Something weird is going on with human sperm production. For decades, scientists have warned that sperm counts are dropping among Western men, but no one has really been able to prove it. In what is now the largest and most comprehensive study of its kind, scientists have presented compelling evidence in support of…
Lots of species do some wild sex stuff. The purple stone crab is no exception: Females have seminal receptacles, a special organ that just holds and stores sperm for later.
In a breakthrough that almost sounds too good to be true, researchers have found a potential new form of birth control that could solve numerous problems. It offers the possibility of being effective for both sexes, no hormonal side effects, and might even be a Plan B that doesn’t piss off anti-abortion advocates.
A team of German scientists were wondering how to deliver medications into the female reproductive tract and realized, hey, why come up with something new? The human body already produces its own little machines perfectly suited to deliver their goods to that same spot. So, why not tame our little sex swimmers as a…
It’s one thing to hear about Michael Phelps winning a gold medal. It’s quite another to actually see him do it.
A popular fertility treatment introduced in the early 1990s has been linked to low sperm counts in men born from the procedure. Scientists aren’t entirely sure why this is happening, but it’s entirely possible that fathers are passing their fertility issues down to the next generation.
For the first time ever, scientists have produced live mice without a fertilized egg cell. The potentially revolutionary technique could one day allow gay men to produce biological offspring, or—even more radically—allow both men and women to self-fertilize.
In preparation for the upcoming Olympics in Brazil, a British long jump champion is planning to freeze his sperm just in case he contracts Zika. It’s meant as a precaution to prevent any future children from developing birth defects, but in reality it’s a complete overreaction based on unfounded fears.
Fruit flies have enormous sperm. This is a well known fact in the scientific community—so well known, in fact, that there’s a name for it: the big sperm paradox. But the massive, spermy problem has long confounded scientists, who couldn’t figure out why such a tiny creature needed such humongous baby batter soldiers.…
Researchers just found an on-off switch for sperm movement. This has the potential to help men who are infertile, but it also has the potential to help all men. It could be an effective form of male birth control.
Scientists from China have made history by taking a cell that’s not a sperm cell and then used it to create a live animal. A similar technique could be used one day to treat infertility in humans.
What you’re seeing in this video is obviously a sperm cell, except it was made in a lab, not a testicle. It’s designed to show how passive elastic swimming can mimic, fairly well, the motions that allow sperm (or fish) to swim.
A mouse’s sperm is much, much larger than an elephant’s sperm. A fruit fly produces the longest sperm known to science. Why do tiny animals make big swimmers, but large animals make small ones?
Sperm usually swim in a 3D shimmy: a spiral wave travels down the whippy flagellum and rotates its head in a circle around its long axis. That “bulk swimming” is fine most of the time, but it isn’t a great option when a sperm cell gets close to a surface. That’s when they switch to “slither” mode.
For the past 25 years, men whose sperm can’t manage the arduous swim across a Petri dish have had the option of injecting a single sperm cell directly into an egg. But that method still left some sterile men out in the cold.
You know the story of mammalian fertilization: millions of sperm enter the vagina, only one fertilizes the egg, more than one messes up the embryo, yadda yadda yadda. Turns out that’s not the only way it can work.
Farming emus means breeding emus. And Irek Malecki of the University of Western Australia thinks that the results could be improved with a bit of artificial insemination. But it’s easier said than done, as detailed in this amusing video.
Women know that menopause can put a “sell by” date on getting pregnant, but common wisdom says that men retain much of their fertility well into old age. That common wisdom is wrong.
Ejaculation may feel like a glorious mess, as uncontrollable as an avalanche or a runaway train. In reality, it’s a tightly choreographed court dance: integrating three different branches of the nervous system, triggering cascades of contractions in smooth and striated muscles, all accompanied by the electrical storm…
Two penguins at the Monterey Bay Aquarium decided to make baby penguins in front of their viewing window. In the process, they showed off a fascinating aspect of bird reproductive biology.