Ameraucana Forum
The Official Ameraucana Forum => Breeding => Topic started by: Lee M Hethcox on March 05, 2015, 06:02:59 PM
-
If you have a pure Ameraucana that is a cross of two colors, do you call it an AOC Ameraucana? I saw someone somewhere state that it's not an Ameraucana then, but an Easter Egger. I consider EEs to be Am/something else crosses.
-
Lee,
I've seen on the BYC forum where posters say Easter Eggers are Ameraucanas crossed with another breed. That would be one way to make an Easter Egger, but there are many other ways that don't involve using a "standard" bred chicken.
The club came up with this definition and I assume we are still using it (it is posted on our site's FAQ page)...
The Ameraucana Alliance defines an Easter Egg chicken or Easter Egger as any chicken that possesses the blue egg gene, but doesn’t fully meet any breed descriptions as defined in the APA and/or ABA standards. Further, even if a bird meets an Ameraucana standard breed description, but doesn’t meet a variety description or breed true at least 50% of the time it is considered an Easter Egg chicken. By definition an Easter Egger is not a breed of chicken.
I never fully agreed with the definition, but a majority did and we've used it since.
AOV can be misleading and here is what I've said regarding it...
For our club AOV has historically meant to mean any variety that isn't one of the recognized varieties. With, black, blue, blue wheaten, brown red, buff, silver, wheaten and white being the only varieties that are recognized/accepted by the APA/ABA, lavender, splash, black gold, chocolate and All Other Varieties are considered AOV, by us, at our sanctioned meets.
-
Following....
This is a question that comes up often in the Easter Egger Chickens group on FB. My statement to someone trying to deviate and call an off color bird, which is especially known to be a cross of two accepted colors... that by the rules and definition currently in place, it is called an Easter Egger. It took me about a year to come to peace with that. But now, as I begin to breed for SOP, I feel it's a nice way to say they are "mutts." Mutts/EE are not a bad thing, they are just not what a true breeder strives for. Until someone starts a "project" color. In doing so, the new color is bred with intent and by the plan of the APA, to become recognized as a color variety within the Ameraucana breed. Until such time that definition changes, I am under the impression they are technically EE until approved. If this is not correct, please let me know?
I do my best to help educate those who ask this question. And this is how I put it to them.
-
Some folks feel a mutt dog is a great pet and I look at chickens kinda like that. A mutt, mixed-breed or Easter egger may be what some prefer for a backyard flock. Only when it comes to exhibition and standard bred animals we have to go with whatever a written "standard" dictates.
I've seen on the BYC forum where some claim that so called project birds, with the blue egg shell gene, are Easter eggers. It just isn't true according to our definition though. As an example, lavender Ameraucanas breed true 100% of the time. That is 50% or more so according to the definition they are Ameraucanas, even though not recognized/accepted by the APA/ABA.
Say some day splash becomes an accepted variety. Then if you "cross two accepted colors" (varieties), black and splash you would actually get another accepted variety, since all the offspring would be blue. And even though blue is accepted it only breeds true 50% of the time, so in my opinion, according to the EE definition they are closer to being Easter eggers than lavenders. ;)
-
Thank you all for the clarification..I understand what the definitions are now. Here's a slightly related question...somewhere in the forums (which I'm not great at navigating yet), I saw someone state that the APA standards are "strictly by phenotype (appearance, right?) not actual genotype".
Is that true? Is that why Icelandics are considered a "landrace" because you can't pin them down by phenotype?
Lee
-
Most of the standards for breeds were written well before modern genetics was very well understood. So yes, the standards are based on phenotype.
I believe one of the requirements for a variety to be recognized is that it has to breed true at least 50% of the time. That is why the color "blue" is recognized. If the requirement were "more than 50%" there is no way blue could qualify, as blue to blue matings yield only 50% blues as a long term average.
-
Yes Mike is right. That is how Walt Leonard, the APA Standards Chairman, explained it to me.
-
Is that why Icelandics are considered a "landrace" because you can't pin them down by phenotype?
