Figure 3.

Dxl genes encode a rapidly evolving protamine. a. Dox gene structure, validated splice structure for functional transcript, and the inferred protamine-like, HMG-box, cytoplasmic, and transmembrane domains of the predicted 157-aa protein. b. Phylogeny of amino acid sequence positions 1–66 predicted for 24 Dxl genes aligned with known protamines, annotated with presence (filled circles) or absence (open circles) of “protamine-like” (blue) and “HMG-box” (red) domains. Dxl genes lacking intact ORFs are not included in the phylogeny.