Some men produce sperm that are poor swimmers, a major cause of infertility. To help, researchers from Germany have developed motorized cyborg “spermbots” that can be guided directly to an egg.
The identical triplets headed home from a Houston hospital today are being called “one in a million” multiples by doctors. The reason we don’t have more identical triplets running around is very simple—and it probably goes against what you’ve heard about twins (or triplets, for that matter).
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.
The New York Times is following a team of doctors at the Cleveland Clinic as they attempt the first uterus transplant in the United States. If successful, the procedure will let women who’ve had a hysterectomy, or who were born without a uterus, carry a fetus to term and give birth.
The birds you see above are all ruffs (Philomachus pugnax): wading birds that summer in marshes through Northern Europe and Asia. All three are wearing different forms of breeding plumage. And all of them are male.
Seahorses are famous for flipping the usual reproductive pattern on its head–a seahorse female impregnates the male by laying eggs in his pouch, and the male cares for the developing babies through an 18 day “pregnancy.” But you have to wonder: how does she get her eggs in there?
Northeastern University biologist Jonathan Tilly is certain he’s found egg-making stem cells in adult mice. If he’s right, it would refute decades-old work that showed female mammals finish making all their eggs before or shortly after birth. This might make it possible to grow new eggs inside the ovaries of older…
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.
Last week at Buzzfeed News, Dan Vergano described the surprising results of a paternity test–the first known case of a man fathering the son of a brother he didn’t know existed. It’s an example of a rare genetic condition known as chimerism.
Biologists already knew that one set of neurons play a big role in triggering puberty. A new study shows that these neurons don’t stop working once puberty ends, but keep running through adulthood, serving as a sort of reproductive timer.
A couple of months ago, the Twitter hashtag #JunkOff got biologists to post photos that displayed the extravagant weirdness of plant and animal genitalia. Yesterday, evolutionary geneticist Tom Houslay dared them to write about what animals actually do with their junk.
As sperm swim they transform chemical energy into motion, the way a car’s engine uses gas to propel you down the road. Like that engine, the process is complicated—if just one part stops working, the whole system can grind to a halt. This idea might lead to a contraceptive for men that’s reversible.
Lots of human cells are specialized, but I can’t think of any that are as stripped down to a single purpose as spermatozoa. Sperm have just one job, and they’ll die doing it.
If you’re trying to save an endangered animal, you need to protect its habitat and change the human behaviors driving it toward extinction. But all that will be meaningless if the animals don’t have babies. And so sometimes, you have to help with that, too.
Southern rockhopper penguins mate for life, but when biologists used light-based geolocators to track their behavior they found that pairs only spent about 20 to 30 days together each year–just enough time to mate and lay eggs.
A male seahorse gets pregnant when his mate deposits her as-yet-unfertilized eggs into a pouch on his belly. He fertilizes them, then carries the developing embryos until they’re ready to feed themselves. At which point he forcefully shoots them into the world.
Menopause is one of the oddest features of human reproductive biology. Not the hot flashes or the forgetfulness, but the fact that older women lose the ability to have babies. Now researchers say that once it appeared, menopause may have had a ripple effect on human mating that helped create the human pair-bond.
The successful union of egg and sperm in fertilization depends on a sperm cell’s ability to get through an egg’s thick protective coating and latch itself to its membrane. A study published in the journal Andrology yesterday gives us our first look at the protein responsible for the tie-down.
The Smithsonian’s National Zoo has been part of an international effort to breed highly endangered giant pandas in captivity ever since Richard Nixon visited China in 1972. But in 43 years, they’ve had only two solid successes–cubs Tai Shan and Bao Bao. They hope the new twins born this weekend will make it four.
Stunning underwater video by Jose Lachat at Aeon shows you major milestones in the life of an Australian flamboyant cuttlefish: including birth, courtship, and egg-laying before death. If you want to skip right to the sexy part, the mating dance starts at 2:19.