You are currently browsing the tag archive for the ‘butterflies’ tag.

Two weeks ago I presented a Nature paper in my lab’s journal club that relates to butterfly research.  It was incredibly beautiful and awe-inspiring work in a discipline that is small and often overshadowed by the glitziness of immunology, cancer, and other biomedical research.  And even though this type of “fringe” science doesn’t directly benefit medicine, the coolest research—in my opinion—is the type that delves into nature’s biggest curiosities.  In this case, this paper is about magentoreception (or the ability to sense magnetism) in butterflies, and its possible role in directing the migration of this insect and other animals that exhibit migratory behavior.

Every year during the fall, thousands of butterflies fly from US and Canada down to Mexico to spend winter at the exact same fir grove.  How spectacular would it be to actually witness this sight in person?  Thousands of orange, fluttering leaves that litter the sky, cover the ground, and land on trunks of trees.  The mysterious thing is that this behavior isn’t taught; it is innate.  Some wiring in their brains allows them to pinpoint the correct direction, through disparate weather and rough terrains, to find their way to safe haven.

About two years ago, the same guy who published the paper I presented, also discovered that the butterfly “compass” is time and sun sensitive.  Say, for example, at 10 AM, the butterflies know to steer to the right of the sun in order to fly southwest.  But at 4 PM, they fly straight toward the sun so that they can maintain the same trajectory.  This means that the butterflies have linked the ability to sense the position of the sun in the sky to their circadian rhythm.  If you take butterflies with a skewed day cycle (ie. wake up at 1 PM instead of 7 AM), they would fly to the right of the sun at 4 PM as if they thought it were 10 AM.  And here’s the kicker: the butterflies require their antennae in order to do this.  This led to the discovery of a separate circadian center in the antennae that is also similar to the circadian clock found in their brains.

Besides from the “time compensated sun compass,” the butterflies also possess two Cryptochrome proteins that are known to be magnetosensitive in other animals; however, to my knowledge, it has not been shown whether butterflies use the earth’s magnetic poles in migration.  In the paper that I presented, the scientists use fruit flies, which also possess their own Cry proteins and exhibits avoidance of magnetic fields, to study butterfly Cry proteins.  First, they expressed butterfly Cry in mutant fruit flies that are unable to generate normal Cry proteins on their own.  Amazingly, they proved that butterfly Cry was enough to rescue the magnetic sensitive behavior in these mutant flies even though they are completely different species!  Second, they show that this effect of the Cry proteins is dependent on UV light.  Finally, they also show that the Cry proteins work through a mechanisms different from the one that has been the convention of thought for a long time.

I can’t wait until they finally find how magnetoreception factors in butterfly behavior and how the Cry proteins are involved at a molecular level.  But even as we are closer to revealing the mechanism of magnetoreception, we are still far from understanding all the factors that combine to initiate the butterflies’ southward journey.  What I love about natural phenomenons like this—which seems so astoundingly complex and beyond understanding—is that they may actually have a strong genetic component that is in itself simple yet sophisticated.  This simple yet intricate nature of such natural mysteries is what drives scientists to come up with unique and creative experiments to explore these questions.  Even if you aren’t a scientist, I hope you share my enthusiasm for such outstanding science as this.

Cheesecake Brownies from Smitten Kitchen

This Saturday I stayed home to recover from a cold.  To satiate my chocolate craving, I made cheesecake brownies.  When they’re fresh out of the oven, the brownie part has a more cake-like texture, which I generally prefer.  If you like your brownies chewy, then just cool them in the fridge for a few hours.  But overall, these were yummy.  Especially since it has cheesecake in it, and cream cheese makes everything taste better.  I wanted there to be a clear separation of cheesecake topping and brownie so I tried not to mix the two layers too much while I was marbling them.  I’d eat it warm with a cup of milk. By the way, I love how Smitten Kitchen always has easy-to-make recipes that usually require no more than two bowls to make!

Advertisements