Breeding different lines???

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Originally Posted by wildlifewarrior

Thanks for the info everybody:sweeet: . It is wierd that axanths aren't compatable, which would suggest that they are on different genes/chromosomes, right? or has that not been looked into yet?

You guys know of any sort of DNA sequencing or chromosome work being done to look into this??

ww

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You are correct.

If two different mutant lines are crossed, and normal looking offspring are produced it suggests that each axanthic mutant line results from a mutation at different gene loci.

To visualize the scenarios:

axanthic1 (a1a1) crossed to axanthic2 (a2a2)--->Mutant phenotype (a1a2) mutant lines are of same locus. (only two spots for different gene versions)

Instead what we find is

axanthic1 (a1a1/A2A2) crossed to axanthic2 (A1A1/a2a2)---->Normal looking offspring which is a double hetrozygote for both axanthic genes (A1a1/A2a2) (4 slots for different gene versions)

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Originally Posted by Mendel's Balls

axanthic1 (a1a1/A2A2) crossed to axanthic2 (A1A1/a2a2)---->Normal looking offspring which is a double hetrozygote for both axanthic genes (A1a1/A2a2)

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So would it then be possible to breed those double hets together and create a group that would be able to breed with both lines in the future?? Because if you bred back to the original parents you would undo what you just accomplished correct?? When i first heard two seperate lines couldn't breed, i figured it must be at two (or more) seperate loci on the chromosomes.

ww

Possibly...but its doubtful if you'd be able to tell the difference. If you bred the DH's together, then you would probably produce Axanthics, but they would be either from strain 1 or 2 in Mendel's example...OR you could make a double homozygous Axanthic but you wouldn't know it probably until you bred it out. If you bred DH Axanthics from two different lines, you could get:

Axanthic 1
Axanthic 2
Axanthic 1 het Axanthic 2 (poss het)
Axanthic 2 het Axanthic 1 (poss het)
Axanthic 1 & 2 (But doubtful you'd know)
het Axanthic 1 (poss het)
het Axanthic 2 (poss het)
DH Axanthic 1 & 2 (poss double het)
normals

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Originally Posted by wildlifewarrior

So would it then be possible to breed those double hets together and create a group that would be able to breed with both lines in the future?? Because if you bred back to the original parents you would undo what you just accomplished correct?? When i first heard two seperate lines couldn't breed, i figured it must be at two (or more) seperate loci on the chromosomes.

ww

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Yes it is Possible but that group the double recessive (a1a1/a2a2) would be hard to produce....you'd only have a 1/16 chance of producing it in each egg of a F1 double het x F1 double het cross........

If you did have a double recessive animal you could bred this F2 back to grandparents (P1) of ethier line and get an axanthic

The generations:

P1 (Two different axanthic lines)

F1 (Double Het for each line)

F2 (1/16 chance of double recessive)

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Originally Posted by ddbjdealer

Possibly...but its doubtful if you'd be able to tell the difference. If you bred the DH's together, then you would probably produce Axanthics, but they would be either from strain 1 or 2 in Mendel's example...OR you could make a double homozygous Axanthic but you wouldn't know it probably until you bred it out. If you bred DH Axanthics from two different lines, you could get:

Axanthic 1
Axanthic 2
Axanthic 1 het Axanthic 2 (poss het)
Axanthic 2 het Axanthic 1 (poss het)
Axanthic 1 & 2 (But doubtful you'd know)
het Axanthic 1 (poss het)
het Axanthic 2 (poss het)
DH Axanthic 1 & 2 (poss double het)
normals

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Great point......you probably wouldnt be able to visually distingush a double homozygous recessive from a single homozgous recessive.

But who knows.....it is unlikely but a double recessive of the two might be visually distinct.......

Ahhh yes the massive punnet square is comming back to me. Im sorry i didn't think that last double het cross question through very well. I guess it would be very difficult to tell them apart other than if you had access to dna sequencing and you could figure out which genes are which!


thanks for all your help everybody!

ww

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Originally Posted by wildlifewarrior

Ahhh yes the massive punnet square is comming back to me. Im sorry i didn't think that last double het cross question through very well. I guess it would be very difficult to tell them apart other than if you had access to dna sequencing and you could figure out which genes are which!


thanks for all your help everybody!

ww

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No need to say sorry.....

You are right that if the DNA sequences were known then this would not be an issue as the case in the mouse.......

Ball Python genetics are at similar stage that Mendel found the pea plant in the 1800's......with no molecular genetics to use, you have to rely on crosses, visual inspection, and inferences.

What is heck is going on here?

IS it my imagination or did a post by another member and a response by me get yanked from this thread?

The other member said that the double homozygote might be detectable because there are visible traits that "traditonally" get passed down with certain axanthic lines.....

And I asked the person if these were genetic traits that were linked to axanthic genes (lines)......(in other words, genetic markers?")

And I asked if these visible traits were only present in the homozygous form?

Maybe the admin, mods can explain to me what's going on here?

This kind of censorship is distribuing form this site.....

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Originally Posted by Mendel's Balls

Ball Python genetics are at similar stage that Mendel found the pea plant in the 1800's......with no molecular genetics to use, you have to rely on crosses, visual inspection, and inferences.

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I give mendel alot of credit, who would have though pea plant selctive breeding trials would later affect so many different species and even become so profitable for some people!

I really enjoy genetics which is why i was trying to get my head around this in the first place!

ww