Page 3 of 9 < 1 2 3 4 5 6 7 8 9 >
Topic Options
#111657 - 02/05/14 05:57 AM Re: wildtype only lighter [Re: KazJaps]
Theropod Offline
Coop Cleaner

Registered: 12/23/13
Posts: 189
Loc: Missouri, USA
A Wheaton, other than Whitehackle, cockerel (eWh/eWh) will be acquired for breeding her to late in season. Early season efforts will concentrate on generating more like her. This type of experiment has been done before giving product already mentioned. Only difference will be this individual will be used to make cross. I hope all this is not result of parties perceiving a lack of experience or formal training in genetics. If all wanted is better documentation, then I will let it slide.


Edited by Theropod (02/05/14 08:02 PM)

Top
#111658 - 02/05/14 06:09 AM Re: wildtype only lighter [Re: Htul]
Theropod Offline
Coop Cleaner

Registered: 12/23/13
Posts: 189
Loc: Missouri, USA
Originally Posted By: Htul
Originally Posted By: Theropod
This shall be addressed using scientific rigor. A family will be genetically fixed to be homozygous for allele in question with test matings used to confirm. Then I will take suggestions on what to cross resulting fowl with to test your hypothesis allele in question is either dominant wheaton or recesive wheaton.


Dominant wheaten is a strange beast - and apparently can behave differently on different genomic backgrounds (eg. refer to Kimball(1960) - http://ps.oxfordjournals.org/content/39/3/768.full.pdf - where RJF/wheaten game gives more obviously wheaten chicks than the BBR game/wheaten game - which results in intermediate chicks); so, just because an allele is fixed in one population, and used as a test cross, is no assurance that it will behave in the same manner against another genetic background (though both may superficially appear similar).

Whilst your experience indicates that you have at least something that strongly resembles Kimball's "RJF/wheaten game" in behaviour, I would also agree with Henk and Kazjaps that the earlier image shows a e+/eWh pullet : to me, the "text-book picture" of e+/eWh is the image that Kazjaps referred to earlier from choc (from: http://www.the-coop.org/forums/ubbthreads.php?ubb=showflat&Number=37021):



that being said - I am not suggesting that the 'lightened' effect that you have observed is necessarily a result of e+/eWh: but that the previous pullet in question, in my opinion, is highly likely to be e+/eWh based.




Why with "text-book" example of heterozygous individuals, no homozygous individuals shown representing wild-type and alternative? Such gives me more confidence in what is being asserted.

Top
#111659 - 02/05/14 07:06 AM Re: wildtype only lighter [Re: Theropod]
Theropod Offline
Coop Cleaner

Registered: 12/23/13
Posts: 189
Loc: Missouri, USA
This hen is of particular importance and picture of her should have been posted in the very beginning. She mother to both pullets at start of thread. She is the one I suspect to be source of variation required to create light colored pullet in question. Since breeding season of 2011 she has produced just over 60 pullets. Most of those pullets looked like her or had a lot of brown on body coming from fathers. Now in line breeding mode where her sons, this season grandsons, and next year great-grandsons, we started to seeing the light morph pop up. Light morph has not been produced by male side line breeding efforte even though they have gone through a similar number of generations. This case even when she has been on of the original dams used to start line-breeding on cockside.



She is nearly as dark has her pullet daughter on right side of lawnmwower. She also lacks the allele coding for barring on feathers and funky pattern on pellage so overall she is a very good approximation of wild-type.


Hen below is daughter of hen above thus half-sister to blanched pullet. This hen carries a complicating allele although breast color and overall coloration is lighter (like blanched pullet) than another morph with barring pattern on secondaries and otherwise wild-type base coloration.








Edited by Theropod (02/05/14 10:53 AM)

Top
#111660 - 02/05/14 10:31 AM Re: wildtype only lighter [Re: KazJaps]
Theropod Offline
Coop Cleaner

Registered: 12/23/13
Posts: 189
Loc: Missouri, USA
I took time to read Kimball (1960). His observations are most similar to mine except for details relating to chick down. Mine have black stripes although central brown stripe is narrower relative to wild-type. I need to check down coloration of adult feathers to determine if they are white (wheaten / *) or grey (non-wheaton). Additionally, Kimball does not indicate Wheaten allele he studied operates from e-locus. Therefore eWh may not be appropriate in my situation. Having two Wheaton alleles operating from different loci is certainly plausible owing to physiological mechanism of the operation.

