Iowa Blues - Breed thread and discussion

[Hurley]

I'll hatch some, would love to see how they grow out and I'm planning to raise up a good sized batch over the summer, anyway. Got the big incubator ready to fire up any time.

Would be fun to do some data collection, my favorite part of research. I can work on a database/check list of traits to record on the chicks and gather photographs for looking back at once they grow out. May help us spot certain indicators of mature appearance.

 

[Hurley]

I've only got one birchen left here, but will definitely pay attention to her chicks to see if anything pops forward. She was a late 2015, still filling out. Her type is reasonable, not the worst or the best of the flock. She's got quite a bit of mossiness on her (which I take to be a type of black restriction).

 

[IowaBlueCurt]

Connie,

Yes, my guess is the mossiness is the key to start working in the right direction. Do you remember about a year and a half ago we had some conversation about the mossey females. At this time breeders were still working on the standard birchen color. Kari has mentioned that the mossey females weren't pretty, and we all agreed with her. At that time I suggested that we use the mossey females to try to pull back the melanization by breeding them to light colored silvers or light colored clean smokeys if anyone would have had one at that time. Glenn and Candy started doing that and now we're starting to see some Er based birds with melanizer reducers showing up. Both of those flocks have the largest number of chestnut chicks hatching. However, there are still a high percentage of chestnut chicks growing up looking too dark yet.

Kari,

If you have a clean smokey (or if you still have that clean smokey you hatched out of the eggs you had gotten from me as she was pretty light colored), I would suggest putting her on your charcoal male as well. I think there'd be a better chance of getting a chestnut that would mature with reduced melanizers.

 

[Hurley]

Yes. Would be interesting to put the lightest of the silvers over the mossiest Birchens and Charcoals as well. You may see more restriction in the heterozygotes and at least then you know what is underlying the ER gene since silvers are always homozygous. Would help to be able to make comparisons when the E genotype is known for sure, not guessing what the 2nd gene is (since ER covers all, but is still influenced differently, potentially). I bet it won't be long before we start having some black restriction at maturity. The genes are still in there.

 

[Wappoke]

1) As Connie shared in the quote above, the desired coloration isn't a 'set' coloration as currently defined in the standard breeds. We aren't looking for straight autosomal barring, or straight penciling. The appearance is what would be imagined if both patterns were competing for the ability to express themselves. Already that complicated the genetic understandings. Naturally, that leads to the possibility that the desired coloration is a hetero on the e locus. Hopefully this isn't the case, but presently we don't know. What has made this project so difficult is that the Iowa Blue doesn't express their genes the way one would expect a "textbook" example to express.


you should get what you want ( competing patterns) if the female is birchen or brown at the E locus, heterozygous at the dark brown locus and homozygous at the pattern locus.

concentric penciling is due to the brown locus and the pattern gene if the dark brown gene is added to the genotype then the bird has autosomal barring

eb/eb Pg/Pg is concentric penciling
eb/eb Pg/Pg Db/Db is autosomal barring


2) Per reading the discussion surrounding the game male and female I posted, it was suggested that maybe dun was involved there and that they might be dun silver, however the geneticists working on those birds I posted stated that based on various breeding crosses it was determined they were Er Db Pg S with modifiers restricting the melanizers. Per their discussion dun was ruled out.

the only diluter left that would produce the color is lavender

3) Now, looking at the game male his breast is not where we were wanting to go. Understand that he's not the perfect example of where we desire to go, but gave the first proof nearly two years ago when I found this info that it was possible to restrict the melanizers on a birchen base (something that was argued to be previously impossible).


Do you mean dilution or restriction. Diluters dilute black to a gray color or dilute red to a cream color. Restrictors restrict black pigment to a certain area of a bird.

Diluters are also inhibitors becasue they inhibit black pigment or red pigment..The cream gene ig is an example of a diluter/inhibitor.


