重组包涵体蛋白质的折叠复性

综述了减少包涵体形成、包涵体分离和溶解以及包涵体折叠复性的策略及其最新进展 .详细讨论了包涵体蛋白质折叠复性的基本原则、包涵体折叠复性促进剂和包涵体折叠复性方法     

富脯氨酸模体研究进展

综述了近年来富脯氨酸模体的研究进展状况,并将其分为PxxP核心序列模体、聚脯氨酸模体、PPxY核心序列模体以及其他类型的模体4类,论述了富脯氨酸膜体的生物学功能及其常出现的原因.     

微体的概念及其发展

微体是一种细胞器,其种类主要包括过氧化物酶体、糖酵解酶体和乙醛酸循环体。本文主要介绍了微体的概念及其发展,乙醛酸循环体和过氧化物酶体之间的关系,过氧化物酶体、糖酵解酶体和乙醛酸循环体的功能。     

中国秀体溞属常见种类记述

秀体溞是枝角类中重要的属,其分类一直存在较大分歧。目前我国秀体溞属有10个种,即短尾秀体溞Diaphanosoma brachyurum Liévin,1848、兴凯秀体溞D.chankensis Ueno,1939、奥氏秀体溞D.orghidani Negrea,1982、模糊秀体溞D.dubium Manujlova,1964、杜蒙特秀体溞D.dumonti Korovchinsky,1996、镰角秀体溞D.excisum Sars,1885、蒙古秀体溞D.mongolianum Ueno,1938、多刺秀体溞D.sarsi Richard,1894、大眼秀体溞D.macrophtalma Korovchinsky & Mirabdullaev,1995、热带秀体溞D.tropicum Korovchinsky,1998。在综合现有文献和研究模式标本的基础上,建立了上述10个种的分类检索表,并对我国最为常见的4个种:短尾秀体溞D.brachyurum Lievin,1848、奥氏秀体溞D.orghidani Negrea,1982、模糊秀体溞D.dubium Manujlova,1964、镰角秀体溞D.excisum Sars,1885的形态特征和地理分布进行了详细描述。分析了目前我国与国际在秀体溞分类上的一些异同,讨论了我国秀体溞分类中存在的同名异种或同种异名的问题。     

植物油体在生物技术中的应用研究进展

油体是植物种子尤其是油料植物种子的重要贮脂细胞器,具有较强的物化稳定性,而且易于通过离心法分离提取。研究表明,油体是由外层的磷脂和油体结合蛋白以及包裹在内部的液态基质（主要为三酰甘油）形成的弹性球体或椭球体。目前,在植物中共发现三类油体结合蛋白,它们主要存在于油体表面。鉴于油体和油体结合蛋白的结构特殊性,二者在生物技术领域得到了广泛应用。本文重点综述了油体在表达纯化外源蛋白方面的优势、策略以及在生产药用蛋白、制备固定化酶、捕捉抗体和药用酶、生产营养素和提高植物抗性等多个领域的研究进展,并介绍了人工油体和油体乳化剂方面的开发应用情况。     

淀粉体发育过程中淀粉核心、晶体结构与淀粉体DNA的关系

在马铃薯块茎、百合鳞茎淀粉体DNA的研究中,使用了3种DNA染色方法,都比较一致地反映了淀粉体DNA的分布和形态。又系统观察了在不同发育时期淀粉体及淀粉体DNA的变化,揭示了淀粉体DNA与淀粉核心、晶体结构的关系。实验证明,淀粉核心是淀粉体DNA最先出现的地方。DNA复制形成了晶体结构(晶体核)以及辐射状的晶体结构,这是淀粉体DNA随着发育时期的增长而不断复制的结果。     

普通小麦减数分裂中单价体的错分裂

本文综述了有关普通小麦减数分裂中单价体错分裂的研究工作,其中包括研究单价体错分裂的意义、单价体错分裂发生的时期、位置、方式以及错分裂发生的原因,单价体错分裂的研究方法及单价体错分裂研究的现状。     

