Dr. Smurf revealed the startling reality of the male reproductive system and what happens when people don't release sperm in ...

Human sperm have long been a subject of fascination—not just for their role in fertilization, but for their remarkable ability to navigate through some of the most viscous environments in the body.

Two new landmark studies show how a seeming tangle of DNA is actually organized into a structure that coordinates thousands of genes to form a sperm cell. The work, published March 3 as two papers in ...

Research into how a father’s choices — such as diet, exercise, stress, nicotine use — may transfer traits to his children has become impossible to ignore. The standard sperm-meets-egg story posits ...