What type and extent of genomic variation exists in co-occurring Prochlorococcus populations?
We will determine what common genomic backbone and superimposed variation exists in the genomes of co-occurring Prochlorococcus. We will initially approach this by fingerprinting the entire BAC library from the environmental location we have found to display highest number of sequence variants in the diversity screening. Depending on the genomic variation encountered in the sample, the fingerprinting will provide us either with completely assembled genomes or with large contiguous portions of the genomes (at a minimum the average Size of a BAC clone). We will completely sequence large regions of the genomes (or contigs) anchored by informational genes and pathways identified largely from the two sequenced ecotypes. This will provide us with a rich comparative dataset and will form the foundation for comparative analysis of the BAC libraries from the different environments. What are the major modes of diversification of these Prochlorococcus populations? We will analyze the gene sequenc