经营强度对毛竹林土壤团聚体稳定性和碳氮磷分布的影响

土壤团聚体是土壤有机质分解、腐殖质形成的主要场所，不同粒径团聚体的组成特征可以衡量土壤肥力状况。为了探明经营强度(施肥、垦复频次)对毛竹林土壤团聚体的影响，以粗放经营毛竹林为对照，以中强度(每4年施肥、垦复一次)和高强度(每2年施肥、垦复一次)集约经营毛竹林为对象，利用干筛和湿筛结合的方法分离毛竹林0～10、10～20和20～30 cm土层土壤水稳性团聚体，分析不同土层中各粒径团聚体有机碳、全氮和有效磷的分布情况。结果表明：经营强度对毛竹林土壤团聚体组成、稳定性以及有机碳、全氮、有效磷含量有显著影响。与对照相比，中、高强度集约经营降低了0～10 cm土层土壤大团聚体比例和团聚体稳定性，增加了20～30 cm土层土壤大团聚体比例和团聚体稳定性，减少了大团聚体有机碳含量以及微团聚体有机碳、全氮和有效磷含量，说明中、高强度经营不利于0～10 cm土层土壤大团聚体的形成和大团聚体对碳的固存，减少人为干扰有利于土壤团聚体对有机碳的积累以及微团聚体对氮、磷的积累。大团聚体质量分数和大团聚体有机碳含量与团聚体稳定性均呈显著正相关，且二者对团聚体稳定性的影响解释最强，因此，大团聚体和大团聚体有机碳含量...     

大肠杆菌中重组蛋白包含体的形成机制及其影响因素

本文介绍了近年有关重组蛋白包含体形成机制的研究进展,探讨了蛋白性质、温度、分子伴随物等因素对包含体形成的影响,从蛋白折迭的角度对包含体这一现象进行了分析,从而为控制外源基因表达产物形成包含体提供理论指导。     

迁移体生物发生的时空图谱

迁移体是2015年被发现的新型细胞器,是在细胞迁移后端收缩丝上生长起来的囊泡状结构。迁移体参与细胞与细胞间、细胞与微环境间的信息交流和物质交换,在胚胎发育、血管新生、线粒体稳态维持、病毒传播等生理病理过程中发挥着重要作用。近年来,研究者们针对迁移体的形成过程展开了系统探索,并逐步揭示了迁移体的生物发生及动态调控机制,为迁移体的功能探索奠定了理论基础,也为以迁移体为抓手的临床应用提供了切入点。该文将对迁移体发生及调控机制的相关研究进行系统梳理,绘制迁移体生物发生过程的时空图谱,以期为迁移体领域的研究提供指导与参考。     

一品红试管苗移栽驯化期叶片的解剖结构变化

对一品红试管苗移栽驯化,同时研究了驯化过程中叶片结构的变化,结果表明,一品红在珍珠岩基质中成活率达98%,随着移栽时间的延长,表皮细胞增大,排列紧密;叶肉细胞间隙减小,栅栏组织细胞长度增加,主脉增厚,导管数目增加,保水,输水和抗逆能力增强。     

Group and matriline differences in the behaviour of rhesus monkey infants

A ‘Monte Carlo’ method was developed for characterizing matrilines of rhesus monkey infants (Macaca mulatta) born to their mothers within six similar captive social groups, according to behavioural measures, and for characterizing social groups according to their matrilines' median scores. Eight- and 16-week-old infants differed according to their groups, but not according to their matrilines, in measures of their activity in the vicinity of their mothers, and the frequencies with which social companions other than the mother initiated social contacts with them while they were out of contact with their mothers. Sixteen-week-olds differed according to their groups in the frequencies with which their mothers rejected them, and 8-week-olds in the frequencies of the social contacts they initiated with companions other than mother while off their mothers. When tested with their mothers, in a mildly disturbing situation away from other social companions, 52-week-olds differed according to their group of origin in time spent out of contact with their mothers. Different groups were seen as producing infants differing in ‘enterprise’ from their eighth week, in the sense of being ready to initiate social contacts with others while off their mothers at 8 weeks, and of being off their mothers in the test at 52 weeks. Cases where the 8-week measures did not reflect infant enterprise could be explained in terms of other aspects of the relationships involving the infants and their mothers in the social group. In particular, matrilines differed consistently in dominance status, and some mothers also received high levels of aggression from other adults. Mothers receiving high levels of aggression were more responsible for maintaining proximity with their 8-week-old infants, and their 8-week-olds were less often involved in social contacts with others.     

