Sex-linked heredity - Cinnamon (heterosomal recessive)

Unfortunately I haven't seen cinnamon-coloured Lineolated Parakeets yet. According to F. Pfeffer (GW 1994) and de Grahl (1974) these birds have got white beaks and light feet. The plumage markings, which usually are black at the Lineolated Parakeet, are strongly brightened and rather a light brown. The main green plumage colour seems to be more yellowish. The young birds have got dark-red eyes, not light-red as known from the Inos, but easy to distinguish from the dark eyes of the type form birds. The eyes get darker by-and-by, so they look like these of type form birds at adult cinnamon birds. Just at a specific incidence of light you can see s dark-red gleam.
The reason for the cinnamon mutation is not a reduction of eumelanin, like it is the case at the Inos. During the production of the melanin several intermediate steps have to passed through. One of the enzymes, which converts the preliminary stage of the melanin into an intermediate, is defect. Thus, not the "end product eumelanin", but just the lighter so called dopachrome (a preliminary product of the melanin) is visible at the cinnamon birds.
Often mutations, which apparently lead to a reduction of melanin in the plumage, are referred to as a cinnamon mutation directly after they appeared. But the definition is clear: cinnamon birds have got absolutely no melanin, but only the brown precursor of the melanin. So, everything which is black at a "normal" bird is brown at a cinnamon. Furthermore, the heredity of the cinnamon mutation is ALWAYS recessive and sex-linked, a further important characteristic of the cinnamon.

1.0 = male bird
0.1 = female bird
The female birds can't be split to "ino" or "cinnamon"!


1.0 green x 0.1 cinnamon = 50% 1.0 green/cinnamon
50% 0.1 green
1.0 cinnamon x 0.1 green = 50% 1.0 green/cinnamon
50% 0.1 cinnamon
1.0 green/cinnamon x 0.1 green = 25% 1.0 green
25% 1.0 green/cinnamon
25% 0.1 green
25% 0.1 cinnamon
1.0 green/cinnamon x 0.1 cinnamon = 25% 1.0 green/cinnamon
25% 1.0 cinnamon
25% 0.1 green
25% 0.1 cinnamon
1.0 cinnamon x 0.1 cinnamon = 100% cinnamon (50% 1.0 und 50% 0.1)

Combination Ino/Cinnamon:

1.0 cinnamon x 0.1 lutino = 50% 1.0 green/cinnamon+ino
50% 0.1 cinnamon.
1.0 lutino x 0.1 cinnamon = 50% 1.0 green/cinnamon+ino
50% 0.1 lutino

Lutino cocks can't be split to "cinnamon"!
Cinnamon-cocks cannot be split to "ino"!

Due to the fact, that as well the mutation for "cinnamon" as for "ino" is located on the heterosomes, i.e. the sex chromosomes, there exists the theoretical possibility of a so called recombination. This would implicate, that both mutations would be located on one chromosome, not as usual on both (at the cock). These birds are named cinnamon-inos at the lovebirds (that phenomenon occurs in maximum 3% of all breeds). This mutation also is called "Lacewing". I don't know, if such a "cross-over-mutation" exists at the Lineolated Parakeets.