Yes, that sounds logical to me because they (Porcelain & Opaline) both have the two factors required to make self blue (Lavender) & buff/tan/brown. The Light Lavenders may have had the recessive genes for buff/tan/brown (omongst others), & if mated together (or other birds carrying hidden factors for both Lavender & buff/tan/brown, & partial spotting) could potentially produce some Porcelain & Opaline Guineas.
I had another look @ that link & yes I see that there Porcelain is said to have buff & blue factors; info can vary a little from one source to another, a bit like the colour charts I guess.
Unfortunate story about the Guineas but interesting. Also interesting about the penned birds; I have been meaning to ask how successful others have been breeding in confined areas? Thank you for info.
perchie.girl :
What do the - and + symbols represent
What is the significance of upper and lower case "d's" are they representing Dominant and recessive?
The negative symbol (-) represents no gene, so d/- tells us that one chromosome in the pair (usually come in pairs) have the gene for buff (d), while the "-" tells us that the other chromosome in the pair doesn't have a gene or form of the gene @ that locus (position).
The positive symbol (+) tells us that the gene is the original wild-type, or that found in the original coloured/typed organism, such as in this case, the wild Pearl Grey Guinea Fowl in Africa. So, D+ is the wild-type @ a particular locus on the chromosome, but @ some point in time a variation (mutation) of this factor occured that changed how the bird would look. Because it is another form of D+ @ the same locus (therefore an allele) & was found to be recessive in nature to its wild-type form D+ it was denoted d, so two doses required for it to express (be seen).
Yes, upper case means "more dominant to", but not always completely so. Examples, D+ is more dominant to its mutated allele d, so:
D+/D+ means the bird has two copies of wild-type @ the D locus, so wild-type trait designated for @ this locus is what we see;
D+/d means that the bird has one copy of wild-type & one copy of the recessive to wild-type mutated buff form d. In this instance the influence from the recessive d won't be seen, or @ least not fully, because its wild-type allele being more dominant will influence what we see moreso.
d/d means that the bird has two copies of the mutated gene @ this particular position (locus) on the pair of chromosomes. So in this case, d will influence what we see & buff will express. But sometimes expression can be altered/masked by other genes @ other loci in the mix. An example is Opaline colour said to be made of (probably amongst other things) both Lavender (l/l) & buff (d/d) mutations. Lavender influence appears to be epistatic (more influencial or dominant) to that of buff, so even though the Opaline bird is pure (has two copies) for both mutations we tend to see the Lavender influence colour-wise moreso. Theoretically, in combination the combined diluting power of l/l & d/d (d/- if on Z chromosome for females because they are genetically Zw) are thought to contribute to the lighter shade seen in Opalines.
Autosomal; Chromosomes are divided into either autosomal or sex-determining. Sex-determining chromosomes are denoted Z & w, while all others are autosomal. Therefore, genes on the sex-determining chromosomes are genes on the Z & w chromosomes, & it is these genes that can allow us to sex birds by colour (or some other trait) due to sex-linked trait expression in some instances.
Edited to correct the mistakes that you always notice after you have posted
