Figure 1. Schematic representation of the PRDM9 gene.

The C₂H₂ zinc finger domain, the subject of this study, consists of a variably sized array of zinc finger repeats, which are represented as differentially colored boxes (allele Pan.t-1 diagrammed here). Each array possesses many distinct ZFs, with some repeating at multiple positions throughout the array. The nucleotide sequence of four internal fingers is shown, and identical codons from different fingers are represented as dots. The high sequence similarity between different fingers demonstrates the repetitive nature of the ZF array. The nucleotide positions that code for the protein’s DNA contact loci are colored in red.