Regularities Related to Introns Lengths Distribution

The regularities in distribution of intron lengths for genomes of 17 species belonging to different taxa (insects, fish, amphibians, reptiles, birds, mammals) were studied. It is shown that the fraction of introns with phase 1 increases with the length of the intron. It was also shown that short and long introns tend to form series. For example, the proportion of short (long) introns that follow short (long) introns is considerably higher than the proportion of short (long) introns in a genome. These patterns are shown for all considered genomes.