Furthermore, when equipped with the template sequence from the telomerase RNA, DRT10 readily synthesized telomeric DNA repeats.

We teamed up with RT aficionado @pentamorfico.bsky.social from the Pinilla-Redondo Lab to build a new phylogenetic tree of RTs across all domains of life.

Remarkably, this revealed that the DRT enzymes are bacterial homologs of TERT.

We found that DRT10 synthesizes tandem-repeat cDNAs through a mechanism strikingly reminiscent of DNA repeat addition by telomerase. But does this similarity represent convergent evolution or shared ancestry?

Forty years ago, Carol Greider and Elizabeth Blackburn discovered an enzyme that solves this problem. Telomerase, which comprises a reverse transcriptase (TERT) and RNA (TR), directly extends chromosome ends by adding DNA repeats templated by the TR.

Genome maintenance by telomerase is a fundamental process in nearly all eukaryotes. But where does it come from?

Today, we report the discovery of telomerase homologs in a family of antiviral reverse transcriptases, revealing an unexpected evolutionary origin in bacteria.

doi.org/10.1101/2025...