The genome of an organism is the whole of its hereditary information encoded in its DNA (or, for some viruses, RNA). This includes both the genes and the non-coding sequences of the DNA. The term was coined in 1920.
Winkler's definition, in translation, runs:
- "I propose the expression genome for the haploid chromosome set, which, together with the pertinent protoplasm, specifies the material foundations of the species ...." p165
However, no single haploid chromosome set defines even the DNA of a species. Because of the huge variety of alleles carried by a population, every individual is genetically different. Even a diploid individual carries genetic variety. For that reason Dobzhansky preferred "set of chromosomes", and the definition now must be broader than Winklers' definition. The genome of a haploid chromosome set is merely a sample of the total genetic variety of a species.
The term 'genome' can be applied specifically to mean the complete set of nuclear DNA (the 'nuclear genome') but can also be used of organelles that contain their own DNA, as with the mitochondrial genome or the chloroplast genome.
|Organism||Genome size (base pairs)||Note|
|Virus, Bacteriophage MS2||3569||First sequenced RNA-genome|
|Virus, Phage Φ-X174||5386||First sequenced DNA-genome|
|Virus, Phage λ||5×104|
|Bacterium, Candidatus Carsonella ruddii||1.6×105||Smallest non-viral genome, Feb 2007|
|Bacterium, Escherichia coli||4×106||Best-researched bacterium.|
|Bacterium, Solibactoer usitatus||1×107||Largest known bacterial genome|
|Protist, Amoeba dubia||6.7×1011||Largest known genome, but disputed.|
|Plant, Arabidopsis thaliana||1.57×108||First plant genome sequenced, Dec 2000.|
|Plant, Genlisea margaretae||6.34×107||Smallest recorded flowering plant genome, 2006.|
|Plant, Fritillaria assyrica||1.3×1011|
|Plant, Populus trichocarpa||4.8×108||First tree genome, Sept 2006|
|Yeast, Saccharomyces cerevisiae||2×107|
|Fungus, Aspergillus nidulans||3×107|
|Nematode, Caenorhabditis elegans||9.8×107||First multicellular animal genome, December 1998.|
|Insect, Drosophila melanogaster aka fruit fly||1.3×108|
|Insect, Bombyx mori aka silk moth||5.30×108|
|Insect, Apis mellifera aka honey bee||1.77×109|
|Fish, Tetraodon nigroviridis, type of Puffer fish||3.85×108||Smallest vertebrate genome known|
|Mammal, Homo sapiens||3×109|
|Fish, Protopterus aethiopicus aka marbled lungfish||1.3×1011||Largest vertebrate genome known|
Note: The DNA from a single human cell has a length of ~1.8 m (but at a width of ~2.4 nanometers).
- by Hans Winkler, Professor of Botany at the University of Hamburg, Germany, as a combination of the words gene and chromosome.Joshua Lederberg and Alexa T. McCray (2001). "'Ome Sweet 'Omics -- A genealogical treasury of words". The Scientist 15 (7).
- An online copy is available here: 
- Winkler H. 1920. Verbreitung und Ursache der Parthenogenesis im Pflanzen- und Tierreiche. Fischer, Jena.
- Dobzhansky T. 1937. Genetics and the origin of species. Columbia N.Y.
- Fiers W. et al (1976). "Complete nucleotide-sequence of bacteriophage MS2-RNA - primary and secondary structure of replicase gene". Nature 260: 500-507.
- Fiers W. et al (1978). "Complete nucleotide sequence of SV40 DNA". Nature 273 (5658): 113-120.
- Sanger F. et al (1977). "Nucleotide sequence of bacteriophage phi X174 DNA". Nature 265 (5596): 687-695.
- Frederick R. Blattner et al (1997). "The complete genome sequence of Escherichia coli K-12". Science 277 (5331): 1453–1462. doi:10.1126/science.277.5331.1453. PMID 9278503. http://www.sciencemag.org/cgi/content/abstract/277/5331/1453.
- ScienceShot: biggest genome ever, comments: "The measurement for Amoeba dubia and other protozoa, which were reported to have very large genomes, were made in the 1960s using a rough biochemical approach which is now considered to be an unreliable method for accurate genome size determinations".
- Greilhuber J. et al. 2006. Smallest angiosperm genomes found in Lentibulariaceae, with chromosomes of bacterial size. Plant Biology. 8: 770-777.
- The C. elegans sequencing consortium (1998). "Genome sequence of the nematode C. elegans: a platform for investigating biology". Science 282: 2012–2018. http://www.sciencemag.org/cgi/content/abstract/282/5396/2012?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&searchid=1&FIRSTINDEX=0&volume=282&firstpage=2012&resourcetype=HWCIT.
- Benfey P. and Protopapas A.D. 2004. Essentials of genomics. Prentice Hall.
- Brown T.A. 2002. Genomes 2. Bios Scientific Publishers.
- Gibson G. and Muse S.V. 2004. A primer of genome science. 2nd ed. Sinauer Assoc.
- Gregory T.R. (ed) 2005. The evolution of the genome. Elsevier.
- Reece R.J. 2004. Analysis of genes and genomes. Wiley.
- Saccone C. and Pesole G. 2003. Handbook of comparative genomics. Wiley.
- Werner E. 2003. In silico multicellular systems biology and minimal genomes. Drug Discov Today. 8(24):1121-7. PubMed
- Witzany G. 2007. Natural genome editing competences of viruses. Acta Biotheoretica. 
- DNA Interactive: the history of DNA science
- DNA from the beginning
- All about the human genome project from Genome.gov
- Animal genome size database
- Plant genome size database
- GOLD:Genomes OnLine Database
- The Genome News Network
- NCBI Entrez Genome Project database
- NCBI Genome Primer
- BBC News - Final genome 'chapter' published
- Software that maps an Artificial Genome sequence to a Network and to a Lineage tree
- IMG The integrated microbial genomes system, for genome analysis by the DOE-JGI.