类胡萝卜素生物合成相关基因的克隆及其遗传工程的研究进展

类胡萝卜素具有重要的生物学功能,尤其对人体健康有着更重要的作用,近年来一直是研究的热点。综述了类胡萝卜素生物合成途径及相关基因的分离,以及运用这些基因提高微生物和植物中类胡萝卜素含量的遗传工程研究进展。     

油菜种子类胡萝卜素总量测定方法的研究

类胡萝卜素是植物中最重要的一类色素,具有抗氧化、预防心血管疾病和癌症、延缓衰老等生物学功能,与人类健康关系密切.培育高类胡萝卜素油菜品种能有效地提升菜籽油的营养保健价值和稳定性,是今后油菜品质育种的一个新方向.研究建立快速、准确和简便的油菜种子类胡萝卜素总量测定方法,是发掘高类胡萝卜素油菜种质资源和开展高类胡萝卜素油菜育种的前提条件.本实验研究了不同提取溶剂、时间、料液比等因素对油菜种子中类胡萝卜素的提取效果和测定结果的影响,确定了最佳的提取和测定条件.建立了快速、准确和简便的油菜种子类胡萝卜素总量测定方法,并测定了30份不同类型油菜种质资源种子中类胡萝卜素总量,为进一步发掘高类胡萝卜素油菜种质资源和开展高类胡萝卜素油菜育种创造了条件.     

植物类胡萝卜素提取与分析技术研究进展

类胡萝卜素是所有光合生物及一些非光合原核生物和真菌合成的亲脂性天然色素,对植物、动物和人都具有广泛的生物学作用。随着现代分析技术的快速发展,越来越多的类胡萝卜素得以发现和利用。该文通过对植物类胡萝卜素的提取、分离纯化、含量测定和结构鉴定等方面的最新研究进展进行系统阐述,以期为植物类胡萝卜素的有效开发利用提供技术支撑。     

类胡萝卜素的生物学功能

类胡萝卜素 (Carotenoids)是一类重要的植物色素 ,在自然界中 ,广泛存在于各种植物中 ,在动物及微生物中也有发现。类胡萝卜素种类很多 ,其中包括人们所熟知的 α-胡萝卜素、β-胡萝卜素、番茄红素等。到目前为止 ,已经鉴定的类胡萝卜素分子共有 6 0 0多种 ,其中具有重要生物学功能的约有 50几种。类胡萝卜素是类异戊二烯化合物 ,由尾 -尾相连的2个二十碳单位构成四十碳的分子母体碳架 ,并从中衍生出许多不同的化合物。类胡萝卜素分子最显著的结构特征是分子中含有由不同数目的双键或单键的长链所构成的中央分子区域 ,形成 1个共轭体系。多…     

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由于类胡萝卜素含量和组成的改变,能够导致植物生理和生化方面的变化。因此,植物类胡萝卜素代谢的调控机制是多元化、多层次的。天津大学农业与生物工程学院季静等研究人员对植物类胡萝卜素生物合成途径进行了综述,对近几年通过基因工程方法提高植物类胡萝卜素积累研究进行了概括。"植物类胡萝卜素生物合成及功能的研究进展"是较为综合系     

利用基因工程改良植物类胡萝卜素的合成

类胡萝卜素(carotenoids)是植物体内存在的一类重要天然色素物质的总称,其生物功能广泛.类胡萝卜素是人类饮食结构中重要的组成部分,并且在医药、化妆品及食品与饲料工业等方面扮演着重要的角色.类胡萝卜素还是一些维生素合成的前体,具有多种保健功能,可以提高人体免疫力,并具有抗癌的功效.目前有大量关于提高植物体内类胡萝卜素含量及定向改变其种类的研究,对类胡萝卜素代谢途径及其调控的理解是这些研究的基础.主要阐述植物天然类胡萝卜素的生物合成及利用基因工程对类胡萝卜素改良的研究进展.     

类胡萝卜素的生物学性质

类胡萝卜素的生物学性质赵文恩韩雅珊戴蕴青（中国农业大学食品系,北京１０００９４类胡萝卜素是属于萜烯基团类的不饱和化合物,因具有多个共轭双键而常称为多烯烃。它在自然界生物体内广泛存在,现已发现了约６００种类胡萝卜素,仅有３８～５０种是作为维生素Ａ前体,...     

高等植物牻牛儿基牻牛儿基焦磷酸合成酶基因的研究进展

牻牛儿基牻牛儿基焦磷酸合成酶(GGPPS)在植物体内催化牻牛儿基牻牛儿基焦磷酸(GGPP)的合成,GGPP是萜类物质、类胡萝卜素、叶绿素及几个重要植物激素合成的前体物,是联系植物体内多条重要次生代谢通路的节点物质。本文综述了植物GGPPS基因近年来的生物学功能研究进展和该基因家族的遗传分类情况,以及GGPPS小亚基基因的重要调控作用,拟为深入研究植物GGPPS基因的生物学功能和萜类含量调控的遗传工程提供新认识和新思路。     

