Defective Feathers

Defective feathering is actually a trait controlled by two genes in Coturnix quail, but they're listed here as one because they only act in tandem. Both genes are autosomal, though one is recessive and one is dominant. The overall affect of both causes the barbs on the feather to become twisted so they could not interlock and create the smooth feather pattern normally seen on birds (2). The presentation is not unlike that of a silkie feather in chickens, though with considerably less "fluff". Chicks with the defective feathering will have short and choppy down at the hatch (1), but feather out with the complete defective trait as they grow. The severity of this ragged look varies from bird to bird, but in general females will be more ragged than the males (1).

The dominant gene has been proven to be lethal in the homozygous form, meaning that the trait cannot breed true. All of the chicks died as embryos (1). This dominant gene is likely responsible for the majority of the gene expression and overall trait. It is lethal in homozygous regardless of the modifier gene, but will not express the defective feathering in heterozygous without this modification (1). This gene overall is thought to be extremely rare, and is not believed to be in public hands whatsoever.

The recessive gene, also called the modifier gene in this scenario, is suggested to be much more common (1). This second gene does not affect nearly as much, nor does it appear to change the bird without the dominant gene.

This mutation is not in public hands, and there have not been reports of the defective feathering traits in other labs.

Breeding with Defective Feathering:

Note: this is a two locus trait, so results are a bit complicated.

Rough Feathering x Rough Feathering = 25% Dead in Shell, 50% Rough Feathered, 25% Normal Feathered

Rough Feathering x Normal Feathering = 50% Normal Feathering, split to Recessive and Dominant, 50% Normal Feathering split to Recessive

Rough Feathering x Normal Split to Recessive = 50% Rough Feathered, 50% Normal Feathered split to Dominant

Rough Feathering x Normal Split to Recessive and Dominant: 25% Dead in Shell, 25% Rough Feathering, 50% Normal Feathering split to Dominant