A Novel System for Proliferation,Maintenance and Plantlets Germination from Somatic Embryo of Soybean

Somatic embryogenesis was successfully induced with auxin in high concentration from immature cotyledons of eighteen varieties of soybean (Glycine max (L.) Merr.) adaptable for planting in Northeast China. The frequency of somatic embryogenesis varied from 0.29% to 77.62% among eighteen genotypes of soybean. The proliferative somatic embryos were gained from ten varieties of soybean at rate of 5.2%-22.1%. For the first time, plantlets were obtained even after subcultured and maintained on solid medium for over one year. This system provided a new and efficient receptor for genetic transformation of soybean.     

人CD46启动子真核表达载体的构建

为了构建人CD46（hCD46）启动子指导目的基因表达的真核表达载体,提取HeLa细胞基因组DNA,用PCR扩增出hCD46基因的启动子区域,序列分析结果表明其与GenBank中hCD46基因5’端某片段的同源性为99.9％。用此启动子替换pcDNA3EGFP中的CMV启动子,并在hCD46启动子和EGFP基因之间插入兔β-球蛋白基因第二内含子（RGI）,得到的重组表达载体转染CHO和SP2/0两种鼠源细胞,流式细胞术检测表明CHO细胞EGFP的表达量高于SP2/0细胞,表达特性与人体CD46相似;RGI可以增强EGFP的表达量,但不改变其表达的组织特异性,提示克隆的hCD46启动子可以用于研制模拟人体CD46基因表达特性的转基因小鼠。     

东北虎幼体消化系统蛋白水解酶的初步研究

蛋白水解酶在许多生命活动中是必需的物质(Vassalli and Pepper,1994)。蛋白质的酶解修饰(Xuet al.,1999)、细胞迁移、组织再生与修复、消化系统对蛋白质的消化等均与蛋白水解酶有关(Baimbridgeet al.,1992),且蛋白水解酶功能失调会导致许多疾病(Teichertet al.,1989)。东北虎(     

不同保存条件下茧蜂标本基因组DNA的降解

探讨了不同保存条件下高温、氧化、化学修饰等对茧蜂标本基因组DNA降解的影响,提出用含50 mmol.L-1乙二胺四乙酸的无水乙醇保存室内寄生蜂标本,并在液面覆盖石蜡油等可行性建议。     

土耳其斯坦叶螨对胡瓜钝绥螨的吸引反应

土耳其斯坦叶螨（Tetranychus turkestani Ugarov ＆ Nikolski）对胡瓜钝绥螨（Amblyseius cucumeris Oudemans）的吸引测试表明,胡瓜钝绥螨对不同螨态的土耳其斯坦叶螨的刺激均能产生显著的吸引反应。胡瓜钝绥螨能捕食土耳其斯坦叶螨的卵,但对土耳其斯坦叶螨的“卵＋丝网＋粪便＋取食斑”没有明显的反应,土耳其斯坦叶螨的若螨I和幼螨是胡瓜钝绥螨最喜欢的猎物。土耳其斯坦叶螨主要通过活动螨对胡瓜钝绥螨产生吸引反应,这种吸引反应能明显提高胡瓜钝绥螨在田间搜索土耳其斯坦叶螨的能力。     

Proanthocyanidins: Gross chemical structures by infrared spectra

IR studies of four proanthocyanidin dimers and all four 4-(2′,4′,6′-trihydroxyphenyl) derivatives of the flavan monomer units of proanthocyanidin     

Evaluation of the Phene Plate generalized microplate for metabolic fingerprinting and for measuring fermentative capacity of mixed bacterial populations

The Phene Plate (PhP) generalized microplate for metabolic fingerprinting and for measuring the fermentative capacity of intestinal bacteria was evaluated. Twelve bacterial species, representing those commonly found in the intestine of humans and animals were employed. Mixtures of bacteria were inoculated in duplicate onto the PhP microplates. Anaerobic conditions were achieved by either incubating the plates under nitrogen atmosphere or by covering the microplates with mineral oil before incubation. Different metabolic fingerprints based on the pattern of substrate utilization were obtained for each bacterial mixture. Metabolic responses of bacterial samples were similar under both anaerobic conditions although the rate of carbohydrate utilization was higher in plates covered with mineral oil. A fermentative capacity value based on the number and the degree of fermented carbohydrates was established for each mixture which differed as the composition of the mixture changed but in general it was higher in samples with more bacterial species. The PhP generalized microplate may thus be used for studying the functional status and metabolic potential of intestinal floras.     