高等植物类胡萝卜素代谢工程研究进展

类胡萝卜素是自然界中种类繁多的天然化合物。植物类胡萝卜素由类异戊二烯碳骨架组成,并含有或没有环氧的、羟基或酮基基团。类胡萝卜素是人类饮食结构中不可缺少的重要成分,具有多种重要的保健功能,并且是安全的食品、饲料和化妆品着色剂。类胡萝卜素植物代谢基因工程的应用旨在增加特殊植物的营养价值、利用植物来生产特殊的类胡萝卜素、提高植物对光氧化的抵抗力及对植物的花色进行修饰等。     

类胡萝卜素在耐辐射奇球菌辐射抗性中的作用

为研究耐辐射奇球菌(Deinococcus radiodurans)中类胡萝卜素的生化合成基因及其在该细菌抗辐射机制中的生物学作用,通过有机溶剂提取及LC-MS技术分析了D. radiodurans所产类胡萝卜素物质的主要组分,运用PCR及基因同源重组技术,对该菌中类胡萝卜素生化合成途径的八氢番茄红素合成酶(phytoene synthase,crtB)及八氢番茄红素脱氢酶(phytoene desaturase,crtI)基因进行了缺失突变,通过表型观察及HPLC定量分析突变株所产类胡萝卜素的组分变化确证突变株构建成功．野生株及crtB 与crtI基因缺失突变株对电离辐射和H₂O₂的敏感性差异比较分析显示,和野生株相比,两种突变株对不同剂量电离辐射和不同浓度H₂O₂的敏感性更强．crtB及crtI基因功能研究表明,这两个关键性合成基因的缺失,导致突变株不能催化合成类胡萝卜素生化合成途径中的重要中间体——番茄红素及一系列下游产物．通过λ原噬菌体紫外线诱导系统、电子自旋共振 (ESR)及DMPO自旋捕集技术,分别在体内和体外评价了其类胡萝卜素的抗氧化能力．结果表明,两种类胡萝卜素对超氧阴离子(O₂^·)及羟自由基(·OH)均表现出较强的清除作用．上述研究结果为探究D. radiodurans的类胡萝卜素合成基因和生物学功能,及类胡萝卜素在D. radiodurans抗辐射机制中的作用提供了新的直接实验证据．     

植物细胞色素P450

对植物细胞色素P450(CYP450)基因的分离,植物CYP450在苯丙烷类物质、芥子油苷及IAA和萜类等物质的生物合成中的功能,以及对天然生物合成与人工合成物质的解毒功能等研究进展作了简要的综述。指出分离植物细胞色素P450基因,并对其生物学功能进行分析以及植物细胞色素P450降解除草剂的机制及其在环境生物修复等方面的应用是今后一段时间内植物CYP450领域的研究热点。     

Identification, Expression, and Nuclear Location of Murine Mage-b2 Protein, a Tumor-associated Antigen

MAGE-1, which was originally identified by reacting with cytolytic T lymphocytes derived from the blood of melanoma patients, is a member of a gene family consisting of 17 structurally related genes. The MAGE genes are expressed only in the testis among normal tissues and in a number of human tumors of various histological types. Murine MAGE (also called SMAGE or Mage) genes were found in a study aimed at detecting mouse genes homologous to human MAGE genes. However, the biological functions of MAGE and Mage are currently unknown. To understand the biological functions of Mage, in the present study a recombinant SMAGE2 (Mage-b2) protein of 43 kDa was produced and monoclonal antibodies reactive with Mage-b2 protein were generated. One monoclonal antibody, smpG4A, specifically recognized a 43 kDa protein in lysates of Mage-b2 mRNA-positive sarcoma cells and of the testis. Immunohistochemistry showed that Mage-b2 is located in the nucleus of Mage-b2 mRNA-positive sarcoma cells. These results should contribute to understanding the biological functions of Mage.     

miR-138生物学功能研究进展*

microRNAs(miRNAs)是真核生物体内高度保守的非编码小分子RNA,具有多种生物学功能,参与疾病发生和发展、细胞增殖和分化等多种病理及生理过程的调控。miR-138作为一种肿瘤抑制因子已在肿瘤发生与治疗中被广泛研究和应用,同时在心血管及神经系统疾病、成骨分化、脂肪生成及卵巢功能维持等生命过程中具有调控作用。在总结分析miR-138相关功能最新研究进展的基础上,对miR-138的潜在研究方向进行了分析、讨论和展望,旨在为进一步深入探明miR-138的生物学功能提供参考和理论依据。     

Identification, Expression, and Nuclear Location of Murine Mage-b2 Protein, a Tumor-associated Antigen

MAGE-1, which was originally identified by reacting with cytolytic T lymphocytes derived from the blood of melanoma patients, is a member of a gene family consisting of 17 structurally related genes. The MAGE genes are expressed only in the testis among normal tissues and in a number of human tumors of various histological types. Murine MAGE (also called SMAGE or Mage) genes were found in a study aimed at detecting mouse genes homologous to human MAGE genes. However, the biological functions of MAGE and Mage are currently unknown. To understand the biological functions of Mage, in the present study a recombinant SMAGE2 (Mage-b2) protein of 43 kDa was produced and monoclonal antibodies reactive with Mage-b2 protein were generated. One monoclonal antibody, smpG4A, specifically recognized a 43 kDa protein in lysates of Mage-b2 mRNA-positive sarcoma cells and of the testis. Immunohistochemistry showed that Mage-b2 is located in the nucleus of Mage-b2 mRNA-positive sarcoma cells. These results should contribute to understanding the biological functions of Mage.     

