三带喙库蚊生殖滞育与其体内脂肪酸变化的关系

本文报道1986年—1988年用气相色谱法对不同生殖状态与不同季节采自上海等地野外的三带喙库蚊Culex tritaeniorhynchus脂肪酸组分及其变化的分析结果.经研究发现雌蚊体内有23—43种脂肪酸,其中棕榈油酸、棕榈酸、油酸及硬脂酸为主要组分,其次为亚油酸、豆蔻酸及花生酸等.不同生殖状态蚊间豆蔻酸与油酸及硬脂酸等具有一定的差异.野外蚊体内脂肪酸组分比实验室蚊少,不同季节的野外蚊体脂肪酸具有明显变化.另外,两种提取脂肪酸的方法比较表明,酸水解法有利于提取长链脂肪酸,碱水解法则有利于提取短链脂肪酸.     

光周期对中华按蚊脂肪含量的影响

光周期是引起蚊虫滞育越冬的主要因素,脂肪是滞育越冬期间的能源物质,研究光周期对中华按蚊(Anopheles sinensis)脂肪含量的影响,对进一步解释该蚊越冬机理具有重要的参考价值。1材料与方法1.1实验蚊株中华按蚊上海株,为本实验室养殖。1.2蚊虫饲养条件温度25±1℃,长光照为16L:8D,短光照为8L:16D。1.3脂肪含量测定法称重法参照王仁赉方法〔1〕,比色法参照Van Handel方法〔2,3〕。2结果2.1称重法测定中华按蚊上海株脂肪含量及体重在短光照和长光照条件下羽化的中华按蚊10日龄平均单个雌蚊脂肪含量、体重分别为163μg、842μg和150μg、100…     

狗尾草和金色狗尾草种群生殖分株生物量结构及生长

采用野外生态学实验方法对狗尾草属狗尾草和金色狗尾草种群生殖分株组分生物量结构及生长情况进行了比较。结果表明:在种内2物种生殖分株组分生物量具有较大的变异特征;组分生物量分配变异系数较小,分别为11.11%~22.77%和12.41%~26.82%;生殖分株营养组分生物量随株高和总生物量增加而均呈现幂函数形式增长,表现为相似的异速生长规律;其中,狗尾草全体拟合方程的R2值在55%~71%,金色狗尾草为62%~81%;在种间,生殖分株各组分除株高存在显著差异外,其余均不显著;生物量分配中,生殖分配和鞘生物量分配呈极显著差异。研究表明,狗尾草属2物种生殖分株在相同生存环境下,组分生物量和生长情况在种内和种间会同时受随机环境因子和自身遗传因子的内外调控,而表现出一定异同点。     

33株尖孢镰刀菌遗传多样性的ISSR分析

为明确尖孢镰刀菌种内各菌株间的遗传差异与亲缘关系,采用ISSR分子标记技术对33株地理来源不同的尖孢镰刀菌进行了遗传多样性分析.结果表明:利用筛选出的11条引物扩增出105条条带,其中多态性条带91条,多态性位点比例为86.7％;遗传相似性与聚类分析结果供试菌株间的遗传相似系数为0.606 ～0.962,平均0.756,当遗传相似系数为0.962时,供试的33株菌可被全部区分开.表明,尖孢镰刀菌基因组在SSR区域具有丰富的多态性.寄主来源相同的供试菌株间的遗传相似性与其地理来源有一定的相关性.     

四膜虫种间骨架蛋白组分的比较研究

以上海四膜虫S1和嗜热四膜虫BF株和BT株为材料,结合显微观察,采用生化抽提、SDS-PAGE电泳、扫描及数据统计,分析与测定了三个不同株四膜虫对数生长期皮层骨架蛋白组分与含量,结果显示嗜热四膜虫的BF与BT株差异较小,两者与上海四膜虫S1株差异则较大,S1株细胞中有92KD、72KD、66KD、32KD、27KD,而BF和BT株细胞中没有,估计这些蛋白的不同与种间亲缘关系及株系、培养条件等有着密不可分的联系.       

