Porcupine

Porcupine is an understudied gene in chickens, pigeons, and quail. They are assumed to be the same gene due to the similar appearance and inheritance, but poor fertility and growth prevented further testing in other species (1). It causes the barbs of the quail to curl together more than normal, creating the look of "porcupine-like" feathers, especially through the wings.

The trait appears once the birds go through their first chick molt, around 5 days old (1). It caused this curling in all of the feathers across the body, though as the quail go through their molt cycles, the feathers start to uncurl a bit. In adult quail, the back feathers just appear slightly abnormal, and the mutation is just most noticeable in the wings (1). There is no issues with the barbs of the feathers themselves (2), just how the feathers interact.

In homozygous form, the mutation also causes increased mortality in the quail, though the gene isn't entirely lethal. There is an increased embryo and chick mortality, and low overall fertility, with females laying few to no eggs and an average fertility of 60% in the eggs that are laid (1).

Breeding with Porcupine:

Porcupine x Porcupine = 100% Porcupine

Porcupine x Wildtype = 100% Porcupine Carriers

Porcupine x Porcupine Carrier = 50% Porcupine, 50% Porcupine Carriers

Porcupine Carrier x Porcupine Carrier = 25% Porcupine, 50% Porcupine Carriers, 25% Wildtype (Note: this is the lowest of the found fertility)

Porcupine Carrier x Wildtype = 50% Porcupine Carrier, 50% Wildtype