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#112499 - 03/25/14 02:51 AM Re: Historical question [Re: Redcap]
KazJaps Offline
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Registered: 08/30/02
Posts: 2819
Loc: Australia
Why American Dominiques?
http://www.dominiquechicken.com/Why_American_Dominiques.html
Quote:
One particular trait that is lost in many of the modern strains is the "eye" that is to be seen at the end of each feather. The shape of the bars and the rounded end of the feather causes this. One could almost call the final bar "lacing".


If you do look at Schilling's Dominique hen, & what I take as the trait the author above is referring to, it is the thin eumelanin bar on the feather tip, but also the very large white bar below it, to produce this phenotype. Why would Pg do this? Whatever the modifier is, it is restricting eumelanin to the tip, expanding the white band substantially. And remember the white band is not phaeomelanin-silver. As I mentioned previously, Smyth believed that Pg was a partial eumelaniser, not a restrictor. Why would a eumelaniser take away pigment on a eumelanin base? I don't know for certain, but it seems counter-intuitive that Pg would produce this phenotype with B.

You could look at Cambar & other similar genotypes (B and Pg-Db, both sex-linked barring & autosomal barring) for any clues.

I'm not aware of sequencing of the Pg mutation as yet, so don't have any clue of the structural gene & modification to it, to produce Pg.

As to laced blue Bl/bl+ Pg-Ml. My guess is that Pg adds intensity to the feather edge, not the other way around & take away intensity from the centre of the feather (leaving a dark edge). This guess is from looking at non-laced blue phenotypes, where you can see in males dark blue tops (neck hackles, wing bow etc), yet light blue body. Add Pg & you get the dark top colour produced as dark lacing on the light blue body too.

Blue Bl is a strange one, as it doesn't seem like Pg-Ml has the same effect on other eumelanin diluters like lavender and chocolate. Except when you combine Bl/bl+ Pg-Ml with choc (see bottom photo):
http://www.orpingtonbantams.co.uk/choc.htm

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#112500 - 03/25/14 09:59 AM Re: Historical question [Re: KazJaps]
Redcap Online   content
Ruler of the Roost

Registered: 08/14/06
Posts: 957
Loc: Germany
Smyth et al. described, that Pg controlls the rearrangement of eumelamin on a continuum from stippling, over pencilling, autosomal barring, spangling, mooney** (something between spangling and buttercup pattern until spangling and lacing) and lacing.
http://documents.kippenjungle.nl/#post14


** compare feather pattern in the picture in 2nd row, 5th column (right mouse click to enlarge)
http://www.derbyshireredcapclub.webeden.co.uk/#/club-photos/4514975513
That's the Taylor line, where my birds comes from

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#112502 - 03/25/14 07:14 PM Re: Historical question [Re: Redcap]
KazJaps Offline
Classroom Professor

Registered: 08/30/02
Posts: 2819
Loc: Australia
Thank you for the OCR version of Smyth's PB&G chapter.

Yes, where there is eumelanin stippling on phaeomelanin background, Pg rearranges this stippling & enhances the eumelanin. Usually there needs to be other modifiers for Pg to express in males (eg, where there is no stippling, etc), eg Co, Db, Bl, Ml, Hf, etc.

As mentioned earlier, Smyth lists Pg (Lg) as a partial eumelaniser in the following 1976 paper (see Figure 1):

Genetic Control of Melanin Pigmentation in the Fowl
http://www.poultryscience.org/docs/pba/1952-2003/1976/1976%20Smyth.pdf
Quote:
The black-intensifying factors shown in Figure I include melanotlc, Ml,which is even more effective when linked with lacing, Lg (Moore and Smyth, 1971).

Moore, J. W., and J. R Smyth, Jr, 1971. Melanotic: Key to a phenotypic enigma in the fowl. J. Hered. 62: 214-219.

The following from Smyth, about his eb/eb Recessive Black line (RBL):
Lg = Pg
Quote:
Our present data indicate that the RBL line carries a number of eumelanin intensifiers, but at this time only two individual genes have been isolated for study. These include melanotlc (Ml), one of the line's major eumelanlzers, and lacing (Lg)." ....]

[....As expected, lacing has its greatest eumelanizing effect on the feather margins, and this effect is intensified in the presence of MI.


Smyth also discovered in his Silver-laced Wyandotte study that Pg (alone, without Ml)) adds eumelanin to the tip of the feather, in eb Co base.

"Lacing" & Lg = Pg
Quote:
Lacing alone results in a black tip, while eumelanin is extended proximally along the margin when Ml is added.


The following diagram is based on Figure 4:


Also the following observation by Smyth, when they extracted the mutations in Silver-laced Wyandotte:
Quote:
When MI-Lg are found in the absence of Co, then the lacing is poorly expressed and associated with secondary pattern effects in the center of the feather.


*Notice that on eb co+/co+ base that Ml-Pg didn't produce exhibition quality double-laced, as in Barnevelders & Indian Games. But in his original paper on this Silver-laced Wyandotte, he did mention that there was an unidentified modifier that enhanced the lacing to produce the exhibition single-laced phenotype (ie Pg-Ml Co alone wasn't exhibition quality lacing).

Inheritance of the Silver-Laced Wyandotte Plumage Pattern
Moore & Smyth
J Hered (1972) 63 (4): 179-184
http://jhered.oxfordjournals.org/content/63/4/179.full.pdf

*Not free access now.

