In this episode, we are joined by Corrado Spadafora of the Institute of Translational Pharmacology and the Italian National Research Council. Spadafora gives us an inside look at how his laboratory discovered that mature sperm cells of several species can take up DNA molecules from outside themselves and bring that DNA to oocytes during fertilization. Because this can compromise the genetic identity of the resulting embryo, the seminal fluid that surrounds sperm protects it from exogenous DNA upon ejaculation.     However, the sperm cells are not protected when still in the epididymous. While Spadafora is more focused on the evolutionary implications of these findings, he does note some possible medical consequences; particularly the suggestion that the father’s lifestyle and environmental conditions could be reflected in the makeup of his children, potentially predisposing them to certain metabolic conditions.   Press play to hear more. If you are interested in reading about his research, you can find his papers on Medline by searching at https://www.ncbi.nlm.nih.gov/pubmed.