Genomes unlock a green toolbox- Organisms that bounce back

Some of the tiniest organisms in the world’s oceans may also be the most resilient.
One of these – a green alga called Micromonas – thrives in oceans around the world, indicating that it is well equipped to tolerate environmental change.Integrated Microbial Biodiversity Program Associate Alexandra Worden recently made important steps to figure out why.

By decoding the genomes of two Micromonas strains – one isolated off New Caledonia in the South Pacific, the other off Plymouth England in the North Atlantic – Dr. Worden’s research group discovered genes that help these organisms capture carbon dioxide from the atmosphere and transport it to the depths of the ocean. This activity influences the carbon cycle, a critical factor of climate change. The Micromonas also capture sunlight, water and nutrients, and produce both carbohydrates and oxygen. This makes them an important food resource within marine food webs.

“The genomes of these algae serve as tools to investigate their ecology – which is their response to environmental change and their interaction with other organisms,” says Dr. Worden. “All of these factors are part of the equation for predicting ecosystem shifts that result from climate change.”

The Micromonas genomes also reveal evolutionary clues about how photosynthesis transformed a desolate planet into the Earth that we inhabit today. Although these algae are oceanic microbes, they share many features with the ancestral organisms that initiated the “greening” of our planet.

“The trees and plants that color our continents are more closely related to aquatic microorganisms – these unicellular algae, in particular – than they are to the animals and fungi with which they cohabit,” says Associate Program Director John Archibald. Comparing the Micromonas strains to one another, and to other characterized algal and plant genomes, will help to demonstrate the dynamic nature of evolutionary processes.

“Micromonas algae might be individually miniscule, but collectively they’re massive in ecological and evolutionary importance.”

This story relates to our research program: Integrated Microbial Biodiversity