Bhattacharya Lab active project: Paulinella Project

This is an electronic version of an article published in Journal of Phycology ©2005,
The Phycological Society of America.

This is an electronic version of an article published in Journal of Phycology ©2006,
The Phycological Society of America.

This is an electronic version of an article published in Journal of Phycology ©2007,
The Phycological Society of America.

Home > Major Projects > Paulinella Project

	image curtesy of microscope image of Paulinella*	press release in scientificamerican.com commentary in terradaily.com press release in sciencedaily.com Recent paper describing the Paulinella plastid genome:
	image curtesy of microscope image of Paulinella*		Minimal plastid genome evolution in the Paulinella endosymbiont by Yoon, H.S., A. Reyes-Prieto, M. Melkonian and D. Bhattacharya. Curr Biol. 2006 Sep 5;16(17):R670-2. Link to PDF version of paper paper listing in PubMed It is an enduring mystery how organelles were first established in eukaryotes. A key player in this saga is the thecate amoeba Paulinella chromatophora which over 100 years ago showed naturalists that once free-living cells could exist as endosymbionts. This species has the honor of being the only known case of an independent primary (cyanobacterial) plastid acquisition and is a model for understanding plastid establishment. The Paulinella plastid, often referred to as the cyanelle, retains typical cyanobacterial features such as peptidoglycan and phycobilisomes, but is considered to be a bona fide endosymbiont because it is no longer bound by a vacuolar membrane but lies free in the cytoplasm, its number is regulated, suggesting genetic integration, and it cannot be cultured outside the host. Paulinella is, however, difficult to culture, and so it has resisted detailed molecular biological investigation. Here we took advantage of a Lambda DASH II phage library made from limited amounts of Paulinella total genomic DNA to reconstruct the evolutionary history of its recently established plastid. Our data show the Paulinella plastid genome to have characteristics typical of cyanobacterial, not plastid genomes.