Table 3.

Comparison of Transition: Transversion and Nonsynonymous:Synonymous SNP Frequencies in Homozygous (Homosite) versus Heterozygous (Heterosite) Murine SNPs

SNP Category	Percent Transition	Percent Transversion	Nonsynonymous (NS) Coding SNPs	Synonymous (S) Coding SNPs	NS:S (P Valuea)
Homozygous	77.7	22.3	708	1,245	1:1.76 (1.65E-14)
Heterozygous	66.3	33.7	272	425	1:1.56 (2.64E-11)

Note.—Murine homosites from chromosomes 1–3 with at least four lines exhibiting the minor allele are shown.

^aP values represent observed SNP frequencies versus those that would be expected if SNPs formed stochastically (Materials and Methods).