first morph question

[Echostatic]

i think i finally understand how you can take different morphs and combine them to get a totally new combination of the 2 morphs together... its because 1 morph may be on one allele and the other is on a different one. but, what im trying to understand now, is if you wanted to cross 2 morphs, how do you know they arent on the same allele?

any links to info better explaining how all of this is determined would be greatly appreciated. or is mixing new morphs just trial and error? i must admit this has been a difficult subject for me to comprehend.

 

[Halley]

what im trying to understand now, is if you wanted to cross 2 morphs, how do you know they arent on the same allele?

If they where the same allele, they would be the same trait. So all different or even similar traits, have to be on a different allele, other wise they would be the same trait.

or is mixing new morphs just trial and error?

It is all done by possible genetic combinations. When combining two line breed traits it might be trail and error, but with gene, you either get it or you don’t.

 

[Echostatic]

line breeding is to try to determine if a visual difference is genetic or not, right? ive been trying to figure out how to reword my original question for a while... i guess, how do people take, for example, a mack snow gecko and mate it to a tremper albino and after breeding back to the parents or eachother, end up with a mack snow tremper albino?

after all, a mack snow is made up of one mack snow gene and one without trait gene, right? the tremper albino is made up of two of the albino genes.

if thats right, breeding them would give you 50% mack snows 100% het for tremper albino and 50% without trait 100% het for tremper albino, right?

if you bred a mack snow het for albino to another with the same genes, wouldnt the offspring be 25% super snow, 50% mack snow het for tremper albino, and 25% without trait het. tremper albino? how do you get both mack snow and tremper albino to show themselves? i dont understand that.

 

[paulh]

i must admit this has been a difficult subject for me to comprehend.

The National Institute of Health has a genetics home reference available on the web. Understand that, and you will be ahead of many herpers who think they are knowledgable. It is aimed at human genetic counseling, but the principles of genetics are the same in all sexually-reproducing living things.

http://ghr.nlm.nih.gov/handbook

You might look at my post in another thread in this forum:

http://www.geckoforums.net/showthread.php?t=24017

And you might look at Wilmer Miller's Survey of Genetics, which is in four parts and can be downloaded from the web if you have a fast connection.

http://www.ringneckdove.com/ and go to the Contents page and look under the Genetics Notes section.

For what it's worth, Miller taught me much of what I know of genetics.

 

[Echostatic]

that looks like it should be helpful. i read that post you linked last night, it helped me understand how it worked a bit better already. ill have to read it again. ill try to read some of what youve linked tonight, it looks like just what i need. thanks a lot

 

[paulh]

after all, a mack snow is made up of one mack snow gene and one without trait gene, right? the tremper albino is made up of two of the albino genes.

if thats right, breeding them would give you 50% mack snows 100% het for tremper albino and 50% without trait 100% het for tremper albino, right?

if you bred a mack snow het for albino to another with the same genes, wouldnt the offspring be 25% super snow, 50% mack snow het for tremper albino, and 25% without trait het. tremper albino? how do you get both mack snow and tremper albino to show themselves? i dont understand that.

A Mack snow leopard gecko's genome contains a Mack snow mutant gene paired with a normal version of the Mack snow mutant, a pair of the normal version of the Tremper albino mutant genes, and something like 20000 other gene pairs. The problem is that you are thinking of only one pair of genes. (Added as an edit: You need to think of two pairs of genes, one having the Mack snow mutant gene or its normal version and the other having the Tremper albino mutant and its normal version. The other 20000 or so pairs can be ignored.) I have a much longer explanation in
http://www.geckoforums.net/showthread.php?t=24017

Mack snow het for Tremper albino X Mack snow het for Tremper albino -->
3/16 super Mack snow (66% probability het Tremper albino)
1/16 super Mack snow Tremper abino
6/16 Mack snow (66% probability het Tremper albino)
2/16 Mack snow Tremper albino
3/16 normal looking (66% probability het Tremper albino)
1/16 Tremper albino

See also the Blue Genes web site:
http://www.animalgenome.org/edu/genetics/main.html

 

[paulh]

When doing a genetics problem, it really helps to identify the genes in the gene pair(s). I will use symbols to avoid enormous wordage.

