MEI4 (meiotic double-stranded break formation protein 4) is an evolutionally conserved protein essential for initiating meiotic recombination through DNA double-strand break (DSB) formation 1. MEI4 functions as a structural component of the DSB machinery on meiotic chromosome 6, where it forms a complex with REC114 and IHO1 to activate DSB formation 12. The protein localizes to discrete foci on chromosome 6 that do not overlap with DSB repair foci, suggesting its role occurs upstream of DNA repair 1. HORMAD1, a chromosome 6 component, is required for MEI4 localization, and the quantitative correlation between axis-associated MEI4 levels and DSB formation indicates MEI4 may be a limiting factor for DSB initiation 3. Clinical relevance is demonstrated by bi-allelic MEI4 variants causing female infertility characterized by preimplantation embryonic arrest, with variants reducing MEI4-DNA interaction and causing oogenesis defects in mouse models 4. Similarly, REC114 variants that impair REC114-MEI4 complex formation cause nonobstructive azoospermia in males 5. The MEI4-REC114 complex is regulated by SCF ubiquitin E3 ligase, which prevents hyperactive DSB formation through proteasome-mediated degradation of associated proteins 6. These findings establish MEI4 as a critical regulator of meiotic recombination with significant implications for human fertility.