Oxidative stress results from an increased production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), which are recognized for their dual roles in the male reproductive system and its diseases. Moreover, they are also closely linked to molecular damage by environmental toxicants and chemotherapy-induced reproductive toxicity, leading to male infertility.

ROS/RNS are involved in maintaining spermatogonial stem cell homeostasis, spermatogenesis, and influence testicular damage and reproductive diseases in humans. They may be indicators to predict male reproductive health and the success of assisted reproductive technology, and therefore they may also be targets to improve reproductive status. Knowledge and understanding of these conditions has led to the development of animal models, assisted reproductive technology, and novel tools for characterising these clinical conditions and providing better care to patients.

The aim of this Special Issue is to collate original research and review articles with a focus on the field of male reproductive system and disease. We are interested in articles that explore aspects of oxidative stress in the male reproductive system and disease in both humans and animal models. The aims of the Special Issue are to identify the effects of oxidative stress on mitosis, meiosis, spermatogonial stem cells, sperm motility, and reproductive diseases. Review articles describing these issues are also welcome.

Potential topics include but are not limited to the following:

• The role of oxidative stress in the male reproductive system and testicular damage
• New cellular and animal models to test and clarify the role of oxidative stress in spermatogenesis, spermatogonial stem cells, mitosis, meiosis, and capacitation
• Role of the molecular mechanisms underlying the generation of ROS/RNS and their oxidation products such as 3-nitrotyrosine on sperm motility, viability, and sperm quality
• Role of oxidative stress in toxin-related damage to the male reproductive system