Interestingly, we found that OA treatment of Trip13Gt/Gt spermatocytes could propel them into MI, despite a report that the same did not occur when wild-type pachytene spermatocytes were treated with the DSB-inducing agents gamma radiation or etoposide [53]. It is possible that the nascent induction of DSBs in pachynema evokes a checkpoint response that cannot be bypassed by OA, whereas the post-strand invasion lesions in TRIP13-deficient spermatocytes do not.