Gene gurus a question.

[walkswithdog]

WWD:
So a black giant and a partridge hen might still yield a black cross bred bird?

Tim:
You would get a black bird but the females will show some red on the anterior end. It could be a small amount on the head or enough to cover the head,hackles and breast. The males will show some red.

Krys:Basically, a blue or black or splash Jersey Giant male on a barred rock female will give offspring which have obvious differences in the down colour at hatch, in that the males of such a mating will have a white headspot on either blue or black down, (depending upon the colour of the sire). Unfortunately the reciprocal cross will just give offspring which all carry the dominant sex linked gene

I can't see that the partridge cross blue/black/splash would help colourwise, because there probably aren't going to be any noticeable sex linked genes at play. Theoretically the offspring ought to be either blue or black with no sexual dimorphism in down colour at hatch.

WWD:
In Tim's example of a black giant to partridge hen I'd get small red indicators.

Let's see if I follow. So if a partridge rock roo mated with a black/blue/splash giant hen - I'd just get partridge/giant crosses? All partridge colored? Is partridge a dominant gene? He's ZZ and partridge(don't know the designation). If she's Black, and BB (all black) then the result is...OH my...
well if partridge doesn't trump black then they're all going to be all black, all carrying the partridge, right?
Or is it a straight crap shoot and some partridge and some black? Nah that would only work second generation.
LOL maybe.

I need to keep reading...But really thank you for the continued help. I love learning.

 

[Krys109uk]

Oh I see. I'm sorry, I misunderstood; I thought you meant you wanted the convenience of sexing at hatch...
With a black/blue/splash cross partridge. You ought to be able to tell that they are cross breeds due to red leakage. The offspring ought to be black because the extended black gene (E) of the Giants is dominant to (or trumps as you say) the dark brown gene (eb) of the partridge. The partridge markings are caused by a gene called pattern gene (Pg).

 

[Krys109uk]

Tim, I hope you don't mind if i ask your opinion. Are the examples you wrote regarding red leakage based on extended blacks crossed with a red such as RIR or New Hampshires? The reason I ask is I'm trying to sort something out in my mind. I've done the sex link thing with red X barred & had results with leakage as you describe. But when I put a big black orp on partridge hens the leakage in the offspring was much less, mostly resricted to the back & shoulders of the males. On mulling his over last night I wondered whether the greater lekage in my red crosses might have been from some of the eumelanin resricting genes of the red. Extra info-- The Partridge Orps are much lighter in colour than the Partridge Rocks I've seen. Do Partridge Rocks carry Mh? If so do you think Mh would be the difference?
Thanks
Krys

 

[walkswithdog]

Quote:
Krys Don't apologize!!!!!! I'm asking in order to learn

So every answer is majorly helpful. Keep talking to me every little bit helps. See more learned - extended black gene E is dominant. dark brow eb, and partridge pattern Pg. See more Learned! Makes me happy.

I really appreciate the posts on this thread. And can't wait to see what Tim says to your question too.

Yes, I'm actually only interested in being able to sort out crosses, not sex at hatch. As long as a partridge cross will leak red, I'm content. Probably produce some very funky odd colored chickens but for meat and eggs, doesn't matter. If purebreds look like purebreds and hybrids look like hybrids, I'm golden.

And I do love learning. In shepherds (dogs) the only color pattern related to sex is what they call grizzling, which adds some sable/greyed hairs into a shepherd with a black saddle or blanket. Rarely if ever are males significantly grizzled but it happens in females to an extensive degree. And doesn't affect the actually sable (wild or agouti or the brindle gene) to any significant degree in either sex.

 

[tadkerson]

Quote:
Partridge roo X black hen =
1. basicly black male and female birds leaking some red,

2. another possibility is black females leaking red and males leaking silver, buff or straw color


Partridge roo X blue hen=

1. blue and black offspring, same as above for black,

2. the blue males will leak silver or lemon, blue females will leak buff to lemon


Partridge roo X splash hen=

1. all blue -the blue males will leak silver or lemon, blue females will leak buff to a lemon color

Tim

 

[walkswithdog]

Tim, wow thanks for the extra information! Yay! I think I'm going to print these out for my chicken notebook.

Well, it certainly will be an interesting color adventure. I don't think I'd be keeping anything other than a few hens of the crosses but it should still yield a clown-colored flock while they grow to dinner size.

 

[tadkerson]

Quote:
Most birds that are black are homozygous (has two genes) extended black or homozygous birchen or heterozygous (split) extended black and birchen. So you never know what the bird carries. In the case of yellow shanked birds the brown gene (eb) is used to make a bird black. Birchen birds need help from other genes in making a bird black so if a birchen (black) bird is crossed with another non black bird they will have a tendency to leak more red. Many genes in chickens are incompletely dominant. When they are heterozygous they do not work as well so you wind up with unpredictable outcomes.

The research I have read and my experience with heterozygous extended black (E/ey, E/eb, E/Wh) females S_ or s+_ and males S/S, S/s+ and s+/s+ are my basis for answering the leaking red question. Incomplete dominance of the birchen allele can also present a problem in making predictions concerning the expression of red pigment in the birds plumage.

Birds that are columbian restricted by the columbian gene or the dark brown gene will leak more red than non columbian restricted birds. If an (extended black ) black bird is columbian restricted you will never know it, so if you cross the black columbian restricted bird with another columbian restricted bird they tend to leak more red as in red sex linked crosses (rhode island red roo on barred rock hen).

I can not answer the last question because I have never seen any research on the subject nor have I segregated mahogany from partridge crossings.
My guess would be that the feather structure is the difference. Even though both birds have soft feathers, the orpingtons have feathering that is not as tight as rocks.

Tim

 

[Krys109uk]

***Birds that are columbian restricted by the columbian gene or the dark brown gene will leak more red than non columbian restricted birds.If an (extended black ) black bird is columbian restricted you will never know it, so if you cross the black columbian restricted bird with another columbian restricted bird they tend to leak more red as in red sex linked crosses (rhode island red roo on barred rock hen).***


Ah this is what I was rather thinking. Well of course-- columbian restrictor would not show under homozygous extended black. As neither black nor partridge patterned birds carry columbian restrictor, which would account for why my black crossed partridge Orps didn't show anywhere near as much leakage.

 

[walkswithdog]

Oh so wayyy cool. I'll just sit here and read genetics stuff all the time...

I figure once I stop learning my brain will freeze up and I'll croak. Bad enough the warranty on my body gave up early.