Oligonucleotide-directed single-base DNA alterations in mouse embryonic stem cells

Area of Science:

• Molecular Biology
• Genetics
• Biotechnology

Background:

• Gene editing technologies are crucial for understanding genetic diseases.
• Developing precise methods for altering genomic DNA in embryonic stem cells is essential for creating accurate disease models.

Purpose of the Study:

• To investigate the efficacy of single-stranded oligodeoxy-nucleotides (ssODN) for precise single-base DNA correction in mouse embryonic stem (ES) cells.
• To evaluate the potential of ssODN-mediated gene correction for generating genetically modified ES cells.

Main Methods:

• Utilized reporter genes (EGFP and LacZ) with inactivating point mutations in mouse ES cells.
• Employed homologous ssODN with a single mismatch at the mutant site to correct reporter gene activity.
• Assessed correction efficiency in both episomal and chromosomal DNA, comparing sense and antisense ssODN orientations.

Main Results:

• Demonstrated successful correction of single-base mutations in both episomal and chromosomal reporter genes in mouse ES cells using ssODN.
• Observed gene correction rates of 0.5-1.0% in CHO-K1 cells and approximately 10(-4) in mouse ES cells.
• Found that antisense ssODN orientation yielded higher gene conversion rates compared to sense orientation.

Conclusions:

• Single-stranded oligodeoxy-nucleotides can effectively introduce specific single-base alterations into the genomic DNA of mouse ES cells.
• While current efficiency is low, ssODN-mediated gene correction offers a potential one-step method for generating precisely mutated ES cells.
• This technique could facilitate the creation of accurate mouse models for studying inherited diseases.