The Oyster’s Garter

Dear Oyster’s Garter,

I’m a coccolithophore, a single-celled marine plant with a shell made of tiny plates. I come from a long line of mighty ocean warriors. Our massive blooms rule the waves, thriving in nutrient-poor waters where punier plankton fear to tread. (I don’t want to sound too scary, though – we are benevolent overlords, bringing nutrients to the barbarian hordes of the open sea.) My ancestors even created the White Cliffs of Dover!

But I fear that I am not living up to my mighty heritage. I was in the middle of our biggest bloom yet, photosynthesizing and asexually dividing just as fast as my chlorophyll could go. And then all of a sudden – BOOM! I found myself undergoing meiosis – sexual division! My beautiful calcium carbonate plates fell off, I lost half my chromosomes, and I grew unsightly scales and a hideous flagella. To make matters worse, just when I had undergone this shameful division, a horde of viruses attacked my bloom, killing most of my buddies. Am I a coward, doomed to drift alone?

Sincerely,

Alone in the Atlantic

Dear Alone,

There comes a time in every young coccolithophore’s life in which your body changes in strange and new ways. New research published in PNAS by Miguel Frada & colleages discovered that when the virus visigoths are beseiging a coccolithophore bloom, some coccolithophores can hide by changing from the diploid (having paired chromosomes) armored non-swimming phase to a haploid (having only one of each chromosome) scaly flagellated phase.

Alone, your disconcerting change saved your life! If you had remained in your attractive plated stage, you would have been killed along with your bloom. But in your haploid phase, the virus couldn’t recognize you. Evolutionary theory predicts that coccolithophores and the viruses that love them should be locked in a “Red Queen” scenario – an arms race with everybody evolving new defenses and infection strategies as fast as they can. But it turns out that you coccolithophores are hiders, not fighters – instead of developing weapons, you use a “Cheshire Cat” strategy of hiding from the viruses right in plain sight.

So, Alone, relax, stop worrying, and enjoy the flagella – remember, in your other phase you can’t swim! Someday you’ll find the right haploid honey to fuse with, regain your plated diploid form, and live to bloom another day.

This is the second “Dear Oyster’s Garter” advice column. I had so much fun writing the first one I just couldn’t stop. As before, the inspiration and style is from my hero, Dr. Tatiana.

M. Frada, I. Probert, M. J. Allen, W. H. Wilson, C. de Vargas (2008). From the Cover: The “Cheshire Cat” escape strategy of the coccolithophore Emiliania huxleyi in response to viral infection Proceedings of the National Academy of Sciences, 105 (41), 15944-15949 DOI: 10.1073/pnas.0807707105

This entry was posted on Wednesday, October 29th, 2008 at 10:51 pm and is filed under Critters, Evolution, Ocean. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.