The characterization and ultrastructure of two new strains of Butyrivibrio

Strains B-385-1 and 2-33 are numerically important components rumen bacterial populations , but they have remained (taxonomically) undefined. In spite of some resemblance to Selenomonas ruminantium in their cell size and in their formation of tufts of flagella, they more closely resemble Butyrivibrio fibrisolvens in the subpolar location of their flagella, in their guanine + cytosine content, and in most biochemical characteristics, including butyrate formation. Cells of these strains stain Gram negative, as do both Selenomonas and Butyrivibrio, but their cell walls closely resemble those of Butyrivibrio in their Gram-positive type of molecular architecture and in their cleavage pattern in freeze-etching. Cells of these strains and of B. fibrisolvens have a very thin (ca. 12 nm) peptidoglycan cell wall; thus, they fail to retain the crystal violet complex of the Gram stain and stain Gram negative. This important structural characteristic of their cell walls places strains B-385-1 and 2-33 within the genus Butyrivibrio and certain morphological and biochemical characteristics distinguish them from B. fibrisolvens.     

Function and structure of inherently disordered proteins

The application of bioinformatics methodologies to proteins inherently lacking 3D structure has brought increased attention to these macromolecules. Here topics concerning these proteins are discussed, including their prediction from amino acid sequence, their enrichment in eukaryotes compared to prokaryotes, their more rapid evolution compared to structured proteins, their organization into specific groups, their structural preferences, their half-lives in cells, their contributions to signaling diversity (via high contents of multiple-partner binding sites, post-translational modifications, and alternative splicing), their distinct functional repertoire compared to that of structured proteins, and their involvement in diseases.     

猕猴桃茎尖超低温保存过程中超微结构观察

应用透射电镜观察了猕猴桃组培苗茎尖细胞在玻璃化法超低温保存过程中的超微结构变化.研究发现:在预培养、PVS2脱水处理过程中,茎尖细胞内液泡逐渐变多、变小,质壁分离愈加显著,表明细胞的抗冻力增强;在随后的冷冻和解冻过程中,部分细胞的质壁分离更加严重,细胞壁与细胞膜之间出现液腔,细胞器变得模糊,有些细胞的细胞膜、甚至细胞壁撕裂,细胞腔内留下破碎的细胞膜和细胞残片,细胞结构破坏严重,这可能是导致材料在恢复培养中死亡的原因之一;部分细胞经过7d的恢复培养后,细胞器清晰,细胞膜完好并紧贴细胞壁,细胞中央出现较大的液胞,具有与对照相似的结构特征,最终存活下来并能够再生植株.     

9个辣椒雄性不育材料花蕾生理生化特性研究

以9个辣椒雄性不育材料及其相应的保持系为试材,对有关花器的植物学性状进行了系统观察和研究,测定了花蕾中过氧化物酶、过氧化氢酶、多酚氧化酶的活性和游离脯氨酸的含量。结果表明:供试9个雄性不育材料和保持系的主要花器性状有一定差异;雄性不育材料的过氧化物酶活性和多酚氧化酶活性均高于相应的保持系, 而过氧化氢酶活性低于保持系;保持系游离脯氨酸含量离于不育材料;所测的3种酶活性和脯氨酸含量在雄性不育材料与保持系间差异显著。     

