ND2NADH dehydrogenase subunit 2

ND2 is a membrane subunit of Complex I (NADH:ubiquinone oxidoreductase). It is one of three subunits, with ND4 and ND5, that resemble bacterial cation/proton antiporters and take part in pumping protons across the inner membrane.

Median length

1,042 bp

Range 843–1,311 bp

Median GC content

43.1%

Middle half 38.0%–47.1%

Species with data

2,334

Of 2,335 genomes

Strand

+ strand

In 2,329 of 2,334 genomes

ND2 in the mitochondrial genome of

Human Homo sapiens

RefSeq NC_012920.1 · 16,569 bp · GC 44.4% · ND2 at 4,470–5,511, 1,042 bp, + strand · Species page

ND2Protein-coding gene

NADH dehydrogenase subunit 2

Position: 4,470–5,511
Length: 1,042 bp
Strand: +
GC content: 43.0%

ND2 across all species

Protein-coding13
rRNA2
tRNA22
D-loop1

Outer ring: + strand, arrows run clockwise. Inner ring: − strand.
Middle ring: GC% of each gene against the whole genome (44.4%, dashed): out is GC-richer, in is AT-richer (full height = 6 points).

GC content of ND2 across classes

2,334 species, reference strand as deposited in RefSeq

Mammalsn 627 · median 37.0% · middle half 35.4%–39.0%

Birdsn 423 · median 44.5% · middle half 43.0%–46.2%

Ray-finned fishesn 895 · median 47.6% · middle half 45.4%–49.2%

Reptilesn 136 · median 39.7% · middle half 38.3%–42.1%

Sharks and raysn 87 · median 39.8% · middle half 38.1%–41.8%

Amphibiansn 47 · median 37.2% · middle half 32.4%–40.7%

Other classesn 119 · median 33.6% · middle half 30.3%–36.4%

Each dot is one species. Boxes span the middle half of the species (25th to 75th percentile) and the thick line marks the median; thin lines run from the lowest to the highest value.

Compare ND2 across taxa

GC content of ND2 against lifespan

One point per species, coloured by class

Hover or tap a point to see the species; select it again to open its page. Legend buttons spotlight a class.

Open in the plot

Correlation with maximum lifespan

All species, each class and each order with enough species

MeasureGC%LengthGC skewAT skew

GC content of ND2 against log₁₀ maximum lifespan in 32 groups; 4 pass q < 0.05. Plot it in the explorer

Correlation of GC content of ND2 with log10 maximum lifespan by group
Group	n	Pearson r	Spearman ρ	q	PIC r	Partial r
All speciesevery class	2,201	−0.02	−0.13	0.29	−0.00	+0.19
Ray-finned fishesclass Actinopterygii	827	−0.01	−0.07	0.75	−0.10	−0.09
Mammalsclass Mammalia	615	+0.36	+0.33	< 0.001 (significant)	+0.12	+0.33
Birdsclass Aves	405	−0.04	−0.06	0.54	+0.05	−0.02
Reptilesclass Reptilia	126	+0.08	+0.09	0.59	+0.01	+0.05
Sharks and raysclass Chondrichthyes	82	+0.08	+0.02	1.00	+0.37	−0.06
Amphibiansclass Amphibia	44	+0.13	+0.13	1.00	+0.38	–
Bivalvesclass Bivalvia	35	−0.31	−0.29	0.58	−0.05	–
Perciformesorder	208	−0.00	−0.22	0.98	+0.08	−0.23
Passeriformesorder	140	−0.07	−0.08	0.59	+0.06	−0.07
Artiodactylaorder	134	+0.38	+0.22	< 0.001 (significant)	+0.02	+0.21
Cypriniformesorder	127	+0.04	−0.03	0.75	+0.07	+0.46
Carnivoraorder	123	+0.28	+0.27	0.009 (significant)	+0.26	+0.30
Primatesorder	112	+0.42	+0.35	< 0.001 (significant)	+0.08	+0.12
Rodentiaorder	87	+0.11	+0.08	0.46	+0.12	+0.05
Squamataorder	60	+0.24	+0.25	0.43	+0.07	+0.37
Charadriiformesorder	51	+0.09	+0.11	0.76	−0.06	+0.09
Testudinesorder	49	−0.06	−0.13	0.94	−0.00	−0.17
Psittaciformesorder	44	−0.23	−0.16	0.31	−0.26	−0.01
Chiropteraorder	43	+0.07	+0.02	0.90	+0.34	+0.03
Clupeiformesorder	38	+0.03	+0.05	0.98	+0.29	–
Pleuronectiformesorder	35	+0.34	+0.17	0.19	+0.13	+0.54
Salmoniformesorder	35	+0.28	+0.20	0.41	−0.02	+0.39
Carcharhiniformesorder	31	+0.03	+0.01	0.95	−0.18	−0.25
Cetaceaorder	28	+0.10	+0.30	0.80	+0.17	−0.12
Anseriformesorder	25	−0.20	−0.18	0.66	+0.23	−0.07
Caudataorder	25	+0.23	+0.09	0.79	+0.42	–
Siluriformesorder	24	+0.42	+0.42	0.14	+0.51	–
Centrarchiformesorder	22	+0.41	+0.13	0.24	+0.19	–
Acipenseriformesorder	21	+0.28	+0.27	0.47	+0.29	−0.04
Rajiformesorder	21	−0.17	−0.11	0.90	+0.51	–
Scombriformesorder	21	+0.30	+0.25	0.73	+0.31	–

