MicroRNAs as potent regulators of gene expression are involved in spermatogenesis, yet their role in response of germline to genotoxic stress is obscure. We studied the microRNAome profile of X-ray irradiated mouse testes using the microarray technique. We found that radiation exposure significantly affected microRNA expression in testes. Mir-709 was the most abundant in both control and irradiated testes, and a big difference in miR-709 levels was observed between the control and exposed group. We found that miR-709 targets the Brother of the Regulator of Imprinted Sites (BORIS), an important regulator of DNA methylation and imprinting. Here, we for the first time show that the DNA damage-induced and ATR/Rfx1-mediated increase of miR-709 expression in exposed testes may be a protective mechanism that effectively decreases a cellular level of BORIS to prevent massive aberrant erasure of DNA methylation after radiation exposure.