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#102487 - 02/24/12 06:23 PM Re: ey revisited [Re: KazJaps]
Terry Offline
Bantam

Registered: 02/19/12
Posts: 47
Loc: Qld Australia
KazJaps said
>"The ey recessive wheaten Red Jungle Fowl line (used by Morejohn, Brumbaugh & Hollander) didn't have Co etc modifiers. It appears to be a mutation that occurred in wild-type Red Jungle Fowl."

I see your point, it might have been a true recessive, rather than an incomplete dominant like the other alleles. Perhaps if this line was maintained and sequenced today it would be different to eWh.
And perhaps all the other Wheaten birds found and assigned ey by later researchers were assumed to be this same mutation, when in fact they were the incomplete dominant eWh allele.
You almost need an historical DNA bank from the specimens used in the early research. Didn't someone mention something about skins being collected? ;-)

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#102490 - 02/25/12 09:49 AM Re: ey revisited [Re: Terry]
Wieslaw Offline
Moderator
Classroom Professor

Registered: 09/18/09
Posts: 3825
Loc: Denmark
Originally Posted By: Terry
So do you call them eWh because they looked like that at a day of age or e+ because they look that way for the rest of their life?


I called my Columbian cock eWh because he was from pure breeding stock and was hatched (nearly) white. Of course I have no possibility to sequence him. I base my opinion on descriptions made by people on this forum. Pure Columbians are said to be always made either on eb or eWh. There is supposed to be a difference between them in the amount of black in the hackles (more on eb) and underfluff colour(white on eWh). My cock had white underfluff, which turned gray at the end. It is said that it can suggest eb/eWh. Poultch even said it can suggest Pg(which I doubt in my case)
I call his children e+/ , because I know that mothers were duckwings , and one ER(which hatched totally different). Other batch of chicks from black hens hatched black, whit more or less white faces.

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#102498 - 02/25/12 04:28 PM Re: ey revisited [Re: Wieslaw]
Poultch Offline
Coop Keeper

Registered: 01/25/10
Posts: 660
Loc: New Zealand
Have you mated him to a furnace hen Wieslaw?
his undercolour is far too subtle to be split eb.
Pg can hide easily on Co wheatons.

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#102499 - 02/25/12 04:49 PM Re: ey revisited [Re: Poultch]
Wieslaw Offline
Moderator
Classroom Professor

Registered: 09/18/09
Posts: 3825
Loc: Denmark
If by furnace you mean melanized wheaton then no. I do not have furnace or wheatons. My rooster was bought as an egg from a man who had bought the rooster's father from Germany. The man had some females with white underfluff and some with dark(on purpose, but I do not remember the explanation what should be good about that)

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#102527 - 02/27/12 08:45 AM Re: ey revisited [Re: Wieslaw]
KazJaps Offline
Classroom Professor

Registered: 08/30/02
Posts: 2864
Loc: Australia
Just one more comment on MC1R sequences of E and ER alleles.....

Going from memory, the Leu133Gln mutation (found in ER-Fayoumi) was sequenced quite early on. This was a unique MC1R mutation, not known to occur in mammals. The Glu92Lys (E92K) mutation was also sequenced early. This mutation has occurred in other species, eg causes black fur in mice. So when this same MC1R Glu92Lys mutation was found in chickens (before E), its not surprising to find someone calling it E - for extension/extended black, when comparing the mutation with other species. But then comes along another chicken MC1R sequence where they find two mutations that have occurred in other species, the previous Glu92Lys mutation coupled with a second one Met71Thr. Met71Thr by itself is also known to cause black extension, eg black wool in sheep. The following from R. Okimoto:
Quote:
The most dominant allele at this locus is the E extended black allele. It differs from wild-type e+ by two mutations that change the amino acid sequence of the gene (Met71Thr and Glu92Lys).....

...Our hypothesis is that you need both mutations to get the blackest bird and that if you have only the Glu92Lys you end up with the birchin black phenotype.


But the problem is that some scientists don't seem to recognise this, ie 3 different MC1R sequences giving black downed chicks and black extension to adults.

---------------------

Bit off topic, but for Terry ....
Originally Posted By: Terry
But then your point that slight differences which do not at first seem important in creating change in the base phenotype, might interract different with other mutations - particularly any that have direct functional involvment with MC1R - like Agouti (when they find it - could it be Mh or Co?). That has great merit. and Pg must have some interraction with MC1R as well.


Co was DNA tested against ASIP (Agouti), and found not to be a mutation of ASIP....

Characterization of Japanese Quail yellow as a Genomic Deletion Upstream of the Avian Homolog of the Mammalian ASIP (agouti) Gene.
(Genetics 178: 777786 (February 2008))
http://www.genetics.org/cgi/content/full/178/2/777
Quote:

ASIP expression in chicken: Dorsal and ventral skin samples were taken from 10 chickens, 2 males with a mottled phenotype and 8 females with a Columbian phenotype.

