论文摘要

豌豆种子中含有豆球蛋白和豌豆球蛋白这两类主要的贮存蛋白,后者是可在亚基结构上所免疫特异蛋白加以区别的混合物。两类蛋白在亚基结构上存在微小的差异,并且在结构和数量上受不同的基因型支配。对豆球蛋白的遗传结构和生物合成的研究表明;有一族为许多前体分子编码的基因,又由这些前体分子产生了分子量约为40×10~3(α球     

IGFBP7基因的结构与功能的研究进展

胰岛素样生长因子结合蛋白7（IGFBP7）是IGFBPs超家族的新成员,结构上除具有与IGFBPs相似的保守N端结构域外,还有特异的Kazal型丝氨酸蛋白酶抑制结构域和免疫球蛋白样C2结构域。除与IGFs结合发挥作用外,还能独立调控细胞凋亡、增殖和迁移等。而至今尚无对水生无脊椎动物IGFBP7的研究报道,结合本实验室的研究综述了目前IGFBP7基因结构和功能上的研究进展,并对今后的研究工作进行了展望。     

通过基因导入保护贮藏种子

美国和澳大利亚的研究人员将常见种子蛋白导入豌豆,这样可保护豌豆种子在贮藏中免受象鼻虫的危害。从各方面看来,上述基因导入都是具有突破性的。从技术角度看,尤其引人注目,因为豌豆等豆科植物的遗传工程难度很大。从应用方面看,贮藏种子的损失(特别是对于以豆类作为蛋白主要来源的发展中国家)是个大问题。多数公司的目标是开发在田间抗害虫(而不是在青贮阶段抗害虫)的rDNA作物。然     

一些(糖)蛋白对胰岛素和其受体结合的影响——胰岛素和非受体蛋白结合的可能性

前文曾报道若干外源凝集素和糖苷对~(125)I-标记胰岛素和其受体结合有影响,并认为在胰岛素受体分子表面可能存在能与伴刀豆球蛋白A等外源凝集素专一结合的糖基(如甘露糖基),而且这些糖基可能参与了和胰岛素的结合。我们也曾观察到牛血清白蛋白存在时,标记胰岛素的凝胶过滤图谱中可出现两个放射活性峰,犹如胰岛素和其受体结合的图谱。为了进一步探讨胰岛素和其受体相互作用的原理,以及牛血清白蛋白中是何种组分和胰岛素结合,本文研究了一些糖蛋白和不含糖基的蛋白对标记胰岛素和人胎盘细胞膜结合的影响;并用高纯度的人胎盘白蛋白代替牛血清白蛋白作保护剂观察标记胰岛素的凝胶过滤行为。人胎盘细胞膜的制备按前文报道。~(125)I-胰岛素的制备见前文。结合实验按前文,37℃保温30分钟后迅速置冰水浴中冷却,4℃保温24小时。表1是一些糖蛋白和不含糖基的蛋白对标记胰岛素和人胎盘细胞膜结合的影响。在     

