Intron and exon length variation in <Emphasis Type="Italic">Arabidopsis</Emphasis>, rice,nematode, and human

As determined by computer sequence analysis, the average exon length in Arabidopsis thaliana, Oryza sativa, Caenorhabditis elegans, and Homo sapiens genes decreases with an increasing number of introns. In A. thaliana and O. sativa, variations in intron and exon lengths with an increasing number of introns are highly correlated. Linear correlation is observed between the total exon length and the number of introns, while the gene length increases in proportion to the number of introns. In human, the average intron and gene lengths depended on the gene density in DNA.