ABOVE: Scanning electron micrographs show mating archaea fused together with cytoplasmic bridges.
REPRINTED WITH PERMISSION FROM I. ROSENSHINE ET AL., SCIENCE, 245:1387 (1989)
The paper
I. Turgeman-Grott et al., “Pervasive acquisition of CRISPR memory driven by inter-species mating of archaea can limit gene transfer and influence speciation,” Nat Microbiol, 4:177–86, 2019.
Naturally occurring CRISPR-Cas systems in bacteria and archaea carry DNA memories of invasions by viruses or plasmids. These DNA sequences, called spacers, instruct Cas proteins to destroy the intruders should they enter the cell again. Curiously, several species of halophilic, or salt-loving, archaea isolated from water near Israel’s Mediterranean coast possess spacers matching the DNA of closely related species, report Tel Aviv University’s Uri Gophna and colleagues.
Archaea can mate by latching together with cytoplasmic bridges and exposing their genomes to each other to be recombined. To test whether archaea pick up spacers during mating, the researchers let two species of ...