Wikipeda says Icelandics (https://en.wikipedia.org/wiki/Icelandic_Chicken) are a "breed", yet under "Landraces" they say...
https://en.wikipedia.org/wiki/Landrace
Landraces are generally distinguished from cultivars, and from breeds in the standardized sense, although the term landrace breed is sometimes used synonymously instead, as distinguished from the term standardized breed[5] in contexts in which the word breed is used expansively.[5]
Icelandic chickens, by definition are a landrace and tend to be relatively genetically uniform, but are more diverse than members of a standardized or formal breed. (http://tend to be relatively genetically uniform, but are more diverse than members of a standardized or formal breed.)
In describing them they use the word "various" for skin color and combs. So, they are a landrace because of their origin and are "relatively genetically uniform", which would mean they would look somewhat similar (phenotype). By APA definition they are not even a "breed" whether recognized/accepted or not.
-
I haven't been on BYC in several years now so I have no idea what it's like now but, from my previous experience, I'd take anything said on there with a grain of salt. The problem with BYC, FB, and many online sites is that things get posted, and oftentimes false, and yet folks then run with it and repeat it which then gets repeated again. And again and again and again.
Also, I agree with you John about the definition of Easter Egger. I don't agree wholeheartedly with it either. Case in point, as I've said before, I have maintained a closed flock for 8yrs and got my start from someone who's bred the variety for 30yrs or so. As part of my breeding plans, at one point, I was trying to eliminate the brown-egg gene modifiers to remove the greenish tint amongst other things. I remember identifying the brown as coming from my #13 line and I got rid of them all. Out of either that year's, or the next following year's crop, I got a couple pullets that laid a white egg. I then used those pullets to color test my males.
Many would try and tell me that those W & BW Ameraucanas laying the white egg weren't Ameraucanas. Additionally, as I imagine everyone here knows, when I'd mate a single Mb bird to another single Mb bird, I'd get some clean faced birds. Supposedly they aren't Ameraucanas either. Yet, if I were to breed that bird back to a double Mb bird, I'd get all single Mb birds - which could be shown!
-
Many would try and tell me that those W & BW Ameraucanas laying the white egg weren't Ameraucanas. Additionally, as I imagine everyone here knows, when I'd mate a single Mb bird to another single Mb bird, I'd get some clean faced birds. Supposedly they aren't Ameraucanas either. Yet, if I were to breed that bird back to a double Mb bird, I'd get all single Mb birds - which could be shown!
Those white egg layers that could be show quality as Ameraucanas wouldn't even meet our definition of Easter Egger. ;D
-
Need a "Like" or Thumbs Up button on here, John. :D Btw, I just identified one of my new pullets that's laying a white egg. She's a Wheaten #8 and I actually took her to the show 2wks ago! One of my nicer W's but I'm thinking I won't breed her now. Funny thing is, she's got a W and 2 BW full-blood sisters that all lay a nice blue egg? ::)
-
Sometimes a pullet will start out laying a paler blue egg, and as time goes by the blue pigment fades out to white, or nearly white. I have always figured those were hetero for the O gene (blue egg gene), but have not been afraid to use them if they were very good in other respects. It's a simple fix. But I would not keep male breeders from them, as they could also be hetero for O.
-
Mike, you mention the O gene. I've seen that mentioned in the past but I read something last year about some university in England (or Australia or somewhere across the pond) doing like a 4-5yr study and determined that the blue in the egg was caused by a retrovirus. Oh heck, rather than try to recall I just went and did a Google. There a real technical report contained in this but this is easier for me to understand: http://www.nottingham.ac.uk/news/pressreleases/2013/august/unscrambling-the-genetics-of-the-chickens-blue-egg.aspx
So, have you heard about this? If'n I'm reading this correctly it's the retrovirus that connects itself to the DNA. What struck me was the part that says, "It's quite remarkable – retroviruses are generally considered to integrate at random locations in the genome, and so the chance of a retrovirus integrating at more or less the same location in two chicken populations is extremely low. Moreover, when appearing in the population, the unusual egg coloration must have attracted the attention of the owners, who must be praised for having selected the trait in subsequent breeding.†Wouldn't that indicate that there is no "blue egg gene" and that it's the virus causing the blue color from the bile to be extracted and inserted into the egg?
