Sex-linked (heterosomal) co-dominant heredity - Edged
A new mutation appeared in Belgium in 2000, which was named "edged" in the following years. This is a mutation, which influences the melanin catabolism. The black pigments are in a way "diluted". Therefore the mutation is called "dilute" in English as well, more exact "dominant dilute", because the heredity is co-dominant. Accordingly there exist, like observable at the dark factor, single (SF) and double factor (DF) birds. But, in contrast to the dark factor, there are no double factor edged hens!
The reason for that phenomenon is quite clear: Female birds have got only one heterosome, male birds two. The latter then could have two mutated genes (DF edged), the hen just one. As we know from the Ino-mutation, for instance, a hen, which owns one mutated colour gene on her heterosome, shows the mutation. Therefore, at a recessive sex-linked heredity a hen can't be split to that mutation. The cocks, in contrast, need to have two mutated genes to show the mutation. Now we have a co-dominant mutation. So the phenotype (i.e. the real colour of the bird) of a single factor (SF) edged hen is the same as of a double factor (DF) edged cock!
Claws and beak are lighter than these of the "non-edged" Lineolated Parakeets, especially at the double factor birds. The eyes are black, both at adults and older chicks. Young chicks seem to have dark red eyes sometimes.
The birds of the green line look a bit more matt, the plumage marking is "washed-out" and especially at the double factor Lineolated Parakeet strongly brightened.
SF = single factor
DF = double factor
Because the "edged factor" could be combined to the dark factors, the following combinations occur for the green line:
- dark green SF edged
- dark green DF edged cocks
- olive green SF edged
- olive green DF edged cocks
Also the blue line has been combined successfully with the edged mutation. Firstly known were the so called "silver" Lineolated Parakeets, mauve coloured, single factor edged birds.
The turquoise Lineolated Parakeet with one "edged factor" is like the wild type with that mutation a little bit lighter, the plumage marking seems "washed-out". At the double factor cock, or the SF edged hen respectively, remains only little blue colour, they looks grey-bluish. The claws are lighter.
As in the green line also in the blue line the dark factors could be combined with the "edged factor". This leads to the following combinations:
- cobalt turquoise SF edged
- cobalt turquoise DF edged cock
- mauve turquoise SF edged
- mauve turquoise DF edged cock
This mutation still is mixed up with the cinnamon mutation. But you can see obviously at these birds, that they have black, not brownish, pigments. And the heredity is not recessive.