It's a commonly held belief: Sperm cells are like runners in an epic race, competing against each other for access to the coveted egg at the finish line. The egg, in turn, waits patiently for the ...

With the help of the ESRF, researchers from Karolinska Institutet (Sweden) have discovered the reproductive mechanism that permanently blocks polyspermy — a pathologic condition that arises when more ...

We all know the drill for reproduction—sperm meets egg. But mice aren’t people. And the same recipe doesn’t work for human reproductive cells. One reason, according to Dr. Mitinori Saitou at Kyoto ...

Researchers at Newcastle University in England report they have coaxed the first human sperm cells from embryonic stem cells, in a remarkable demonstration of how quickly the field of stem-cell ...

The success of in vitro fertilization (IVF) depends on numerous factors, including the viability of sperm. A recent study from the University of Illinois Urbana-Champaign introduces a novel method to ...

Scientists have created human eggs containing genes from adult skin cells, a step that someday could help women who are infertile or gay couples have babies with their own genes but would also raise ...

Well-documented reports spanning 25 years have yielded mounting evidence that sperm counts are tumbling in industrialized countries. (See my April 20, 2017 post Going, Going, Gone? Human Sperm Counts ...

Scientists have used human skin cells to create fertilizable eggs capable of producing early embryos, an advance that could expand possibilities for fertility treatment, according to new research. The ...

A microscope image of a human egg contains a nucleus taken from a skin cell. (Mitalipov Laboratory at Oregon Health & Science University) WASHINGTON — Oregon scientists used human skin cells to create ...