Sperm may play a big role in reproduction, but they are the smallest cells in the male body. The average length of a sperm is about 0.05 millimeters. Men's bodies are constantly producing new sperm.

A new study suggests that human sperm cells defy Newton’s third law by using a unique motion to swim through thick fluids ...

A new study shows that lab-grown sperm cells can be derived from stem cells. July 9, 2009 — -- The face of infertility-- in literature, in the media, in advocacy groups -- is so predominantly ...

They observed the pattern of electric charges that are distinctive to CatSper’s activation in individual mice sperm cells. There were clear spikes when the temperature surrounding the cell went ...

The sperm portion of that cocktail consists of developed or mature male sex cells that can fertilize a mature female sex cell - called an ovum or an egg, says Moss.

She described the sperm protein bundle as a kind of key, which fits with a lock on an egg cell. In fish, that lock is a protein named Bouncer — appropriately, as the sperm head can’t enter the ...

Adding them to the sterile embryos of a different living animal ultimately converts these stem cells into germ cells, such as sperm or eggs. This is the mouse-rat chimera testis cryosection.

Now 26, Hsu and his doctors are waiting to see if an experimental transplant of these cells, extracted from a tissue sample taken back in 2011, will be able to restart sperm production. The ...