Plays a role in the different steps of crossover formation during meiotic recombination. Participates in the crossover differentiation step of crossover-specific recombination intermediates through its interaction with PRR19. In addition, stimulates crossover formation through the interactions with RFC3 and RFC4 and simultaneously regulates cell-cycle progression through interactions with CDC34 and subsequent ubiquitination of WEE1. May also participates in an active deselection process that destabilizes or removes excess pre-CO intermediates. . This is the function of CNTD1 (cyclin N-terminal domain containing 1, ENSG00000176563).