大豆细胞质雄性不育系与保持系atp6基因的RNA编辑比较研究

对大豆细胞质雄性不育系NJCMS1A与其保持系NJCMS1B的atp6基因的RNA编辑进行比较研究.结果在不育系NJCMS1A与保持系NJCMS1B的atp6-3基因保守区中均发现2个编辑位点,但互不相同,并且导致了氨基酸的不同变化;mtDNA 序列分析显示,atp6-3基因转录本保守区在不育系NJCMS1A与保持系NJCMS1B间存在1个碱基的差异;另外还发现atp6-1、atp6-2和atp6-3的表达在不育系NJCMS1A与保持系NJCMS1B间存在明显差异.     

科技论文题名及其编辑加工

通过部分实例分析了目前科技论文题名存在的主要问题,结果表明,部分科技论文题名在形式上存在谦虚性、夸张性和无意义词语以及非公知公用缩写词的问题,在结构上存在语法错误等问题,在内容上存在文不对题的问题。针对这些问题,提出在编辑加工科技论文题名时,分别采取删除、改写的处理方法,使科技论文题名符合相关标准要求。     

棉花叶绿体基因组的研究进展

近年来,随着分子生物学技术的应用与发展,对棉花叶绿体基因组也有了新认识。本文概述了棉花叶绿体基因组的研究进展,从棉花叶绿体基因组的图谱、功能基因的克隆及研究、叶绿体RNA编辑以及叶绿体转化等方面进行了介绍和评述,并对其在基础研究与应用研究中的前景进行了展望。     

基因组编辑系统CRISPR-Cas9研究进展及其在猪研究中的应用

规律成簇的间隔短回文重复(CRISPR)及其相关的蛋白(Cas)原本是细菌抵御病毒的获得免疫系统,人们很快发现其应用潜力,即RNA引导的核酸酶Cas9对靶DNA进行基因组编辑:敲除、敲入、敲降。CRISPR-Cas9是继ZNF、TALENS技术之后的第三代基因组编辑技术,具有突变效率高、成本低、制作简单、能够诱导多位点同时突变等特点。除了基因工程功能外,CRISPR-Cas9系统还具有基因调控、基因组标记功能、大片段删除、全基因组扫描与编辑RNA等,且发展到CRISPR3.0,并继续开发其新应用。从2012年底开始,CRISPR的一系列创新性应用开启了整个基因组编辑研究的革命,成为生命科学领域的技术明星。文章对其最新进展进行了综述,并对其在猪中的应用及潜力进行了展望。     

CRISPR/Cas9系统及其在粮油作物遗传改良中的研究进展

CRISPR是细菌或古生菌对入侵到体内的病毒,通过核酸特异性识别、Cas9蛋白酶切割产生的一种天然免疫系统。基于CRISPR/Cas9系统的基因组编辑技术,通过sgRNA介导和Cas9蛋白切割实现对靶基因的定点编辑。因其操作简便、编辑效率高、适用范围广的特点,迅速成为研究植物、动物、微生物基因功能的重要手段。同时,随着大量基因组信息和相应数据库的广泛建立,CRISPR/Cas9技术利用反向遗传学,配合生物信息技术,成为遗传改良、创新特异种质的一种极有效的新手段。本文主要对CRISPR/Cas系统的基本原理、CRISPR/Cas9基因编辑技术的作用机制,以及CRISPR/Cas9技术在粮油作物遗传改良、品种选育研究中取得的进展进行了综述,为遗传育种工作者利用该技术进行遗传改良和品种优化升级育提供有效的参考。     

多酚氧化酶基因NtPPOE差异表达的效应分析

为研究烟草中多酚氧化酶基因的功能,本研究从GenBank中挑选一个烟草多酚氧化酶基因Polyphenol oxidase E(基因登录号:NW_015916967.1),命名为NtPPOE。构建NtPPOE基因的CRISPR载体和超表达载体,分别得到NtPPOE基因抑制/过量表达的转化植株。研究表明,基因敲除植株NtPPOE基因相对表达量降低,PPO活性降低,多酚类物质含量升高;超表达植株NtPPOE基因相对表达量升高,PPO活性升高,多酚类物质含量降低。NtPPOE基因表达量与PPO酶活性呈正相关,与多酚类物质含量呈极显著性负相关,NtPPOE基因的表达影响了烟草多酚代谢。本研究通过分析NtPPOE基因差异表达产生的效应,初步验证了NtPPOE基因的功能,并得到了NtPPOE基因抑制/过量表达的突变植株,为PPO基因功能研究和不同PPO活性品种的育种提供材料基础。     

辣椒线粒体基因转录本编辑位点研究

以辣椒细胞质雄性不育系北A及其相应保持系北B为材料,比较分析了nad2、atpA和cob 3个线粒体基因转录本的编辑位点。结果表明,atpA基因转录本在不育系与保持系中都未发生编辑。nad2基因在不育系中的编辑位点共有10处,与保持系相比增加了3处非C-U的特异编辑位点。cob基因在不育系与保持系中的编辑位点都有6处,除5处共同的C-U编辑外,不育系和保持系各有1处U-C和G-U的特异编辑位点。保持系比不育系相应位点的编辑频率偏高。编辑大多改变了编码氨基酸的种类,增加了编码蛋白质的疏水性。推测不育胞质特异的线粒体基因转录本编辑可能与辣椒细胞质雄性不育有关。     

Effects of electroporation treatment using different concentrations of Cas9 protein with gRNA targeting Myostatin (MSTN) genes on the development and gene editing of porcine zygotes

This study was conducted to investigate the effect of seven concentrations of Cas9 protein (0, 25, 50, 100, 200, 500, and 1,000 ng/µl) on the development and gene editing of porcine embryos. This included the target editing and off‐target effect of embryos developed from zygotes that were edited via electroporation of the Cas9 protein with guide RNA targeting Myostatin genes. We found that the development to blastocysts of electroporated zygotes was not affected by the concentration of Cas9 protein. Although the editing rate, which was defined as the ratio of edited blastocysts to total examined blastocysts, did not differ with Cas9 protein concentration, the editing efficiency, which was defined as the frequency of indel mutations in each edited blastocyst, was significantly decreased in the edited blastocysts from zygotes electroporated with 25 ng/µl of Cas9 protein compared with that of blastocysts from zygotes electroporated with higher Cas9 protein concentrations. Moreover the frequency of indel events at the two possible off‐target sites was not significantly different with different concentrations of Cas9 protein. These results indicate that the concentration of Cas9 protein affects gene editing efficiency in embryos but not the embryonic development, gene editing rate, and non‐specific cleavage of off‐target sites.     

Repetitive DNA Sequences in Wheat and Its Relatives

Repetitive DNA sequences form a large portion of eukaryote genomes. Using wheat ( Triticum )as a model, the classification, features and functions of repetitive DNA sequences in the Tritieeae grass tribe is reviewed as well as the role of these sequences in genome differentiation, control and regulation of homologous chromosome synapsis and pairing. Transposable elements, as an important portion of dispersed repetitives,may play an essential role in gene mutation of the host. Dynamic models for change of copy number and sequences of the repetitive family are also presented after the models of Charlesworth et al. Application of repetitive DNA sequences in the study of evolution, chromosome fingerprinting and marker assisted gene transfer and breeding are described by taking wheat as an example.