Chronic exposure to diesel exhaust particulate matter impairs meiotic progression during spermatogenesis in a mouse...

Exposure to ambient PM_2.5 may correlate with the decline of semen quality, and the underlying biological mechanism has not been fully understood. In the present study, mice were intratracheally instilled with diesel exhaust PM_2.5 (DEP), and its effects on the spermatogenic process as well as the alterations of testicular gene expression profile were assessed. Our results showed that chronic exposure to DEP impaired the fertility of male mice without influencing their libido. Compared with Vehicle-exposed group, the sperm count and motility from DEP-exposed mice were significantly decreased. In addition, immunohistological staining of γH2AX and DMC1, biomarkers for meiotic double strand breaks (DSBs), demonstrated that chronic exposure to DEP comprised the repair of meiotic DSBs, thus disrupting the spermatogenesis. Deep RNA sequencing test showed altered expressions of testicular genes including the GnRH signaling pathway. In summary, our research demonstrated that chronic exposure to DEP may disrupt spermatogenesis through targeting the meiotic recombination, providing a new perspective for the research on the male reproductive system damage caused by air pollution.