What a fascinating bit of research you've thrown me!
Caveat - am not a scientist. Can understand some level of scientific articles due to many years as a medical librarian, but articles on genetics are an entirely different sort of language entirely, so my following comments are couched very much as "I think" and "I believe" and so on.
After about 30mins of very basic research, I have discovered - somewhat to my astonishment - that scientists are, indeed, at the stage of being able to identify, isolate, and "insert" genes for specific traits from one breed of chicken into another breed of chicken.
I mean ok, poultry have been doing this since time immemorial using good ol' sexual reproduction :), which over time "expresses" all the interesting things we see in poultry today. But now human scientists believe they can identity the genes responsible for (some) specific traits, splice them out, and deliver them into another chicken breed, so that the offspring of that chicken now has the new traits.
One still needs to wait for the offspring to incubate, hatch, and survive in order to demonstrate the new traits have, indeed, come through. It's not instant.
Is it reliable at this stage? That's the key question, and I honestly don't know.
Scientists can do this because chickens were the first to have the "complete" genomic sequence available, although this 2023 article seems to imply there's still more to be known: https://www.pnas.org/doi/10.1073/pnas.2216641120
So it is _theoretically_ possible that commercial poultry researchers are hoping to reduce the 3-week to 8-month wait (depending on the trait you're looking to introduce) wait to identify whether a new desirable trait has been introduced. (3 weeks if you're just looking for something that shows up as soon as a chick has hatched, such as down colour/pattern. 6-8 months if you need to know if a trait comes through in eggs, such as eggshell colour. Even longer if you want to know if a trait comes through in the next generation).
Whether they actually are - you are quite correct, we don't know. And won't know, at this point in time because of - as you accurately say - the whole commercial-in-confidence thing.
I could speculate on the *likelihood*, based on doing research around the reliability (or otherwise) of insertion of individual traits.
Leghorns are among the highest egg producers of the heritage breeds, and almost certainly feature in the commercial brown egglaying varieties. A blue egglaying, high-production layer is still very much a holy grail in commercial poultry production, and we know it doesn't yet exist - or there'd be more blue eggs on the shelves.
The fact that Cream (or Crested - two names for the same bird) Legbar is NOT a commercial layer bird rather suggests that the introduction of the blue eggshell does reduce egg production to a level that's impractical on a commercial level.
And, in fact, the article doesn't answer the question about egg production - because it was published in 2020, and the experiment hadn't finished yet. The Leghorns did seem to be laying blue eggs, without any need to crossbreed them with Aracuanas - so the genetic modification did work at that level. I think.
But answers around the inheritability of the trait, and the reliability of the laying, and so on, seemed up in the air.
We also know that genetic insertion is used to create egg whites that hold particular proteins for human medicinal use. Again, using egg white for this purpose isn't new, but using "insertion" rather than sexual reproduction to create those proteins is. https://www.bbc.com/news/uk-scotland-47022070 (caveat on this one - media-friendly article, language may be imprecise and content overly generalised. But I believe it's broadly accurate).
So it's possible that commercial egglaying research is at a similar state - yes, it can be done, but the results aren't necessarily more reliable, and almost certainly not yet cheaper, than the more prosaic mating of particular birds together.
Or it is perfectly possible that isolation and insertion of very specific traits such as egg quantity, quality, and size; lack of broodiness and responsiveness to external factors; aggression/friendliness; sex-linkage; and so on, have indeed been identified and are inserted into specific parent birds in order to produce eggs that hatch into birds that contain (all? most? some?) of the necessary traits.
I honestly don't know.
And if readers have an objection to the use of genomic manipulation of this type, then maybe it's another reason to avoid the commercial egg and meat production industries wherever possible, by not buying or "rescuing" commercial layer birds, and - where possible - avoiding the consumption of eggs from commercial egg farms (impossible as that might be at times, if you don't have your own poultry).
If the origins of the Isa Brown are strictly commercial in confidence how do you know it is not GM in the strict sense in which that word is used?
What a fascinating bit of research you've thrown me!
