While I struggle to wrap my head around understanding Dominate White v Recessive White, some genetics begin to slowly creep in. I give credit to Sonoran Silkies and Tim Adkerson for the generosity of their combined knowledge shared on BYC and other chicken related forums I often frequent.
I can understand breeding recessive whites together create an OFF switch for color. The color of the chick down can and does vary wildly from strain to strain but every chick I've ever hatched out from this pairing produced 100% white offspring.
Breeding recessive White to any color gives multitudes in variety of colors and most are muddy versions in my experience. It all depends what is the hidden genotype under the recessive White.
Dominate White is more complex. This is an explanation that makes sense to me. This by Tadkerson
" Dominant white causes a construction error in the vesicles. The dominant white gene prevents the proper construction of the vesicles (plastic bags) that transport the black pigment to the follicle. The construction error prevents the black pigments from being transported into the cells that make the feathers. The bird can make black pigment, it is not transported into the cells that make the feathers.
Red pigment is different. The construction error does not effect the transfer of the red pigment. That is why dominant white birds show red pigment and not black pigment.
You can think of it like this- black pigment comes in big boxes and red pigment comes in small boxes. The small boxes can be transferred but the big boxes can not be transferred. The vesicle is not constructed so it can transfer the big boxes but it will transfer the small boxes.
You can get some black in a bird that that only carries one dominant white gene because not all of the vesicles are improperly constructed so some feathers can be black.
You can get red in a bird that has one or two dominant white genes because the construction of the vesicles does not effect the transfer of the red pigment."
This from Sonoran:
Recessive white is indeed an offswitch. At the cellular level it prevents the formation of all pigment. It can be leaky, allowing a bit in occasionally on a feather here or there, but overall is pretty non-leaky. Dominant white, on the other hand works differently, and is very leaky. It is more like a filter than an offswitch--it doesn't prevent pigment from forming, but it does prevent it from being placed in the feather. One copy prevents black pigment from entering feathers; two copies also prevents red pigment. Exchequer leghorns are leaky dominant white. Red pyle is dominant white."
I can sort of understand how this would apply to Paints. And how Red Pyle pops up in some Paint pairings.
This information will help me in putting these Paint x Recessive White F1 into future breeding pens. Half of these fifteen chicks are of a Partridge type that will go into the free ranging layer flock. I like Partridge but not the muddy kind. Two are Black/Dark Blue (they haven't feathered out completely) two are Paint, and three are what appear incomplete Dominate White. It is those last three that I really wonder about. If I put them in my all white breeding pens, will they introduce Red Pyle type markings? Not something I care for. Will they be valuable in a Paint pen? I could see how the offspring would get lighter and lighter in the skin and over all lose Silkie traits that call for slate.
That's the thing about project breeding. What to do with the surplus.
He is my first and only with this color so far. They may end up calling them appaloosa silkies and not mentioning the color of the spots at all, who knows?
