Send to

Choose Destination
Trends Genet. 2001 Aug;17(8):425-8.

On the total number of genes and their length distribution in complete microbial genomes.

Author information

Center for Biological Sequence Analysis, BioCentrum-DTU, The Technical University of Denmark, Building 208, DK-2800 Lyngby, Denmark.


In sequenced microbial genomes, some of the annotated genes are actually not protein-coding genes, but rather open reading frames that occur by chance. Therefore, the number of annotated genes is higher than the actual number of genes for most of these microbes. Comparison of the length distribution of the annotated genes with the length distribution of those matching a known protein reveals that too many short genes are annotated in many genomes. Here we estimate the true number of protein-coding genes for sequenced genomes. Although it is often claimed that Escherichia coli has about 4300 genes, we show that it probably has only approximately 3800 genes, and that a similar discrepancy exists for almost all published genomes.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center