SYMBOLS of alleles:
M – the presence of melanin (black pigment)
G – the presence of guanine (сonditionaly blue pigment)
E – the presence of astaxanthin (red pigment)
X – the presence of lutein (yellow pgiment)
m -the lack or reduction of melanin quantity (black pigment)
g – the lack or reduction of guanine quantity (сonditionally blue pigment)
e – the lack or reduction of astaxanthin quantity (red pigment)
x – the lack or reduction of lutein quantity (yellow pigment)
4 pigments and two basic rules:
1. Recessive alleles of each gene reduces the amount of color pigment granules, which are coded by the formation of these same genes, and the phenotype of color almost does not occur.
2. The more recessive alleles of genes in the color genotype, the smaller the quantity of pigment cells.
4 genes = 4 base color (black, red, yellow and blue/white)
Classical mendelian inheritance for each gene – dominant (M, G, E, X) and recessive (m, g, e, x) and interaction between these genes.
For example, if we have cross between 5-7 pairs with genotypes “MM GG ee xx” and “mm gg EE XX” in F2 we recieve ALL 16 variants of colors genotype.
Source; Genetika Guppy