Figure 1

Intron/exon numbers and AS frequency. A: Percentage of alternatively spliced genes in different eukaryote genomes vs. the average number of introns per gene. Discontinuous line is an estimated interval for intron density of the ancestor of animals and plants (from 3.5 [18] to 7.0 [15]). B: Frequency of AS versus intron numbers per gene for the 8 species showing relatively high values of AS. Abbreviations: Hsa (Homo sapiens), Mmu (Mus muscullus), Gga (Gallus gallus), Dre (Danio rerio), Cel (Caenorhabditis elegans), Dme (Drosophila melanogaster), Ath (Arabidopsis thaliana), Sce (Saccharomyces cerevisae), Spo (Schizosaccharomyces pombe), Ecu (Encephalitozoon cuniculi), Pfa (Plasmodium falciparum), Cne (Cryptococcus neoformans).