F1-F2-C1 question

[RedRidge]

This seems like a good place to bring up the genetics question of the day.
This question pertains to creating BC1s from Rhodebars and HRIR:

Consider the four different ways to achieve BC1s...
Option 1: you originally bred a RB male to a HRIR female, then for your BC1 you would breed your F1 female back to RB male.
Option 2: you originally bred a RB male to a HRIR female, then for your BC1 you would breed your F1 male back to HRIR female.
Option 3: you breed a HRIR male to a RB female and then breed an F1 male to a RB female.
Option 4: you breed a HRIR male to a RB female and then breed an F1 female to a HRIR male.

Statistically your BC1 result options will be the same... but... Will one breeding path lead to easier interpretation and identification than the other?
I believe it is going to be more difficult to identify e+e+ vs. e+eWh than I had originally hoped and I'm trying to "guess" if identification of heterozygous wildtype might be easier with one path than another.
IOW... using really dark HRIR chicks is a two edged sword.

Does anyone have a SWAG about the results without having to raise them out and breed them to find out?
I'm toying with doing this 2 or even all 4 ways if necessary but was curious other folks experience. Getting the barring is easy but identify hidden wheaten to eliminate it to assure autosexing isn't as straight forward.
I'm just trying to determine if i should toss another cross in the bator.

 

[tadkerson]

This seems like a good place to bring up the genetics question of the day.
This question pertains to creating BC1s from Rhodebars and HRIR:

Consider the four different ways to achieve BC1s...
Option 1: you originally bred a RB male to a HRIR female, then for your BC1 you would breed your F1 female back to RB male.
Option 2: you originally bred a RB male to a HRIR female, then for your BC1 you would breed your F1 male back to HRIR female.
Option 3: you breed a HRIR male to a RB female and then breed an F1 male to a RB female.
Option 4: you breed a HRIR male to a RB female and then breed an F1 female to a HRIR male.

Statistically your BC1 result options will be the same... but... Will one breeding path lead to easier interpretation and identification than the other?
I believe it is going to be more difficult to identify e+e+ vs. e+eWh than I had originally hoped and I'm trying to "guess" if identification of heterozygous wildtype might be easier with one path than another.
IOW... using really dark HRIR chicks is a two edged sword.

Does anyone have a SWAG about the results without having to raise them out and breed them to find out?
I'm toying with doing this 2 or even all 4 ways if necessary but was curious other folks experience. Getting the barring is easy but identify hidden wheaten to eliminate it to assure autosexing isn't as straight forward.
I'm just trying to determine if i should toss another cross in the bator.

Genetics 101

Barring is sex linked so the results are not the same concerning inheritance of barring in the F1 and the BC1 with the scenarios you have listed. For example, in scenario 4 none of the BC1 will be barred.

Sex linked genes are found on sex chromosomes. Birds use the ZW system to determine sex. Males are ZZ and females are ZW; barring is linked to the Z chromosome. Mammals use the XY system.

There would be no difference in the scenarios if the barring was autosomal ( gene linked to chromosomes that do not determine sex).

You want to use option 1; the BC1 male chicks will have two barring genes and the BC1 females will have one. That is what you want.

With the E locus allele, it all depends on the dominance of the wheaten allele over the wild type allele or if the HRIR are brown at the E locus or light wheaten or dark wheaten at the E locus.

What was the down color of the RB you are using in the cross and what was the down color of the HRIR you are using in the cross?

Pics would be great. If you purchased them from an individual get them to send you pictures of the chicks they produce.

Tim

 

[RedRidge]

I'll post some pics but... You have mailed the problem. I purposely choose RB with dark down and my hrir are very dark too. What this has created is a lot of F1 who are all dark, no wheaten looking. About half have obvious stripes, the other half have either less subtle or a lack of stripes but all are dark.

 

[nicalandia]

I'll post some pics but... You have mailed the problem. I purposely choose RB with dark down and my hrir are very dark too. What this has created is a lot of F1 who are all dark, no wheaten looking. About half have obvious stripes, the other half have either less subtle or a lack of stripes but all are dark.

Tim is a good Teacher RedRidge..


Tim as one would expect, Wheaten seem to be Recessive and Codominant at times on this type of crosses, RedRidge produce some chicks that appear to be nearly pure for e+/e+ and some that look in the middle, yet none that look like pure wheaten, mind you this cross was made using Pure Rhodebar(wildtype chick down) and H.RIR females, maybe his line is Recessive wheaten or maybe recessive wheaten never existed and its just the nature of wheaten to behave the way it does..

anyways here are his wiltype looking chicks

Quote:

 

[RedRidge]

Quote:
And here are the remainder of the chicks... So in addition to the photo above, this is the entire first F1 hatch crossing a RB (who I hatched who was dark and easily autosexed) to some of my HRIR hens. Keep in mind that the flash has lighten these down colors some... especially the first two shots on the tan background instead of navy.






This last pic is of the HRIR when they were hatched a year ago... as you can tell they were pretty dark...

 

[tadkerson]

And here are the remainder of the chicks... So in addition to the photo above, this is the entire first F1 hatch crossing a RB (who I hatched who was dark and easily autosexed) to some of my HRIR hens. Keep in mind that the flash has lighten these down colors some... especially the first two shots on the tan background instead of navy.






This last pic is of the HRIR when they were hatched a year ago... as you can tell they were pretty dark...

It appears that the pseudo-wild type chicks may be recessive wheaten and wild type or wild type and brown; the other wheaten chicks are dominant wheaten and wild type.

I would back cross a F1 female(s) that had wheaten down as a chick to a RB. This way the BC1 that are wild type ( the keepers) will have a distinct down color (wild type) over the wheaten/wild type heterozygous ( wheaten down) chicks. All the wild type down chicks should be homozygous (purebred) for wild type.


Tim

 

[RedRidge]

But I'm not seeing any wheaten. Are you?

 

[tadkerson]

But I'm not seeing any wheaten. Are you?

The chicks above are expressing the wheaten down color. If these are F1, then they are carrying the dominant wheaten and the wild type alleles. When you back cross the F1 wheaten down chicks to the Rhodebar, then the back cross chicks that have wild type down are pure for wild type, the other chicks will have the wheaten type down and be heterozygous.

The F1 with this type of down color

when back crossed to a RB will produce more chicks with this color and purebred wild type chicks. There are differences between purebred wild type and the above down color but why complicate things.

Tim

 

[RedRidge]

But I'm not seeing any wheaten. Are you?

The chicks above are expressing the wheaten down color. If these are F1, then they are carrying the dominant wheaten and the wild type alleles. When you back cross the F1 wheaten down chicks to the Rhodebar, then the back cross chicks that have wild type down are pure for wild type, the other chicks will have the wheaten type down and be heterozygous. The F1 with this type of down color

when back crossed to a RB will produce more chicks with this color and purebred wild type chicks. There are differences between purebred wild type and the above down color but why complicate things. Tim

No please. .. Go ahead and complicate it. Show us the differences between these heterozygous wildtype and some homozygous wild type. I'm very visual. .. I'd like to see the differences.

 

[melroseladi]

No please. .. Go ahead and complicate it.
Show us the differences between these heterozygous wildtype and some homozygous wild type. I'm very visual. .. I'd like to see the differences.

X2

Penny