Typical figures: vertebrates

We'll use the example of vertebrates. On average, a vertebrate gene is around 30Kb long, out of which the coding region is only about 1-2Kb long. The average coding region consists of 6 exons, each about 150bp long. The promoter is about 6bp long and appears about 30bp upstream of the transcription start site (TSS). Huge deviations from the average are observed. For example, the gene called dystrophin is 2.4MB long. Blood coagulation-factor VIII has 26 exons whose size varies from 69bp to 3106bp. Intron number 22 produces 2 transcripts unrelated to this gene, one for each strand. Other typical figures are transcription rate of less than 50b/sec and splicing process taking several minutes. Figure shows typical length distribution of introns and exons in human genes.

  

Figure: Distribution of intron and exon lengths [].