Study links genes and environment in side‑blotched lizards' mating cycle

A new study published in Science explains how genetic and environmental factors produce the rock‑paper‑scissors style mating cycle of the side‑blotched lizard, a species long observed in California hills to cycle among three male throat‑color strategies. Early work by Barry Sinervo and Curtis Lively described three male types — orange, blue and yellow — with distinct behaviours: orange males hold large territories and fight, blue males defend small territories and cooperate with other blues, and yellow males attempt sneaky matings.

Sinervo and Lively modelled the shifts among the three types as a rock‑paper‑scissors game, and Dr. Lively recalled, "I remember him jumping up in the coffee shop and shouting, 'It's rock‑paper‑scissors!'" Ammon Corl and colleagues spent years assembling a side‑blotched lizard genome and sequencing individuals in the wild because the males do not develop throat colours in captivity.

They found a simple genetic difference between orange and blue males: orange is a recessive trait associated with lower levels of a protein called SPR, which helps make pigments and neurotransmitters. "The story crystallized, and it all fell into place," Dr.

Key Topics

Science, Side-blotched Lizard, Merced California, Ammon Corl, Barry Sinervo, Spr Protein