Mad Science Monday, 2/14/2011

Happy Valentine's Day! I almost didn't get a post up today, but then I saw the perfect article to fit the holiday. Without further ado, I give you:

Mad Reference! "Extreme Aggression in Male Squid Induced by a β-MSP-like Pheromone." Hanlon RT, et al. Current Biology (online) February 10, 2011 (via National Geographic). Pheremones that induce aggression in a phallic animal during mating? Sounds like a Valentine's Day Mad Science Monday to me!

Mad Background and Observations! When longfin squid (Loligo pealeii) get together to breed, the females lay egg sacs. The males rush in and touch these sacs, and go into full-on pon farr rage.

Mad Hypothesis! A protein in the eggs acts as a pheremone, sending the males into this rage. Even without females present, this pheremone would set male longfin squid into gladiator mode.

Mad Experiment! The experiments are laid out really well in the apparently non-embeddable video at the top of the National Geographic article. They basically performed four trials (plus probably more trials with other proteins before they settled on the main candidate, but those aren't covered in this particular video and paper):

1. Trial with no stimulus (to establish baseline behavior of a group of male squid in their tank)
2. Trial with natural eggs (to establish what aggression looks like)
3. Trial with flask streaked with recombinant Loligo β-microseminoprotein (β-MSP, their candidate pheremone)
4. Trial with flask with no Loligo β-MSP (to make sure the pheremone matters in trial 3)

They All Laughed, But! β-MSP appears to be the thing that's necessary to piss off squid. The flask had eggs inside (to get the males to touch it), and I would've liked to see a trial without the eggs, but it'd be hard to isolate that it was the chemical doing the angering, not, say, poking them with a pheremone-tipped stick. The controls also established pretty well that β-MSP was the factor causing the aggression, although a sealed flask of eggs did produce a little more aggression than the stimulus-free control.

Mad Engineering Applications! This quote from the NatGeo article is what made me consider this research for Mad Science Monday: 

"We don't know of anything like this that exists in humans," Hanlon added. "But when we researched microseminoproteins in the literature, we found that they occur in mammal semen and, more importantly, that nobody has looked at what functional effect they have.

"We hope that our discovery stimulates research in that direction."

So they found a protein that turns male squid into gladiators, and a similar protein in humans... and they're hoping their research stimulates research. Clearly these guys are working on breeding their minion army.

Have any suggestions for Mad Science Monday (particularly articles published with full text in free online journals)? I'd love to read them in the comments!

Posted in: biology,mad science