The Immune Response to Artificial Proteins Containing Biologically Active Fragments of Human IFN-α2 and Insulin

A study was made of the humoral immune response of BALB/c mice to various doses of artificial proteins that contained biologically active fragments of human interferon 2 (IFN-2) and insulin. The insulin fragment had no effect on the response to any protein construct. The IFN-2 fragment increased the titer of antibodies against the construct. Mapping of continuous B epitopes with immune sera revealed several antigenic determinants, the C end of the IFN-2 fragment with the adjacent de novo protein region being immunodominant. The more effective binding of serum antibodies with the constructs containing the IFN-2 fragment was attributed to antibody interaction with the fragment and to better recognition of the entire protein construct by the immune system.     

人工感染雏鹅新型病毒性肠炎病毒的形态发生及宿主细胞的超微结构变化

应用超薄切片及电镜观察发现,人工感染雏鹅新型病毒性肠炎病毒(gosling new type viral enteritis virus,NGVEV)后不同时间宰杀的及发病的雏鹅,其心、肝及小肠上皮细胞的细胞核(质)中均有典型腺病毒粒子.病毒侵害的靶器官主要是小肠粘膜上皮细胞,以上皮细胞微绒毛断裂、脱落开始,进一步发展为上皮细胞核畸形,固缩,核仁消失,核膜模糊和胞核崩解;胞浆严重空化,形成含有很多病毒粒子的"封入体";粗面内质网严重扩张呈囊状,其上的核蛋白体严重脱落;线粒体外膜破裂或嵴断裂及空化,部分受到损害的线粒体充满大量的病毒粒子;形成肠道栓子的外层假膜由大量的病毒粒子、细菌以及坏死的肠上皮细胞组成.肝和心的损害主要发生于感染早期,其粗面内质网和线粒体出现类似于小肠粘膜上皮细胞的变化.病毒在细胞核复制和装配,通过芽生或核膜的破裂而进入胞质,病毒于胞浆中主要是以"封入体"的形式存在,此外还有少量游离病毒.病毒释出细胞外可通过细胞膜芽生或破裂方式,也可通过与核外膜紧密联系的特殊膜性管道将病毒由胞核运至胞外.还讨论了小鹅瘟与雏鹅新型病毒性肠炎在超微结构上的区别.     

Finite element analysis of Stryker Xia pedicle screw in artificial bone samples with and without supplemental cement augmentation

A validated, using in vitro biomechanical testing, finite element model was used to evaluate the affects of (1) cement augmentation and (2) an intact posterior cortex in osteoporotic bone. The presence of augmentation and/or a posterior cortical cortex increased the stabilization of the pedicle screw 2–5 fold. Placement of cement influenced failure load and toggle; with distal placement having the largest increase in failure load and decrease in cephalad–caudad toggle. The presence of posterior cortex caused a decrease in the amount of toggle, a proximal shift of the center of rotation and an increase in the maximum failure force.     

Construction of a Bacterial Artificial Chromosome Library of TM-1, a Standard Line for Genetics and Genomics in Upland Cotton

A bacterial artificial chromosome （BAC） library was constructed for Gossypium hirsutum acc. TM-1, a genetic and genomic standard line for Upland cotton. The library consists of 147 456 clones with an average insert size of 122.8 kb ranging from 97 to 240 kb. About 96.0% of the clones have inserts over 100 kb. Therefore, this library represents theoretically 7.4 haploid genome equivalents based on an AD genome size of 2 425 Mb. Clones were stored in 384 384- well plates and arrayed into multiplex pools for rapid and reliable library screening. BAC screening was carried out by four-round poiymerase chain reactions using 23 simple sequence repeats （SSR） markers, three sequence-related amplified polymorphism markers and one pair of primers for a gene associated with fiber development to test the quality of the library. Correspondingly, in total 92 positive BAC clones were identified with an average four positive clones per SSR marker, ranging from one to eight hits. Additionally, since these SSR markers have been localized to chromosome 12 （A12） and 26 （D12） according to the genetic map, these BAC clones are expected to serve as seeds for the physical mapping of these two homologous chromosomes, sequentially map-based cloning of quantitative trait loci or genes associated with important agronomic traits.     