-
Mike, you mention the O gene. I've seen that mentioned in the past but I read something last year about some university in England (or Australia or somewhere across the pond) doing like a 4-5yr study and determined that the blue in the egg was caused by a retrovirus. Oh heck, rather than try to recall I just went and did a Google. There a real technical report contained in this but this is easier for me to understand: http://www.nottingham.ac.uk/news/pressreleases/2013/august/unscrambling-the-genetics-of-the-chickens-blue-egg.aspx
So, have you heard about this? If'n I'm reading this correctly it's the retrovirus that connects itself to the DNA. What struck me was the part that says, "It's quite remarkable – retroviruses are generally considered to integrate at random locations in the genome, and so the chance of a retrovirus integrating at more or less the same location in two chicken populations is extremely low. Moreover, when appearing in the population, the unusual egg coloration must have attracted the attention of the owners, who must be praised for having selected the trait in subsequent breeding.†Wouldn't that indicate that there is no "blue egg gene" and that it's the virus causing the blue color from the bile to be extracted and inserted into the egg?
Very interesting article. Thanks for sharing it. I remember reading something similar on worldpoultry.net It's wild to think that a retrovirus introduced the beautiful blue colour! :)
-
Very interesting article.
I think it is the same article we have a link to on our Links to chicken genetics sites (http://ameraucanaalliance.org/forum/index.php?topic=28.0) tread, but with on a different site. Not to take away from the subject here, but that is a pinned topic for easy reference in the future.
-
Mike, you mention the O gene. I've seen that mentioned in the past but I read something last year about some university in England (or Australia or somewhere across the pond) doing like a 4-5yr study and determined that the blue in the egg was caused by a retrovirus. Oh heck, rather than try to recall I just went and did a Google. There a real technical report contained in this but this is easier for me to understand: http://www.nottingham.ac.uk/news/pressreleases/2013/august/unscrambling-the-genetics-of-the-chickens-blue-egg.aspx
So, have you heard about this? If'n I'm reading this correctly it's the retrovirus that connects itself to the DNA. What struck me was the part that says, "It's quite remarkable – retroviruses are generally considered to integrate at random locations in the genome, and so the chance of a retrovirus integrating at more or less the same location in two chicken populations is extremely low. Moreover, when appearing in the population, the unusual egg coloration must have attracted the attention of the owners, who must be praised for having selected the trait in subsequent breeding.†Wouldn't that indicate that there is no "blue egg gene" and that it's the virus causing the blue color from the bile to be extracted and inserted into the egg?
Royce, the retrovirus was just the cause of the genetic mutation. It is still the O gene that passes on the blue egg trait from one generation to another.
Mutations of genes happen. Once they are modified or changed they are passed on like any other gene is. From the text of the original article, "Oocyan is an autosomal dominant trait in chicken resulting from an accumulation of biliverdin in the eggshell, leading to blue/green shelled eggs . . ." Terms like autosomal dominant refer to genes, not viruses. At least that is the way I'm understanding it.
-
I hear ya, Mike, about genetic mutations being passed on to subsequent generations once they occur. That makes sense. And no doubt you know a whole lot more than me about genetics that I do. But what's confusing me are a couple of things.
The first is the narrative that says, "A retrovirus is a virus that, unlike most cellular organisms, carries its genetic blueprint in the form of ribonucleic acid (RNA). It reproduces itself in a host cell using a special enzyme called ‘reverse transcriptase’ which transcribes RNA into deoxyribonucleic acid (DNA). This makes it possible for genetic material from a retrovirus to become permanently incorporated into the DNA of an infected cell." This doesn't sound like a gene mutation to me. Am I missing something?
Second is the following statement that says, "In this case, the retrovirus’ effect was to trigger an accumulation of a green-blue bile pigment called biliverdin in the eggshell as the egg develops in the hen." This sounds like it's the retrovirus that's the "trigger"?