......The presence of an apparently functional ASIP gene in chickens poses the question of why no good candidates for mutations at this gene are known among the large numbers of described pigmentation variants (Smyth 1990).



I wonder if Co (or maybe even Mh) is on CBD103 (K locus in dogs)? In dogs, there are three alleles on CBD103: K^bk (dominant black), k^br (brindle), k^y (yellow- phaeomelanin). Plus research suggests the dominant red mutation occurring in Canadian Holstein cattle may be Beta-defensin related too (DEFB103).

A couple more candidates for red intensifiers:
ATRN (Mahogany in mice)
MGRN1 (Mahoganoid in mice)

Db turned out an unusual one, a mutation on SOX10, and not previously known to give a Db like phenotype in other species.

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#102531 - 02/27/12 09:00 PM Re: ey revisited [Re: KazJaps]
Terry Offline
Bantam

Registered: 02/19/12
Posts: 47
Loc: Qld Australia
KazJaps said
"Co was DNA tested against ASIP (Agouti), and found not to be a mutation of ASIP...."

Are you referring to the report that ASIP expression was found in 8 Columbian fowl. This does not preclude Co as being Agouti, since only null mutations of Agouti would block ASIP expression, other alleles would still have expression, just altered in some way, but still likely to show up in their test for its presence.

It is interesting that a number of studies in mice and Jap quail show that MC1R is epistatic for Agouti if MC1R is occupied by an extended black allele. It seems the continuous expression of MC1R in these cases prevents ASIP from having any action. This would correlate with the view that Co has no action on ER.

But also your other suggestion of CBD103, it is also modulated through MC1R, which is epistatic to it in similar circumstances as well. An interesting comment I found in the article on the K locus in dogs was :-

"CBD103 is a member of a large family of secreted peptides with structures similar to that of Agouti and is highly expressed in dog skin."

Whilst the normal function of any one of these similar peptides might not have anything to do with pigmentation, if they are so similar to Agouti, then mutation could alter their function in some cases and result in effects on plumage. Therefore the possibilities are enormous and no doubt we will be surprised when the true identity of the Co locus is found.

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#105972 - 10/12/12 05:49 AM Re: ey revisited [Re: Terry]
tyuks Offline
Feather

Registered: 01/13/11
Posts: 24
Loc: Hungary
So if I am getting the odd wheaten (like 1 in 4) from wildfarbig x brown leghorns (that I suspect may have some eb based on irregular eye stripes) does this mean:

A. One of the parents is e+/eWh and a melanizer from the wildfarbig (I think Ml from the black heads)is making it recessive? And the wheaten offspring are e+/eWh that don't carry the melanizer?

or

B. Both parents are e+/eWh and it is acting as a simple recessive in the presence of melanizers?

or both A and B

or this is the debatable ey.

Two generations ago I had the first one pop up in purchased Araucana eggs (supposedly pure but I hatched a straight comb in the same batch, so who knows). She is the grandmother of this batch. She was yellow down with thin black dorsal stripes. Like matchstick thin. She was also Co/co and red enhanced.

The one wheaten hen I've kept has willow shanks. Dad was id+/Id.

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#105973 - 10/12/12 06:33 AM Re: ey revisited [Re: tyuks]
Wieslaw Offline
Moderator
Classroom Professor

Registered: 09/18/09
Posts: 3825
Loc: Denmark
Hi tyuks. As far as I know nobody can answer your question with certainty. You are actually in a position to tell us once you find out. It would be lovely if you could make some crosses to pure e+.

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#105974 - 10/12/12 07:56 AM Re: ey revisited [Re: Wieslaw]
tyuks Offline
Feather

Registered: 01/13/11
Posts: 24
Loc: Hungary
Funny, I'm sort of a roo collector, and that's the one thing I don't have. Out of 10 different phenos. The 3 e+ I have have Mh or Ml or B.
I'll have to pick up a brown leghorn roo at the open air market this Sunday. End of season... should be cheap.
Thanks for the reply.

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#105988 - 10/13/12 08:18 AM Re: ey revisited [Re: tyuks]
Lanae Offline
Chicken

Registered: 02/02/12
Posts: 123
Loc: Willits, California
Hi Tyuks,

The standard color of the black breasted red araucana here in the US calls for a bird based on wheaten, but with Mh. Which is a darker color than the wheatens you find in other breeds. That correct color has all but been lost out to the breeding of the wild type bbr in the araucana. I find it wonderful that you have hatched a wheaten hen. There is a book written about araucana and it states that the correct wheaten color will pop up in wild type breedings from time to time and you can breed the wheatens together to stabilize the color and then only wheatens will hatch. So it sounds like it is some sort of hidden recessive.

Lanae

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