Length of ND2 against log₁₀ maximum lifespan in 32 groups; 7 pass q < 0.05. Plot it in the explorer

Correlation of Length of ND2 with log10 maximum lifespan by group
Group	n	Pearson r	Spearman ρ	q	PIC r	Partial r
All speciesevery class	2,201	+0.14	−0.11	< 0.001 (significant)	−0.00	−0.06
Ray-finned fishesclass Actinopterygii	827	+0.01	+0.03	0.82	−0.06	−0.10
Mammalsclass Mammalia	615	+0.34	+0.16	< 0.001 (significant)	+0.10	+0.15
Birdsclass Aves	405	−0.05	−0.14	0.39	−0.04	−0.01
Reptilesclass Reptilia	126	+0.46	+0.47	< 0.001 (significant)	+0.08	+0.25
Sharks and raysclass Chondrichthyes	82	−0.04	−0.12	1.00	−0.04	+0.12
Amphibiansclass Amphibia	44	−0.03	−0.00	1.00	+0.11	–
Bivalvesclass Bivalvia	35	+0.28	+0.29	0.61	+0.09	–
Perciformesorder	208	−0.03	+0.01	0.80	+0.02	−0.20
Passeriformesorder	140	+0.26	+0.34	0.026 (significant)	+0.03	+0.08
Artiodactylaorder	134	+0.15	+0.08	0.17	+0.15	+0.20
Cypriniformesorder	127	+0.12	+0.12	0.36	+0.05	−0.26
Carnivoraorder	123	+0.29	+0.31	0.007 (significant)	+0.19	+0.02
Primatesorder	112	+0.25	+0.25	0.014 (significant)	+0.03	+0.01
Rodentiaorder	87	+0.77	+0.78	< 0.001 (significant)	+0.10	+0.65
Squamataorder	60	−0.05	−0.08	0.90	−0.00	+0.15
Charadriiformesorder	51	+0.02	+0.01	0.94	+0.08	−0.12
Testudinesorder	49	−0.03	−0.05	0.95	+0.12	−0.13
Psittaciformesorder	44	+0.07	+0.05	0.81	+0.08	+0.16
Chiropteraorder	43	+0.07	+0.04	0.90	+0.15	+0.06
Clupeiformesorder	38	−0.08	−0.08	0.96	−0.86	–
Pleuronectiformesorder	35	+0.10	+0.12	0.78	+0.14	−0.06
Salmoniformesorder	35	+0.01	−0.01	0.99	−0.01	−0.05
Carcharhiniformesorder	31	−0.33	−0.32	0.42	−0.28	−0.10
Cetaceaorder	28	+0.13	+0.23	0.73	−0.14	−0.47
Anseriformesorder	25	+0.31	+0.29	0.43	−0.04	+0.22
Caudataorder	25	−0.15	−0.29	0.84	+0.23	–
Siluriformesorder	24	−0.05	−0.15	0.89	−0.08	–
Centrarchiformesorder	22	+0.33	+0.52	0.35	+0.40	–
Acipenseriformesorder	21	+0.21	+0.20	0.63	+0.11	−0.13
Rajiformesorder	21	−0.07	−0.11	0.96	+0.08	–
Scombriformesorder	21	−0.16	−0.14	0.89	−0.26	–