MicroRNA通路中的关键因子Dicer-1和Argonaute-1对豌豆蚜免疫防御的影响

【目的】研究microRNA(miRNA)通路中两个关键组分Dicer-1和Argonaute-1(Ago-1)在豌豆蚜Acyrthosiphon pisum抵御细菌和真菌侵染中的作用,加深对豌豆蚜免疫防御系统的了解。【方法】用qRT-PCR检测细菌金黄色葡萄球菌Staphylococcus aureus和大肠杆菌Escherichia coli以及真菌球孢白僵菌Beauveria bassiana分别侵染后豌豆蚜成蚜体内Dicer-1和Ago-1的表达量;通过注射法利用RNAi技术对豌豆蚜成蚜Dicer-1和Ago-1进行沉默后,感染金黄色葡萄球菌、大肠杆菌和球孢白僵菌,检测豌豆蚜体内细菌和真菌的增殖和统计豌豆蚜成蚜存活率。【结果】与0.85% NaCl溶液处理的对照组相比,金黄色葡萄球菌、大肠杆菌和球孢白僵菌侵染豌豆蚜成蚜后,其体内Dicer-1和Ago-1的表达量发生了一定程度的上调。RNAi干扰Dicer-1后,感染金黄色葡萄球菌36 h时豌豆蚜成蚜中细菌菌落数显著高于对照组(注射dsLTA)的,但感染后7 d时的存活率与对照组无显著差异;感染大肠杆菌12和24 h时豌豆蚜成蚜体内的细菌菌落数均显著高于对照组的,但感染后7 d时的存活率显著低于对照组的;感染球孢白僵菌后6 d,豌豆蚜成蚜体内真菌孢子数显著高于对照组的,但感染后7 d时的存活率显著低于对照组的。RNAi敲降Ago-1后感染金黄色葡萄球菌,豌豆蚜成蚜体内细菌菌落数在36 h时显著高于对照组的,但感染后7 d时的存活率显著低于对照组的;感染大肠杆菌后,在24 h时豌豆蚜成蚜体内细菌菌落数显著高于对照组的,感染后7 d时的存活率略低于对照组的,但无显著差异;感染球孢白僵菌后6 d,豌豆蚜成蚜体内真菌孢子数显著高于对照组的,但感染后7 d时的存活率显著低于对照组的。【结论】豌豆蚜miRNA通路中的两个关键组分Dicer-1和Ago-1参与了豌豆蚜抵御细菌和真菌侵染的免疫防御反应,尤其在抵御真菌的防御反应中有重要作用。     

若干外源凝集素对胰岛素与其受体相互作用的影响

本文研究了若干外源凝集素对胰岛素与其脂肪细胞胰岛素受体相互作用的影响。结果表明与D-甘露糖和D-葡萄糖专一结合的外源凝集素,如ConA(伴刀豆球蛋白A)、豌豆及蚕豆凝集素可抑制~(125)Ⅰ-胰岛素与其受体的结合。与D-半乳糖专一结合的外源凝集素,如蓖麻凝集素Ⅰ和天花粉凝集素基本上不抑制~(125)Ⅰ-胰岛素与其受体的结合,在低浓度时有一定程度的促进胰岛素与受体结合的能力。另外两个和低聚糖专一结合的半夏凝集素和PHA(菜豆凝集素)的效应和蓖麻凝集素Ⅰ等类似。这些结果说明在胰岛素受体分子表面可能存在着与ConA等专一结合的糖,而且它们在胰岛素受体与胰岛素结合部位的附近。而和其他几个外源凝集素专一结合的糖或低聚糖链则和胰岛素受体与胰岛素结合的部位相距较远,并就这些凝集素对胰岛素与受体结合的促进作用进行了讨论。     

若干外源凝集素对胰岛素与其受体相互作用的影响

本文研究了若干外源凝集素对胰岛素与其脂肪细胞胰岛素受体相互作用的影响。结果表明与D-甘露糖和D-葡萄糖专一结合的外源凝集素,如ConA (伴刀豆球蛋白A)、豌豆及蚕豆凝集素可抑制~(125)I-胰岛素与其受体的结合。与D-半乳糖专一结合的外源凝集素,如蓖麻凝集素I 和天花粉凝集素基本上不抑制~(125)I-胰岛素与其受体的结合,在低浓度时有一定程度的促进胰岛素与受体结合的能力。另外两个和低聚糖专一结合的半夏凝集素和PHA (菜豆凝集素)的效应和蓖麻凝集素I 等类似。这些结果说明在胰岛素受体分子表面可能存在着与ConA等专一结合的糖,而且它们在胰岛素受体与胰岛素结合部位的附近。而和其他几个外源凝集素专一结合的糖或低聚糖链则和胰岛素受体与胰岛素结合的部位相距较远,并就这些凝集素对胰岛素与受体结合的促进作用进行了讨论。     

