“…Additionally, many of the same proteins involved in somatic cell checkpoints, including ATM, H2AX, ATR, TOPBP1, RAD9A, RAD1, and HUS1, are expressed during meiosis, and most are known to localize along meiotic chromosomes. 5,14,15,[33][34][35]76,83 A variety of meiotic defects have been shown to lead to cell cycle arrest and apoptosis between zygonema and midpachynema in stage IV of the seminiferous epithelium. 77 These include cases of complete absence of DSBs (such as in Spo11 mutants), 88 impaired DSB repair (such as in Dmc1 and Msh5 mutants), [89][90][91] autosomal asynapsis, 92,93 or impaired MSCI.…”