Glycosyltransferases: managers of small molecules

Studies of the glycosyltransferases (GTs) of small molecules have greatly increased in recent years as new approaches have been used to identify their genes and characterize their catalytic activities. These enzymes recognize diverse acceptors, including plant metabolites, phytotoxins and xenobiotics. Glycosylation alters the hydrophilicity of the acceptors, their stability and chemical properties, their subcellular localisation and often their bioactivity. Considerable progress has been made in understanding the role of GTs in the plant and the utility of GTs as biocatalysts, the latter arising from their regio- and enantioselectivity and their ability to recognize substrates that are not limited to plant metabolites.     

The Color of My Skin: A Measure to Assess Children's Perceptions of Their Skin Color

The Color of My Skin is an instrument developed to assess children's internalized idea (abstraction) of the color of their skin; their satisfaction with that color; the desire, if any, to change the color of their skin; and their affect regarding their skin color. The assessment is part of a questionnaire utilized in a 3-year longitudinal study that examines psychosocial development, physical health, and behavioral adjustment of Puerto Rican children (N = 257) reared in the Greater Boston area. The results demonstrate that children's internalized representation of their skin color is a construct that can be reliably and validly measured. The children's ratings of their skin color were not associated with their sex, school grade, ethnic identity, the child's or the parent's nativity, or the racial or ethnic compositions of 3 social contexts: their neighborhood, their classmates, and their closest friends. Puerto Rican children did not show a preference for light-colored skin. Moreover, there were no significant differences in self-esteem based on the child's self-reported skin color. The lack of association between self-esteem and skin color was interpreted in light of a developmental tendency prevalent in early to middle childhood to place a positive value on different aspects of one's self. Whereas almost all children (96%) reported being happy or very happy with their color, 16% of the children would like to change their skin color if they could (51% to a lighter and 46% to a darker color).     

Biotechnological potential of pectinolytic complexes of fungi

Plant cell wall-degrading enzymes, such as cellulases, hemicellulases and pectinases, have been extensively studied because of their well documented biotechnological potential, mainly in the food industry. In particular, lytic enzymes from filamentous fungi have been the subject of a vast number of studies due both to their advantages as models for enzyme production and their characteristics. The demand for such enzymes is rapidly increasing, as are the efforts to improve their production and to implement their use in several industrial processes, with the goal of making them more efficient and environment-friendly. The present review focuses mainly on pectinolytic enzymes of filamentous fungi, which are responsible for degradation of pectin, one of the major components of the plant cell wall. Also discussed are the past and current strategies for the production of cell wall-degrading enzymes and their present applications in a number of biotechnological areas.     

Regulation of food provisioning in the Antarctic petrel; the importance of parental body condition and chick body mass

1. Two hypotheses may explain how long-lived seabirds regulate the food provisioning to their chick. The fixed level of investment hypothesis states that the parents provide food for their chick according to an intrinsic rhythm, independent of their chick's need. The flexible investment hypothesis states that the parents adjust their food provisioning both according to their chick's and their own need.
2. We tested how the Antarctic petrels adjust the food-provisioning according to their own body condition or to their chick's need. First, we selected parents in poor and good body condition. Then we gave all parents randomly a chick of different body mass, but of the same age. We then measured the chicks daily until they were fed for the first time after swapping.
3. Parents in good body condition at hatching were more likely to produce a chick that was still alive 9 days after hatching than parents in poor body condition. Chick body mass at day 9 and at the end of the guarding period was positively related to the mean body condition of the parents at hatching.
4. The meal size provided by parents in good body condition was larger than that provided by parents in poor body condition. Parents in good body condition delivered more food to small than to large chicks, whereas no such relationship was found among parents in poor body condition.
5. Our results suggest that the Antarctic petrel parents adjust the amount of food delivered to their chick according to both the chick's need and their own body condition, and that the ability to respond to the chick's need is dependent upon their own body condition.