Ms = Mack snow mutant gene
Ms^+ = normal version of the Mack snow mutant gene

ta = Tremper albino mutant gene
ta^+ = normal version of the Tremper albino mutant gene

The + character is internationally recognized as the symbol for a normal gene.

// stands for a pair of chromosomes. Ms//Ms^+ means a pair of chromosomes with a Mack snow mutant gene in one chromosome and a normal version of the Mack snow mutant in the same spot on the other chromosome.

Mack snow gecko = Ms//Ms^+ ta^+//ta^+
Tremper albino gecko = Ms^+//Ms^+ ta//ta

Ms//Ms^+ ta^+//ta^+ X Ms^+//Ms^+ ta//ta -->
1/2 Ms//Ms^+ ta^+//ta (Mack snow het Tremper albino)
1/2 Ms^+//Ms^+ ta^+//ta (normal looking but het Tremper albino)

Ms//Ms^+ ta^+//ta (Mack snow het for Tremper albino) X Ms//Ms^+ ta^+//ta -->
3/16 Ms//Ms ?//ta (super Mack snow 66% probability het Tremper albino)
1/16 Ms//Ms ta//ta (super Mack snow Tremper abino)
6/16 Ms//Ms^+ ?//ta (Mack snow 66% probability het Tremper albino)
2/16 Ms//Ms^+ ta//ta (Mack snow Tremper albino)
3/16 Ms^+//Ms^+ ?//ta (normal looking, 66% probability het Tremper albino)
1/16 Ms^+//Ms^+ ta//ta (Tremper albino)

Note that 1/4 of all the babies are Ms//Ms, 2/4 are Ms//Ms^+, and 1/4 are Ms^+//Ms^+. At the same time, 1/4 of all the babies are ta^+//ta^+, 2/4 are ta^+//ta, and 1/4 are ta//ta. Because we can't tell the difference between the ta^+//ta^+ and the ta^+//ta, those are added together to make 3/4 ?//ta and called 66% probability het Tremper albino.

 

[Echostatic]

ok... so from that pairing, you are having to consider 2 different pairs on genome, right? one pair being mack snow/normal and the other being tramper albino/normal? its hard to grasp this i think because i do best with illustrations. partly why your assembly line explanation was so helpful and why i did terribly in math back in school.

so a small part of that assembly line would look something like this, the part were interested in.

MS/normal
TA/normal

and since it takes 2 geckos to make a baby...

MS/normal MS/normal
TA/normal TA/normal

so theres 4 pairs of genes, making 8 individual genes. the baby will have 2 pairs of genes, each parent passing on 2 of their 4 genes randomly. so what you would hope to get out of that would be most likely...

MS/MS
TA/TA

because that would give you a mack super snow tremper albino.

(i hope the formatting translates over when i post this)

and for other morphs, they take up spots on that assembly line above and below the small section considered so you can mix them with mroe to create different looking gecko morphs. am i on the right track?

edit: this was posted in reply to the post you made before all the symbols. im gonna have to look closely at that one... im mind boggled at the moment.

 

[Echostatic]

Ms = Mack snow mutant gene
Ms^+ = normal version of the Mack snow mutant gene

ta = Tremper albino mutant gene
ta^+ = normal version of the Tremper albino mutant gene

The + character is internationally recognized as the symbol for a normal gene.

// stands for a pair of chromosomes. Ms//Ms^+ means a pair of chromosomes with a Mack snow mutant gene in one chromosome and a normal version of the Mack snow mutant in the same spot on the other chromosome.

Mack snow gecko = Ms//Ms^+ ta^+//ta^+
Tremper albino gecko = Ms^+//Ms^+ ta//ta

theres a few things here im not getting. what is the normal version of a mutant gene? how does the normal version of a mack snow gene differ from the normal version of a tremper albino gene? or are they what is referred to as "without trait"?

i also dont understand this

Mack snow gecko = Ms//Ms^+ ta^+//ta^+
Tremper albino gecko = Ms^+//Ms^+ ta//ta

youve added a place for albino in the mack snow and a place for mack snow in the albino. unless they are both occupied by the "without trait" genes? i think i just need a little clarification. im probably getting hung up on nothing.