凡纳滨对虾白斑综合征病毒广西株变异区基因的比较分析

对凡纳滨对虾白斑综合征病毒(White spot syndrome virus,WSSV)广西株变异区ORF14/15基因序列进行比较分析,了解WSSV广西株遗传进化差异及其与各地WSSV毒株间的遗传进化关系。考虑地理和时间因素选取2010年5月至2013年7月采自广西凡纳滨对虾主要养殖地区北海、钦州和防城港的40份WSSV阳性的凡纳滨对虾样品,PCR扩增、克隆样品中WSSV的ORF14/15基因并对其进行序列测定与比较分析。40份样品中有25份的ORF14/15基因被成功克隆和测序,其中22株为619bp,3株为620bp;相对于此区域最为完整的TH-96-Ⅱ株,25株WSSV广西株的ORF14/15基因均在中间缺失了5 949bp,仅剩5′端的190bp和3′端的429bp(430bp),与印度株IN-05-Ⅰ缺失大小和位置相同;在变异区25株WSSV广西株中有16株核苷酸序列同源性为100%,其余毒株间的同源性也在97.9%以上,仅存在单个碱基的变异;基于变异区构建的系统进化树显示,WSSV广西地方株在遗传上相距较近,全部与印度株IN-05-Ⅰ聚在一个大的分支,而与目前发表的其他毒株均相距较远。广西养殖凡纳滨对虾中流行的WSSV毒株变异区ORF14/15基因的变异类型为中间大片段缺失,广西各地流行的WSSV毒株间无明显的地域和时间差异;WSSV广西株与印度株IN-05-Ⅰ的遗传进化关系最近。     

广谱碳源产油酵母菌的筛选

对10株酵母菌利用不同单糖为碳源条件下菌体内积累油脂的能力进行了初步考察,并对菌油进行了分离和脂肪酸组成分析。实验发现,以葡萄糖为唯一碳源时有9株菌油脂含量超过自身细胞干重的20%,可以界定为产油微生物。其中6#菌(T.cutaneumAS2.571)利用葡萄糖发酵菌体油脂含量达到65%(W/W)。所有实验菌株都能同化多种单糖,其中1#菌(L.starkeyiAS2.1390)、4#菌(R.toruloidesAS2.1389)和11#菌(L.starkeyiAS2.1608)表现出对碳源利用的广谱性,能转化五碳糖木糖和阿拉伯糖并在菌体内积累油脂,油脂含量最高达到26%。脂肪酸组成分析结果表明,菌油富含饱和及低度不饱和长链脂肪酸,其中棕榈酸、油酸和亚油酸三者之和占总脂肪酸组成的90%以上,脂肪酸组成分布类似于常见的植物油。这些结果对利用产油微生物转化木质纤维素水解混合糖获取油脂资源的研究具有重要意义。     

龙眼叶片膜脂脂肪酸组分与龙眼耐寒性的关系

龙眼叶片膜脂不饱和脂肪酸含量和脂肪酸不饱和度与龙眼不同品种的耐寒性呈正相关;在年周期中,不饱和脂肪酸含量的变化与龙眼耐寒性的变化呈现平行关系;龙眼叶片膜脂脂肪酸组分含量反映着龙眼品种间耐寒性遗传上的差异,可作为耐寒性的鉴定指标。     

烤烟根系分泌物中单糖的组分含量及其相关分析

以4个不同烤烟品种为研究材料,采用盆栽试验,运用高效毛细管区带电泳法测定各品种根际土、非根际土、根系及叶片中的单糖组分及含量,并分析其相关关系,探究根系分泌物中糖类的分泌特性。结果表明：在各样品中,共检出木糖、葡萄糖、半乳糖、核糖、阿拉伯糖和鼠李糖6种糖;不同品种根际土、非根际土、根系及叶片中检出的糖组分及含量均存在差异;同一品种中,叶片最高,根系次之,根际土和非根际土最低;相关性分析表明,木糖、阿拉伯糖、葡萄糖、鼠李糖和半乳糖总量在根际土、非根际土、叶片和根系间呈正相关关系,各单糖组分间均呈正相关关系,部分组分呈显著或极显著相关关系。研究表明,不同烤烟品种根系分泌这些单糖存在品种差异,且根系分泌单糖可能是一个沿浓度梯度的扩散过程。     

