Figure 1

Exon/intron structure of mammalian genes for α-, β- and γ-crystallins. Exons are shown as boxes with ORF in thicker boxes. CRYB genes coding for β-crystallins vary in 5^′-exon structure. The exons encoding the four structural motifs of the β-crystallin and γ-crystallin proteins are indicated by 1, 2, 3, and 4. Some mammals have an alternatively spliced exon in the first intron of CRYAA, but in humans this is a pseudoexon.