The Institute for Genomic Research, 9712 Medical Center Drive, Rockville, Maryland 20850, USA. scottp@tigr.org
What is the minimum number of genes or functions necessary to support cellular life? The concept of a 'minimal genome' has become popular, but is it a useful concept, and if so, what might a minimal genome encode? We argue that the concept may be useful, even though the goal of defining a general minimal genome may never be attained.