Recio wrote:Hi everybody
I have a problem with genetics
: grey is an autosomical dominant structural colour. On the green series everything is OK.
But in the blue series, you just need one gene carrying the blue mutation in order to obtain a grey bird.
I respectfully disagree. Because the Blue mutation is autosomal recessive, two Blue genes (one from each parent) is required to produce visual Blue and visual Grey birds.
Recio wrote:
I have read that it could happen if the grey and the blue locus were very closed each other, and in fact every grey mutation would be a "grey+blue" mutation.
Don't confuse the Grey mutation with the Grey color. The Grey mutation produces the Grey color ONLY IF mixed with the Blue mutation. A GreyGreen ringneck for instance carries the Grey factor but is by no means grey in color because it does not carry two Blue genes.
Recio wrote:
If it was true I supossed that somebody would have obtain a crossingover dissociating these 2 mutations, but I have not hear about this.
Crossing-over only happens when two genes reside on the same chromosome... such as with all the sex-linked mutations being that these mutations reside on the sex chromosome.
Autosomal crossover is only known to exist between the Blue and Dark Factors... hence it is alot harder to produce Cobalts than it is to produce Violets.
Recio wrote:
Another possible explanation could be that grey is an autosomical mutation of the same locus that blue, so grey would be another allele of blue (like aqua, turkish, ...).
It is not possible for Grey to be an allele of Blue or vice versa. One inherits dominant and the other recessive. Alleles are essentially the same gene, albeit a mutation... and they still reside on one and the same locus. The production of a Grey color is proof enough that they are not of the same locus as no individual will ever have three copies of the same gene.
Blue does have two known co-alleles (Turquoise and Aqua) and possibly a third (Emerald).
What is more possibly an allele of the Grey locus would be the Slaty mutation. Slaty acts like a structural mutation and also inherits dominant just like the Grey factor.