Evidence for Symbiont-induced Alteration of a Host's Gene Expression: Irreversible Loss of SAM Synthetase from Amoeba proteus

ABSTRACT. Symbiont-bearing xD amoebae no longer produce a 45-kDa cytoplasmic protein that functions as S-adenosylmethionine synthetase in symbiont-free D amoebae. The absence of the protein in xD amoebae is attributable to xD amoeba's failure to transcribe the corresponding gene as a result of harboring bacterial symbionts. However, xD amoebae have about half the level of enzyme activity found in D amoebae, indicating that they use an alternative source for the enzyme. xD amoebae originated from D amoebae by bacterial infection and now depend on their symbionts for survival. xD amoebae exhibit irreversible nucleolar abnormalities when their symbionts are removed, suggesting that X-bacteria supply the needed enzyme. A monoclonal antibody against the 45-kDa protein was produced and used as a probe in cloning its corresponding cDNA. The product of the cDNA was found to have S-adenosylmethionine synthetase activity. These results show how symbiotic X-bacteria may become essential cellular components of amoebae by supplementing a genetic defect for an amoeba's house-keeping gene that is brought about by an action of X-bacteria themselves. This is the first reported example in which symbionts alter the host's gene expression to block the production of an essential protein.     

Uncovering the Nutritional Landscape of Food

Recent progresses in data-driven analysis methods, including network-based approaches, are revolutionizing many classical disciplines. These techniques can also be applied to food and nutrition, which must be studied to design healthy diets. Using nutritional information from over 1,000 raw foods, we systematically evaluated the nutrient composition of each food in regards to satisfying daily nutritional requirements. The nutrient balance of a food was quantified and termed nutritional fitness; this measure was based on the food’s frequency of occurrence in nutritionally adequate food combinations. Nutritional fitness offers a way to prioritize recommendable foods within a global network of foods, in which foods are connected based on the similarities of their nutrient compositions. We identified a number of key nutrients, such as choline and α-linolenic acid, whose levels in foods can critically affect the nutritional fitness of the foods. Analogously, pairs of nutrients can have the same effect. In fact, two nutrients can synergistically affect the nutritional fitness, although the individual nutrients alone may not have an impact. This result, involving the tendency among nutrients to exhibit correlations in their abundances across foods, implies a hidden layer of complexity when exploring for foods whose balance of nutrients within pairs holistically helps meet nutritional requirements. Interestingly, foods with high nutritional fitness successfully maintain this nutrient balance. This effect expands our scope to a diverse repertoire of nutrient-nutrient correlations, which are integrated under a common network framework that yields unexpected yet coherent associations between nutrients. Our nutrient-profiling approach combined with a network-based analysis provides a more unbiased, global view of the relationships between foods and nutrients, and can be extended towards nutritional policies, food marketing, and personalized nutrition.     

不同年代大豆品种根系活力的变化及其与植株生物量的关系

为探索不同年代大豆品种根系活力的变化及其与植株各器官生物量和根系伤流液重量的关系。以吉林省1923~2009年间育成的27个大豆品种为材料进行田间试验,在四叶期(V4),盛花期(R2),结荚盛期(R4)和鼓粒盛期(R6)测定根系活力、伤流液重量和植株各器官生物量。结果表明,随生育期的推进,植株器官生物量不断增加,而根系活力和伤流液重量则呈单峰曲线变化,在R4期达到最大。在R4期,植株根系活力、根系伤流液重量和器官生物量与育成年代均呈显著或极显著正相关,但在V4、R2和R6期均未达到显著水平。在R4期,根系活力与根系伤流液重量、植物器官茎、叶和根生物量呈显著或极显著正相关;各品种间地上部器官生物量与根系活力的比值差异不显著。大豆的遗传改良使地上部器官与根系活力协同演进,在根系活力增强的同时植株器官生物量和根系伤流液重量也增加,且在R4期,根系活力与植物器官生物量和根系伤流液重量相关最为密切;可以把R4期的根系活力作为高产育种的指标之一。