# Genetics for retards



## Mujician (Mar 7, 2007)

The above mentioned is me! - Can somebody tell me what all the funny words mean that are used to describe morphs - like: het, mack, hypo etc!!! Cheers!


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## paulh (Sep 19, 2007)

Here are definitions for homozygous, heterozygous (slang form is "het"), and allele. The named mutant genes are in the royal python.

A gene pair is homozygous when two identical copies of an allele are present in a gene pair.

The two alleles can be two normal alleles, two identical dominant mutant alleles, two identical codominant mutant alleles, or two identical recessive mutant alleles. A super pastel morph royal python is homozygous because it has two pastel alleles. An albino morph royal python is homozygous because it has two copies of the recessive albino allele.

A gene pair is heterozygous when the two alleles in a gene pair are different.

The gene pair may contain a normal allele paired with a dominant mutant allele, a normal allele paired with a codominant mutant allele, a normal allele paired with a recessive mutant allele, or two different mutant alleles. A gene pair containing a spider mutant gene and a normal gene is heterozygous. A gene pair containing an albino mutant gene and a normal gene is heterozygous. "Heterozygous" does not specify that the animal has any given appearance. "Heterozygous" only specifies that the two genes in a gene pair are not identical.

Alleles are different versions of a gene. The pastel mutant gene and the normal version of the pastel mutant gene are alleles. The albino mutant gene and the normal version of the albino mutant gene are alleles. But the pastel mutant gene and the albino mutant gene are not alleles. They are different genes, not different versions of the same gene. The pastel and albino genes are located on different chromosomes or different parts of the same chromosome (nobody knows which).

Hypo generally mean hypomelanistic. In other words, there is less melanin (black) pigment than normal.

Mack refers to one of the mutant genes in the leopard gecko, I believe.

Hope this helps.


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## Ssthisto (Aug 31, 2006)

Mack Snow is an incompletely dominant gene in leopard geckos. One dose (Heterozygous) makes a leopard gecko that hatches out with white bands instead of yellow, and reduces the amount of yellow the gecko shows as it grows up.

Two doses of Mack Snow (homozygous) makes Super Snow - completely removing all yellow, altering the pattern and giving the animal striking solid-coloured eyes.


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## PSGeckos (Jul 15, 2007)

Ssthisto said:


> Mack Snow is an incompletely dominant gene in leopard geckos. One dose (Heterozygous) makes a leopard gecko that hatches out with white bands instead of yellow, and reduces the amount of yellow the gecko shows as it grows up.
> 
> Two doses of Mack Snow (homozygous) makes Super Snow - completely removing all yellow, altering the pattern and giving the animal striking solid-coloured eyes.


Found a cracking site yesterday expalining all about the Mack morph, even i understood it!!!
Mack Leopard Geckos - Genetics


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## HABU (Mar 21, 2007)

oh the days when it was all just about getting them to eat.....


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## Ssthisto (Aug 31, 2006)

Eh, I like playing with genetics. Much more fun than trying to assist-feed a tiny baby gecko that has no interest in helping you.


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## Great-Geckos (Jul 25, 2007)

Ssthisto said:


> Eh, I like playing with genetics. Much more fun than trying to assist-feed a tiny baby gecko that has no interest in helping you.


Hmm, not sure about that - I think they are both on a par actually!! Both are extremely difficult - although I have been assist feeding a baby gecko for two months or more now - have been learning genetics for more than that - but still don't manage it.:smile:


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## Ssthisto (Aug 31, 2006)

*chuckle* I find genetics MUCH easier. Also less frustrating since your genetic calculations don't fail to thrive or die on you.


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## Morbid (Dec 11, 2006)

HABU said:


> oh the days when it was all just about getting them to eat.....


I too remember those days... :cheers:


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## DavidBra (Sep 19, 2006)

Ssthisto said:


> *chuckle* I find genetics MUCH easier. Also less frustrating since your genetic calculations don't fail to thrive or die on you.


On the web sites and tools that do all the complicated % calculations must have a maths formula behind them. Do you know the formula?


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## Ssthisto (Aug 31, 2006)

It's all based on quarters and quarters of quarters, David 

Basically, for any gene you're talking about there are four "possible" options and two slots for them to go into. One slot is allocated to one of the two genes coming from Mum, one slot is allocated to one of the two genes coming from Dad.

Add another gene, and you're talking about sixteen possible combinations (though if you're crossing two like animals, you'll get sixteen combinations that are all exactly the same).

Add another and you've got 64 possible permutations.

And so on.


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## pankthesnake (Sep 29, 2007)

Ssthisto said:


> Eh, I like playing with genetics. Much more fun than trying to assist-feed a tiny baby gecko that has no interest in helping you.


I totally agree with this, but as I've been out of the hobby for a few years I am now playing catch up with all the new corn snake genes and combinations, but I still enjoy it.

I am also considering purchasing leopard geckos for the first time, so I am currently studying the genetics of these as well as corns.


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## eeji (Feb 22, 2006)

for a basic starter on corn snake genetics, have a look here: :: Ians Vivarium - Introduction to Corn Snake genetics ::
The basics can be applied to pretty much anything.


