Insights in DNA fragmentation

Jordi Ribas-Maynou ^*

• Unit of Cell Biology and Medical Genetics; Department of Cell Biology, Physiology and Immunology, Autonomous University of Barcelona, Bellaterra, Spain

A comprehensive evaluation of sperm quality is required in order to decipher the specific contribution of paternal gametes to fertility rates. In this regard, achieving good sperm quality is essential to ensure the gamete's ability to reach the fertilization site, undergo the physiological changes associated with capacitation, and penetrate the egg (Delgado-Bermúdez et al., 2022). During this process, sperm chromatin remains tightly packaged in protamines that confer extraordinary protection against genotoxic agents (Ribas-Maynou et al., 2022). However, once fertilized, protamines need to be replaced by histones and sperm chromatin must be able to form the paternal chromosomes without losing of DNA integrity. Sperm DNA damage has been identified for decades as a factor directly associated with male infertility, preventing pregnancy or its progression (Lewis and Aitken, 2005). The present special issue includes three original papers and two reviews on the topic of DNA damage, providing new insights into our understanding of human fertility. First, in the research by Fu and collaborators, entitled "Elevated sperm DNA fragmentation is correlated with an increased chromosomal aneuploidy rate of miscarried conceptus in women of advanced age undergoing fresh embryo transfer cycle" (Fu et al., 2024), researchers retrospectively analyzed a cohort of IVF/ICSI patients who underwent miscarriage to investigate whether sperm DNA study" (Li et al., 2023), the authors evaluated whether a second ejaculation within 59 a short interval could benefit sperm quality in oligoasthenoteratozoospermic 60 patients undergoing ICSI. Their work on sibling oocytes demonstrated that sperm 61 quality improved in terms of motility, morphology, and DNA damage compared to 62 the first ejaculation, which translated into a higher rate of good-quality 63 blastocysts. However, in their cohort, no statistically significant improvement in 64 live birth rates was observed. 65Finally, two reviews were accepted in this special issue. 66First, the review by Romano and colleagues (Romano et al., 2023) days) and long abstinence (>2 days) and observed that shorter abstinence 81 periods were associated with higher progressive motility and lower DNA damage. 82Additionally, a meta-regression analysis revealed an inverse relationship 83 between abstinence duration and sperm DNA damage. Therefore, their meta-analysis suggests shorter abstinence periods could be beneficial for patients 85 undergoing assisted reproduction. 86