性质驱动烤烟根际细菌群落的组配及其共现性网络互作

【目的】解析土壤微生物在植物根际的组配机制对于认识和维护农田生态系统的稳定性至关重要。【方法】通过Illumina高通量测序和生物信息学分析方法明确了我国主要种植烟草生态区烤烟根际土壤细菌群落与土壤理化性质的互作关系。【结果】烤烟根际细菌类群主要为放线菌纲(Actinobacteria)、α-变形菌纲(Alphaproteobacteria)、γ-变形菌纲(Gammaproteobacteria)和嗜热油菌纲(Thermoleophilia)。细菌群落组成按生态区聚类,且样本空间距离和细菌群落相似度显著负相关。共现性网络分析表明,烤烟根际细菌群落间协同作用大于拮抗作用,武陵秦巴生态区、黄淮平原生态区、南岭丘陵生态区和沂蒙丘陵生态区细菌群落高度模块化,小单胞菌属(Micromonospora)为南岭丘陵生态区和黄淮生态区细菌共现性网络的网络中心,Bryobacter和气单胞菌属(Arenimonas)为南岭丘陵生态区细菌网络的模块核心,其菌群特性而非相对丰度决定了其在稳定细菌网络中的重要作用。冗余分析结果证实pH、有效铁、交换性镁和有效锰能显著影响烤烟根际细菌群落结构。【结论】烤烟根际细...     

中华蜜蜂和意大利蜜蜂感染囊状幼虫病毒后免疫及发育相关基因表达比较

【目的】本文旨在探究囊状幼虫病毒(sacbrood virus, SBV)对中华蜜蜂(Apis cerana cerana,简称中蜂)和意大利蜜蜂(Apis mellifera ligustica,简称意蜂)工蜂幼虫发育和免疫基因、营养代谢基因、抗病毒基因、细胞发育及代谢相关基因表达的影响。【方法】从蜂群中移取2日龄的中蜂和意蜂幼虫,在培养箱(34℃, RH 85%)进行人工饲养,3日龄时接种SBV病毒,每天观察记录死亡情况,并通过实时定量PCR (real-time quantitative polymerase chain reaction, RT-qPCR)检测4日龄和7日龄幼虫体内SBV基因相对表达量,及免疫基因(Apidaecin、Abaecin、Hymenoptaecin、Denfensin、Lys-1、Pgrp-lc、Kenny、Domeless)、营养代谢基因(Ilp1、Hex110、Vg)、抗病毒基因(Dis3、Dicer、Ago1)、细胞组成及发育调控基因(Vhdl、Co-1-iv)以及细胞代谢和调控基因(Mta1)的表达水平。【结果】通过分析比较发现,感染相同剂量...     

枯草芽孢杆菌聚谷氨酸合成途径相关基因功能研究

聚谷氨酸(polyglutamic acid, PGA)作为一种天然多功能的聚合物,近年来成为研究的热点。由于很难通过化学方法合成,微生物发酵是目前生产聚谷氨酸的有效途径。【目的】从基因水平探究枯草芽孢杆菌聚谷氨酸合成途径中degS、degQ、degU、swrA、rocA、putM基因的功能,通过分子改造实现对代谢途径的调控。【方法】以枯草芽孢杆菌为出发菌株,通过对代谢途径中相关基因进行敲除或过表达,分别构建degS、degQ和degU基因缺失的重组菌,swrA、rocA和putM基因过表达的重组菌,借助菌株胞外聚谷氨酸积累的变化分析影响途径的关键节点。【结果】在摇瓶发酵条件下,重组菌Bacillus subtilis 168-swrA、Bacillus subtilis 168-rocA、Bacillus subtilis 168-putM的胞外聚谷氨酸含量分别是原始菌株的1.28倍、1.47倍和1.37倍。重组菌Bacillus subtilis 168-ΔdegS、Bacillus subtilis 168-ΔdegQ、Bacillus subtilis 168-ΔdegU的胞外...     

TaTPP-7A positively feedback regulates grain filling and wheat grain yield through T6P-SnRK1 signalling pathway and sugar–ABA interaction

Grain size and filling are two key determinants of grain thousand-kernel weight (TKW) and crop yield, therefore they have undergone strong selection since cereal was domesticated. Genetic dissection of the two traits will improve yield potential in crops. A quantitative trait locus significantly associated with wheat grain TKW was detected on chromosome 7AS flanked by a simple sequence repeat marker of Wmc17 in Chinese wheat 262 mini-core collection by genome-wide association study. Combined with the bulked segregant RNA-sequencing (BSR-seq) analysis of an F₂ genetic segregation population with extremely different TKW traits, a candidate trehalose-6-phosphate phosphatase gene located at 135.0 Mb (CS V1.0), designated as TaTPP-7A, was identified. This gene was specifically expressed in developing grains and strongly influenced grain filling and size. Overexpression (OE) of TaTPP-7A in wheat enhanced grain TKW and wheat yield greatly. Detailed analysis revealed that OE of TaTPP-7A significantly increased the expression levels of starch synthesis- and senescence-related genes involved in abscisic acid (ABA) and ethylene pathways. Moreover, most of the sucrose metabolism and starch regulation-related genes were potentially regulated by SnRK1. In addition, TaTPP-7A is a crucial domestication- and breeding-targeted gene and it feedback regulates sucrose lysis, flux, and utilization in the grain endosperm mainly through the T6P-SnRK1 pathway and sugar–ABA interaction. Thus, we confirmed the T6P signalling pathway as the central regulatory system for sucrose allocation and source–sink interactions in wheat grains and propose that the trehalose pathway components have great potential to increase yields in cereal crops.