20 February 2018

Massive crossover elevation via combination of HEI10 and recq4a recq4b during Arabidopsis meiosis

Serra, H., Lambing, C.A., Griffin, C.H., Topp, S.D., Nageswaran, D.C., Underwood, C.J., Ziolkowski, P.A., Seguela-Arnaud, M., Fernandes, J.B., Mercier, R. and Henderson, I.R. - Proceedings of the National Academy of Sciences USA, 2018


During meiosis, homologous chromosomes undergo reciprocal crossovers, which generate genetic diversity and underpin classical crop improvement. Meiotic recombination initiates from DNA double-strand breaks (DSBs), which are processed into single-stranded DNA that can invade a homologous chromosome. The resulting joint molecules can ultimately be resolved as crossovers. In Arabidopsis, competing pathways balance the repair of ∼100–200 meiotic DSBs into ∼10 crossovers per meiosis, with the excess DSBs repaired as noncrossovers. To bias DSB repair toward crossovers, we simultaneously increased dosage of the procrossover E3 ligase gene HEI10 and introduced mutations in the anticrossovers helicase genes RECQ4A and RECQ4B. As HEI10 and recq4a recq4b increase interfering and noninterfering crossover pathways, respectively, they combine additively to yield a massive meiotic recombination increase. Interestingly, we also show that increased HEI10 dosage increases crossover coincidence, which indicates an effect on interference. We also show that patterns of interhomolog polymorphism and heterochromatin drive recombination increases distally towards the subtelomeres in both HEI10 and recq4a recq4b backgrounds, while the centromeres remain crossover suppressed. These results provide a genetic framework for engineering meiotic recombination landscapes in plant genomes.

Read the entire publication

Share this:

Receive updates from the Crop Science Centre

Thanks! We’ve received your email.

Sorry, something went wrong.

By submitting this form, you are consenting to receive marketing emails from: The Crop Science Centre, Lawrence Weaver Rd, Cambridge, CB3 0LE, GB. You can revoke your consent to receive emails at any time by using the SafeUnsubscribe® link, found at the bottom of every email. Emails are serviced by Constant Contact.