Harmful DNA:RNA hybrids are formedin cisand in a Rad51-independent manner

Abstract

DNA:RNA hybrids constitute a well-known source of recombinogenic DNA damage. The current literature is in agreement with DNA:RNA hybrids being produced co-transcriptionally by the invasion of the nascent RNA molecule produced in cis with its DNA template. However, it has also been suggested that recombinogenic DNA:RNA hybrids could be facilitated by the invasion of RNA molecules produced in trans in a Rad51-mediated reaction. Here, we tested the possibility that such DNA:RNA hybrids produced in trans constitute a source of recombinogenic DNA damage taking advantage of Rad51independent single-strand annealing recombination assays and new constructs designed to induce expression of mRNA transcripts in trans in the yeast Saccharomyces cerevisiae. We show that unscheduled and recombinogenic DNA:RNA hybrids are formed in cis during transcription and in a Rad51independent manner.

The makings of TERRA R-loops at chromosome ends

“…The mechanism of R-loop formation by APOLO has remained unknown. In S. cerevisiae, it has been reported that Rad51p mediates hybridization of transcripts to homologous chromosomal loci distinct from their site of synthesis [78], though another paper disputed this conclusion [79]. Finally, R-loop formation is well documented for the bacterial CRISPR-Cas9 DNA endonuclease [80], in which Cas9 bends the DNA to allow guide RNA infiltration into the double helix.…”

A Review of SARS-CoV-2, Responsible for COVID-19: History, Biology, Infection Mechanism, Antigenic Vaccines, Their Risks and how an Alternate RBD Vaccine is Safer?

“…DNA: RNA hybrids constitute a well-known source of recombinogenic DNA damage [71]. Spontaneous mitotic recombination is a well-known process, and it is also enhanced by transcription [72].…”

A Review of SARS-CoV-2, Responsible for COVID-19: History, Biology, Infection Mechanism, Antigenic Vaccines, their Risks and How an Alternate RBD Vaccine is Safer?

“…Also, there are several evidences for live, attenuated viral RNA vaccines to recombine with similar or other viral genome in circulation in the recipient's plasma, affecting the effectiveness of RNA vaccines [69,70]. DNA: RNA hybrids constitute a well-known source of recombinogenic DNA damage [71].…”