不同启动子在水稻悬浮细胞中诱导外源基因的表达

为进一步提高外源基因在水稻悬浮细胞中的表达水平,以花椰菜花叶病毒(Ca MV)35S启动子为对照,克隆了玉米泛素蛋白启动子(Ubi)、水稻肌动蛋白启动子(Actin)以及水稻Oscc1启动子,以GFP为报告基因,通过启动子串联的方式,构建了10个植物表达载体:p CAMBIA 1304 35S-GFP、Ubi-GFP、Actin-GFP、Oscc1-GFP、35S/Ubi-GFP、35S/Actin-GFP、35S/Oscc1-GFP、Ubi/Actin-GFP、Ubi/Oscc1-GFP、Actin/Oscc1-GFP,采用根瘤农杆菌介导的方法,将表达载体导入日本晴胚性愈伤,经悬浮培养分别获得转基因的悬浮细胞系,利用荧光显微镜、酶标仪检测GFP荧光强度,用Western blot检测GFP蛋白质的表达水平。结果发现串联启动子明显强于单个启动子驱动的GFP蛋白质表达水平。在10个表达载体中,35S/Ubi、Ubi/Actin和Ubi/Oscc1是3种优化的启动子组合,其中Ubi/Oscc1串联启动子驱动GFP的表达水平最高,约为对照35S启动子的3倍。     

bcl-x基因在两株鼻咽癌细胞中的转录和表达

目的：研究细胞凋亡相关基因bcl-x在人鼻咽癌高分化上皮细胞株CNE-1和低分化上皮细胞株CNE-2Z中的转录和表达。方法：分别抽提两种细胞的总RNA，通过逆转录PCR(RT-PCR)检测bcl-x基因的转录；同时制备两种细胞的蛋白质样品。经免疫印迹检测bcl-x基因的表达。结果：在两株鼻咽癌细胞中均检测到bcl-xL的转录和表达。但没有bcl-xs的表达。结论：bcl-xL在人鼻咽癌高、低分化上皮细胞株中均有表达。但表达量没有明显差异提示其表达可能与细胞分化程度无关。     

Human brain tumor--derived cell lines: growth rate reduced by human fibroblast interferon

The biological response modifier human beta-interferon had pronounced antigrowth effects on various histologic types of human brain tumor cells but no effects on a nontransformed cell line, MRC-5. The cultures of brain tumor cells showed severe alterations indicative of cell injury and death after exposure to beta-interferon for 2 to 6 days. Similar results were obtained with cells freshly explanted from human brain tumors. The results indicate that it may be possible to use fresh, explanted tumor tissue to identify patients who might benefit from therapy with beta-interferon.     

Human lineage-specific amplification, selection, and neuronal expression of DUF1220 domains

Extreme gene duplication is a major source of evolutionary novelty. A genome-wide survey of gene copy number variation among human and great ape lineages revealed that the most striking human lineage-specific amplification was due to an unknown gene, MGC8902, which is predicted to encode multiple copies of a protein domain of unknown function (DUF1220). Sequences encoding these domains are virtually all primate-specific, show signs of positive selection, and are increasingly amplified generally as a function of a species' evolutionary proximity to humans, where the greatest number of copies (212) is found. DUF1220 domains are highly expressed in brain regions associated with higher cognitive function, and in brain show neuron-specific expression preferentially in cell bodies and dendrites.     

水稻杂种一代及其亲本分蘖期根系基因的差异表达

以汕优６３组合为材料,运用ｍＲＮＡ差异显示技术研究了亲本与杂种一代分蘖期根系基因的差异表达。结果表明,与苗期相比,分蘖期根系基因的表达在质和量上都有显著的改变。质的改变有：Ｆ１特异表达的基因,Ｆ１特异表达的基因,Ｆ１减弱表达的基因,Ｆ１表现沉默（含父强母弱和父弱母强）和Ｆ１增强表达;量的改变有：Ｆ１弱势表达,Ｆ１强势表达２种类型。目前已回收了部分差异的ｃＤＮＡ条带,其中差异条带ＲＴ１的Ｎｏｒｔｈｅ     

Interdependence of cell growth and gene expression: origins and consequences

In bacteria, the rate of cell proliferation and the level of gene expression are intimately intertwined. Elucidating these relations is important both for understanding the physiological functions of endogenous genetic circuits and for designing robust synthetic systems. We describe a phenomenological study that reveals intrinsic constraints governing the allocation of resources toward protein synthesis and other aspects of cell growth. A theory incorporating these constraints can accurately predict how cell proliferation and gene expression affect one another, quantitatively accounting for the effect of translation-inhibiting antibiotics on gene expression and the effect of gratuitous protein expression on cell growth. The use of such empirical relations, analogous to phenomenological laws, may facilitate our understanding and manipulation of complex biological systems before underlying regulatory circuits are elucidated.     

