Fish genomics: A mini-review on some structural and evolutionary issues

This brief outline of fish genomics will concentrate on some general genome features, as investigated in our laboratory using a “compositional approach”. In the first phase (1976–1991) the main experimental tool was density gradient ultracentrifugation, both analytical and preparative. This led to a number of conclusions that were very relevant as far as the genome structure and evolution of vertebrates are concerned. After an intermezzo (1991–2001) in which investigations started to take advantage of the short but increasing supply of nucleotide sequences, a second phase (2001–present) developed on the basis of completely sequenced fish genomes. This led us to the current level of knowledge and to further insights.