Weird Science Weekly: Sperm have a sweet tooth


Weird Science happens all around us, every day. In this installment of Weird Science Weekly, I gather some of past week's strangest examples, such as sperm with a sweet tooth, LEGO legs and a genitalia-waggling defence mechanism.

Sperm like sweet and savory flavours

We all learned the different basic flavours in elementary school — sweet, sour, bitter, salty, and umami (depending on how old you are) — but did you learn that your tongue isn't the only home to taste receptors in your body?

You might be surprised to find out that other parts, including your stomach, intestines and even your lungs and brain have taste genes. The taste genes work as signaling pathways in the body; your tongue uses taste receptors to deploy proteins that tell your brain what you're tasting. Other tissues use them for something else entirely. But the pathway is governed by the same receptors.

Researchers studying the sense of taste at The Monell Center in Phildephia revealed this week that these receptors have another surprising role - taste receptors in the testicles and sperm are crucial to fertility. Turns out that sperm and testicles (tasteicles?) like sweet and savory flavours, and when they can't sense them, they aren't working right.

The study was done using mice and the initial goal was to breed mice who were mutant (or defective) for two different genes; TAS1R3, involved in sweet and umami tastes receptors, and GNAT3, involved in converting the receptor into a signal to the brain. Mice lacking one or the other were no problem to breed, but they weren't able to breed any that lacked both. To get around that problem, they engineered some mice with no GNAT3 and the human version of TAS1R3 — which comes with a handy chemical on/off switch.

These mice were fertile until the researchers a drug to shut down the TAS1R3; as soon as that happened, bam, sterile mice. The effect was reversed fairly quickly when the drug was removed from the diet.

Why should we be interested in mouse sperm? Well, for one thing, the drug used to shut down the human-version TAS1R3 is part of a class we use to treat high cholesterol. It's also used a lot in agriculture as a herbicide. Infertility is on the rise around the world — shown in studies from Canada and India and the UK, just as a small sample — and not just among farmers with high cholesterol. This discovery that sperm are highly dependent on sweet and savory taste receptors could open up new doorways in potential treatment for infertile men. Failing that, maybe we could at least investigate rodent birth control.

[ Related: WSW: Anti-terrorism technology now used to save British cakes ]

Woman builds own leg from LEGO

"I hope you step on a LEGO" is a good curse for most of us. It wouldn't have any effect on Christina Stephens, though, except to make her a little taller on one side.

Stephens, who lost part of her left leg last year, recently accepted a coworker's challenge to build herself prosthetic out of the Danish bricks and, after only two days, she was successful.

Stephens plans to continue her building, planning a "Lego Leg 2.0" with a functional ankle and foot.

LEGO legs weren't the only prosthetics making the viral rounds this week. 3D printers have been in the tech news frequently lately, for everything from potential space pizza to bionic ears. The latest recipient of a high tech 3D-printed body part is Buttercup the duck, of Arlington, Texas. Born with a deformed foot, the bird sanctuary where he lives decided to contact NovaPrint and see if there was a way to, well, make him walk like a duck.

Hawk Moths have an unusual defence mechanism

Moths in Malaysia have developed a unique way to scare off the bats seeking to eat them. Researchers revealed this week that some hawk moths — which range all over the globe and have wing spans 4 to 10 cm across — wiggle their genitals when under attack.

The jiggling privates serve a purpose greater than being an odd threat display. The male moths use part of their genetalia, used for holding females while they mate, to emit ultrasound noises.

Science Now reports the scientists speculate the rapid clicks emitted by the moths might "warn the bats that they're trying to mess with a fast-moving, hard-to-catch prey, or they might jam the bat's ultrasound signals." Apparently the female moths can make the sound as well, although the researchers haven't worked out how just yet. In any case, shaking their groove thing to confuse their predators may be among the more unique defence strategies in the animal kingdom. Although it has some stuff competition from the likes of the exploding Malaysian ant or the horned lizard that shoots blood from its eyes.

[ Related: WSW: Baby chickens are smarter than children ]

Obama tests an battery soccer ball

The US President kicked around a new idea for small-scale energy production on his trip to Tanzania this week.

The ball — dubbed the Soccket by its creators at Uncharted Play — converts kinetic energy generated by kids (and adults) playing with it into battery power. The secret is a "pendulum-like mechanism" inside the ball; a magnet that jiggles back and forth in an inductive coil when the ball moves, effectively making the ball an electromagnet. A mere 30 minutes of playtime can power an LED lamp for up to 3 hours.

With more than 1.2 billion people worldwide still without access to electricity, and an estimated 3 billion-plus soccer fans in the world this kind of clean, renewable mini-powerplant really is a bright idea.

Australian dog working to save bees

And I can't even get my dog to come when she's called.

Bees — more specifically, how many of them are dying — have been in the news a lot lately in North America and Europe. Having long been used to seeing the little workers buzzing around flowers, we're now learning about colony collapse disorder, how pesticides might be involved and that the U.S. alone may have lost up to 50 per cent of the hives needed to pollinate many of the nation's fruits and vegetables. Just last month, humans helped the process along by killing an estimated 50,000 bees in an Oregon parking lot.

In the land down under, apiarist Josh Kennett has enlisted man's best friend into the fight against American foulbrood, which sounds like the name of a new reality show but is, in fact, one of the most destructive bee diseases out there. There's no cure for it; the best offense is knowing it's there so you can quarantine the hive.

Dogs are actually used for this task in North America as well, but we have the option of doing it in the cold winter months, when the bees are snoozing and aren't around to sting the canine investigators. In South Australia, Kennett realized they needed a different approach and thus the idea of the pooch beekeeper suit was born.

Kennett's black Labrado Bazz has already been trained to sniff out the disease, and the suit is ready to go. The only remaining challenge, he told ABC, is to get Bazz used to wearing it as the dog is a little weirded-out by being all covered up.

You can't really blame him.

[ More Geekquinox: Scientists produce functional human livers from stem cells ]

Keep your eyes on the wonders of science, and if you spot anything particularly strange you'd like me to check out for next week, comment below or drop me a line on Twitter!

(Photos courtesy: Getty, Barber and Kawahara, Uncharted Play/PopMech, Josh Kennett)

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