Is it possible to reverse Mutations back to Normals

[vettepilot_6]

So it is highly likely then we have no pure normal Java Sparrows in Australia?? From what I am reading here it is an extremely high chance they are now all carrying the autosomal recessive gene? And one can only say they are 95% normal in reality? Rats thought I might of been on to something....Looks like I will have a couple of mutation birds after all.....

[natamambo]

Definitely possible, but you would need to keep some of the mutation to test breed back to for confirmation, if you breed a mutation to a split, then you would get 50% mutations and 50% splits, split to split gives you 25% mutation, 50% split and 25% no mutation, the problem comes in identifying which are the splits which are the normals, you then need to test breed all the normal looking birds to the mutation to identify which ones produce the mutation and which don't. All the splits will produce the mutation, the normals will just produce splits. So it requires some test breeding but you can get there in the end and confirm it by breeding back to the original mutation.

Have to disagree Maz - it's in reality impossible with autosomal recessive mutations.
* The figures you quote are averages in a population, not in an individual nest. The ratio for an individual bird is reset for each bird in a nest, eg for each and every bird from a split to split there is a 1/4 chance that bird is split.
* You could produce nests of entirely normal birds phenotypically and you have no idea who is what genotypically. Thus even your test matings only prove two birds are split if and when a mutant appears. Ths may take multiple clutches from the same pair while you continue to randomly and unknowingly create splits.

The real issue is that you can't assume if no mutants appear in a nest or even a season both parents are genetically normal and you now have dozens of offspring to test after just the first year.

[Tiaris]

For each phenotypically normal looking bird bred from split to split parents, the chance is 2/3 of it being a split & 1/3 chance of it being pure normal.
Each split to normal pair produces half splits & half normals.
So there definitely are pure normals out there. The problem is identifying them as such.

[finchbreeder]

It is genetically possible. However, as already stated it is also always uncertain. You breed with whatever normal looking birds you have/can get. And sell off any non normals. But of course you do not know if the gene is there unless it shows. And even when you think you are breeding with normal birds who will produce normals you may not be. For two reasons, one records only go so far, and two mutations originally turned up by spontanious genetic alteration, and will continue to do so. If people want normal birds just use those you think are and accept the reality of genetics. Remove any mutations and their parents from the avairy and keep going. Then bequeth your collection to another normal lover. Over many generations it will work. But odds are you won't be arround to see it. No reason not to try, life is about the project not the result.
LML

[vettepilot_6]

For each phenotypically normal looking bird bred from split to split parents, the chance is 2/3 of it being a split & 1/3 chance of it being pure normal.
Each split to normal pair produces half splits & half normals.
So there definitely are pure normals out there. The problem is identifying them as such.

So if you used the same parents for say 4yrs and no young were a visual split would it be safe to say they are normal parents?

[finchbreeder]

You can, but only with 99% certainty at most. For the reasons I gave above.
LML

[Tiaris]

If the splits are always visually identifiable, definitely yes.

[vettepilot_6]

If the splits are always visually identifiable, definitely yes.

Hmm thats the trouble with Java Sparrows..you do get the odd one that is not visual (no white under chin) Are their other Java mutations that are not autosomal recessive that would be easier to reverse? ie Fawn version?

[finchbreeder]

I believe the cinnamon/fawn is sex linked, but have not ever kept them.
LML

[vettepilot_6]

I believe the cinnamon/fawn is sex linked, but have not ever kept them.
LML

Okay if they are and I was lucky to find a pair of Fawns how do I go about reversing them? and do fawns have pink or dark eyes? ones I have kept in the past had pink eyes, so I always assumed they were split for something else..