It depends on whether the parents are hetero or homozygous gray, and if hetero, whether they pass their gray gene or not
Does it make the greying out process faster?
Being homozygous gray typically means earlier and faster graying.
Does the grey modifier have the same effect as the dilution modifier.
IE cream one on Bay buckskin two perlino
No. The cream gene is visible from the start, meaning the horse is born bay or Perlino, and doesn’t change. Gray horses are born the underlying color, such as bay, but almost always look like the adult color, meaning, instead of the non-gray foal tan/grayish lower legs, the bay foal going gray would have black lower legs. Then each shed produces more and more white hairs as the graying process progresses
Can a horse have two grey modifiers? Or does the allelle have only a receptor for one?
All of these have 2 forms - on and off. The On version might have multiple forms - bay vs brown for example. Cream and Pearl is another example - both on the same gene, 2 different versions of On.
Is the greying process different in a horse with two grey parents?
It’s about whether the horse is hetero- or homozygous gray. A horse can have 2 gray parents, both heterozygous gray, or 1 homozygous and 1 hetero gray parent, and be heterozygous himself.
Is there a correlation between the rate of greying out and melanoma growth?
GG horses (faster and earlier graying) are more likely to develop melanomas than Gg horses
Is there a hypothesis about where the grey modifier first appeared and why?
It’s been around for probably 1000s of years
Is it possibly a mutation of Roan?
Entire separate gene
Does the grey modifier have a special effect on the base color besides the greying process itself.
It does on the foal coat, where the coat is already darkened, which is the first step of the graying process. That’s why bay-going-gray foals are born with black lower legs instead of tannish/grayish
Does a bay grey differently than a chesnut?
No. All colors can go roany-looking, or dappled. That is more based on the genetics of that individual/that line, than the color
I do have concerns about melanoma because dam was grey and had to be euthed due to melonomas that had matastasized. Spread from the gut into her mouth and had some in her mane.
That is the thankfully uncommon result of the melanoma process - not the tumors being malignant, but them growing large enough in critical body function areas.
He has zero melannomas so far and I check him regularly. He is fifteen and still very dark for his age. Still has black on his knees and hocks.
At the flea bitten stage now. Lost his dapples???
TIA
If he’s in the flea-bitten stage, that’s what makes him “dark”, not a reduction of the graying process.
