A new model for studying organelle formation

Two new strains of plankton discovered off the coast of Japan offer a window into the process of organelle creation.

Many algae and plants contain photosynthetic organelles called plastids that are considered remnants of free-living cyanobacteria. In most cases, the genomes of the original cyanobacteria have mostly been lost, but in some rare cases their nuclei have been retained.

Now, a team co-led by scientists at the University of Tsukuba has described two distantly related strains of single-celled plankton called dinoflagellates, each containing algae-derived compartments that are still midway through transforming from internal residents into fully co-opted organelles.

Genetic analyses showed signs of DNA transfer from the compartments’ vestigial nuclei to the host nuclear genome. This genetic integration is less advanced than in other plankton groups. 

The researchers thus propose using the newly discovered dinoflagellates as model organism for studying organelle formation in action.