葡萄的膜脂和脂肪酸组分与抗寒性关系的研究

分析了葡萄的种子、茎、叶、树皮、叶绿体、叶片愈伤组织和黄化幼苗的膜脂主要组分。种子的膜脂脂肪酸不饱和度与品种抗寒性成正相关。茎的膜脂脂肪酸含量随季节呈周期性变化,膜脂脂肪酸不饱和度随气温的降低而升高。秋季取样的茎、叶片、叶绿体的膜脂脂肪酸不饱和度与品种抗寒性成正相关。抗寒品种具有较高的亚油酸/棕榈酸比值,近亲品种的膜脂组分近似,可以看到遗传性的影响。夏季取样的茎、叶片、叶绿体的膜脂脂肪酸含量的变化无明显规律性,品种间无明显差异。25℃培养的黄化幼苗和愈伤组织经7℃处理后,两者的脂肪酸不饱和度都略有增加,,与品种的抗寒性也有一定联系。     

用微卫星标记技术对国内BALB/c小鼠遗传质量的分析

为了解和掌握国内BALB/c小鼠遗传质量状况,验证微卫星标记技术在近交系小鼠遗传检测中应用的可靠性,应用所筛选的小鼠不同染色体上的14个微卫星基因座,通过PCR扩增对北京、上海、沈阳、广州、长春、重庆和哈尔滨7个地区11个厂家提供的BALB/c小鼠进行遗传质量分析.结果北京、上海、哈尔滨及广州地区7家BALB/c小鼠在14个基因座均呈现一条清晰条带,且群体间呈单态性.沈阳、广州、长春和重庆4个群体有8个基因座在群体内表现杂合或呈多态性;其中沈阳和长春分别在1个基因座上表现多态性和杂合;广州另一群体有4个基因座出现杂合或多态性;重庆群体有7个基因座表现为杂合或多态性,在D10Mit180基因座与上海群体比较呈现多态性.     

中国不同地区和人群HDV cDNA的筛选、克隆及抗原编码区基因异质性的分析

为研究我国不同地区不同人群中ＨＤＶ毒株的感染分子特征,从我国河南、内蒙、北京、四川、广西、西藏、新疆、辽宁、上海等地的ＨＤＶ健康携带者、慢性丁肝病人与重症肝炎病人中筛选获得１０余份ＨＤＶ－ＲＮＡ阳性血清。经逆转录一多聚酶链反应（ＲＴ－ＰＣＲ）交叉扩增获得ＨＤＶ抗原编码区的ｃＤＮＡ片段并克隆到ＰＧＥＭ－３Ｚｆ（－）或ＰＧＥＭ－Ｔ载体上,经序列分析研究其基因结构特点,结果表明：中国的ＨＤＶ毒株基因型均为Ⅰ型,但至少存在ⅠＡ、ⅠＢ两个亚型,ＨＤＶ毒株在不同地区间存在异质性,其中河南－１、－２、－３株及新疆株与台湾株同源性较高（核苷酸与氨基酸同源性分别大于９２．１％与８６．９％）．当为ⅠＡ型;内蒙－１、四川、广西、西藏－１、辽宁、北京株与美国－１株同源性较高（核苷酸与氨酸同源性分别大于９４．３％与８８．８％）,当为ⅠＢ亚型;上海株与意大利株的核昔酸同源性最高,为９８．１％。研究证明我国新疆、内蒙、西藏等地区抗ＨＤ阳性率比其他省市高并不是由于存在其他基因型所致。     

Characterization and toxicity to mosquito larvae of four Bacillus sphaericus strains isolated from Brazilian soils.