Current progress in non-Edg family LPA receptor research

Lysophosphatidic acid (LPA) is the simplest phospholipid yet possesses myriad biological functions. Until 2003, the functions of LPA were thought to be elicited exclusively by three subtypes of the endothelial differentiation gene (Edg) family of G protein-coupled receptors — LPA₁, LPA₂, and LPA₃. However, several biological functions of LPA could not be assigned to any of these receptors indicating the existence of one or more additional LPA receptor(s). More recently, the discovery of a second cluster of LPA receptors which includes LPA₄, LPA₅, and LPA₆ has paved the way for new avenues of LPA research. Analyses of these non-Edg family LPA receptors have begun to fill in gaps to understand biological functions of LPA such as platelet aggregation and vascular development that could not be ascribed to classical Edg family LPA receptors and are also unveiling new biological functions. Here we review recent progress in the non-Edg family LPA receptor research, with special emphasis on the pharmacology, signaling, and physiological roles of this family of receptors. This article is part of a Special Issue entitled Advances in Lysophospholipid Research.     

Systems genetics analyses predict a transcription role for P2P-R: Molecular confirmation that P2P-R is a transcriptional co-repressor

Background  

The 250 kDa P2P-R protein (also known as PACT and Rbbp6) was cloned over a decade ago and was found to bind both the p53 and Rb1 tumor suppressor proteins. In addition, P2P-R has been associated with multiple biological functions, such as mitosis, mRNA processing, translation and ubiquitination. In the current studies, the online GeneNetwork system was employed to further probe P2P-R biological functions. Molecular studies were then performed to confirm the GeneNetwork evaluations.     

Histone deacetylase 10, a potential epigenetic target for therapy

Histone deacetylase (HDAC) 10, a class II family, has been implicated in various tumors and non-tumor diseases, which makes the discovery of biological functions and novel inhibitors a fundamental endeavor. In cancers, HDAC10 plays crucial roles in regulating various cellular processes through its epigenetic functions or targeting some decisive molecular or signaling pathways. It also has potential clinical utility for targeting tumors and non-tumor diseases, such as renal cell carcinoma, prostate cancer, immunoglobulin A nephropathy (IgAN), intracerebral hemorrhage, human immunodeficiency virus (HIV) infection and schizophrenia. To date, relatively few studies have investigated HDAC10-specific inhibitors. Therefore, it is important to study the biological functions of HDAC10 for the future development of specific HDAC10 inhibitors. In this review, we analyzed the biological functions, mechanisms and inhibitors of HDAC10, which makes HDAC10 an appealing therapeutic target.     

多烯类抗生素合成基因簇中ABC转运蛋白研究进展

ABC转运蛋白家族是一个广泛存在于不同生物细胞中且功能保守的膜蛋白亚家族;它们是一类单向底物转运泵,通常以主动转运方式完成多种分子的跨膜转运。随着抗生素合成基因簇相关研究的开展,越来越多的簇内ABC转运蛋白被鉴定出来,对其生物学功能的研究正逐渐成为热点。多烯类抗生素作为一类重要的抗真菌药物,能够有效避免真菌产生耐药性,具有非常重要的临床价值。本文以多烯类抗生素合成基因簇为对象,综述了在其中所发现的ABC转运蛋白的研究进展,综合分析了其结构特性与功能间的关系,并对研究应用进行了展望。     

Building Taxon Substitution Guidelines on a Biological Control Foundation

When a species becomes extinct, its ecological functions are lost as well. Taxon substitution is a controversial approach to restoring such functions via introduction of non‐native species known to serve similar functions elsewhere. Due to the possibility of nontarget effects from such introductions, taxon substitution has been proposed and implemented in only a few systems, but these attempts have successfully restored functions. As a conservation tool, taxon substitution bears similarity to biological control, wherein species are also introduced for their ecological function with consideration of potential nontarget effects. To improve both the safety and efficacy of taxon substitution, regulatory bodies that currently issue guidelines for biological control can do the same for taxon substitution. Indeed, many biological control guidelines would apply well to taxon substitution. We examine the standard practices followed by biological control programs and propose corresponding taxon substitution guidelines. Integration of taxon substitution into the existing national and international environmental management conversation will improve the tool and has the potential to enhance conservation efforts across a wide diversity of systems if appropriate and stringent precautions are taken.     

Statistical theories of functions and the problem of epidemic disease

Several decades ago, Christopher Boorse formulated an influential statistical theory of normative biological functions but it has often been claimed that his theory suffers from insuperable problems such as an inability to handle cases of epidemic and universal diseases. This paper develops a new statistical theory of normative functions that is capable of dealing with the notorious problem of epidemic and universal diseases. The theory is also more detailed than its predecessors and offers other important advantages over them. It is argued here that statistical theories of biological functions should not be so quickly dismissed.