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Discussion Starter #1
Question for the genetics gurus out there. Most of us have seen the "white/albino" inferalanis that have been posted here in the past. It has yet to be determined if it is indeed genetic (although most things point to that) and what exactly the mutation should be called, hence the quotes. My question is that if indeed it is genetic would it be possible that one would be able to see characteristics of the trait in the tadpole stage but not in the adult stage of frogs that carry the gene but don't display the trait? The reason that I am asking this is that I have the WC adult pair that has produced the offspring from which the "white" frogs are descended. I have started paying more attention to the f1 tads and notice that every now and again I get a few tads that start out very light in comparison to the the standard solid black tads. I have marked these tads and now that they are about a month old they look pretty much the same as the others, solid black. I'm wondering if that could be any indication that they carry the gene?

Thanks,
Robb
 

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Robb,
I have also produced amelanistic tincs (patricia's though) and am fairly certain that it is a genetic mutation. It actually, from the clutches i've produced, been a very simple recessive mutation (25% of my offspring have the double recessive and are amelanistic).
As for your question:
"...would it be possible that one would be able to see characteristics of the trait in the tadpole stage but not in the adult stage of frogs that carry the gene but don't display the trait? "

I would say that in this case *probably* not. If all tadpoles hatched out white and then expressed melanin later in life it could be possible in that the mutation just delays expression of pigment. HOwever, since my tadpoles (75% Of them anyway) hatch out pigmented, then develop normally, I would say that the chances are that you would not see the amelanistic trait in tadpoles but not the adult stage. HOwever, my mutation may be COMPLETELY different than the inferalanis one that you are referring to. Without decent analysis of these mutations we're just speculating...
hope this helps,
Ben
 
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Many gene variants are not clearly/cleanly dominant or recessive. Sometimes, with only one copy of the "good" gene, only half the normal gene product is made and you will see an appearance somewhere between fully abnormal and normal. I don't doubt that at certain stages of development the abnormality appears more pronounced in many genes and their variants. But I have no specific knowledge about such color-related genes. [genetic jargon reduced for public consumption :)]

Steve
 

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Just want to point out something that might have been overlooked:

If it follows Mendelian's, you have one carrier parent...

The albinos will show up in F2, but not F1.

...
 

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I think it is a simple recessive trait. Only one of Robbs' frogs is carrying it. That would mean about 25% of the offspring from that pair are carrying it. When two heterozygous carriers of the simple recessive gene mate about 25% should be albino. 25% should be normal genotype and 50% should be normal phenotype but have a genotype where the recessive gene is present. Time will tell. As far as I know none of the "albinos" have reached maturity yet. If or when the "albinos" reach maturity it should be easy to do some back crosses to figure out what is going on. Of course their is a possible it will be a weak trait and they will all fail to thrive. From early reports it doesn't seem that this is the case.
 

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I highly doubt the "lighter" tads are showing the trait that in F2s produce albinos (I prefer the laymen's term to anything scientific, as it encompasses more, and is more general). Simple genetic traits (such as the implied recessive here) are much like an on/off switch, in this case they either have melanin or they don't. This is not a co-dominant trait, so you don't have an animal thats only carrying "half" outwardly showing signs of the gene (this is the only case off the top of my head where a carrier would outwardly show signs of a genetic trait like Robb implied).

In the albinos, the tad showed an interesting color change as it grew... basically whatever new cells the tad developed lacked melanin (which would imply the melanin containing cells are left over from the cells mommy had in the egg) creating an interesting patchwork of colored/noncolored cells. I would take a wild guess and say an albino female would lay melanin-lacking eggs (white), and the tadpole would start out white and either continue to stay that way (albino) or if the male sperm donor didn't transmit an albino gene, the tadpole would show melanin in the new cells as it grows (opposite of what we see in the albino tads). Simple on/off.

As far as I understand... the same system and genetics controls if melanism is expressed in the tadpoles and adults (the cells don't switch from albino to non-albino or the other way around just because of metamorphosis), while the cells do get swapped around a bit during metamorphosis, the colors themselves are produced (or not produced) the same in both stages. The only thing I can think of where a lack of a color in one stage is not noticable in the other, would be with colors only present in one stage.
 

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The way I looked at your frog's genetic is actually going backward. I know you haven't been producing albinos, but your F1/F2 produced albinos...

So if it in fact follows Medelian (not some jumping genes etc) and if you run thru several different pundit squares scenarios (the link explained what it is)... the only explanation you'll find is that only one of the parent carries an albino gene...

Here's the explanation:

let A = normal pigment, a = albino,

AA x Aa (your frogs)
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AA, Aa - first offsprings (F1) genetic combination possibilities (50:50). Out of this if you (lucky) breed both Aa, then:

Aa x Aa
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AA, Aa, aa - second offsprings F2 (25:50:25) will produce albinos (aa).

It's a bit limited trying to explain all of this on a msg board, so if all of this does not make sense, come to NWFF, I'll let you buy me a beer and I'll go over this. :)
 

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I'll take a stab at this...Although it would be much easier to do with a punnet square I have no idea how to incorporate this in the board.

The guess is that one of the original frogs is carrying the gene for albinism making it heterozygous (het) for albino, but looking normal! When Robb bred the two frogs together, you get ALL normals 50% of them carry the gene for albinism. SO theoretically half are carrying the albino gene, half aren't. When you breed two hets together you get roughly 1 in 4 that are homozygous (show the trait), 2 that are hets, and 1 that is normal. That's how you see 66% probable hets in snakes, gex, etc. because 1 is homozygous, the other 3 all look the same, but you don't know which 2 carry the gene. So Robb produced 50% hets in the F1's, sold them to other people who happened to pair hets together, now every "normal" froglet produced by the pair that produced the albino's are 66% hets. Sorry if this didn't help anybody.

Melissa, I don't know on the T + form?! T - albino retics/ball pythons have some bright colors, most T + that I have seen are kind of washed out or faded looking?!

Ben C, do you have any pics of the albino patricias? If so I would love to see them!
 

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Discussion Starter #15
A friend of mine suggested that possibly there are other recessive traits that "tag along" with the albino trait. One of those traits could cause carriers to be a lighter tadpole. Just a theory and I'm dumbing down what he said because I'm a bit ignorant on a lot of the genetics terminology. If he wants to go into more detail I'm sure he'll make a post.
 

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KeroKero said:
As far as I understand... the same system and genetics controls if melanism is expressed in the tadpoles and adults (the cells don't switch from albino to non-albino or the other way around just because of metamorphosis), while the cells do get swapped around a bit during metamorphosis, the colors themselves are produced (or not produced) the same in both stages. The only thing I can think of where a lack of a color in one stage is not noticable in the other, would be with colors only present in one stage.


Let me play devil's advocate on this one...

it is possible that there are genes that turn on and off during stages of development. This "white tad" may be that case. Perhaps there is a gene that influences pigment production during the tad stage. Similar to a baby human born with blond hair that turns brown later in life. To get really complicated, the gene may only need to be present on one allele to be expressed, which could lend credibility to Robb's theory that the het frogs could start out as lighter colored tads. This trait (lighter pigment tads) may or may not be a piggyback gene to the amelanistic gene that produces Melissa's white frogs..... um... ouch... that hurts the brain.
 
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