Also look at feathers presented in following thread. Pullet also carries the blanching allele although another complicating allele also involved. Down at base of feathers is not white even though her breast is of the blanched color morph.

http://www.the-coop.org/forums/ubbthreads.php?ubb=showflat&Number=111317#Post111317

I will pull feathers from sire of blanched pullet and check those was well. Based on eWh hypothesis, dam to pullet in question does not carry eWh, so sire must.

Top
#111669 - 02/05/14 08:01 PM Re: wildtype only lighter [Re: Theropod]
Theropod Offline
Coop Cleaner

Registered: 12/23/13
Posts: 189
Loc: Missouri, USA
Cock below is was mated back to his mother to yeild blanched pullet. To my eye he does not repressent a Wheaton adult male, certainly not a homozygous repressentative. Most obvious character is coloration in hackles varies to give a lighter band near base and were saddle is markedly lighter than back. Best picture I have.



According to Kimbal (1960)the underfluff of Wheaton birds, homozygous and heterozygous for Wheaton in "black-breasted red", should be white while those homozygous for wild-type should be gray. Following image depicts sampled feathers from sire of blanched pullet.

To my eyes the under fluff of sampled feathers is not white and can be interpretted as you like. This to me is evidence he does not carry a Wheaton allele. Parentage of blanched pullet is certain. This means mother below is a carrier or pullet is a recepient of a novel wheaton allele derived through mutation in one of her parents. Odds of that are low in my opinion.



At next opportunity pullet will be sampled for underfluff color determination.

Could similar examples be acquired from the "textbook examples" posted previously in thread?

Top
#111674 - 02/06/14 04:35 AM Re: wildtype only lighter [Re: Theropod]
Piet Offline
Flock Leader

Registered: 10/07/10
Posts: 262
Loc: Belgium
grey or black underfluff colour does not rule out wheaten

Top
#111676 - 02/06/14 05:20 AM Re: wildtype only lighter [Re: Piet]
Theropod Offline
Coop Cleaner

Registered: 12/23/13
Posts: 189
Loc: Missouri, USA
Kimball (1960) used that as a key character for defining Wheaton. He also indicated extended black (E) at the e-locus whether homozygous or heterozygous could cover effects of Wheaton allele even when latter homozygous. You may know additional examples of other genes coding for increased eumelanin in feathers that can mask effects of Wheaton? Very importantly, do birds I have pictured appear to carry those Wheaton masking genes?

Top
#111678 - 02/06/14 08:03 AM Re: wildtype only lighter [Re: Theropod]
KazJaps Offline
Classroom Professor

Registered: 08/30/02
Posts: 2792
Loc: Australia
Kimball had some unusual genetics theories (not uncommon for other researchers to disagree at times).

Eg, Smyth in PB&G, p118:
Quote:
An interesting gene cluster hypothesis for the E locus was proposed previously by Kimball (1954a, 1954b), but was flawed by incorporation of the nonexistent columbian allele (e) into a multiple allelic series with E and e+.


See the following paper:
Elliot Kimball
Genetics of Birchen Plumage Pattern in the Fowl
Poultry Science (1954) 33 (3): 472-481 doi:10.3382/ps.0330472
Full paper.
Eg, Fig 1 schematics

E || e^+ || ER
---------------------------
Br || bR || BR

B = Black (b = non-black)
R = restricted (r = non-restricted)
*notation like dominant/recessive inheritance

* E allele = Br (black, no restriction)
* e+ allele = bR (no black, restriction)
* ER allele = BR (black, restricted)

It was like he was suggesting 'independent pattern units' of an allele, & maybe nearby clusters.

Also the ER & 'restricted' notation was based on early 1900's genetics research, using blue birds on solid eumelanin base. 'Restricted' was in reference to homozygous phenotype of blue (whitish), had little to do with E locus alleles phaeomelanin/eumelanin distribution.

But, Kimball's test breeding data & observations are useful.

