玉米胚发育过程中热激蛋白的合成

35S-Met标记玉米胚蛋白合成结果表明,热激处理(42℃)与对照(25℃)的蛋白合成趋势相近,热激抑制16 DAP的蛋白合成,增加22和34 DAP蛋白合成.SDS-PAGE自显影图谱表明,热激诱导16DAP的胚合成86.4、80.0、73.2 kD等3种分子量较高的热激蛋白,22DAP后热激诱导合成86.4、80.0、73.2、24.4、18.2、16.8和13.6 kD等7种分子量的热激蛋白.2D-PAGE自显影图谱进一步显示,热激诱导22和28 DAP的胚合成近20种热激蛋白,其中超过10种为小分子热激蛋白.特异热激蛋白BiP(HsP70)、PDI(HsP60)Western blot表明,这2种热激蛋白在玉米胚发育过程均有高水平的表达,热激对其合成影响不明显.     

不同活力玉米种子胚萌发期间热激蛋白的合成

玉米（Ｚｅａ ｍａｙｓ Ｌ．）种子在萌发期间热激处理（４２℃）时蛋白质合成率低于对照（２５℃）;高活力种子胚热激蛋白的合成率最高。在４２℃热激处理时玉米种胚子合成的热激蛋白的分子量分别为７３、６５、６２、５４、１８ｋＤ等５种。高活力种胚合成的热激蛋白在最上高于低活力种子,高活力种胚合成的特异性热激蛋白５６ｋＤ可以作为衡量种子活力的指标。双向电泳表明高低活力种子间热激蛋白的合成有更多质上的差异。     

菜豆热激蛋白在生物膜上的定位

选用菜豆 Phaseolus vulgris L. 下胚轴 ,运用35S- Met标记放射自显影和二维电泳技术 ,研究热激蛋白 HSPs 的表达和在生物膜组分中的定位 .实验结果表明 ,盐溶蛋白中主要HSPs为 70 k D HSPs和小分子量 HSPs,而小分子量组 HSPs大量富集在质膜和液泡膜组分中 .     

温度,热激蛋白与高粱育性的变化

高粱不育系3A在热激(43～45℃)诱导下结出了种子,由不育系转变为可育系。比较3A和3B线粒体在热激条件的热激蛋白得知,它们的热激蛋白是由核编码的,在细胞质中合成后才运到线粒体中,热激2h,3A出现70、31、24、18和16kDa 5条蛋白带,3B除出现上述5条蛋白带外还多出现96、94kDa 2条,而且70kDa含量比3A大。热激4h,3B的96、94kDa消失,两系趋于一致。此时,3A和3B线粒体总蛋白比热激前大量增加。此后HSPs急剧降低。热激8h,3B线粒体仅有70、31、24和16kDa 4条蛋白带,70kDa特别明显,而3A则全部消失。从而表明,HSPs在3B中是稳定的,在3A中是缺乏或不稳定的,这些差异可能与3B育性稳定性及3A不育性有关。     

昆虫小分子量热激蛋白的研究进展

昆虫小分子量热激蛋白(Small heat shock proteins,s HSPs)是最早被发现的热激蛋白,但是有关它们的研究相对较少。本文对昆虫小分子量热激蛋白的最新研究成果进行了总结,旨在引起人们对该类蛋白的关注,以便进一步研究其功能,探讨其可能的应用前景。目前研究表明:昆虫小分子量热激蛋白是其所有热激蛋白中最不保守的家族。同时,它们通常拥有一个α-晶状体结构域;分子量范围一般在12~43 ku;具有分子伴侣的活性。每种昆虫体内拥有多种s HSPs,而且其功能也各不相同。这些热激蛋白在昆虫的生长发育、生殖以及滞育等重要生命活动中起着重要的作用;同时在抵御不良环境以及适应性进化中也具有重要意义。随着研究的深入,还将会有更多的昆虫s HSPs被鉴定,它们更多的功能也将被逐渐发掘。     

人工老化处理的卷心菜种子的热激蛋白合成

高活力卷心菜种子蛋白质合成速率比中等活力和低活力种子高很多。热激处理(42℃)下,蛋白质合成显著下降,但高活力种子的蛋白质合成能力仍然显著高于中等和低活力种子。高活力和中等活力种子主要合成分子量为70 kD和一些小分子量的热激蛋白。在低活力种子中检测不到热激蛋白的合成。4种热激蛋白（1种HSP90和3种HSP70）的Western blot检测结果表明,只有1种热激蛋白（HSP70）与种子活力有关。     

植物热激蛋白的研究进展及其应用

热激蛋白是一组在进化上高度保守的蛋白质,是生物体受环境胁迫时产生应激反应,降低正常基因的表达,并启动热激基因而产生的一种特殊蛋白质,能使机体抵御不良的环境。本文综述了植物热激蛋白的种类、特点、诱导合成、细胞定位及其在生命科学研究中的应用。     

人工老化自理的卷心菜种子的热激蛋白合成

高活力卷心菜种子蛋白质合成速率比中等活力和低活力种子高很多。热激处理（４２℃）下,蛋白质合成显著下降,但高活力种子的蛋白质合成能力仍然显著高于中等和低活力种子。高活力和中等活力种子主要合成分子量为７０ｋＤ和一些小分子量的热激蛋白。在低活力种子中检测不到热激蛋白的合成。４种热激蛋白（１种ＨＳＰ９０和３种ＨＳＰ７０）的Ｗｅｓｔｅｒｎ ｂｌｏｔ检测结果表明,只有１种热激蛋白（ＨＳＰ７０）与种子活力有关。     

HeLa细胞热休克蛋白的代谢动力学

 HeLa细胞经45℃,15min应激后,可诱导一组分子量为100,85,73,70,54kD的热休克蛋白,其中分子量为73/70kD的HSP产量最高。在产生HSP的同时,正常蛋白质合成受到抑制,并在随后数小时内恢复。HSP73/70在应激后能迅速诱导产生,应激后4—6小时为其合成高峰,10小时后明显减少,24小时恢复正常。其分解遵循指数规律,半衰期为49.9小时。     

热激对水稻幼苗耐冷性及热激蛋白合成的诱导

萌发的水稻种子经42℃热激处理后其幼苗的耐冷性明显增强,膜伤害程度降低,脯氨酸含量增加,超氧物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性和抗氧化物质抗坏血酸含量增加,而膜脂过氧化的关键酶脂氧合酶(LOX)活性及其产物丙二醛(MDA)含量下降.并且热激诱导萌发的水稻胚合成78、70、64、60、46、38、24、17、16kD的热激蛋白(HSP),其中属于HSP70的内质网结合蛋白(BiP)的合成与水稻幼苗耐寒性的提高有关.     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.