genetics of eye coloration

[pgpoultry]

Can anyone enlighten me about green eyes?

In my flock they seem to have started with a now deceased Splash Brahma roo........predominant body colour white with piercing green eyes. His offspring all seem to have green eyes. He fathered some Blue Partridge Brahma chooks....all green eyed. crosses with Naked Necks from one of his Blue Partridge Brama sons....green eyes. Background plumage on these birds is either light (cream or white) or 'blue'.

This is the guy who started my green eyed monsters.

Here's on of his sons.

And a daughter

Thanks....

 

[Meara]

 

[centrarchid]

Here is my eye color issue with pictures.

First image of wild-type reddish brown of jungle fowl.

Second of dark eye on black breasted red game hen.

Third of game hen shortly after hatch.

 

[tadkerson]

Quote:
Tim,

I failed to photograph these guys at hatch. Will have to repeat matings next year to see again. Do males have to have two copies of idM to exhibit dark eyes. Not a single of my males has dark eyes at this time.

Jim

Genetics 101

dermal melanin Massachusetts (idM)

idM is a sex-linked allele to dermal melanin id+ and Id dermal melanin inhibitor. Males will have two of the alleles- females will be hemizygous and have one allele.

Id/idM males ( game or jungle fowl) would have white shanks at hatch and have normal eye color. Id is incompletely dominant so the Id/idM adult bird may show some light gray pigment in the shanks. Some times genetically white shank chicks will have yellow shanks at hatch. Shank color is best determined at sexual maturity.

idM/idM and e+/e+ males would be effected by the allele and have blue shanks at hatch and brown to dark brown eyes at sexual maturity. Eye color on chicks is not reliable because the eye color will change over time. This only applies if the birds do not carry an inhibitor of dark eye color.

If your dark eyed game or game hybrid females carry idM, they should have blue shanks.

I have not worked with idM so I am applying information according to Smyth.

Eye color is complicated, sex linked, pleiotropic, hypostatic, epistatic, autosomal, dominant, recessive etc.. Lots to learn about on eye color. I do not worry much about eye color- I am busy with other genetics. I would like to do some work with eye color but do not have the facilities. Some day I will have a large chicken barn- then I can work on more.

Tim

 

[centrarchid]

Quote:
Tim,

I failed to photograph these guys at hatch. Will have to repeat matings next year to see again. Do males have to have two copies of idM to exhibit dark eyes. Not a single of my males has dark eyes at this time.

Jim

Genetics 101

dermal melanin Massachusetts (idM)

idM is a sex-linked allele to dermal melanin id+ and Id dermal melanin inhibitor. Males will have two of the alleles- females will be hemizygous and have one allele.

Id/idM males ( game or jungle fowl) would have white shanks at hatch and have normal eye color. Id is incompletely dominant so the Id/idM adult bird may show some light gray pigment in the shanks. Some times genetically white shank chicks will have yellow shanks at hatch. Shank color is best determined at sexual maturity.

idM/idM and e+/e+ males would be effected by the allele and have blue shanks at hatch and brown to dark brown eyes at sexual maturity. Eye color on chicks is not reliable because the eye color will change over time. This only applies if the birds do not carry an inhibitor of dark eye color.

If your dark eyed game or game hybrid females carry idM, they should have blue shanks.

I have not worked with idM so I am applying information according to Smyth.

Eye color is complicated, sex linked, pleiotropic, hypostatic, epistatic, autosomal, dominant, recessive etc.. Lots to learn about on eye color. I do not worry much about eye color- I am busy with other genetics. I would like to do some work with eye color but do not have the facilities. Some day I will have a large chicken barn- then I can work on more.

Tim

Tim, dark eyed birds have blue to grey-green shanks. You can look at mine. This is in same population with the pattern gene question that may exhibit buff red quills. But let us keep this simple.

Jim

 

[tadkerson]

Jim,

Sounds like sex linked dermal melanin. It will darken the eyes of birds. Females get one id+ allele and have darker eyes, male needs two id+ alleles to have darker eyes in e+ birds. That would be the simplest explanation.

Tim

 

[centrarchid]

Quote:
Appears male requires two id+ alleles with whatever genetic make-up produces the following.

He throws 50% dark-eyed daughters when bred to wild-type females.

 

[Meara]

What about green eyes? And I've heard sometimes blue eyes crop up. What's going on genetically for those colors?

 

[centrarchid]

Meara,
I have yet to see green eyes in chickens and having enough trouble figuring out my genetic issues. To keep your question from being buried in my generic question, restate your question in thread with title stressing genetics of green eyes.




Same hen with dark eyes showing green-grey shanks. Legs not proper slate grey or blue so maybe a further modifier operating to put yellow coloration in legs?

 

[tadkerson]

Quote:
Appears male requires two id+ alleles with whatever genetic make-up produces the following.
https://www.backyardchickens.com/forum/uploads/41527_dsc00103.jpg

He throws 50% dark-eyed daughters when bred to wild-type females.

A heterozygous male ( yellow or white shanks- may show some light gray color) would produce 50% dark shanked and dark eyed females and 50% white or yellow shanked and bay eyed females. That works.

Tim