Guillardia Theta

Guillardia theta is a marine, biflagellate cryptomonad alga and the only described species in the genus Guillardia, first identified in Connecticut by biologist Richard Guillard during the 1960s. Though rare in natural environments, it cultivates readily in the laboratory and has become the subject of extensive study since its discovery, valued in particular because it is the only cryptomonad to have its nucleus, its residual nucleomorph and its plastid genomes all fully sequenced. This makes it a leading model organism for studying secondary endosymbiosis, the process by which its plastid was acquired from a red alga, and for studying photosynthetic regulation; researchers have also isolated light-sensitive proteins called anion channelrhodopsins from it for use in neuroscience research.