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## Ssthisto (Aug 31, 2006)

pankthesnake said:


> I totally agree with this, but as I've been out of the hobby for a few years I am now playing catch up with all the new corn snake genes and combinations, but I still enjoy it.
> 
> I am also considering purchasing leopard geckos for the first time, so I am currently studying the genetics of these as well as corns.


*nod* I haven't kept up with all the trade names myself - but then again, it's easy enough to find out the ingredients for most combinations when you ask  Far as I'm concerned something like a Glacier Stripe isn't so bad when you break it down into the ingredients (Anery, Amel, Lavender, Stripe) and then realise that "Glacier" is one trade name, and that "Snopal" and possibly "Pearl" refer to the same thing.... Brand names, but the same basic ingredients.


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## DavidBra (Sep 19, 2006)

Ssthisto said:


> It's all based on quarters and quarters of quarters, David
> 
> Basically, for any gene you're talking about there are four "possible" options and two slots for them to go into. One slot is allocated to one of the two genes coming from Mum, one slot is allocated to one of the two genes coming from Dad.
> 
> ...


So what you are saying that if you take say a simple example of Amel x Normal het.Amel. easy to do this in your head 50% Amel and 50% Norm H.amel. But to do this in a computer program you would create a table in say a database with 4 options xx xy yx yy then transpose the amel or normal into the formula.........doh :crazy: or would you replicate the pundit square in rows and columns but what the sql be then to add up the results.


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## pankthesnake (Sep 29, 2007)

Ssthisto said:


> *nod* I haven't kept up with all the trade names myself - but then again, it's easy enough to find out the ingredients for most combinations when you ask  Far as I'm concerned something like a Glacier Stripe isn't so bad when you break it down into the ingredients (Anery, Amel, Lavender, Stripe) and then realise that "Glacier" is one trade name, and that "Snopal" and possibly "Pearl" refer to the same thing.... Brand names, but the same basic ingredients.


Would be nice if all the major breeders would stick to the same trade names for each combination, but I doubt that'll ever happen.

I've only been back in the hobby since the summer and am pretty much up to date with all the genes now, even the ultra one which seems to confuse so many, but keep tripping up over all the different trade names.


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## paulh (Sep 19, 2007)

DavidBra said:


> So what you are saying that if you take say a simple example of Amel x Normal het.Amel. easy to do this in your head 50% Amel and 50% Norm H.amel. But to do this in a computer program you would create a table in say a database with 4 options xx xy yx yy then transpose the amel or normal into the formula.........doh :crazy: or would you replicate the pundit square in rows and columns but what the sql be then to add up the results.


I wrote a computer program that would do genotypes. The interface was poor, but it would do the calculations. The Punnett square is a very bad algorithm for such a program because of all the adding. I used the FOIL technique for each locus and then nested loops to make the combinations, the way an automobile odometer works.


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## Reiyuu (Sep 21, 2007)

Ok.. another idiot here who did genetics years back in biologyy but cant remember for the life of ehr how to do it... If I crossed a Mack Albino jungle male to an APTOR female what would I get?


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## Ssthisto (Aug 31, 2006)

Jungle may or may not be inheritable.
APTOR is composed of Albino, Reverse Striped (AKA "Tremper Patternless") and Tangerine.

Therefore, you would expect:

50% Albino offspring which may show enhanced orange colouring and/or pattern abnormalities
50% Mack Albino offspring with yellow/orange colouring and/or pattern abnormalities.

I don't QUITE see the point of mixing the two, given that the point of an APTOR is to have enhanced yellow/orange and the point of a Mack Snow is to have NO yellow/orange


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## Reiyuu (Sep 21, 2007)

like i said.. I have no idea. I just like what i like and one happens to be male one happens to be female.. could be interesting mix though


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## paulh (Sep 19, 2007)

eeji said:


> for a basic starter on corn snake genetics, have a look here: :: Ians Vivarium - Introduction to Corn Snake genetics ::
> The basics can be applied to pretty much anything.


I looked at that page. I must remember it. It gets filed under "Genetics: the deep end of the pool. Throw a newbie in and watch him drown."


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## eeji (Feb 22, 2006)

paulh said:


> I looked at that page. I must remember it. It gets filed under "Genetics: the deep end of the pool. Throw a newbie in and watch him drown."


:?::?::?: too confusing for newbies???


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## Ssthisto (Aug 31, 2006)

Yes - it goes into too much detail too fast, Ian.

Really, to get them into it, start with a simple analogy - the twin seats on a train one is a good one. Where each gene pair is represented by a twin seat on the train that is "reserved" for a specific gene family (like the "Anery Family"), and only two of the correct genes can sit in that twin seat.


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## eeji (Feb 22, 2006)

ah well!! I read it as a newbie to genetics and understood it, thats why i decided to put it on the site (its written by someone else).
Maybe a re-think is in order


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## paulh (Sep 19, 2007)

The file does a two locus Punnett square without showing how to do a one locus Punnett square.