Four Bacillus sphaericus strains, S1, S2, S5, and L2, isolated from Brazilian soils, were found to be toxic to larvae of the mosquitoes Culex pipiens and Anopheles stephensi at a level similar to that of strain 2362 which is now used operationally. Like strain 2362, the four strains belonged to the serotype H5 and produced major proteins of apparent molecular weights of 125, 110, 56, and 43 kDa. These latter two proteins were immunologically related to toxins of the same molecular weight as B. sphaericus 2362. Although the four Brazilian strains were very similar to strain 2362, gas chromatography analysis of the fatty acids revealed that these strains were different from strain 2362 and from each other, except for a possible similarity between strains S1 and S5.     

Composition and positional distribution of fatty acids in polar lipids from Chlorella ellipsoidea differing in chilling susceptibility and frost hardiness

The composition and positional distribution of fatty acids in the polar lipids from 4 strains of Chlorella differing in chilling susceptibility and frost hardiness were analyzed by enzymatic hydrolysis and gas-liquid chromatography. Analysis of the polar lipids from chilling-sensitive, chilling-resistant and chilling-sensitive revertant strains of Chlorella ellipsoidea IAM C-102 showed that the sum of palmitic and trans -3-hexadecenoic acid in phosphatidylglycerol (PG) is about 60% for the sensitive strains and 53% for the resistant strain. The sum of dipalmitoyl and 1-palmitoyl-2-( trans -3-hexadecenoyl) PG as estimated from the positional distribution of their fatty acids, is about 10% in the case of each of the three strains. The contents of unsaturated fatty acids in phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were higher in the resistant than in the sensitive strain. This suggests that unsaturation of fatty acids in not only PG but also PC and PE is involved in chilling sensitivity of Chlorella . On the other hand, lipid changes during the development of frost hardiness of C. ellipsoidea IAM C-27, a frost hardy strain, were examined. The results showed that fatty acids in most lipid classes are unsaturated in the hardening process but their degree of unsaturation is not greatly different from that of the chilling-resistant strain, suggesting that not only unsaturation of fatty acids in lipids but also other factors are necessary for the development of frost hardiness.     

Cell Envelope Changes in Solvent-Tolerant and Solvent-Sensitive Pseudomonas putida Strains following Exposure to o-Xylene

Solvent-tolerant and -sensitive Pseudomonas putida strains were studied to determine their cell envelope changes following exposure to o-xylene. Both strains produced trans-unsaturated fatty acids. The tolerant strain showed an increase in total fatty acids, an increase in saturated fatty acids, and modified lipopolysaccharide. It is suggested that these envelope modifications aid in survival at high concentrations of organic solvents.     

Composition of Fatty Acids and Carbohydrates in Leptospira

The fatty acid and monosaccharide composition of four pathogenic and two saprophytic strains of Leptospira was analyzed by gas chromatography (GC) and GC-mass spectrometry. Among the fatty acids, palmitic acid was most abundant and constituted 30 to 50% of the total fatty acids. Even-numbered unsaturated acids including octadecenoic, hexadecenoic, octadecadienoic, and tetradecadienoic acids comprised 40 to 60% of the total fatty acids. Tetradecanoic acid was about 5% in saprophytic strains, but 1% or less in pathogenic strains. The amount of chloroform-methanol extract of L. biflexa strain Ancona was 14 to 20% of the dry weight of the cell. Tetradecadienoic acid was found in the chloroform-methanol insoluble fraction, suggesting the presence of the acid in a bound form. GC analysis of monosaccharides revealed the existence of arabinose, xylose, rhamnose, mannose, galactose, glucose, glucosamine, and muramic acid in the cells. Among the neutral sugars, glucose was a minor component and was especially low in pathogenic strains. Total pentose content was about two to three times greater than total hexose.     

