From microbial genomics to meta-genomics

Modern microbial genomics is best exemplified by determination of the complete nucleotide sequences of whole genomes. To date, the sequences of at least 11 nuclear genomes have been completed, with many more in progress. Most are microbial, with exceptions such as the eukaryotic genome Saccharomyces cerevisiae. Genomics, while built upon foundations laid in the era of classical genetics, has grown by leaps and bounds because of three significant technological advances: 1) high-throughput sequencing and automation technology, 2) sophisticated bioinformatics and sequence analysis tools, and 3) microarray or 'chip' technology for expression, resequencing, and polymorphism analysis. These technological advances have made it possible to generate massive amounts of nucleotide sequence data from a series of random, overlapping, and redundant clones and to assemble these data into contiguous sequences, with the final goal of elucidating complete gene structure at single nucleotide resolution. In the immediate future, linear genomics will be replaced by functional genomics and pathogens compared on an evolutionary scale.