Correlation of mouse strain genotype with integrin α₂ expression phenotype. Successive generations of breeding of FVB and C57 mice led to 20 offspring designated as FVB/C57 × FVB/C57 (F2). These mice were phenotyped for platelet integrin α₂ expression and genotyped with a marker flanking the integrin α₂ gene (ITGA2). (A) Map of the ITGA2 gene showing the position of the primer set (D13mit260) used to distinguish the 2 mouse strains. (B) Ethidium-stained agarose gel of PCR products. The first 2 lanes have products from the F0 parental FVB and C57 strains, the last 4 lanes are 4 of the F2 cross (FVB/C57 × FVB/C57) samples showing the 3 possible genotype patterns. (C) Flow cytometric analysis of platelet surface integrin α₂ expression of the 20 F2 offspring. The result of each F2 mouse is shown in descending order of α₂ expression.