There are up to 750 million sperm cells contained in a single ejaculation, but it only takes one sperm cell to fertilize a woman’s egg. The testes also produce the hormone testosterone, which is ...

Scientists have spent decades studying the extraordinary abilities and anatomy of human sperm, ... Pregnancy & Birth Man gets sperm-making stem cell transplant in first-of-its-kind procedure.

Scientists have 3D printed human testicular cells and identified promising early signs of sperm-producing capabilities. The researchers hope the technique will one day offer a solution for people ...

That’s how long it took Nayernia’s team to nurture sperm from embryonic stem cells, using a special cocktail of growth factors, nutrients and retinoic acid, a derivative of vitamin A.

Researchers have created human sperm from embryonic stem cells. The embryonic stem cells were cultured in a new medium containing vitamin A derivative (retinoic acid), using a new technique.

Gametes -- egg cells and sperm cells -- hold half of the amount DNA found other cells of an organism. A human cell has 23 pairs of matched chromosomes, or bundles of DNA; sperm and egg cells have ...

Related Stories. Daily sex reduces damaged sperm, Science Online, 01 Jul 2009; Stem cell bill bans human-animal 'hybrids', Science Online, 03 Mar 2009 Sperm grown in the lab fertilises eggs ...

Almost every type of human cell is powered by mitochondria, bean-shaped organelles that use oxygen to synthesize usable energy.* These structures evolved billions of years ago from free-swimming ...

They then inserted the cells into the testes of mice, where they became very immature human sperm cells, the researchers report. "It's much easier than we actually expected," Pera told Shots.

Human sperm have been created using embryonic stem cells for the first time in a scientific development which will lead researchers to a better understanding of the causes of infertility ...

British scientists claimed Wednesday to have created human sperm from embryonic stem cells for the first time, an accomplishment they say may someday help infertile men father children. The ...