GC skew of ND2 against log₁₀ maximum lifespan in 32 groups; 6 pass q < 0.05. Plot it in the explorer

Correlation of GC skew of ND2 with log10 maximum lifespan by group
Group	n	Pearson r	Spearman ρ	q	PIC r	Partial r
All speciesevery class	2,201	−0.25	−0.32	< 0.001 (significant)	−0.10	−0.09
Ray-finned fishesclass Actinopterygii	827	−0.12	−0.16	0.001 (significant)	−0.15	+0.11
Mammalsclass Mammalia	615	−0.16	−0.21	< 0.001 (significant)	−0.02	−0.16
Birdsclass Aves	405	−0.13	−0.13	0.027 (significant)	+0.04	−0.08
Reptilesclass Reptilia	126	+0.08	+0.08	0.64	−0.08	+0.08
Sharks and raysclass Chondrichthyes	82	−0.10	−0.07	1.00	+0.59	+0.03
Amphibiansclass Amphibia	44	−0.08	−0.10	1.00	+0.26	–
Bivalvesclass Bivalvia	35	+0.14	+0.16	0.84	+0.07	–
Perciformesorder	208	−0.04	−0.02	0.74	−0.05	+0.39
Passeriformesorder	140	+0.22	+0.22	0.048 (significant)	+0.16	+0.01
Artiodactylaorder	134	−0.05	+0.09	0.65	+0.00	+0.00
Cypriniformesorder	127	−0.05	−0.03	0.71	+0.09	+0.49
Carnivoraorder	123	+0.04	−0.00	0.83	−0.03	−0.09
Primatesorder	112	−0.19	−0.16	0.070	+0.02	+0.08
Rodentiaorder	87	+0.24	+0.27	0.080	−0.04	+0.07
Squamataorder	60	−0.08	−0.12	0.88	−0.03	+0.14
Charadriiformesorder	51	+0.17	+0.15	0.56	+0.09	+0.11
Testudinesorder	49	−0.45	−0.50	0.23	−0.14	−0.38
Psittaciformesorder	44	+0.25	+0.14	0.27	+0.00	+0.01
Chiropteraorder	43	+0.13	+0.13	0.90	−0.12	+0.13
Clupeiformesorder	38	−0.17	−0.16	0.77	−0.20	–
Pleuronectiformesorder	35	−0.04	−0.11	0.90	+0.26	+0.28
Salmoniformesorder	35	+0.05	+0.07	0.95	−0.50	+0.53
Carcharhiniformesorder	31	−0.29	−0.20	0.45	−0.16	+0.22
Cetaceaorder	28	+0.17	+0.16	0.63	−0.08	−0.13
Anseriformesorder	25	−0.14	−0.09	0.75	+0.01	−0.04
Caudataorder	25	−0.14	−0.10	0.84	+0.24	–
Siluriformesorder	24	−0.39	−0.40	0.19	−0.34	–
Centrarchiformesorder	22	−0.27	−0.08	0.45	−0.06	–
Acipenseriformesorder	21	−0.66	−0.29	0.013 (significant)	−0.71	−0.44
Rajiformesorder	21	+0.18	+0.16	0.90	+0.77	–
Scombriformesorder	21	−0.31	−0.22	0.73	−0.26	–

AT skew of ND2 against log₁₀ maximum lifespan in 32 groups; 8 pass q < 0.05. Plot it in the explorer

