必威体育精装版基因敲除,RNA干扰,Mir.ppt

MIRNA谱与肿瘤预测、转归相关： N Engl J Med. 2005 Oct 27;353(17):1793-801 A MicroRNA signature associated with prognosis and progression in chronic lymphocytic leukemia. MIRNA功能研究中的问题与挑战 功能研究的复杂性 新 miRNA的发现 思考题 RNAl转录的基本过程 原核生物启动子的基本结构 增强子及其特点 转录终止的两种机制 原核生物与真核生物mRNA的特征比较 真核生物转录后加工的主要方式 遗传密码的特质，请选择1种加以具体说明 蛋白质合成的过程 什么是S-D序列？ 信号肽假说？ 组成性表达？适应性表达？ 什么是操纵子？ 正转录调控？负转录调控？ 乳糖操纵子的结构，简述相互独立的cAMP-CRP与阻遏调控体系。 弱化子，及其调控机制。 真核生物DNA水平上的基因表达调控？ 转录活性因子的结构以及作用特点 转录后水平的调控机制？ 翻译水平的调控机制？ SiRNA与Mir的异同？ (a) When exogenous DNA is introduced into ES cells, random insertion via nonhomologous recombination occurs much more frequently than gene-targeted insertion via homologous recombination. -Recombinant cells in which one copy of the gene X (orange) is disrupted can be obtained by using a recombinant vector that carries gene X disrupted with neor (light red), a neomycin-resistance gene, and, outside the region of homology, tkHSV (purple), the thymidine kinase gene from herpes simplex virus. -Ganciclovir is cytotoxic for recombinant ES cells carrying the tkHSV gene. Nonhomologous insertion includes the tkHSV gene, whereas homologous insertion doesnt; therefore, only cells with nonhomologous insertion are sensitive to ganciclovir. (b) Positive Selection: Recombinant cells are selected by treatment with neomycin, since cells that fail to pick up DNA or integrate it into their genome are neomycin-sensitive. Negative Selection: The surviving recombinant cells are treated with ganciclovir. Only cells with a targeted disruption in gene X, and therefore lacking the tkHSV gene, will survive Embryonic stem (ES) cells heterozygous for a knockout mutation in a gene of interest (X) and homozygous for a marker gene (here, black coat color) are transplanted into the blastocoel cavity of 4.5-day embryos that are homozygous for an alternate marker (here, white coat color). The early embryos then are implanted into a pseudopregnant female. Some of the resulting progeny are chimeras, indicated by their black an