Genome Sizes

Table of Genome Sizes (haploid)

	Base pairs	Genes	Notes
φX174	5,386	11	virus of E. coli
Human mitochondrion	16,569	37
Epstein-Barr virus (EBV)	172,282	80	causes mononucleosis
Nanoarchaeum equitans	490,885	552	This parasitic member of the Archaea has the smallest genome of a true organism yet found.
nucleomorph of Guillardia theta	551,264	511	all that remains of the nuclear genome of a red alga (a eukaryote) engulfed long ago by another eukaryote
Mycoplasma genitalium	580,073	485	two of the smallest true organisms
Mycoplasma pneumoniae	816,394	680
Chlamydia trachomatis	1,042,519	936	this bacterium causes the most common sexually-transmitted disease (STD) in the U.S.
Rickettsia prowazekii	1,111,523	834	bacterium that causes epidemic typhus
Treponema pallidum	1,138,011	1,039	bacterium that causes syphilis
Mimivirus	1,181,404	1,262	A virus (of an amoeba) with a genome larger than the six cellular organisms above
Pelagibacter ubique	1,308,759	1,354	smallest genome yet found in a free-living organism (marine α-proteobacterium)
Borrelia burgdorferi	1.44 x 106	1,738	bacterium that causes Lyme disease [Note]
Campylobacter jejuni	1,641,481	1,708	frequent cause of food poisoning
Helicobacter pylori	1,667,867	1,589	chief cause of stomach ulcers (not stress and diet)
Thermoplasma acidophilum	1,564,905	1,509	These unicellular microbes look like typical bacteria but their genes are so different from those of either bacteria or eukaryotes that they are classified in a third kingdom: Archaea.
Methanococcus jannaschii	1,664,970	1,783
Aeropyrum pernix	1,669,695	1,885
Methanobacterium thermoautotrophicum	1,751,377	2,008
Haemophilus influenzae	1,830,138	1,738	bacterium that causes middle ear infections
Streptococcus pneumoniae	2,160,837	2,236	the pneumococcus
Neisseria meningitidis	2,184,406	2,185	Group A; causes occasional epidemics of meningitis in less developed countries.
Neisseria meningitidis	2,272,351	2,221	Group B; the most frequent cause of meningitis in the U.S.
Encephalitozoon cuniculi	2,507,519	1,997	(plus 69 RNA genes); a parasitic eukaryote.
Propionibacterium acnes	2,560,265	2,333	causes acne
Listeria monocytogenes	2,944,528	2,926	2,853 of these encode proteins; the rest RNAs
Deinococcus radiodurans	3,284,156	3,187	on 2 chromosomes and 2 plasmids; bacterium noted for its resistance to radiation damage
Synechocystis	3,573,470	4,003	a marine cyanobacterium ("blue-green alga")
Vibrio cholerae	4,033,460	3,890	in 2 chromosomes; causes cholera
Mycobacterium tuberculosis	4,411,532	3,959	causes tuberculosis
Mycobacterium leprae	3,268,203	1,604	causes leprosy
Bacillus subtilis	4,214,814	4,779	another bacterium
E. coli K-12	4,639,221	4,377	4,290 of these genes encode proteins; the rest RNAs
E. coli O157:H7	5.44 x 106	5,416	strain that is pathogenic for humans; has 1,346 genes not found in E. coli K-12
Agrobacterium tumefaciens	4,674,062	5,419	Useful vector for making transgenic plants; shares many genes with Sinorhizobium meliloti
Salmonella enterica var Typhi	4,809,037	4,395	+ 2 plasmids with 372 active genes; causes typhoid fever
Salmonella enterica var Typhimurium	4,857,432	4,450	+ 1 plasmid with 102 active genes
Yersinia pestis	4,826,100	4,052	on 1 chromosome + 3 plasmids; causes plague
Schizosaccharomyces pombe	12,462,637	4,929	Fission yeast. A eukaryote with fewer genes than the four bacteria below.
Ralstonia solanacearum	5,810,922	5,129	soil bacterium pathogenic for many plants; 1681 of its genes on a huge plasmid
Pseudomonas aeruginosa	6.3 x 106	5,570	Increasingly common cause of opportunistic infections in humans.
Streptomyces coelicolor	6,667,507	7,842	An actinomycete whose relatives provide us with many antibiotics
Sinorhizobium meliloti	6,691,694	6,204	The rhizobial symbiont of alfalfa. Genome consists of one chromosome and 2 large plasmids.
Saccharomyces cerevisiae	12,495,682	5,770	Budding yeast. A eukaryote.
Cyanidioschyzon merolae	16,520,305	5,331	A unicellular red alga.
Plasmodium falciparum	22,853,764	5,268	Plus 53 RNA genes. Causes the most dangerous form of malaria.
Thalassiosira pseudonana	34.5 x 106	11,242	A diatom. Plus 144 chloroplast and 40 mitochondrial genes encoding proteins
Neurospora crassa	38,639,769	10,082	Plus 498 RNA genes.
Naegleria gruberi	41 x 106	15,727	This free-living unicellular organism lives as both an amoeboid and a flagellated form. 4,133 of its genes are also found in other eukaryotes suggesting that they were present in the common ancestor of all eukaryotes. The great variety of functions encoded by these genes also suggests that the common ancestor of all eukaryotes was itself as complex as many of the present-day unicellular members.
Caenorhabditis elegans	100,258,171	21,733	The first metazoan to be sequenced.
Arabidopsis thaliana	115,409,949	~28,000	a flowering plant (angiosperm) See note.
Drosophila melanogaster	122,653,977	~17,000	the "fruit fly"
Anopheles gambiae	278,244,063	13,683	Mosquito vector of malaria.
Tetraodon nigroviridis (a pufferfish)	3.42 x 108	27,918	Although Tetraodon seems to have more protein-encoding genes than we do, it has much less "junk" DNA so its total genome is about a tenth the size of ours.
Rice	3.9 x 108	28,236
Sea urchin	8.14 x 108	~23,300
Zebrafish	1.2 x 109	15,761
Dogs	2.4 x 109	19,300
Humans	3.3 x 109	~21,000	[Link to more details.]
Mouse	3.4 x 109	~23,000
Amphibians	109–1011	?
Psilotum nudum	2.5 x 1011	?	Note