 

[paulh]

Good questions.

The normal version of a gene is the most common version of a given gene found in the wild population. The normal appearance of an animal is the most common appearance found in the wild population. If we define trait as a difference from the most common appearance in the wild population, then a without trait gecko means a normal gecko.

Unfortunately we do not know how the normal version of the Mack snow mutant gene differs from the normal version of the Tremper albino mutant gene. That would require sequencing the hundreds or thousands of base pairs in the DNA that makes up the two genes. Right now those genes are the equivalent of sealed black boxes. They seem to act differently, but we won't know much more than that until they are opened up with sequencing.

Mack snow gecko = Ms//Ms^+ ta^+//ta^+. Going back to the assembly line analogy. One assembly line is equivalent to the genome (the totality of genes) of the Mack snow gecko. A second assembly line is equivalent to the genome of the Tremper albino gecko. There are many thousands of stations in each assembly line, and there are two machines (a gene pair) at each station. We ignore almost all of the stations because as far as we can tell, they are identical in both geckos. There are differences in two stations, the Ms station and the ta station, as far as we can tell. The Mack snow gecko's assembly line has an Ms machine and an Ms^+ machine at the Ms station. The Mack snow also has two ta^+ machines at its ta station. The Tremper albino geckos assembly line has two Ms^+ machines at its Ms station and two ta machines at its ta statiion.

Some people think of a Mack snow gecko as "without Tremper albino gene". This is not a good way to think of them. The two normal genes at the Mack snow gecko's ta station are humming along, quietly doing their duties in adding pigment to the leopard gecko and not making trouble. In machine terms, the Mack snow mutant gene and the Tremper albino mutant gene are sputtering and coughing, overheating, leaking oil, and spitting bearings all over the assembly line's floor. They are only occasionally doing what they are supposed to do or have broken down completely.

 

[Echostatic]

ah, ok. so we dont know how the normal versions of the mack snow and tremper albino geckos differ, but we do know that they do not have the traits that the "mutant" genes have.

so every leopard gecko carries all of the genes for every morph combination possible, but for the most part the vast majority of the gene pairs are considered to be "normal".

and when you say the mack snow and tremper albino genes are broken down and barely or non-funcional in the machine terminology, (as destructive as it sounds from that analogy) that would be the desired effect as they are unable to add the pigment that they normally would.

if ive got all that right, i think ill be able to better understand whats going on with the different morphs... im going to have to look over your symbol explanation now that i think i understand later tonight.

 

[paulh]

so a small part of that assembly line would look something like this, the part were interested in.

MS/normal
TA/normal

The Mack snow gecko's assembly line looks like ... Ms//Ms^+ ... ta^+//ta^+ ..., where ... means many stations are ignored. Except when in a mating with a Tremper albino gecko, the ta^+//ta^+ would also be ignored. Then the assembly line would look like ... Ms//Ms^+ ... .

The Tremper albino gecko's assembly line looks like ... Ms^+//Ms^+ ... ta//ta ..., where ... means many stations are ignored. Except when in a mating with a Mack snow gecko, the Ms^+//Ms^+ would also be ignored. Then the assembly line would look like ... ta//ta ... .

If the battery of my car goes bad, I have to pay attention to it and fix it, cussing all the way. At the same time, I ignore the ignition switch and the spark plugs and the gas tank because they are not giving any problems. I may ignore the gas tank and spark plugs, but they are still present in the car. In the same way, the Ms^+//Ms^+ genes may be ignored but are still present in a Tremper albino leopard gecko.

I must log out now. Good discussion.

 

[paulh]

ah, ok. so we dont know how the normal versions of the mack snow and tremper albino geckos differ, but we do know that they do not have the traits that the "mutant" genes have.

We know that the normal genes do not produce (not have) the physical effects in the gecko that the mutant genes produce.

so every leopard gecko carries all of the genes for every morph combination possible, but for the most part the vast majority of the gene pairs are considered to be "normal".

In other words, the Mack snow gecko has the normal versions of the bell albino mutant gene, the enigma mutant, the giant mutant, the hypo mutant, and on and on.

Going now.

 

[Echostatic]

hmm... this is all very interesting, youve given me a lot to think about and i thank you for it