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#117288 - 09/19/18 08:32 AM Autosexing gene involvement
Etienne Offline
New Egg

Registered: 09/08/18
Posts: 7
Loc: Continental Europe
Hi,
I have seen a few posts about the autosexing breeds and breeding (not interested in sex-link), which is quite interesting
What I understood so far is that the barred gene (B) is on the Z chromosome, and if present homozygously on males it shows differently on the day-old chicks than the females (or heterozygous males). This does not work with all background colors, only with some.
I made some trials on Henk69 chicken calculator
http://www.edelras.nl/Henk69/kruising.html
For example, crossing a barred rooster with a white female, which gives in F2 barred offspring out of which the recessive white has to be selected out to have an autosexing breed.
While playing around with the calculator, some crosses are way more complicated, for example the F2 of a barred rooster and a buff female. Here the selection of an autosexing breed seems quite impossible, with all the hidden genes.

What I am looking for are tree things:

1) a paper/book where the effect of the different genes are shown, especially in relation to the autosexing properties (B) or else. Does it exist?
2) A place where to look up the genetic background of different breeds. Does it exist?
3) If there are other ways to differentiate chicks at hatch (autosex, no F1), a place to look it up. I saw something about wildtype markings but do not remember where.

Can someone help me with one or another of these points?
Thanks

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#117292 - 09/25/18 01:05 PM Re: Autosexing gene involvement [Re: Etienne]
Wieslaw Offline
Moderator
Classroom Professor

Registered: 09/18/09
Posts: 3844
Loc: Denmark
Welcome to the coop.

ad 3) we have a collection of chicks at hatch here:
http://www.the-coop.org/forums/ubbthreads.php?ubb=showflat&Number=91532#Post91532

Additional sources : there are many videos on youtube from numerous hatcheries with day old chicks . You write f.eks. wyandotte chicks, and it will show from Murray McMurray hatchery. Other hatcheries have also videos. American hatcheries also show many chick pictures of the breeds they hatch on their sites.

Pictures of chicks of autosexing breeds or varieties can be googled by writing: legbar chicks.


There are also numerous old threads on other autosexing breeds as Rhodebars and Campbars (I hope there are still pictures of them)


For effects of different genes(but not necessarily in relation to the autosexing properties), you can start here:
http://www.edelras.nl/chickengenetics/mutations1.html

I will try to write more in the weekend.




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#117293 - 09/29/18 02:36 AM Re: Autosexing gene involvement [Re: Wieslaw]
Etienne Offline
New Egg

Registered: 09/08/18
Posts: 7
Loc: Continental Europe
Thanks for your reply. I dint't get a notice per email, that's why I only reply now.

Maybe to explain the point of my question: I want an autosexing breed selected on productivity, and am looking for an easy way to sex them. The goal is to have something which can easily be bred into a rather broad range of breeds.

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#117294 - 10/02/18 05:35 AM Re: Autosexing gene involvement [Re: Etienne]
Hen-Gen Offline
Ruler of the Roost

Registered: 10/01/05
Posts: 1164
Loc: Island of Fetlar, Shetland
Good afternoon Etienne.
The Welbar is an example of what you require. They lay a large brown egg and if you Google Image Welbar chicks you will see how easy they are to sex. They have the mode of inheritance of the barring gene that if a Welsummer cockerel is mated to a Welbar hen then all the pullets are ostensibly Welsummers.
I hope this partly answers your question.
In terms of a suitable book I would recommend An Introduction To Color Forms of the Domestic Fowl by Brian Reeder. (Note the spelling of “ Color”- this is how it is spelled in the USA).
The presence of the barring gene as either two copies as in a cockerel or as one copy as in a pullet in autosexing breeds leads to an over all lightening effect on the chicks down and a larger more diffused head spot.
Perhaps the most distinctive sexual difference is found in a breed called the 55 flowery Leghorn (google image it).


Edited by Hen-Gen (10/02/18 05:46 AM)
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#117296 - 10/02/18 09:45 AM Re: Autosexing gene involvement [Re: Etienne]
Wieslaw Offline
Moderator
Classroom Professor

Registered: 09/18/09
Posts: 3844
Loc: Denmark
Originally Posted By: Etienne
Maybe to explain the point of my question: I want an autosexing breed selected on productivity, and am looking for an easy way to sex them.


It depends on how much you expect from productivity. As far as I know, NONE of the autosexing breeds can equal production hybrids.

Quote:" 2) A place where to look up the genetic background of different breeds. Does it exist?"

