| Subject: |
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Re: Genetics |
| Name: |
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ron cloutier |
| Date Posted: |
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Mar 7, 08 - 10:00 AM |
| Email: |
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ask |
| Website: |
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http://www.ladygouldianfinch-ca.com/ |
| Message: |
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Htisten; fuirst let me thank you for your kind rematks.
I am glad you are enjoying the site.
You must fotgive my lte reply but so much going on with chicks that I have not been to the site in some days.
Kristen; all the research I have done states that yes there
has to be 2 oh headed genes present, as well as a red
headed gene.
The post bellow leads me to believe that even after 9
generations or so the oh gene has not been bred out
completely and that is why the oh appeared.
Mutations can occur spontaneously at any time.
Even if you have bred it out for generations the likelihood
is minute ( 0.0003333333) but still possible.
Somewhere in the lineage far back there must be an orange
headed ancestor for the hen.
What is orange headed exactly:
Orange headed is a variant in which astaxantin production is
lower and luteins much higher in certain facial feathers
giving it the orange appearance.
Why did this ccur?
In the wild this mutation can spring up 1 in every 3000
birds.
Orange headedness is a very complex mutation as it requires
many genes to be in favour for the colouration to appear
visually.
Because the red head is a carotenoid form as is orange it is
more then likely that what the bird is visually displaying
is a variation in intensity of carotenoids expressed.
Even when pairing split birds with the black headed gene to
each other you will not get the visual orange headed birds
but 50% that are not fully visually expressing ( the black
masking it) it and 50% split to the BH head colour.
It is only when two red head/orange headed split birds are
paired that the orange will be visible.
So yes you do need it somewhere in the backround. Do both
parents need it for it to be expressed?
Yes they do so someplace way back there is this trait in the
birds.
Why has it not been bred out?
I do not think any trait can be totally bred out all we can
do as breeder's is try to make the probability of occurence
all that much lower by maintaining " pure" ( or as pure as
possible) head colour lineages.
Can it be prevented?
Nope. As stated it can occur at any time if the gene is present all it takes is the right combination.
Hope this helps answer your question : )
Ron  |
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