Michael Deutsch, Manyuan Long. Gallus gallus , Rattus norvegicus , Arabidopsis thaliana , Zea mays , Schizosaccharomyces pombe , Aspergillus , Caenorhabditis elegans and Drosophila . We purged redundant genes to avoid the possible bias brought about by redundancy in the databases. On average, a eukaryotic gene contains 3.7 introns per kb protein coding region. The variable intron-exon structures of the 10 model organisms reveal two interesting statistical phenomena, which cast light on some previous speculations.
Genome size seems to be correlated with total intron length per gene.
For example, invertebrate introns are smaller than those of human genes, while yeast introns are shorter than invertebrate introns. However, this correlation is weak, suggesting that other factors besides genome size may also affect intron size. Introns smaller than 50 nt are significantly less frequent than longer introns, possibly resulting from a minimum intron size requirement for intron splicing.