Correlation of AT skew of ND2 with log10 maximum lifespan by group
Group	n	Pearson r	Spearman ρ	q	PIC r	Partial r
All speciesevery class	2,201	+0.36	+0.37	< 0.001 (significant)	+0.12	+0.15
Ray-finned fishesclass Actinopterygii	827	+0.25	+0.20	< 0.001 (significant)	+0.17	+0.10
Mammalsclass Mammalia	615	+0.28	+0.19	< 0.001 (significant)	+0.11	+0.18
Birdsclass Aves	405	+0.21	+0.26	< 0.001 (significant)	+0.04	+0.13
Reptilesclass Reptilia	126	−0.25	−0.25	0.032 (significant)	+0.07	−0.16
Sharks and raysclass Chondrichthyes	82	+0.07	+0.06	1.00	−0.35	+0.01
Amphibiansclass Amphibia	44	−0.05	−0.06	1.00	−0.12	–
Bivalvesclass Bivalvia	35	+0.15	+0.32	0.83	+0.18	–
Perciformesorder	208	+0.15	+0.19	0.067	−0.02	−0.12
Passeriformesorder	140	−0.25	−0.25	0.027 (significant)	−0.02	+0.02
Artiodactylaorder	134	+0.04	−0.06	0.70	+0.04	−0.02
Cypriniformesorder	127	+0.25	+0.24	0.030 (significant)	−0.04	−0.39
Carnivoraorder	123	+0.06	+0.12	0.62	+0.23	+0.27
Primatesorder	112	−0.01	+0.04	0.90	−0.07	−0.08
Rodentiaorder	87	−0.09	−0.10	0.54	+0.19	+0.04
Squamataorder	60	+0.04	+0.03	0.92	+0.11	−0.15
Charadriiformesorder	51	−0.05	−0.02	0.88	−0.14	−0.08
Testudinesorder	49	+0.18	+0.14	0.62	+0.06	+0.15
Psittaciformesorder	44	−0.23	−0.16	0.32	−0.11	+0.06
Chiropteraorder	43	+0.10	+0.08	0.90	+0.16	+0.08
Clupeiformesorder	38	+0.16	+0.18	0.80	+0.29	–
Pleuronectiformesorder	35	−0.33	−0.28	0.19	−0.20	−0.46
Salmoniformesorder	35	−0.15	−0.15	0.74	+0.36	−0.32
Carcharhiniformesorder	31	+0.23	+0.17	0.60	+0.05	−0.22
Cetaceaorder	28	+0.28	+0.36	0.40	+0.16	−0.40
Anseriformesorder	25	−0.11	−0.02	0.80	+0.04	−0.05
Caudataorder	25	−0.14	−0.15	0.84	−0.22	–
Siluriformesorder	24	+0.51	+0.57	0.074	+0.47	–
Centrarchiformesorder	22	−0.05	−0.02	0.90	+0.00	–
Acipenseriformesorder	21	+0.67	+0.26	0.013 (significant)	+0.70	+0.47
Rajiformesorder	21	−0.35	−0.53	0.89	−0.74	–
Scombriformesorder	21	+0.67	+0.68	0.095	+0.48	–

n: species with both values in the group.
Pearson r, Spearman ρ: strength of the link with log₁₀ lifespan, from −1 to +1; Spearman uses ranks, so a few extreme species weigh less.
q: p-value adjusted for testing every mtDNA feature in the same group (Benjamini–Hochberg); rows with q < 0.05 are highlighted.
PIC r: the same test on phylogenetically independent contrasts, which removes similarity that comes from shared ancestry.
Partial r: the link with lifespan after accounting for body mass (log₁₀ adult weight), since bigger animals tend to live longer.

ND2 aligned across species

2,315 species, 734 columns; 348 columns have a residue in at least half of the species, and in 90 of those one residue is in 90% or more. MAFFT v7.526, FFT-NS-2 (progressive)

Loading the alignment of ND2: 2,315 species, 734 columns.

