通过稀有鮈鲫(Gobiocypris rarus)卵膜蛋白质组测序鉴定黏性卵膜中富集的透明带蛋白(Zona pellucida glycoproteins,Zps),建立可用于卵型研究的稀有鮈鲫zp基因突变体和转基因斑马鱼(Danio rerio)。实验收集稀有鮈鲫胚胎(1hour post fert...通过稀有鮈鲫(Gobiocypris rarus)卵膜蛋白质组测序鉴定黏性卵膜中富集的透明带蛋白(Zona pellucida glycoproteins,Zps),建立可用于卵型研究的稀有鮈鲫zp基因突变体和转基因斑马鱼(Danio rerio)。实验收集稀有鮈鲫胚胎(1hour post fertilization,hpf),分离收集足量卵膜,提取卵膜中的蛋白质进行测序分析。将测序数据进行拼接并与鲤科鱼类蛋白质进行比对,选取匹配度和丰度最高的基因zp2l2和zp4l进行实验。分别在zp2l2和zp4l的第一个外显子、第六个外显子设计CRISPR/Cas9敲除靶点,构建zp基因突变体。扩增斑马鱼zp3.2基因上游启动子序列(2874 base pairs,bps)和zp2l2、zp4l编码序列(1137、3009 bp),通过无缝克隆(Infusion cloning)将zp3.2启动子连接进入具有Tol2转座元件的质粒中,构得质粒pT2AL-zp3.2-eGPF;再将zp2l2、zp4l编码序列克隆到pT2AL-zp3.2-eGPF质粒中,得到可用于胚胎注射的转基因质粒pT2AL-zp3.2-zp2l2-eGPF和pT2AL-zp3.2-zp4l-eGPF。体外转录合成转座酶mRNA与构建的转基因质粒混合进行斑马鱼胚胎显微注射。通过稀有鮈鲫胚胎显微注射及三代鉴定,成功在稀有鮈鲫中敲除zp2l2和zp4l获得稳定遗传的纯合突变体;稀有鮈鲫zp转基因斑马鱼经传代鉴定,筛选得到了可稳定遗传的转基因品系Tg(zp3.2:zp2l2-eGPF)和Tg(zp3.2:zp4l-eGPF),这2个转基因品系的绿色荧光蛋白在斑马鱼胚胎发育的15d(days post fertilization,dpf)开始在卵巢和肝脏中表达。实验构建zp2l2和zp4l稀有鮈鲫突变体和转基因斑马鱼的方法,为鲤科鱼类卵型形成机制的研究提供了可行的实验思路和技术路线。展开更多
This study compares the relative efficacy of the continuation task and the model-as-feedbackwriting (MAFW) task in EFL writing development. Ninety intermediate-level Chinese EFL learnerswere randomly assigned to a con...This study compares the relative efficacy of the continuation task and the model-as-feedbackwriting (MAFW) task in EFL writing development. Ninety intermediate-level Chinese EFL learnerswere randomly assigned to a continuation group, a MAFW group, and a control group, each with30 learners. A pretest and a posttest were used to gauge L2 writing development. Results showedthat the continuation task outperformed the MAFW task not only in enhancing the overall qualityof L2 writing, but also in promoting the quality of three components of L2 writing, namely, content,organization, and language. The finding has important implications for L2 writing teaching andlearning.展开更多
文摘通过稀有鮈鲫(Gobiocypris rarus)卵膜蛋白质组测序鉴定黏性卵膜中富集的透明带蛋白(Zona pellucida glycoproteins,Zps),建立可用于卵型研究的稀有鮈鲫zp基因突变体和转基因斑马鱼(Danio rerio)。实验收集稀有鮈鲫胚胎(1hour post fertilization,hpf),分离收集足量卵膜,提取卵膜中的蛋白质进行测序分析。将测序数据进行拼接并与鲤科鱼类蛋白质进行比对,选取匹配度和丰度最高的基因zp2l2和zp4l进行实验。分别在zp2l2和zp4l的第一个外显子、第六个外显子设计CRISPR/Cas9敲除靶点,构建zp基因突变体。扩增斑马鱼zp3.2基因上游启动子序列(2874 base pairs,bps)和zp2l2、zp4l编码序列(1137、3009 bp),通过无缝克隆(Infusion cloning)将zp3.2启动子连接进入具有Tol2转座元件的质粒中,构得质粒pT2AL-zp3.2-eGPF;再将zp2l2、zp4l编码序列克隆到pT2AL-zp3.2-eGPF质粒中,得到可用于胚胎注射的转基因质粒pT2AL-zp3.2-zp2l2-eGPF和pT2AL-zp3.2-zp4l-eGPF。体外转录合成转座酶mRNA与构建的转基因质粒混合进行斑马鱼胚胎显微注射。通过稀有鮈鲫胚胎显微注射及三代鉴定,成功在稀有鮈鲫中敲除zp2l2和zp4l获得稳定遗传的纯合突变体;稀有鮈鲫zp转基因斑马鱼经传代鉴定,筛选得到了可稳定遗传的转基因品系Tg(zp3.2:zp2l2-eGPF)和Tg(zp3.2:zp4l-eGPF),这2个转基因品系的绿色荧光蛋白在斑马鱼胚胎发育的15d(days post fertilization,dpf)开始在卵巢和肝脏中表达。实验构建zp2l2和zp4l稀有鮈鲫突变体和转基因斑马鱼的方法,为鲤科鱼类卵型形成机制的研究提供了可行的实验思路和技术路线。
文摘This study compares the relative efficacy of the continuation task and the model-as-feedbackwriting (MAFW) task in EFL writing development. Ninety intermediate-level Chinese EFL learnerswere randomly assigned to a continuation group, a MAFW group, and a control group, each with30 learners. A pretest and a posttest were used to gauge L2 writing development. Results showedthat the continuation task outperformed the MAFW task not only in enhancing the overall qualityof L2 writing, but also in promoting the quality of three components of L2 writing, namely, content,organization, and language. The finding has important implications for L2 writing teaching andlearning.
