Fig. 1.

Schematic generation of the two α-triplications (ααα^anti3.7 and ααα^anti4.2) through homologous recombination between the duplicated α-globin genes. a Generation of the ααα^anti3.7 triplication and the three subtypes of rightward deletion (-α^3.7I,II,III) due to unequal crossing over between two misaligned Z boxes of the α1- and α2-globin genes and reciprocal events; b Generation of the ααα^anti4.2 triplication and deletion of –α^4.2 from recombination between the two misaligned X-homology boxes. Note: X, Y, Z, homology boxes; A, Apa I restriction site