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.
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.
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.
Women who are over 40 have a notoriously hard time getting pregnant by in-vitro fertilization (IVF), and it’s long been assumed that their problem stems from “old eggs”. But a preprint now available online at the Journal of Endocrinology suggests that the real problem might be the aging of the cells that surround the…
A sperm’s journey from vagina to egg is only 15 centimeters long, but it’s a race with attrition.
British scientists have finally figured out how sperm is able to connect with an egg. The process is facilitated by a molecule dubbed Juno, a protein that allows sperm to dock to the surface of an egg. The discovery could introduce new fertility treatments and birth control.
The image of a copulating frog dressed in tight-fitting pants sounds quite silly, but it was done in the name of serious research. In fact, more than one biologist dressed up their frogs to solve the mysteries of fertilization.
Mammals generally have evolved the same basic, boring way for males to fertilize an egg: just send a bunch of tiny individual sperm into the female reproductive organs. But in insects like the diving beetle, it gets way more insane.
Deep sea fish assimilating males for extra sperm, flies frozen mid-coitus for 20 million years, and a walrus's penis bone... it's all part of "Sexual Nature", a new exhibition at London's Natural History Museum that spotlights the many awesomely strange forms that animal intercourse can take. Let's go on a Valentine's…
Many space age dreams involve humans spreading out into the far reaches of the galaxy, but our extraterrestrial breeding program might need a little help. Scientists in Japan have found microgravity may function as a form of birth control.