Bioinformatics Application: Eukaryotic Gene Count and Evolution

  • Meena K. Sakharkar
  • Pandjassarame Kangueane


In this chapter, we describe the comparison of gene numbers in different eukaryotic genomes. Unlike prokaryotes, eukaryotic genes are often split into exons (coding sequence segments) and introns (non-coding sequence segments). However, the number of exons and introns vary in different genes across diverse genome species. It is found that the intron number varies from 0 to $>$100 in different eukaryotic genes. This results in SEG (Single exon genes) and MEG (multi exon genes). Thus, SEG have 0 intron and MEG have at least one intron. Consequently, we compared the SEG and MEG fraction across different eukaryotic genomes. The comparison helped to discuss the evolutionary selection of SEG and MEG fraction in eukaryotic genomes.


Genome Size Eukaryotic Genome Gene Density Genome SEGE Gene Count 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Benson, D.A., Karsch-Mizrachi, I., et al. (2000) GenBank. Nucleic Acids Res28(1), 15–8.PubMedCrossRefGoogle Scholar
  2. Brosius, J. (1999) Many G-protein-coupled receptors are encoded by retrogenes. Trends Genet15(8), 304–5.PubMedCrossRefGoogle Scholar
  3. Fink, G.R. (1987) Pseudogenes in yeast? Cell49(1), 5–6.PubMedCrossRefGoogle Scholar
  4. Harrison, P.M., Hegyi, H., et al. (2002) Molecular fossils in the human genome: identification and analysis of the pseudogenes in chromosomes 21 and 22. Genome Res12(2), 272–80.PubMedCrossRefGoogle Scholar
  5. Lander, E.S., Linton, L.M., et al. (2001) Initial sequencing and analysis of the human genome. Nature409(6822), 860–921.PubMedCrossRefGoogle Scholar
  6. Sakharkar, M., Long, M., et al. (2000) Exlnt: an Exon/Intron database. Nucleic Acids Res 28(1), 191–2.PubMedCrossRefGoogle Scholar
  7. Sakharkar, M.K. and Kangueane, P. (2004) Genome SEGE: a database for ’intronless’ genes in eukaryotic genomes. BMC Bioinformatics5, 67.PubMedCrossRefGoogle Scholar
  8. Sakharkar, M.K., Kangueane, P., et al. (2002) SEGE: A database on ’intron less/single exonic’ genes from eukaryotes. Bioinformatics18(9), 1266–7.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Meena K. Sakharkar
    • 1
  • Pandjassarame Kangueane
    • 2
  1. 1.Nanyang Technological UniversitySingapore
  2. 2.Biomedical InformaticsIndia

Personalised recommendations