Under the Results and mapping intervals, it says "Variant effect prediction indicates that none of the SNPs results in non-synonymous mutation (Table 1). Structural variant (SV) analyses identify two SVs (c26830 and c129246) common to the oocyan chickens. SV c129246 is located in the PDE3A gene, ~65 kb upstream of the target interval; whilst c26830 is within the target interval, in the intergenic space between the two candidate genes, SLCO1C1 and SLCO1B3." This sounds to me like the retrovirus is inserting itself between these to genes.
Then there are these two statements, "Quantitative real-time PCR analysis of European oocyan chicken indicates over-expression of the SLCO1B3 gene (P<0.05) in the shell gland and oviduct. Predicted transcription factor binding sites in the long terminal repeats (LTR) indicate AhR/Ar, a modulator of oestrogen, as a possible promoter/enhancer leading to reproductive tissue-specific over-expression of the SLCO1B3 gene."
And "Based on these results, we used the UB gene as the internal control for normalization of the levels of expression of the four target genes (SLCO1C1, SLCO1B3, HMOX1, and PDE3A). The average relative quantitative (RQ) values are presented in Table S2 together with significance values following Student's t-test. For the qRT-PCR runs, each target gene was analysed in triplicate in each tissue. Significant (P<0.05) over-expression of SLCO1B3 is observed in the shell gland (~19 fold increase) and oviduct (~180 fold increase) of oocyan chickens (Figure 3). The EAV-HP integration is in opposite orientation to its solute carrier neighbours, and the over-expression of SLCO1B3 suggests the retrovirus to be acting as an enhancer insertion. We found no significant association between blue eggs and the over-expression of HMOX1."
What is confusing to me here is that there is no mention of an "O gene" anywhere.
In the first paragraph of the "Discussion" it says, "The close genomic proximity of the EAV-HP integration to SLCO1B3, its unique presence in oocyan chickens and the tissue-specific over-expression of the solute carrier, known to transport bile salts such as biliverdin, strongly supports the retroviral insertion as the causative mutation of the oocyan phenotype in Mapuche fowl and their modern (European and North American) descendants."
This seems to me to be saying the retroviral insertion is what's causing the blue color since we know that phenotype is appearance vice genotype.
My eyes are starting to glass over from all this stuff so I'm gonna end with this and finish reading the paper again tomorrow. But this paragraph here seems to indicate to me that the retrovirus causing the blue egg is a continuing phenomenon and not a one time thing that just created a mutation that was then passed down.
"The EAV-HP retrovirus lacks a pol domain, rendering it self-replication defective [20], and so it would likely require an infecting virus acting in trans for it to proliferate. It is entirely possible that an exogenous virus might facilitate the proliferation of EAV-HP within the genome as has been demonstrated previously for the Rous Sarcoma virus (RSV; [21]). The close genomic proximity (23 bp) of the different insertion sites, observed in Mapuche fowl and Dongxiang chicken, suggests a possible integration site preference for EAV-HP, as has been suggested for several retroviruses [22]. Active ongoing insertion and segregation of EAV-HP in chicken populations have been shown with a typical prevalence of 10 to 15 copies per genome [23], [24]. Such EAV-HP genome dynamism is thought to play a recombinant role in the emergence of exogenous avian retrovirus ALV-J due to a uniquely similar env sequence with the ALV-J prototype HPRS-103 [23]. An intact EAV-HP, including pol gene, has previously been identified in G. sonneratii [25], and EAV-HP proviruses with intact pol and env genes have also been found in domestic chicken [23]. Borisenko [26] found the EAV-HP pol gene to be more closely related to that of RSV than of other retroviridae. The expressed EAV-HP transcripts in some lines [23], [27] and pol sequence homology with RSV support therefore the possibility that a helper virus might be contributing to the continued segregation of EAV-HP."
So, with all that being said, what am I missing and where am I going wrong? PLEASE educate me and maybe some others. Oh great Master Obi-Wan Kenobi, do enlighten us!! :o