I will add more later

 

[Hurley]

eb/eb Pg/Pg is concentric penciling
eb/eb Pg/Pg Db/Db is autosomal barring

The thing that confuses me about our birds is that I've not had any adults grow out fully barred, not one extending beyond juvenile plumage out of hundreds. Has anyone else? The juvenile plumages exhibits the barring, but I have yet to have any end up barred as adults. By 1/4 - 1/2 - 1/4 odds of db vs. Db in incomplete dominant fashion, we should have had some barred adults, shouldn't we? Because then you could keep barreds to breed to penciling to get 100% hets with the patterns fighting, but that thought process. If the key to the changing patterns for our guys is simply db/db vs. Db/db vs. Db/Db, then we really should have had a fair number of barred birds in adult plumage with the number of IBs starting to be produced. We see some more penciled than others, but I haven't seen the same with barring. I agree that we've got mix matching of the genes in our guys, but where are the barred phenotypes?

Also, what adds the stippling/fading over the back of the hens where the pattern fades/blurs?

As for the dilutors, I'm trying to figure out the mechanism in Herman and the like. Seems like they are lighter at the tips of the feathers, which would be more in line with inhibition of black extension to me, but it isn't cut and dried on / off like lacing. The feathers seem to fade gradually out and the effect seems to enhance with age, or so I've been told. Can anyone confirm or has anyone seen these in present day flocks to tell us what the whole feather looks like?

 

[IowaBlueCurt]

I've wondered the same thing concerning Db and the lack of solidly autosomal barred individuals. I've had one charcoal male that had a decent amount of autosomal barring at adulthood but didn't express the trait until his adult plumage grew in, which was weird and not "normal' of the gene.

Is it possible there are modifiers acting on the autosomal barring present in our stock? I've seem pictures of Fayoumi and Ostfrischische in Europe which express a shattered look to their barring even though they are DbDb. I suppose in the purebreds the 'perfect' bird would be free of the shattering and so our autosomal barred breeds today have been rid of the modifiers which shatter the color and have been bred to express modifiers which make the barring clear and precise. Thus giving most the impression that autosomal barring must be clear and clean as they haven't seen birds which have expressed a shattered appearance before.

 

[IowaBlueCurt]

"Restrictors restrict black pigment to a certain area of a bird."

Wappoke - I believe we are working with a restrictor of some sort and not a diluter. What has made this so difficult is that geneticist Phil Sponenberg and other amateur chicken geneticists from Europe believe that it is the modifiers restricting the black pigment and not a specific gene modifying the pigment. Phil was unable to isolate the genes responsible for creating the coloration and suggested that it was a possible mutation, but to him seems less likely. Normally, I wouldn't put much credence on it being a mutation as everyone seems to say that when they have something in their flock they can't explain, however, Phil has spent decades studying poultry genetics at Virginia Tech, so his suggestion of a mutation shouldn't be cast off too quickly. That said, his analysis was this -

1 Option) Unknown modifier or modifiers allowing small amounts of black pigment to remain in the feather, while removing small amounts of black pigment causing a 'bluing' effect. These modifiers are not the restricting genes themselves (Db, Co, etc.) but modifers altering the color and pattern genes. If this is the case, the modifers would appear to have a very limited ability to fully express. Also their expression would be vary random and sporadic throughout the length of the feather which is not how the restrictor genes operate.

2 Option) A possible mutation.

What are your thoughts on this? I'm glad you jumped into this discussion as it's nice to have another genetic mind at work here.

 

[Wappoke]

"Restrictors restrict black pigment to a certain area of a bird."

