Analysis of genomic patchiness of Haemophilus influenzae and Saccharomyces cerevisiae chromosomes

We have analysed some aspects of the primary structure of the chromosome of the prokaryote Haemophilus influenzae and of the eukaryote Saccharomyces cerevisiae that share the same G + C content. In particular, we have investigated genomic patchiness over the gene size level (10 Kb) and that patchiness due to long homogeneous tracts. Long polypurine and polypyrmidine tracts that are largely over-represented in S. cerevisiae chromosomes and under-represented in H. influenzae, are responsible for a large fraction of long correlation signals. Generating mechanisms of long homogeneous tracts are DNA replication slippage and duplication events that appear to be linked processes driving chromosome primary structure evolution. (C) 1996 Academic Press Limited