Genome erosion in a nitrogen-fixing vertically transmitted endosymbiotic multicellular cyanobacterium.

ABSTRACT:

Background

An ancient cyanobacterial incorporation into a eukaryotic organism led to the evolution of plastids (chloroplasts) and subsequently to the origin of the plant kingdom. The underlying mechanism and the identities of the partners in this monophyletic event remain elusive.

Methodology/principal findings

To shed light on this evolutionary process, we sequenced the genome of a cyanobacterium residing extracellularly in an endosymbiosis with a plant, the water-fern Azolla filiculoides Lam. This symbiosis was selected as it has characters which make it unique among extant cyanobacterial plant symbioses: the cyanobacterium lacks autonomous growth and is vertically transmitted between plant generations. Our results reveal features of evolutionary significance. The genome i

SUBMITTER: Ran L 

PROVIDER: S-EPMC2900214 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature