Chocolate Laced Blue?

[nicalandia]

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is this in response to sonoran Silkies post?


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Because they are different genes?

 

[Henk69]

I guess. Everybody would benefit from that knowledge though...

 

[nicalandia]

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Thanks

 

[tadkerson]

Genetics 101

The blue gene causes the packets of pigment to be round and the pigment is not found in certain parts of the feather ( eg hooklets). The pigment in the packets is still eumelanine (black) it is just that the two things cause the feather to look blue.

A black feather will have rod shaped packets and will be packed into every part of a feather.

The dun gene probably ( guessing on my part) works like the dominant white gene. The dun gene is an allele to the dominant white gene. The dominant white gene has a packaging problem ( is complicated so this is the best explanation) and the pigments can not get to the feather follicle cells( No UPS in the cells) therefore the feather is white. The pigments are there they are just not delivered.

It would appear that the dunn gene ( only one allele) allows for some of the black pigments to be delivered to the follicle so you get a gray to slate colored bird.

If a cell is signaled to make black pigments, and there is a low level of a certain molecule the cell goes ahead and makes red pigment and does not make black pigment.

With a chocolate bird, there is competition in making the red pigment vs the black pigment. You get a mix of the two pigments plus some of the black is not delivered.

Can you get a a blue bird with chocolate lacing? I would say no. If the dunn gene works similar to the dominant white gene all of the bird would be diluted to a chocolate color. The blue gene would further dilute certain areas of the bird- leaving the pyle zone of the male chocolate and the lacing chocolate. The remainder of the bird (not the pyle or lacing) would be a reddish brown color because the blue gene and the dunn gene would dilute most of the black.



Tim

 

[Henk69]

Also the eumelanin molecule is chemically different.

I understood that the packaging and transporting of the (eu)melanin coincides with the chemical maturing of it.

If chocolate were dependant on red pigment (pheomelanin) than the absence of autosomal red and sexlinked gold would be important.
My dun silver duckwings have neither and are still chocolate colored.

 

[Mahonri]

Very educational thread. I'm still figuring it all out in my puny brain.

 

[Sonoran Silkies]

Thanks, Tim. You explain things very well. I've seen different hues on my chocolate coloured birds (some more of a taupe, others more a rich chocolate hue), and suspected it to be silver/gold difference.

Can you add explanations of how lav and choc dilutions work?

 

[nicalandia]

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then How "Platinum Blue" is possible today?, what I mean is one could have a shade of "Blue" as in Platinum "Blue". with Chocolate colored Lacing(based on dun)

below are pullets from Henk,

Left one is Dun, right one is "Platinum Blue" and the one at the bottom is Plain old Blue(Bl/bl+)

 

[tadkerson]

Quote:
then How "Platinum Blue" is possible today?, what I mean is one could have a shade of "Blue" as in Platinum "Blue". with Chocolate colored Lacing(based on dun)

below are pullets from Henk,

Left one is Dun, right one is "Platinum Blue" and the one at the bottom is Plain old Blue(Bl/bl+)
http://i1085.photobucket.com/albums/j437/nicalandia/DunPlusBluePludPlatinumBlue.jpg

Genetics 101


Gray to slate dun birds are silver or they produce enough black pigment to cover any red pigment present.

Chocolate birds are dun with a red pigment- the gold allele or some kind of autosomal red is adding the red pigment that is causing the chocolate color.
The red color could be due to some mechanism interfering with the amount of tyrosine found in the cell. Low levels of tyrosine switch the cell from black pigment to red pigment production. This way you would get a mixture of red and black pigments. There are tests for the presence of red pigment ( pheomelainin) verses black pigment ( eumelanin). This could be easily carried out in a laboratory. I do not have access to a laboratory.

The other option is what Henk has suggested- black eumelainin and brown eumelanin are being produced making the chocolate color. I have not read anything on brown eumelanin production. All I know is there is such a thing.



Tim

 

[nicalandia]

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so Platinum Blue is Only Possible on a Silver Background because if not they will have a Chocolaty hue to it? therefore a "Platinum Blue" colored Body bird can Only have a Dun/Slate colored Lacing(using andalusian blue genetic make up) instead of "Chocolate" colored lacing..


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I've been wondering about the difference of Dun/Slate and Chocolate for some time now, and now that you point that out, it seems logical..

let me find some pics...