蚕豆豆类胰岛素基因的cDNA克隆及序列分析

为探明豆科植物中豆类胰岛素基因的结构特征与进化关系,在已获得大豆豆类胰岛素基因的基础上,以蚕豆种子胚根mRNA为材料,采用RT-PCR技术,克隆了蚕豆豆类胰岛素基因的cDNA序列,编码的前体多肽包括信号肽、成熟型豆类胰岛素及另一多肽的45个氨基酸残基。DNA序列分析表明,克隆片段与大豆和豌豆的同源性分别为62.5%和58.7%。在氨基酸水平上分别具有44.2%和43.6%的同源性,其中存在着高度保守的半胱氨酸位点,它们在维持豆类胰岛素的空间结构与生理功能方面,可能具有重要的作用。 Abstract:In order to elucidate the relationship between the structural features of leginsulin gene in legume plants and their phylogenetic significance,we have cloned the cDNA sequence of leginsulin gene from radicles of broad bean (Vicia faba) via RT-PCR techniques according to the leginsulin gene sequence we previously obtained from soybean (Glycine max).The cloned cDNA encoded for a precursor protein consisting of the signal peptide,mature leginsulin and an additional 45 amino acids of another polypeptide.A sequence search for homology comparison revealed the cloned leginsulin cDNA fragment shares 62.5% and 58.7% similarity to soybean and pea,respectively.The results also shown that leginsulin cDNA from broad bean presents 44.2% and 43.6% amino acid sequence homology with soybean and pea (Pisum sativum),respectively,and that there exists highly conserved cysteine sites among the leginsulin cDNAs,which may play a crucial role in maintaining the three-dimensional structure and the physiological functions of leginsulin.     

黑豆盐溶球蛋白的研究

对经凝胶过滤后的黑豆盐溶球蛋白进行Native-PAGE及双向SDS-PAGE电泳分析,结果表明黑豆7S球蛋白是由3个以非共价键相结合的亚基(MW:84．7kD,72．6kD和49．2 kD)连接而成;黑豆11S球蛋白中则含有以共价键相结合的亚基,同时也可能存在非共价键结合的亚基。其在还原条件下,可分解出5个肽链(MW：38．4kD,35．4kD,34．5kD,21kD和20．6kD),且在电泳图片上明显分为两个区域。     

钙结合蛋白S100A16对胰岛素抵抗的作用研究

目的探究钙结合蛋白S100A16在胰岛素抵抗中的作用。方法用S100A16抗体进行免疫沉淀,然后用蛋白质谱分析寻找与S100A16相互作用的蛋白。实验1转染Vector质粒的HepG2细胞作为对照,用转染shRNA质粒、S100A16过表达质粒干预作为处理组。实验2以慢性胰岛素刺激细胞构建胰岛素抵抗模型,采用转染shRNA质粒的细胞作为对照,用未转染和转染Vector质粒干预作为处理组。实验3以不做任何处理的细胞作为对照,在胰岛素抵抗模型中用吡格列酮干预作为处理组。Western blot检测相关蛋白的表达水平。组间比较采用成组t检验。结果与转染Vector质粒比较,转染S100A16过表达质粒中胎球蛋白A表达(1.39±0.54比2.85±0.25)水平上调(P<0.05);与转染Vector质粒比较,转染shRNA质粒胎球蛋白A蛋白表达(0.36±0.03比0.20±0.03)水平降低(P<0.01)。在胰岛素抵抗条件下,与转染shRNA质粒的细胞比较,未转染和转染Vector质粒的IRS-2蛋白表达(0.11±0.04比1.65±0.48)水平上调(P<0.01);与不做任何处理的细胞比较,用吡格列酮处理的细胞IRS-2表达(0.26±0.11比0.52±0.05)水平上升(P<0.01)。结论S100A16在HepG2细胞中通过胎球蛋白A促进胰岛素抵抗。     

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.