All alignment files

Codon usage of ND2

Vertebrates, vertebrate mitochondrial code

Most used codons

Share of all 774,308 sense codons of ND2 in 2,231 vertebrates

CUALeu7.2%
AUAMet5.4%
ACAThr5.0%
ACCThr4.8%
AUCIle4.4%
CUCLeu4.1%
AUUIle4.0%
GCCAla3.9%

Preferred codon for each amino acid

Most used synonymous codon and its RSCU, pooled by class; darker cells show a stronger preference

Preferred codon and RSCU for each amino acid in ND2, by class
Amino acid	All vertebratesn 2,231	Mammalsn 627	Birdsn 423	Ray-finned fishesn 895	Reptilesn 136	Sharks and raysn 87	Amphibiansn 47
PheF · 2 codons	UUC1.16	UUC1.14	UUC1.59	UUU1.02	UUC1.39	UUU1.00	UUU1.38
LeuL · 6 codons	CUA2.26	CUA2.94	CUA2.70	CUA1.69	CUA2.91	CUA1.87	UUA1.83
IleI · 2 codons	AUC1.04	AUC1.06	AUC1.40	AUU1.15	AUC1.11	AUU1.07	AUU1.44
MetM · 2 codons	AUA1.65	AUA1.82	AUA1.59	AUA1.36	AUA1.79	AUA1.74	AUA1.74
ValV · 4 codons	GUA1.63	GUA1.88	GUA1.68	GUA1.40	GUA1.87	GUA1.99	GUA1.74
SerS · 6 codons	UCA2.16	UCA2.69	UCA2.17	UCC1.97	UCA2.19	UCA2.57	UCA2.51
ProP · 4 codons	CCA1.61	CCA1.86	CCA1.82	CCC1.81	CCA2.49	CCA1.92	CCA2.24
ThrT · 4 codons	ACA1.63	ACA1.98	ACC1.65	ACC1.76	ACA1.93	ACA1.73	ACA1.99
AlaA · 4 codons	GCC1.84	GCC1.71	GCC1.76	GCC1.91	GCC1.90	GCC1.86	GCC1.68
TyrY · 2 codons	UAC1.27	UAC1.17	UAC1.61	UAC1.24	UAC1.38	UAU1.00	UAU1.19
HisH · 2 codons	CAC1.55	CAC1.50	CAC1.56	CAC1.60	CAC1.51	CAC1.26	CAC1.37
GlnQ · 2 codons	CAA1.73	CAA1.88	CAA1.70	CAA1.64	CAA1.84	CAA1.88	CAA1.85
AsnN · 2 codons	AAC1.35	AAC1.38	AAC1.60	AAC1.22	AAC1.47	AAC1.28	AAU1.01
LysK · 2 codons	AAA1.77	AAA1.88	AAA1.79	AAA1.61	AAA1.87	AAA1.92	AAA1.88
AspD · 2 codons	GAC1.42	GAC1.38	GAC1.40	GAC1.47	GAC1.37	GAC1.45	GAC1.17
GluE · 2 codons	GAA1.73	GAA1.86	GAA1.74	GAA1.59	GAA1.80	GAA1.93	GAA1.79
CysC · 2 codons	UGC1.29	UGC1.31	UGC1.55	UGC1.20	UGC1.26	UGU1.33	UGC1.08
TrpW · 2 codons	UGA1.76	UGA1.90	UGA1.75	UGA1.64	UGA1.85	UGA1.91	UGA1.82
ArgR · 4 codons	CGA2.38	CGA2.94	CGA2.34	CGA1.98	CGA3.07	CGA2.24	CGA2.82
GlyG · 4 codons	GGA1.72	GGA2.16	GGA1.69	GGC1.46	GGA2.13	GGA1.87	GGA1.94

RSCU (relative synonymous codon usage) compares a codon with even use of all codons for its amino acid: 1 means no preference, and the maximum equals the number of synonymous codons. Counts are summed over vertebrate species and read with the vertebrate mitochondrial code (NCBI table 2); other animals use different codes and are left out.