Wappoke - I believe we are working with a restrictor of some sort and not a diluter. What has made this so difficult is that geneticist Phil Sponenberg and other amateur chicken geneticists from Europe believe that it is the modifiers restricting the black pigment and not a specific gene modifying the pigment. Phil was unable to isolate the genes responsible for creating the coloration and suggested that it was a possible mutation, but to him seems less likely. Normally, I wouldn't put much credence on it being a mutation as everyone seems to say that when they have something in their flock they can't explain, however, Phil has spent decades studying poultry genetics at Virginia Tech, so his suggestion of a mutation shouldn't be cast off too quickly. That said, his analysis was this -

1 Option) Unknown modifier or modifiers allowing small amounts of black pigment to remain in the feather, while removing small amounts of black pigment causing a 'bluing' effect. These modifiers are not the restricting genes themselves (Db, Co, etc.) but modifers altering the color and pattern genes. If this is the case, the modifers would appear to have a very limited ability to fully express. Also their expression would be vary random and sporadic throughout the length of the feather which is not how the restrictor genes operate.

2 Option) A possible mutation.

What are your thoughts on this? I'm glad you jumped into this discussion as it's nice to have another genetic mind at work here.

Chickens are one organism that is prone to mutations and still can survive because man uses the mutations to benefit his fancy for chickens. From what I can gather, the genes that produced an Iowa Blue have become, for the lack of a better word, extinct. If you do not have them in your iowa blue population, you will never see them be expressed.

The way I read #1. Sponenberg is indicating the bluing effect is not due to the restrictors because restrictors do not work like the modifier; a modifier would affect the way the restrictor works. The modifier would cause the black that is restricted to certain areas of a bird's body to be changed to a blue color.

All inhibitors act in a way that changes color that we view in a feather. In a way you could think of an inhibitor as a modifier. The inhibitor causing changes in the way color is normally added to a feather. Dominant white is an inhibitor because of the way it effects how black pigments are packaged on the cell level. The cells in the feather follicle do not recognize the way the black pigments are packed so they destroy the package and the pigments. No black pigments so you get a white feather. The lavender gene affects the number of black pigment packages (melanocytes) that are transported to the feather follicle cells. Some make it to the follicle so you get a gray feather. A mixture of black and unpigmented areas on the barbs in the feather make a gray feather.

 

[Hurley]

Chickens are one organism that is prone to mutations and still can survive because man uses the mutations to benefit his fancy for chickens. From what I can gather, the genes that produced an Iowa Blue have become, for the lack of a better word, extinct. If you do not have them in your iowa blue population, you will never see them be expressed.

That is the question. Is the gene (are the genes) extinct?

Thought 1) Was that effect caused by a single gene? If caused by a single gene, with the degree of line breeding/in breeding performed, it would be very surprising to have never seen it pop up if present in present day flocks, but there is the chance it is bouncing around under the radar if it were recessive. In breeding would have been the quickest way to pick that up, though, and there has been plenty of that, given how many bottle necks the breed has encountered.

Thought 2) Was the effect caused by a pair/group of genes in concert, only expressing if all present (for instance)? More of positive chance the genes are still in the mix, just haven't hit the jackpot yet. (This goes with thought 4.)

Thought 3) Was the original look a selectively bred look and we've lost that selection? If yes, can we push back towards the look through selection?

Thought 4) Was the original look on the ER locus, but unfortunately masked by black extension? If yes, are we getting back closer with the charcoals?

Thought 5) We aren't going to know until we test them out. We've put a lot into silvers the last two years and now have a better handle of the range of that morph, and they are gorgeous, though the roosters have been frustrating. We haven't explored the extent of phenotypes possible with the charcoal population yet, and I think this begs performing to see if any surprises show up with numbers and multiple line crosses to see if we can hit that magic "jackpot" combination. It would be so much nicer if we had a genetic blueprint to follow, true. We also haven't had the color photo of the original appearance up until recently so it has given us a lot to think about and more ground to explore. There is the chance that the blued out black appearance is a genetic combination that is lost to us, but there is a chance that it is not. We're just not going to know until we try. I would say I agree that the best chance lies in the charcoal/birchen lines on the ER locus, from the most recent historical findings and discussions. We're pretty much with charcoals where we were with silvers just a few short years ago. Can't wait to see what can be produced from the ER end of the spectrum!