Comparisons of population density and genetic diversity in artificial and wild populations of an arborescent coral,Acropora yongei: implications for the efficacy of “artificial spawning hotspots”

We are developing techniques to restore coral populations by enhancing larval supply using “artificial spawning hotspots” that aggregate conspecific adult corals. However, no data were available regarding how natural larval supply from wild coral populations is influenced by fertilization rate and how this is in turn affected by local population density and genetic diversity. Therefore, we assessed population density and genetic diversity of a wild, arborescent coral, Acropora yongei, and compared these parameters with those of an artificially established A. yongei population in the field. The population density of wild arborescent corals was only 0.27% of that in the artificial population, even in a high‐coverage area. Genetic diversity was also low in the wild population compared with the artificial population, and approximately 10% of all wild colonies were clones. Based on these results, the larval supply in the artificial population was estimated to be at least 1,400 times higher than that in wild A. yongei populations for the same area of adult population.     

枸杞新品系NQ-2开花生物学研究

为探讨枸杞新品系NQ-2纯系种植结实率低的原因,采用TTC法、联苯胺—过氧化氢法、花粉—胚珠比、杂交指数和套袋试验等方法,对NQ-2花粉活力、柱头可授性及繁育系统等进行了研究。结果表明:NQ-2单花花期为3~4 d,花后8 h散粉结束,开花当天花粉活力最高,花粉寿命可持续9 d以上;开花前一天柱头已具可授性,开花第1天柱头可授性最强,开花第3天柱头基本失去可授性;枸杞新品系NQ-2平均花粉-胚珠比8615,OC I=4,结合人工授粉实验结果确定其繁育系统为专性异交。自交不亲和是导致NQ-2纯系种植落花落果结实率低的主要原因。     

Bacterial Artificial Chromosomes: A Functional Genomics Tool for the Study of Positive-strand RNA Viruses

Reverse genetics, an approach to rescue infectious virus entirely from a cloned cDNA, has revolutionized the field of positive-strand RNA viruses, whose genomes have the same polarity as cellular mRNA. The cDNA-based reverse genetics system is a seminal method that enables direct manipulation of the viral genomic RNA, thereby generating recombinant viruses for molecular and genetic studies of both viral RNA elements and gene products in viral replication and pathogenesis. It also provides a valuable platform that allows the development of genetically defined vaccines and viral vectors for the delivery of foreign genes. For many positive-strand RNA viruses such as Japanese encephalitis virus (JEV), however, the cloned cDNAs are unstable, posing a major obstacle to the construction and propagation of the functional cDNA. Here, the present report describes the strategic considerations in creating and amplifying a genetically stable full-length infectious JEV cDNA as a bacterial artificial chromosome (BAC) using the following general experimental procedures: viral RNA isolation, cDNA synthesis, cDNA subcloning and modification, assembly of a full-length cDNA, cDNA linearization, in vitro RNA synthesis, and virus recovery. This protocol provides a general methodology applicable to cloning full-length cDNA for a range of positive-strand RNA viruses, particularly those with a genome of >10 kb in length, into a BAC vector, from which infectious RNAs can be transcribed in vitro with a bacteriophage RNA polymerase.     

柑橘大实蝇生物、生态学及辐照不育技术最新研究进展

柑橘大实蝇是柑橘类果树的一种重要害虫,近几年在我国柑橘种植区的危害呈上升趋势,给柑橘产业造成了巨大损失。本文概述了环境因素包括温度、光周期、营养状况(饥渴)以及水淹对柑橘大实蝇生物学特性和成虫行为的影响,柑橘大实蝇成虫和幼虫人工饲养技术参数,柑橘大实蝇蛹滞育机制,辐照不育关键技术包括最佳辐照剂量和辐照时期,及其在湖北柑橘园柑橘大实蝇防控中的应用与示范情况等,并指出了尚需进一步开展的研究内容。     

Avoidance of an aposematically coloured butterfly by wild birds in a tropical forest

1. Birds are considered to be the primary selective agents for warning colouration in butterflies, and select for aposematic mimicry by learning to avoid brightly coloured prey after unpleasant experiences. It has long been thought that bright colouration plays an important role in promoting the avoidance of distasteful prey by birds. 2. The hypothesis that warning colouration facilitates memorability and promotes predator avoidance was tested by means of a field experiment using distasteful model butterflies. Artificial butterflies with a Heliconius colour pattern unknown to local birds were generated using bird vision models, either coloured or achromatic, and hung in tree branches in a tropical forest. Two sequential trials were conducted at each site to test avoidance by naïve and experienced predators. 3. There was a significant reduction in predation in the second trial. Also, coloured models were attacked less than achromatic models. Specifically, coloured butterflies were attacked significantly less in the second trial, but there was no significant decrease in predation on achromatic models. 4. The present results imply an important role for colour in enhancing aversion of aposematic butterflies. It has also been demonstrated that previous experience of distasteful prey can lead to enhanced avoidance in subsequent trials, supporting mimicry theory.