Johnson D, Crawford M, Cooper T, Claeys Bouuaert C, Keeney S, Llorente B, Garcia V, Neale MJ.

Concerted cutting by Spo11 illuminates meiotic DNA break mechanics.

Nature. 2021 Jun;594(7864):572-576. doi:10.1038/s41586-021-03389-3

Pairs of double strand breaks created by Spo11 causes loss of short oligonucleotides, creating a cap repaired by homologous recombination.

“High-resolution analysis of deproteinized Spo11-oligos showed [a ladder of] periodicity of around 10 nt [that] ranges in length from around 33 nt to more than 100 nt” “The ladder also arose in rad50S-mutant and Mre11-nuclease-defective strains of S. cerevisiae, which, like the sae2∆ mutant, cannot remove Spo11 from DSB ends. Notably, the ladder depended on the catalytic activity of Spo11” “we refer to this ladder as hyperlocalized ‘Spo11 double cuts’ (Spo11-DCs).”

“because Spo11-DCs of less than 30 nt in length are not detected on gels and are depleted from filtered Spo11-oligo libraries, we propose that adjacent Spo11 complexes that are capable of making double cuts must, in vivo, interact with DNA from the same direction, thereby generating a ladder of Spo11-DCs with periodicity dictated by the helical pitch of DNA (around 10.5 bp).”

“the global frequency of Spo11-DCs was disproportionately associated with regions of stronger Spo11 activity”

“Deep sequencing of meiotic progeny identifies recombination scars that are consistent with repair initiated from gaps generated by adjacent Spo11 DSBs.”

“We envision a mechanism in which multiple Spo11 proteins assemble with other pro-DSB factors to create a platform that enables concerted Spo11-DSB formation”