If you expect a list with a stamp "VALID" for all chickens from each breed, then there are none. I have seen some papers in one country, but it can only be a list of PRESUMED genotypes, and not PROVED. Nobody ever have made the crosses necessary for establishing genotypes of each color of each breed.

It is usually made this way: if something is red, then it has Mh(mahogany), though it might not be the case(there are probably multiple red enhancing genes), and so on.

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#117298 - 10/03/18 02:07 AM Re: Autosexing gene involvement [Re: Wieslaw]
Hen-Gen Offline
Ruler of the Roost

Registered: 10/01/05
Posts: 1164
Loc: Island of Fetlar, Shetland
I’d agree with and respect what Wieslaw says.
It occurred to me later that some strains of some breeds are semi-autosexing. Appropriate strains of Barred Rocks can be sexed with about 85% accuracy from the size and form of the head spot taken in conjunction with the degree of pigmentation in the legs.
It is also claimed that some strains of Welsummers can be autosexed though I have no experience of these.
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#117299 - 10/09/18 07:04 AM Re: Autosexing gene involvement [Re: Hen-Gen]
Etienne Offline
New Egg

Registered: 09/08/18
Posts: 7
Loc: Continental Europe
Thanks Hen-Gen and Wieslaw. While googling I also found 55 flowery, which seems an interesting breed, although probably not selected on production anymore in most places.
About the barring and the sexing: if I understood well, the BB / B- as autosexing tool only works if it is combined with a dark pattern in the chicks.
If I take the picture of GSC
Originally Posted By: GSC
Hope this helps.

E, e+, ER, eb, and ebc can be combined with the barring to get an auto-sexing breed, right? And the autosexing only works if only one of the down colors is present in the population. Did I get it right?
If so, and I want to cross a breed to get the autosexing, I will need to select in F2 or in the backcross the ones with e+e+ for example, as well as the barring.

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#117303 - 10/14/18 12:35 PM Re: Autosexing gene involvement [Re: Etienne]
Wieslaw Offline
Moderator
Classroom Professor

Registered: 09/18/09
Posts: 3844
Loc: Denmark
Originally Posted By: Etienne
Thanks Hen-Gen and Wieslaw. While googling I also found 55 flowery, which seems an interesting breed, although probably not selected on production anymore in most places.
About the barring and the sexing: if I understood well, the BB / B- as autosexing tool only works if it is combined with a dark pattern in the chicks.
If I take the picture of GSC
Originally Posted By: GSC
Hope this helps.

E, e+, ER, eb, and ebc can be combined with the barring to get an auto-sexing breed, right? And the autosexing only works if only one of the down colors is present in the population. Did I get it right?
If so, and I want to cross a breed to get the autosexing, I will need to select in F2 or in the backcross the ones with e+e+ for example, as well as the barring.


Basically yes. Provided the females and males have the same genotypes differing only in number of dosis of the B gene, you should be able to see the difference.
You can also apply B^sd (another allel in the barring locus),but it is more rare. It is supposed to be present in Norwegian Jaerhoens.

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#117305 - 10/16/18 01:10 AM Re: Autosexing gene involvement [Re: Wieslaw]
Etienne Offline
New Egg

Registered: 09/08/18
Posts: 7
Loc: Continental Europe
Thanks. By "basically yes", you mean that ALL the other genes need to be identical as well? Are other genes than dominant white and homozygous receccive white interferring with the e+e+BB // e+e+B- autosexing?

Regarding B^sd: is a population where B^sd and B are mixed autosexable? In other words, do e+e+BB, e+e+BB^sd and e+e+B^sdB^sd look the same, and e+e+B- and e+e+B^sd- look the same as well? (as chicks, down color)


Edited by Etienne (10/16/18 01:11 AM)

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#117308 - 10/17/18 12:57 AM Re: Autosexing gene involvement [Re: Etienne]
Wieslaw Offline
Moderator
Classroom Professor

Registered: 09/18/09
Posts: 3844
Loc: Denmark
I had some black barreds at some point(there is a picture somewhere in an old thread), where some pullets looked lighter than others, thus could be mistaken for cockerels, so possibly an influence from a melanizing gene or other.

Quote: "Regarding B^sd: is a population where B^sd and B are mixed autosexable? In other words, do e+e+BB, e+e+BB^sd and e+e+B^sdB^sd look the same, and e+e+B- and e+e+B^sd- look the same as well? (as chicks, down color)"

I do not think anybody knows.

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