Essential roles of the ANKRD31-REC114 interaction in meiotic recombination and mouse spermatogenesis

DNA double-strand breaks (DSBs) initiate meiotic recombination. ANKRD31 recently emerged as a DSB regulator particularly important in the pseudoautosomal regions (PARs) of sex chromosomes. ANKRD31 interacts with multiple proteins, including DSB-promoting REC114. To test if this interaction is important, we generated mice with Ankrd31 mutations that either reduced (missense) or eliminated (C-terminal truncation) the ANKRD31–REC114 interaction without diminishing contacts with other partners. Eliminating the interaction mimicked an Ankrd31 null, with delayed DSB formation, defective DSB repair, and altered DSB locations including absence of PAR breaks. When the ANKRD31–REC114 interaction was instead attenuated, DSB formation was again delayed globally, but DSB locations and repair were affected little if at all. The missense Ankrd31 allele showed a dosage effect, wherein combining it with the null or C-terminal truncation allele resulted in intermediate phenotypes. Our results show that ANKRD31 function is critically dependent on its interaction with REC114, and that defects in ANKRD31 activity correlate with the severity of interaction disruption. Overall design: Detection of single-stranded DNA in the genome of mouse testis cells