Affiliations: Center for Bioinformatics and Computational Biology,
The University of Iowa, Iowa City, IA – 52242, USA | Coordinated Laboratory for Computational Genomics, The
University of Iowa, Iowa City, IA – 52242, USA | Department of Biomedical Engineering, The University
of Iowa, Iowa City, IA – 52242, USA | Department of Biochemistry, The University of Iowa,
Iowa City, IA – 52242, USA | Department of Internal Medicine, The University of
Iowa, Iowa City, IA – 52242, USA] | Department of Biological Sciences, The University of
Iowa, Iowa City, IA – 52242, USA | Department of Electrical and Computer Engineering, The
University of Iowa, Iowa City, IA – 52242, USA | Department of Ophthalmology, The University of Iowa,
Iowa City, IA – 52242, USA
Abstract: Most transcriptional regulatory elements are located in non-coding
DNA. In particular, some first introns play a vital role in transcriptional
control and splicing. The length and GC-content of first exons and introns in
complex organisms suggests that these structural units are likely to be
important functional elements in large genomes. Hence, in this paper we perform
a systematic comparison of exon-intron structure and GC content on all known
genes in the human genome. Our in-silico analysis found that the GC content of
introns and exons varies significantly depending on their length. On average,
the first intron of a gene is significantly longer than other introns in the
same gene. Our results also show that first introns and exons are more GC rich
than last and internal. This study provides insight into the structure of
eukaryotic genes. These results confirm and expand the previously identified
regulatory potential of first exons and introns.
