Table 1. Mutation spectra inferred from single nucleotide polymorphisms in human and mouse populations.^a.

No	N X N	N Y N	X	Y	Total number of SNPs	Fraction	N′X′N′	N′Y′N′	X′	Y′	Total number of SNPs	Fraction	Difference (%)
	Human SNPs
1	AGC	ATC	G	T	312,720	0.37	GAT	GCT	A	C	310,244	0.36	0.79
2	CAA	CTA	A	T	227,826	0.27	TAG	TTG	A	T	229,630	0.27	0.79
3	ACT	ATT	C	T	2367,625	2.77	AAT	AGT	A	G	2375,298	2.78	0.32
4	AAA	AGA	A	G	1729,945	2.02	TCT	TTT	C	T	1734,336	2.03	0.25
5	TAT	TTT	A	T	544,308	0.64	AAA	ATA	A	T	543,030	0.64	0.23
6	GAG	GTG	A	T	287,742	0.34	CAC	CTC	A	T	288,408	0.34	0.23
7	GCG	GTG	C	T	2008,008	2.35	CAC	CGC	A	G	2008,195	2.35	0.01
8	TAA	TGA	A	G	1448,254	1.69	TCA	TTA	C	T	1448,196	1.69	0.00
	Mouse SNPs
1	CGA	CTA	G	T	38,698	0.26	TAG	TCG	A	C	38,235	0.25	1.20
2	AAG	ATG	A	T	88,927	0.59	CAT	CTT	A	T	89,884	0.59	1.06
3	GAG	GCG	A	C	50,929	0.34	CGC	CTC	G	T	50,724	0.33	0.40
4	CAG	CCG	A	C	56,636	0.37	CGG	CTG	G	T	56,410	0.37	0.40
5	GAT	GTT	A	T	63,675	0.42	AAC	ATC	A	T	63,432	0.42	0.38
6	ACT	ATT	C	T	384,248	2.53	AAT	AGT	A	G	384,516	2.54	0.07
7	TAT	TTT	A	T	103,335	0.68	AAA	ATA	A	T	103,323	0.68	0.01
8	AAG	AGG	A	G	299,963	1.98	CCT	CTT	C	T	299,979	1.98	0.01

Notes.

^aData are shown only for eight reverse complementary pairs of triplets out of total 48 pairs. For the complete data set see Table S1.