Comparing Human, Chimp, and Mouse Genomes

The graphs below indicate the similarity between the human genome and those of the chimpanzee and the mouse as they are mapped to identical locations in the human genome. Since the chimpanzee genome is closer in evolutionary time to the human genome, the chimp chromosomes map very closely to human chromosomes. The mouse genome is more distant in evolutionary time from human, and thus its chromosomes do not map as closely as do the chimp chromosomes.

The white areas indicate areas of the human genome that either do not map well to the other genome, or are areas of centromeres and telomeres where the genome sequence is unknown. Chromosome numbering is purely arbitrary, based upon early microscopic estimates of chromosome length. The chimpanzee genome has 23 numbered chromosomes, the human genome has 22 numbered chromosomes (chimp chromosomes 2a and 2b map to human chromosome 2), the mouse genome has 19 numbered chromosomes. The X and Y sex chromosomes have unique names, as well as other unique characteristics.

Mouse genome mapped on the human genome

This image shows the 34% of the mouse genome that maps to identical sequence in the human genome. The matching locations are jumbled, indicating rearrangements of the two genomes since their last common ancestor, approximately 75 million years before present. (reference)

Chimpanzee genome mapped on the human genome

This image shows the 95% of the chimpanzee genome that maps to identical sequence in the human genome. The consistency of the color indication demonstrates the close identity between the two genomes since their last common ancestor, approximately 5 million years before present. (reference) The human chromosome 2 actually aligns to two separate chimp chromsomes, now called chr2a and chr2 and represented here by the same color. These chromosomes were formerly named chr12 and chr13 but have been renamed by the Chimp Sequencing Consortium to reflect the fact that they share a common origin with human chr2.

Data for these two figures were assembled from the Genome Browser at UC Santa Cruz by Hiram Clawson and Kate Rosenbloom. 09 June 2006