Never Encourage a teacher -What I know about color genetics Lesson #2A

[mibirder]

Chris - regarding RIR genotype

I don' definitively know and don' have any experience with them, but both Van Dort et als and Reeder referenced the genotype as eWh/eWh rather than E/E which is what I relied upon. I also read from "older" references that RIR was based upon recessive e ( which was before other alleles of the e-series were recognized). I am making the assumption that these older references were using E-e for the e series as we do today (which may not be true).

Also neither reference listed Co as a genetic component in RIR. What they listed was:

Van Dort et als (for black tailed red varieties)
eWh/eWh s+/s+ Ar+Ar+ DiDi MhMh,
eWh/eWh s+/s+ Ar+Ar+ DiDi MhMh MlMl,
eWh/eWh s+/s+ Ar+Ar+ DbDb MhMh, and
eWh/eWh s+/s+ Ar+Ar+DbDb MhMh 'rb''rb'

Reeder
eWh/eWh s+/s+ ApAp DbDb MhMh
eWh/eWh s+/s+ ApAp DbDb MhMh 'rb''rb'

I know the Malay was one of breeds interbred to create the RIR, but I don't recall reading RIR being EE based.
Ah genetics go figure.

Dave

 

[Chris09]

The thing is the Rhode Island Red isn't truly a Black Tailed Red it more a Red Columbian or a "Modified" Red Columbian if you will.

I find it some what confusing that the genetic component that you posted does not list Co even though nearly every breeder and nearly every old text on the Rhode Island Red breed states that the Rhode Island Red carries Co in its make up. Note that even in the American Standard of Perfection, it says any bird with a entirely White feather showing in the surface is a disqualification.

I do understand that some of the old lines of Reds had Dark Brown Leghorn add were others did not, also the Rose Comb Reds make up is different than the Single Comb.
(Some of the Rose Comb Reds had the old Rose Comb Red Java added.)

Chris

 

[mibirder]

Chris -

I thought the same regarding the Co (from breeders) as you've noted.

Crawford (Poultry Breeding and Genetics, 1990) did list at least a single dose of Co (ey/ey Co/? db/db Mh/Mh - ey = recessive wheaten). He cited a study from Malone (1975) in exhibition RIR stock. So maybe it is an oversight by Van Dort and Reeder - even though their books are much newer and in both. I'd be curious to know if that's the case or not - It would seem to be so (an oversight).

Dave

 

[Chris09]

Quote:
There might have been a oversight Van Dort and Reeder because Crawford's theory makes more sense to me and matches Lewis Stevens book Genetics and evolution of the domestic fowl.

Back some time ago I found a study done on the color of the Rhode Island Red titled "INHERITANCE, OF PLUMAGE COLOR IN THE RHODE ISLAND RED BREED OF DOMESTIC FOWL" By FRANK A. HAYS Massachusetts Agricultural Experiment Station, Amherst, Massachusetts Received December 5,1925 it is old but has some good reading in it.
http://www.genetics.org/content/11/4/355.full.pdf

In his conclusions he states;
1. Rhode Island Red color pattern is a complex of several factors. Three factors are chiefly concerned in the make-up of the different phenotypes.
2. Bay pigment depends on the presence of a gene B, which is autosomal and epistatic to gold (S).
3. The sex-linked pattern factor L carries gold and to some extent influences the distribution of pigment and its intensity.
4. The autosomal gene E may or may not be present and determines the presence of smutty color in feather fluff.
5. Gene E is not essential in breeding for “standard” color because genes B and L together give the ideal color pattern.

Chris

 

[tinychicky]

Quote:
Wheaten from one parent, BBR from the other. That's where the fawn color comes from. As for the white and gray, pics could help.




By "well put" I was mainly referring to the analogy of the different E locus though. Didn't read it all through as nicalandia admitted too

thanks. i don't have a good pic right now, but i can discribe her for you:
dark fawn head fading down the hackle to white on the back. tail is white tipped with fawn. fluff is white. breast is dark rich fawn fading to white tipped with fawn, then pure white along the keel. white thighs/hocks. foot feathers white tipped with a bar of gray, a bar of fawn then more white. wing shoulders are white and dark fawn barred. primary coverts are white with a bar of gray, a bar of fawn and a white tip, secondary coverts are white tipped with a bar of fawn then more white. primaries are gray with white lacing. secondaries are faint gray that grows darker toward the tip of the feather with white lacing and a bar of fawn at the tip of the gray. as a chick her down was pale yellow with a spot of buff on the back of the head. i hope this helps. so she's definatly by the ameraucana, not the barnyard mutt? can expect green eggs?

 

[mibirder]

Chris -

I put our basic Co in RIR to David Hancox (one of et als in Van Dort et als) and here is his response:

"The genotype for black-tailed reds has been found to most commonly be a combination of s+ Gold &
db Dark Brown, but Co Columbian has segregated in some lines of birds, and both Co & db has also been segregated. All will produce the BTRed pattern."

With no reason to doubt his response, I guess the way to think about it might be - While Co has been traditionally used in RIR lines, it is not genetically necessary to have it in all RIR. I think the "most commonly" in his response is rather interesting.

Regarding older resources, I often get lost in reading them as some of the symbols and understanding of the genes have been upgraded and modified that I have to sit down and write out a road map to follow the discussion LOL. For example the use of ey for the recessive form of eWh. It took a bit to figure that one out on my part.


Dave

 

[Chris09]

Quote:
I think that the Co gene was a "extra" when it came to creating the R.I. Red, they didn't need the Co gene but it came when breeding to the Brahma. It was a catch 22.

Chris

 

[mibirder]

Chris -

I also just received a nice response regarding Co from Van Dort:

"RIR are wheaten based.
There is always a discussion whether a bird has Co or Db, or both.
Genetypes are proposed and based on breeder's experiences.
In Europe they are Db based and not Co, which can be seen in testmatings
to e+ and F1 crossed together.
In testmating the e-allele should be considered as well.


Best sign is: is there black in lower hackle of roosters?
There is always in hens, is this true?
Don't forget the columbian action of Mh as well.
The almost black/red shade is part of the whole genotype.
We still don't have prove for recessive black, and does this black behave
the same like 'ordinairy' black?

The RIR exhibition colour can't be remade on any other breed, even not
when they are wheaten based. Why not? We don't know this."

Adage: The more you think you know, the more there is to know!

Dave

 

[Henk69]

In my european crosses the columbian restrictor looked like Co.
Presence of Db should be clear from a cross with extended black or birchen.

 

[Chris09]

Quote:
As for Black in the lower hackles, depending on breeding some do and some don't. I will post ome information on it on another here.
I am sorry to say I don't have the answer to the rest of the questions at this time, but but should be able to answer then next fall as I do have some extra R.I. Red hen that I will be doing some test breeding to.
I have a Blue male that I had planed on breeding to a R.I. Red hen in the spring so I will see how the Black reacts to Blue and weather I get Blue and Black in the offspring's wing.

Unfortunately I don't have any pure e+ stock on the farm, plenty of eWh but no e+. I will be going to a a few sale between now and spring so I may get one picked up.
Now question, When test-mating the R.I. Red to e+ and F1 crossed together what would there offspring look like if Db or Co?


Chris