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

This following post has a summary on the early history of wheaten research & the different inheritance modes, phenotypes noted. Also discusses why the name changes to Dominant Wheaten & Recessive Wheaten (ie Kimball's Wh was later established as an allele of the E locus, therefore name change to eWh, & Hollander called it "Dominant Wheaten" to distinguish it from ey, which was also changed from "Yellowish White" to "Recessive Wheaten"):
http://www.the-coop.org/forums/ubbthreads.php?ubb=showflat&Number=30535#Post30535


Eg, have a look at Morejohn's paper:

PLUMAGE COLOR ALLELISM IN THE RED JUNGLE FOWL (GALLUS GALLUS) AND RELATED DOMESTIC FORMS
(Morejohn, V. 1954)
http://www.genetics.org/cgi/reprint/40/4/519.pdf

*There are some E locus allele chick down illustrations, some hets, but unfortunately Morejohn didn't test breed eWh Dominant Wheaten.

Quote:
Why with "text-book" example of heterozygous individuals, no homozygous individuals shown representing wild-type and alternative? Such gives me more confidence in what is being asserted.


Unfortunately these researchers didn't publish het. wheaten adult hen photos (apparently Smyth et al. also found eWh het. phenotypes with eb & ER too)!! We have to go by test breeding data & descriptions given. There are some old posts with photos of Smyth's ey tester line (obtained by Campo et al. for their research into Spanish breeds) & there was a post of Morejohn's ey mutant Red Jungle fowl. On the rare occasion, you can come across some photos in journal papers, eg segregated ER (from Fayoumi), Smyth's eb tester line, his ebc Buttercup segregates, etc...

Top
#111679 - 02/06/14 08:28 AM Re: wildtype only lighter [Re: KazJaps]
Theropod Offline
Coop Cleaner

Registered: 12/23/13
Posts: 189
Loc: Missouri, USA
Thanks KazJaps,

I will follow leads you provided tonight.

Looks like I am obligated to the test breeding regardless with known controls. When eWh cockerel acquired, I will get a full sibling pullet as well to generate reference chicks. Looks like a couple dozen birds will be reared this summer just to investigate genetics behind a morph that never really was considered important.

Top
#111680 - 02/06/14 08:31 AM Re: wildtype only lighter [Re: KazJaps]
KazJaps Offline
Classroom Professor

Registered: 08/30/02
Posts: 2792
Loc: Australia
Note that Morejohn's ey ("Yellowish White") is a wheaten phenotype with dark undercolour (same as e+).

There are old threads here discussing the fact that undercolour can be variable with E locus alleles (particularly males), due to other modifiers. Ie, white undercolour & bleaching of wing flights, hackles, tails, etc can occur on multiple E locus alleles (personally seen it on eWh, e+/e+ & ER bases). That is why I advised against Whitehackles to test with (where this white bleaching trait is not selected against, & is an extreme example).

--------------------------
Here is a description given by an Australian OEG breeder on this wheaten/wild-type intermediate phenotype (not a text book - these are Game breeders):

* Note, in this context:
"Partridge" = e+ wild-type, salmon breasted female (UK OEG full name is: "Black Breasted Red - Partridge)".
"Wheaten" = eWh Dominant Wheaten, wheaten phenotype female (UK OEG full name is: "Black Breasted Red - Wheaten").
The Royal Fowl, page 94
Quote:
Genetically partridge is incompletely dominant over wheaten, the F1 usually being partridge on top and wheaten on the breast.....]

[....The Wheaten chick is a lovely pure cream colour. The hybrid has some faint striping down the back and on the head or has black marks.


The author also discusses in general the variations in phenotype of multiple OEG sub varieties/lines, eg due to phaeomelanin modifiers etc. For example, "Light Reds" are traditionally wheaten based, & named after the lighter phaeomelanin. But the author notes that not all "Light Red" phenotype Game roosters are wheaten. Ie there are old beliefs with broad correlations, but not necessarily based on accurate accounts of genotypes (eg lighter phaeomelanin in roosters does not mean eWh or ey wheaten alleles).
And if not an E locus allele, segregate out mutation(s) on to e+ wild-type (much more information is known on mutation characteristics on an e+ base).

Top
Page 3 of 9 < 1 2 3 4 5 6 7 8 9 >


Moderator:  Admin @ The Coop, Henk69