Cross-table 45: Ino-opaline

by combination of the lutino and the opaline colour variety

inheriting double sex-linked

First year: Mating an rose opaline cock and an ino hen.

Mating hen 1
ino
(i)
cock 1
opaline
(o)
1-0 wildtype ( /i/o)
0-1 opaline (o)

Starting from the idea that spreading and intensity of the red pigment is stimulated by the M-d (melanin distribution) factor the combination of the rose opaline and the ino colour variety seems to be the best idea. This is not easy to realise because the two mutation factors involved are laying on the sex-chromosome. Crossing over of a factor from one chromosome to be combined with the other factor on the other chromosome is needed. First we have to breed a double split cock. Result of the mating of nino hen and opaline cock.


Second year: Combination of the wildtype, double split cock ( /i/o) with an ino, an opaline or a wildtype hen.

mating hen 1
0-1 ino
(i)
hen 2
0-1 opaline
(o)
hen 3
0-1 wildtype
(-)
cock 1
wildtype
( /i/o)
1-0 ino(i/o)
1-0 ino (i)
1-0 wildtype (/i/o)
1-0 ino (io)*
0-1 ino (i)
0-1 opaline(o)
0-1 ino (io)* 0-1 wildtype(-)
1-0 opaline (o/i)
1-0 opaline (o)
1-0 wildtype (/i/o)
1-0 wildtype (/io)*
0-1 opaline (o)
0-1 ino (i)
0-1 ino (io)* 0-1wildtype (-)
10wildtype(/i/o)
1-0 wildtype (/i)
1-0 wildtype (/o)
1-0 wildtype (-)
1-0wildtype(/io)*
0-1 ino (i)
0-1 opaline (o)
0-1 ino (io)* 0-1 wildtype (-)

Result: In the second year crossing over is possible in all the three matings. The percentage of crossing over is small, about 14 %. In all three matings 7 % wildtype cocks ( /io) and 7% ino-opaline hens (io) with combined mutation factors is possible. The problem of this results is that we can not select the colour varieties with a combination of the two mutation factors by visual inspection. Only experimentation can used to find out what birds have the combined io factors.

Now we have to keep to our purpose. The breeder who want to combine the factors chooses the combination with the rose opaline hen. The purpose was breeding ino with a lot of red. The choise of the mating with the opaline hen is obvious.


Third year: Using the ino hen (io) and the wildtype cock ( /io) with combined factors

mating hen 1 ino-opaline (io)
cock 1 ino-opaline

(io)

1-0 ino-opaline (io) 0-1 rubino (io)
cock 2 wildtype (/io) 1-0 ino-opaline (io) 1-0 wildtype (/io) 0-1 ino-opaline (io) 0-1 wildtype (-)

We know that the percentage of combined factors is small and selection by visual inspection is impossible.In the table an ideal choise is made. In the praxis the wildtype cocks and ino hens are used also because of the unknown genetical make up. This is worked out in table 45a.

Result: The best results come from the combination of a wildtype cock split for the combined factor and a rubino hen. We avoid mating birds with red eyes. Only the results of this mating , birds with combined factors, can be named ino-opaline.

The name rubino is most used when birds show a lot of red pigment in the back, rump and wings and tail. The name rubino is not based on the possession of combined mutation factors. There are rubino with a lot of red pigment. Although most of them have a yellow band on the wings. The ideal is a total red bird with white flights.

Discussion: The common idea is that the possession of red pigment is stimulated by the distribution factor of the eumelanin that causes the rose opaline. According to this opinion birds with combined factors shall have the most red pigment. This are the ino-opaline birds.

Suppose that the inheriting of the red pigment is independent. Then intensifying the red pigment is possible in an other way.

1. Choosing wildtype birds with more red pigment than normal. A red belly and red margins of the wing coverts show us the possession of red pigment. May be it cost time to develop rubino in this way, but the red ino has but one mutation factor (i) and is easy to breed.

2. A combination of the ino with a red pastel (or red fallow) is possible also. The red pastel has a lot of red pigment. The red pastel was developed already at the time that the development of the opaline just started. It is much more easy to make a combination of a sex-linked and a recessive mutation factor, because we have not to wait till a crossing over takes place. I think this is a more easy way to reach the goal.

Conclusion:
Probably both ideas are used in praxis. The genetic qualities of the rubino can be different. To show this I developed the cross-tables 42 and 42a.

Abbreviations:
(i) = ino-colour variety( /i) = split ino
(o) = opaline ( /o) = split opaline
( /i/o) = split ino, split opaline, mutation factors at different chromosomes
(io) = combined ino-opaline

( /io) = split ino-opaline , combined mutation factors
(-) = wildtype, no mutation factors

* = crossing over

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Copyright 2004 by Bob Fregeres

E-mail: fregeres@bourkes-parakeet.nl

2/2/04