The following by Smyth (1976 Melanin paper] on the effects of Ml-Pg on Bl:

Quote:
Recent observations by Cote (1976) suggest that the linked combination of Ml-Lg is also responsible for the black marginal lace found on blue plumage Bl/bl+. It is suggested that the blue genotype is ineffective against eumelanin present in association with Ml-Pg. This also leads one to speculate on the role of these mutations in the black hackle and black plumage of the Blue Andalusian Male.


Of course, B is different to Bl in dilution, but it just doesn't make sense that Pg on eumelanin would reduce the B barring eumelanin band to the feather tip, then produce a larger B white band (lack of eumelanin pigment, not phaeomelanin). My guess is that on a barred buff columbian phenotype that Pg/Pg would add a small eumelanin tip (incomplete lace-spangle) to buff & white banded (barred) feathers. Ie, Pg is a partial eumelaniser.

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#112503 - 03/25/14 07:37 PM Re: Historical question [Re: KazJaps]
Redcap Online   content
Ruler of the Roost

Registered: 08/14/06
Posts: 957
Loc: Germany
Thank You for the description.
Smyth mentioned, that Barring (B) will be expressed totally different on other E-loci than in E.

Quote:
The expression of B on non-E backgrounds is more variable, but in general, black feathers are barred in the presence of B, but the expression of the barring is less precise, as in the Old English Crete Game. Barred red or buff columbian stocks have been developed, including the Gold Barred Rock (Punnett and Pease, 1928) and the Gold Barred Basque (Campo and Orozco, 1980). The expression of head spotting is more variable on pheomelanic backgrounds, and is enhanced in chicks with darker head coloration (Punnett and Pease, 1928; Jaap, 1941). Barring also is expressed, although again imprecisely, on autosomal blue (Bl/bl+) feathers (Lippincott, 1921; Smyth, unpublished). This probably explains the lack of popularity of blue barred breeds among breeders of exhibition poultry.
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#112505 - 03/25/14 08:44 PM Re: Historical question [Re: Redcap]
KazJaps Offline
Classroom Professor

Registered: 08/30/02
Posts: 2819
Loc: Australia
Here is that Punnett & Pease paper:

Genetic studies in poultry. VI. The Gold Barred Rock.
R. C. Punnett and M. S. Pease. 1928
Journal of Genetics. Volume 19, Number 3, 337-350
http://www.ias.ac.in/jarch/jgenet/19/337.pdf

The authors note that the buff is too pale, & that the Gold Barred Rock breed is still in an imperfect state.

There is a photo of feathers from the Gold Barred Rock (GBR) male (eumelanin & phaeomelanin on the same feathers), showing that the B white barring has equal effect on both eumelanin & phaeomelanin (a straight line across the feather).

When they crossed the GBR (B/b+) male with a Barred Plymouth Rock female, they produced some single-laced in F2 (also columbian phenotype).
This indicated that the Barred Plymouth Rock female had Pg-Ml.

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#112510 - 03/26/14 01:16 AM Re: Historical question [Re: KazJaps]
Redcap Online   content
Ruler of the Roost

Registered: 08/14/06
Posts: 957
Loc: Germany
Interesting - so it could be possible, that Dominiques were actually B/B(b+) Pg/Pg+ Ml/ml+ or B/B(b+) Pg/Pg Ml/ml+

I just found a study about Ancobar, a nice phenotype, aswell.
http://jhered.oxfordjournals.org/content/32/7/221.full.pdf
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#112526 - 03/29/14 01:48 PM Re: Historical question [Re: Redcap]
Redcap Online   content
Ruler of the Roost

Registered: 08/14/06
Posts: 957
Loc: Germany
I just want to show the Ancobar phenotype





Again, just for comparison Dominique feathers and Barred Plymouth Rock feathers (1920)
https://archive.org/stream/matingbreedingof00lamo#page/122/mode/2up
https://archive.org/stream/matingbreedingof00lamo#page/80/mode/2up
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#112832 - 05/30/14 04:05 PM Re: Historical question [Re: Redcap]
Redcap Online   content
Ruler of the Roost

Registered: 08/14/06
Posts: 957
Loc: Germany
Originally Posted By: KazJaps

A further study of the E pattern locus in the fowl.
Brumbaugh, J. A., and W. F. Hollander,
Iowa State Journal of Science. (1965) Vol 40, No 1. : 51-64.
Digital version will follow

http://documents.kippenjungle.nl/#post15
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#114455 - 06/09/15 12:26 PM Re: Historical question [Re: Redcap]
Wieslaw Offline
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Registered: 09/18/09
Posts: 3775
Loc: Denmark
This one is (mainly) for Americans.

In The Minorca fowl (1893), by Harrison T.H.( no longer available on wayback machine? The link supplied by Kazjaps does not work) I have found a piece of information, that in the 1800's in UK, any black hen was "risking" to be called Spanish



Then I read a description of creation of Plymouth Rocks, with a footnote saying , that the Black Spanish in the text was in fact "some sort of Minorca"




Now I have a problem with a history of leghorns from the same book. It also says Spanish in the crosses. Somehow it does not seem right for me, why would anybody use Spanish. I have a suspicion, that it could be Minorca also in this case. Any other sources of history of leghorns other than The Poultry Book (1903) Volume 1 by Harrison Weir ?


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#114456 - 06/09/15 12:46 PM Re: Historical question [Re: Wieslaw]
Redcap Online   content
Ruler of the Roost

Registered: 08/14/06
Posts: 957
Loc: Germany
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