Human monocytic cell lines derived from cord leukocytes by co-cultivation with irradiated CM-S cells

The CM-S cell line was established from the bone marrow of a child with congenital hypoplastic anemia and resembles its monocyte-macrophage lineage. Lethally x-irradiated CM-S cells from various passages and clones, representing different stages in the progression of the transformed growth phenotype, were tested for their ability to affect the survival and proliferation of normal human cord or adult blood leukocytes in co-culture. One clone, CM-SM, which is tumorigenic in athymic mice, consistently immortalized umbilical cord mononuclear cells but did not immortalize adult peripheral blood leukocytes. Six autonomous monocyte-like diploid cell lines were obtained and all were found to be of cord origin. Three lines were tumorigenic in athymic mice. Attempts to immortalize human leukocytes with cell-free supernatants from CM-S cells were unsuccessful.     

促肝细胞再生磷酸酶-3蛋白在5株癌细胞中的表达

目的研究促肝细胞再生磷酸酶-3(phosphatase of regenerating liver-3,PRL-3)在5株癌细胞(HO-8910PM、CNE-2Z、A549、JAR和BEL-7402)中的表达情况,为选择合适的细胞株克隆PRL-3基因奠定基础。方法用Western blot分析PRL-3在5株癌细胞(HO-8910PM、CNE-2Z、A549、JAR和BEL-7402)中的表达。结果PRL-3蛋白在5株癌细胞中都有表达:在HO-8910PM与CNE-2Z中呈高度表达,在A549和BEL-7402中呈中等程度表达,而在JAR中呈低度表达。结论PRL-3在5株癌细胞中均有表达,可选择高表达的HO-8910PM或CNE-2Z细胞克隆PRL-3基因。     

LIR1基因在水稻中的组织特异性表达

水稻LIR1是LIR(light-induced rice)蛋白家族的一员,受光与生物钟的调节,在植物光反应及生物节律性调控方面有重要作用。为了研究水稻LIR1的生理功能,利用半定量RT-PCR技术对水稻‘珍汕97B’LIR1基因做了根、叶鞘、叶片及穗的组织特异性表达分析,同时构建了启动子的GUS基因融合表达载体LIR1∷GUS转化烟草,利用GUS组织化学染色检测GUS基因在烟草组织器官中的表达情况。研究结果表明:LIR1基因在水稻叶片中的表达量较高,而在叶鞘、穗与根中表达量较低;GUS染色主要集中在叶片组织及茎中,而在植株的根部不显色。     

Creation of valuable breeding lines of triticale with short-stem gene H1

On the basis of the dominant short-stem gene H1, promising lines of hexaploid triticale combining the short-stem trait with a set of valuable breeding traits are obtained. It is shown that as a result of shortening plant height, it is possible not only to preserve but also to increase grain yield and quality significantly.     

猪TPST1基因的克隆、序列分析及真核表达载体的构建

酪氨酸硫化转移酶(Tyrosylrotein sulfotransferase,TPST)在酪氨酸硫化修饰过程中起调节作用.试验参照人、鼠、牛等动物的TPST1 mRNA全长序列设计引物,通过电子克隆结合RT-RCR的方法首次克隆获得包括完整CDS区的猪TPST1基因cDNA序列(HQ439987),分析其核苷酸序列及...     

Human hepatocellular carcinoma cell lines secrete the major plasma proteins and hepatitis B surface antigen

Analysis of the cell culture fluid from two new human hepatoma-derived cell lines reveals that 17 of the major human plasma proteins are synthesized and secreted by these cells. One of these cell lines, Hep 3B, also produces the two major polypeptides of the hepatitis B virus surface antigen. When Hep 3B in injected into athymic mice, metastatic hepatocellular carcinomas appear. These cell lines provide experimental models for investigation of plasma protein biosynthesis and the relation of the hepatitis B viru genome to tumorigenicity.     

Human prolactin: 24-hour pattern with increased release during sleep

Human prolactin was measured in plasma by radioimmunoassay at 20 minute intervals for a 24-hour period in each of six normal adults, whose sleep-wake cycles were monitored polygraphically. A marked diurnal variation in plasma concentrations was demonstrated, with highest values during sleep; periods of episodic release occurred throughout the 24 hours.