The Double Nickase Plasmid features a U6 promoter for sgRNA expression, a 20 nt targeting sequence, and a gRNA scaffold to guide Cas9n. It includes a CBh promoter for Cas9n (D10A) and puromycin resistance, GFP for transfection verification, and nuclear localization signals (NLS). The 2A peptide allows co-expression of Cas9n and Puro from a single promoter, enabling precise genome editing with reduced off-target effects.
The Double Nickase Plasmid features a U6 promoter for sgRNA expression, a 20 nt targeting sequence, and a gRNA scaffold to guide Cas9n. It includes a CBh promoter for Cas9n (D10A) and puromycin resistance, GFP for transfection verification, and nuclear localization signals (NLS). The 2A peptide allows co-expression of Cas9n and Puro from a single promoter, enabling precise genome editing with reduced off-target effects.
Cas9n Nickase gRNA Plasmid Targeting: Dual gRNA plasmids create single-strand nicks at precise DNA sequences for efficient genome editing using Cas9n Nickase.
This image illustrates the Cas9n Nickase mechanism used for precise genome editing. Two plasmids (Plasmid 1 and Plasmid 2) are shown, each containing a targeted DNA sequence. The system utilizes single-guide RNAs (sgRNA) to direct Cas9n Nickase to specific genomic locations, represented by the blue and pink DNA strands. The sgRNA scaffold aids in guiding Cas9n to the 20 nucleotide (nt) target sequence on the DNA. Cas9n makes single-strand cuts at NCC and NGG sites, enabling precise gene modifications without creating double-strand breaks.
The Double Nickase Plasmid features a U6 promoter for sgRNA expression, a 20 nt targeting sequence, and a gRNA scaffold to guide Cas9n. It includes a CBh promoter for Cas9n (D10A) and puromycin resistance, GFP for transfection verification, and nuclear localization signals (NLS). The 2A peptide allows co-expression of Cas9n and Puro from a single promoter, enabling precise genome editing with reduced off-target effects.
人类 **LMNA** 基因编码 **lamin A**,它是核纤层(nuclear lamina)的核心组成成分,能够提供机械稳定性,并在细胞核周边组织更高阶的染色质结构。Lamin A 通过与核纤层相关结构域(LADs)参与基因组调控,影响转录程序、DNA 复制时序和表观遗传状态,同时在细胞周期过程中维持核膜完整性。LMNA 还与 DNA 损伤信号通路及力学信号转导(mechanotransduction)通路发生交互,将细胞骨架产生的力与核形态和基因表达联系起来。Lamin A 稳态的破坏与多种核纤层蛋白病(laminopathies)相关,包括心肌病和肌营养不良等谱系疾病、早衰表型,以及与癌症和干细胞生物学相关的核形态异常。
Lamin A 双切酶质粒(h)由一对匹配的质粒组成,专为在 human 细胞系中对 LMNA 位点进行高特异性编辑而设计。每个质粒分别表达Cas9 D10A切口酶和针对LMNA内不同DNA链的独特sgRNA。当这两种切口酶被引导至相邻但位于DNA链相反侧的位点时,会产生错位的单链切口,从而共同形成错位双链断裂,这需要两个引导RNA在靶位点上协同发挥作用。由此产生的DNA断裂通过内源性细胞修复途径(最常见的是非同源末端连接(NHEJ))得到修复,从而导致插入或缺失,进而破坏LMNA的功能。通过要求双sgRNA在靶位点结合,双切口方法提高了编辑特异性,并为需要对靶向精度进行额外控制的应用提供了互补的CRISPR策略。