Caveat - am not a scientist. Can understand some level of scientific articles due to many years as a medical librarian, but articles on genetics are an entirely different sort of language entirely, so my following comments are couched very much as "I think" and "I believe" and so on.
After about 30mins of very basic research, I have discovered - somewhat to my astonishment - that scientists are, indeed, at the stage of being able to identify, isolate, and "insert" genes for specific traits from one breed of chicken into another breed of chicken.
I mean ok, poultry have been doing this since time immemorial using good ol' sexual reproduction :), which over time "expresses" all the interesting things we see in poultry today. But now human scientists believe they can identity the genes responsible for (some) specific traits, splice them out, and deliver them into another chicken breed, so that the offspring of that chicken now has the new traits.
One still needs to wait for the offspring to incubate, hatch, and survive in order to demonstrate the new traits have, indeed, come through. It's not instant.
Is it reliable at this stage? That's the key question, and I honestly don't know.
Scientists can do this because chickens were the first to have the "complete" genomic sequence available, although this 2023 article seems to imply there's still more to be known: https://www.pnas.org/doi/10.1073/pnas.2216641120
So it is _theoretically_ possible that commercial poultry researchers are hoping to reduce the 3-week to 8-month wait (depending on the trait you're looking to introduce) wait to identify whether a new desirable trait has been introduced. (3 weeks if you're just looking for something that shows up as soon as a chick has hatched, such as down colour/pattern. 6-8 months if you need to know if a trait comes through in eggs, such as eggshell colour. Even longer if you want to know if a trait comes through in the next generation).
Whether they actually are - you are quite correct, we don't know. And won't know, at this point in time because of - as you accurately say - the whole commercial-in-confidence thing.
I could speculate on the *likelihood*, based on doing research around the reliability (or otherwise) of insertion of individual traits.
For eg, I just read quite an interesting - if mildly incomprehensible - article on creating blue egg-shell laying Leghorn hens. (https://ec.europa.eu/research/participants/documents/downloadPublic?documentIds=080166e5cc2aa6a0&appId=PPGMS).
Leghorns are among the highest egg producers of the heritage breeds, and almost certainly feature in the commercial brown egglaying varieties. A blue egglaying, high-production layer is still very much a holy grail in commercial poultry production, and we know it doesn't yet exist - or there'd be more blue eggs on the shelves.
The fact that Cream (or Crested - two names for the same bird) Legbar is NOT a commercial layer bird rather suggests that the introduction of the blue eggshell does reduce egg production to a level that's impractical on a commercial level.
And, in fact, the article doesn't answer the question about egg production - because it was published in 2020, and the experiment hadn't finished yet. The Leghorns did seem to be laying blue eggs, without any need to crossbreed them with Aracuanas - so the genetic modification did work at that level. I think.
But answers around the inheritability of the trait, and the reliability of the laying, and so on, seemed up in the air.
We also know that genetic insertion is used to create egg whites that hold particular proteins for human medicinal use. Again, using egg white for this purpose isn't new, but using "insertion" rather than sexual reproduction to create those proteins is. https://www.bbc.com/news/uk-scotland-47022070 (caveat on this one - media-friendly article, language may be imprecise and content overly generalised. But I believe it's broadly accurate).
So it's possible that commercial egglaying research is at a similar state - yes, it can be done, but the results aren't necessarily more reliable, and almost certainly not yet cheaper, than the more prosaic mating of particular birds together.
Or it is perfectly possible that isolation and insertion of very specific traits such as egg quantity, quality, and size; lack of broodiness and responsiveness to external factors; aggression/friendliness; sex-linkage; and so on, have indeed been identified and are inserted into specific parent birds in order to produce eggs that hatch into birds that contain (all? most? some?) of the necessary traits.
I honestly don't know.
And if readers have an objection to the use of genomic manipulation of this type, then maybe it's another reason to avoid the commercial egg and meat production industries wherever possible, by not buying or "rescuing" commercial layer birds, and - where possible - avoiding the consumption of eggs from commercial egg farms (impossible as that might be at times, if you don't have your own poultry).