Genetics help?

[_Lucian_]

My question is about the genetics of morphs, and specifically how to figure the outcome of babies on a punnet square.... However I already know the basics of that... Ab+Ab=AA,Ab,Ab,bb, etc...

But what about when one, or both of the parents has a double het? Like perhaps it's Abb?

To clarify, I'll use my Leopard Gecko as an example. My leo is a Murphy's Patternless, het for Tremper Albino. Both Murphy's Patternless and Tremper albino are recessive morphs, meaning to become a Murphy's patternless, he needs the gene from both his parents, so on a punnet square he would be represented as "mm", so where does the Tremper come in? Would it instead be represented as "mmt" with an extra column?

I assume it would look like this?

--------m-------m-------t--
-----------------------------
m--|--mm--|--mm--|--mt
-----------------------------
m--|--mm--|--mm--|--mt
-----------------------------
t --|---mt---|--mt---|--mt
-----------------------------

If that's the case, the offspring, assuming you get one of each outcome, would be 4 Murphy's Patterless, and 5 Normal het for both MP and Tremper?

Thanks for the help!

 

[Neon Aurora]

Here is what it would look like.

m = Murphy's Patternless
t = Tremper albino

The capital letters would represent a wild type allele at that locus. Since there are two alleles for each trait, you have to represent both. Visual murphy's = mm and het tremper = Tt (one wild type allele and one tremper).

For the offspring, you would get 25% murphy's patternless, 50% murphy's patternless het tremper, and 25% tremper albino patternless.

 

[_Lucian_]

Here is what it would look like.

m = Murphy's Patternless
t = Tremper albino

The capital letters would represent a wild type allele at that locus. Since there are two alleles for each trait, you have to represent both. Visual murphy's = mm and het tremper = Tt (one wild type allele and one tremper).

For the offspring, you would get 25% murphy's patternless, 50% murphy's patternless het tremper, and 25% tremper albino patternless.

Oh okay. That helps a lot. Still a tad confusing, but I understand a lot better than before. I assume the mmtt is the Albino Patternless since both traits are shared equally? && I assme that means mmTT is Murphy's patternless, but wouldn't having the double wildtype make it a normal??

 

[Neon Aurora]

Yes, mmtt is albino patternless. Each gene consists of two alleles (which is what we are representing with the letters). Since we chose to represent murphy's patternless with an "m" and tremper albino with a "t" and both traits are recessive, mmtt is both murphy's and albino. MmTt, for example, would be a wild type het murphy's and het tremper (let me know if you need this explained).

The mmTT is murphy's patternless not het tremper. Normal, or wild type, isn't determined by just one gene. This is tough to explain sometimes. When I say "t" represents tremper and "T" wild type, I don't mean T is the allele for "normal" I mean that it is a non-tremper albino allele. So in TT, it means there are no tremper albino alleles present. So your gecko is not het tremper or visual tremper. It is just murphy's patternless.

When we do punnett squares, we don't really use anything to represent wild type, because it is really just the lack of mutations. Say I wanted to pair a wild type and a bell albino. I would say that I am going to represent the bell albino mutation using a "b". So my pairing would be wild type (BB) x bell albino (bb). What I am representing with this is that one of my geckos has two mutant alleles at this locus (or location of gene on the chromosome) and one gecko has no mutations there.

Does that make sense? Sometimes I get a little mucky explaining that. I'm happy to answer whatever questions are not clear. =)

 

[_Lucian_]

Yes, mmtt is albino patternless. Each gene consists of two alleles (which is what we are representing with the letters). Since we chose to represent murphy's patternless with an "m" and tremper albino with a "t" and both traits are recessive, mmtt is both murphy's and albino. MmTt, for example, would be a wild type het murphy's and het tremper (let me know if you need this explained).

The mmTT is murphy's patternless not het tremper. Normal, or wild type, isn't determined by just one gene. This is tough to explain sometimes. When I say "t" represents tremper and "T" wild type, I don't mean T is the allele for "normal" I mean that it is a non-tremper albino allele. So in TT, it means there are no tremper albino alleles present. So your gecko is not het tremper or visual tremper. It is just murphy's patternless.

When we do punnett squares, we don't really use anything to represent wild type, because it is really just the lack of mutations. Say I wanted to pair a wild type and a bell albino. I would say that I am going to represent the bell albino mutation using a "b". So my pairing would be wild type (BB) x bell albino (bb). What I am representing with this is that one of my geckos has two mutant alleles at this locus (or location of gene on the chromosome) and one gecko has no mutations there.

Does that make sense? Sometimes I get a little mucky explaining that. I'm happy to answer whatever questions are not clear. =)

I mostly understand. Thanks a lot.