RNA-driven genetic changes in bacteria and in human cells.

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Recent studies in yeast demonstrated RNA's role as a template for DNA synthesis during double-strand break (DSB) repair.
• The potential for RNA to mediate DNA modification and repair in other organisms remained largely unexplored.

Purpose of the Study:

• To investigate whether RNA-containing oligonucleotides can serve as templates for DNA repair and modification in bacteria (Escherichia coli) and human cells (HEK-293).
• To determine if RNA-mediated DNA repair is conserved beyond yeast and to elucidate the mechanism of action.

Main Methods:

• Utilized single-strand DNA oligonucleotides with embedded ribonucleotide tracts to repair a defective lacZ gene in E. coli.
• Employed DNA oligonucleotides with embedded ribonucleotide tracts and RNA-majority oligonucleotides to repair a double-strand break in the GFP gene in HEK-293 cells.
• Analyzed strand bias in gene correction to assess the mechanism of RNA-containing oligonucleotide integration.

Main Results:

• RNA-containing oligonucleotides successfully served as templates for chromosomal gene correction in E. coli.
• RNA-containing oligonucleotides facilitated DSB repair and introduced base changes in genomic DNA of human HEK-293 cells.
• Observed consistent strand bias for RNA-containing oligos and DNA oligos, indicating they are not converted to cDNA before annealing.

Conclusions:

• RNA sequences can directly template DNA modification and repair in both bacterial and human cells, extending findings from yeast.
• RNA-mediated DNA repair is a conserved biological process across different species.
• The study demonstrates a novel mechanism for genetic modification and remodeling involving RNA templates in vivo.