Figure 1. Sequences on the sex chromosomes (equivalent to lizard Chromosome 6) are present in half-quantities in the females of the colubrid garter snake and viperid rattle snake, reflecting degeneration of the W chromosomes.

Boid sex chromosomes and all snake autosomes (e.g., the equivalent of lizard Chromosome 5), on the other hand, don't differ in their representation between the sexes.