Effect of Biotin on Fatty Acids and Phospholipids of Biotin-Sensitive Strains of Rhizobium japonicum

The effect of biotin on fatty acids and intact lipids was studied by comparing a biotin-requiring, a biotin-inhibited, and a biotin-indifferent strain of Rhizobium japonicum. These organisms were grown in a defined medium with added levels of 0, 0.3, and 0.5 μg of biotin per liter, and were analyzed for fatty acids and lipid components. Myristic, palmitic, and octadecenoic acids were found to be the major fatty acids in these strains. The indifferent strain also contained large amounts of C₁₉ cyclopropane acid and small amounts of a C₁₇ cyclopropane acid. Several unidentified acids were present in the other two strains. The percentages of fatty acids showed statistically significant changes corresponding with changes in level of biotin in the medium. When biotin concentration was increased in the medium, the C₁₈ monoenoic acids of the biotin-requiring strain increased significantly, and those of the biotin-inhibited and biotin-indifferent strains decreased significantly. Palmitic acid showed a statistically significant increase in the indifferent strain with increasing biotin concentration. The principal intact lipid components in these strains are phospholipids. The major phospholipids are phosphatidylserine, phosphatidylcholine, phosphatitidylethanolamine, and cardiolipin. These phospholipids were not affected by biotin level and were independent of medium composition.     

Different cellular fatty acid pattern behaviours of two strains of Listeria monocytogenes Scott A and CNL 895807 under different temperature and salinity conditions

Cells of two strains of Listeria monocytogenes CNL 895807 and Scott A were grown to late exponential phase at different growth temperatures (37, 20 and 4 degrees C) with or without NaCl (7%), and their fatty acid compositions were analysed. The results showed that low thermal adaptation response of L. monocytogenes CNL was different than that of the Scott A strain, and it was based on both an increase of anteiso-branched-chain fatty acids and a significant decrease of straight-chain fatty acids. However, the main modifications observed in the Scott A strain when grown at a low temperature were a decrease of the proportion of ai17:0 and an increase of ai15:0. In hyperosmotic medium and over the entire temperature range (4 degrees C, 20 degrees C and 37 degrees C) the two L. monocytogenes strains showed a cellular fatty acid profile dominated by ai15:0. In addition, a decrease of the two major straight-chain fatty acids (14:0 and 16:0) was observed in the CNL strain. These results demonstrated that the CNL strain showed different behaviours of low thermal and salt adaptation to maintain membrane fluidity, which are based both on an increase of anteiso-branched-chain fatty acids, and a significant decrease of straight-chain fatty acids.     

Gas chromatography analysis of cellular fatty acids and neutral monosaccharides in the identification of lactobacilli

Cellular fatty acids and monosaccharides in a group of 14 lactobacilli were analyzed by gas chromatography and the identity of the components was confirmed by gas chromatography-mass spectrometry. From the same bacterial sample, both monosaccharides and fatty acids were liberated by methanolysis, and in certain experiments, fatty acids alone were released by basic hydrolysis. The results indicate that basic hydrolysis gave more comprehensive information about the fatty acids, but the analysis of monosaccharides was found to be much more useful in distinguishing between different species of lactobacilli. The method described allowed differentiation of 11 of 14 Lactobacillus species, and even single colonies isolated from agar plates could be used for analysis without subculturing.     

RAPD方法用于区分中国烟粉虱的生物型

应用RAPD－PCR技术研究了中国大陆10个烟粉虱种群的生物型情况,聚类分析表明,这10个种群中包含了3种生物型：烟粉虱B型,广西型（南宁南瓜寄主）和福建型（福州地瓜）。值得注意的是,在福建并存着两种烟粉虱生物型,即苷蓝上的B型烟粉虱和甘署上的福建福州型,研究表明烟粉虱B型已经传入中国,至少在北京,山东,新疆,福建,广东等地都有发生和分布,广西型和福建型是否中国的本地土种群还需进一步研究。