There are lesser items. The symbols (R and r, B and b) do not match the symbols in the web site's Morph Guide and never were legitimate in the first place. One gene for black pigment and one gene for red pigment is dumbing it down terribly. There are better ways to get the point over. Throwing off dominant and recessive alleles in one sentence. Calling a wild type corn black and an amelanistic corn white. Etc.


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## eeji (Feb 22, 2006)

paulh said:


> The file does a two locus Punnett square without showing how to do a one locus Punnett square.
> 
> There are lesser items. The symbols (R and r, B and b) do not match the symbols in the web site's Morph Guide and never were legitimate in the first place. One gene for black pigment and one gene for red pigment is dumbing it down terribly. There are better ways to get the point over. Throwing off dominant and recessive alleles in one sentence. Calling a wild type corn black and an amelanistic corn white. Etc.


This is to simplify things - r for red and b for black
define legitimate? everyone uses a different system - there are no 'official' symbols
thats the point of it
this is a hypothetical example of a fictional snake

...but yes there probably better ways to explain it. I didn't write the article, maybe i should do my own. One post is saying its too confusing and another post is saying its dumbed down too much - where is the middle ground, understandable to n00bs?


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## Ssthisto (Aug 31, 2006)

What I would start with explaining is that each gene gets its OWN pair (with a few exceptions).

Otherwise, you get people thinking an animal can be het Amel OR het Anery but not both, because it "doesn't have any room". 

The second thing to point out is how ONE gene works in a punnett square - first with a visual X a het, then a pair of hets, then a visual to a het. 

Then you can get into the more complex side of things with multiple genes. 

I think it's oversimplifying to say corns have two pigments, red and black and that the morphs work with these - simply because that isn't how it works. For example, mechanically speaking:

Lavender appears to reduce all pigments - Yellow, Black AND Red - it's a 'hypopigmentation' deal.
Charcoal appears to be (when not mixed with Anery) a hypermelanistic, anerythristic, hypoxanthic job.
Anerythristic is hypermelanistic, anerythristic.
Caramel is the truest anerythristic - it subtracts red and ONLY red.
Amelanistic is straightforward until you combine it with ultra to produce what acts like T+ albinos....
And so on.


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## paulh (Sep 19, 2007)

eeji, the web page file is titled "Corn Snake Genetics". Corn snakes are real snakes, not fictional snakes. A reader is entitled to believe that the contents correspond to reality.



Ssthisto said:


> What I would start with explaining is that each gene gets its OWN pair (with a few exceptions).
> 
> Otherwise, you get people thinking an animal can be het Amel OR het Anery but not both, because it "doesn't have any room".


 Here is an analogy. There are many thousands of gene pairs. Each pair is equivalent to a station in an assembly line with a pair of machines at each station. Each station in the line does one step in making the final product. If all the machines work as expected, what rolls off the assembly line is normal. If the machines at one station do not work right, what rolls off the assembly line is abnormal. How the product is abnormal depends on what station is not working right and on whether the machinery there is working too much, working only a little, or not working at all.

A mechanic pays attention to a broken machine and ignores the ones that are working correctly. In the same way, when we do a Punnett square, we pay attention to the abnormal gene(s) and ignore the genes that are working as expected.



Ssthisto said:


> Lavender appears to reduce all pigments - Yellow, Black AND Red - it's a 'hypopigmentation' deal.
> Charcoal appears to be (when not mixed with Anery) a hypermelanistic, anerythristic, hypoxanthic job.
> Anerythristic is hypermelanistic, anerythristic.
> Caramel is the truest anerythristic - it subtracts red and ONLY red.
> ...


I do not think that the charcoal and anerythristic mutant genes produce any hypermelanistic effects. I think most of the effects are on the red pigment.

And I think that the effect of the caramel gene could be described as a reduction in the amount of red pigment. We see the result of the reduction as yellow rather than orange red. That may be an artifact of our vision system. But as far as I know, nobody has done much more that eyeball the mutant snakes. There is a lot of research that needs to be done to really figure out what the mutants do or don't do.

Ultra, ultramel and amelanistic are fairly easy to understand. When there are two ultra mutant genes in the melanin synthesis assembly line, both work a little, and the snake can produce approximately 20% as much melanin as when there are two normal genes there. When there are two amelanistic mutant genes, neither gene works, and the snake can produce approximately 0% as much melanin as when there are two normal genes present. When there is an ultra mutant paired with an amelanistic mutant, the ultra mutant works a little and the amelanistic mutant doesn't work at all. The result is the snake can produce approximately 10% as much melanin as when there are two normal genes present. The percentages are probably not exactly equal to what happens in the snake, but it gives the idea of what happens.


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## eeji (Feb 22, 2006)

paulh said:


> eeji, the web page file is titled "Corn Snake Genetics". Corn snakes are real snakes, not fictional snakes. A reader is entitled to believe that the contents correspond to reality.


...


Ians Vivarium said:


> Now let's apply our "mini-lesson" in genetics to the corn snake.


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## DavidBra (Sep 19, 2006)

paulh said:


> I wrote a computer program that would do genotypes. The interface was poor, but it would do the calculations. The Punnett square is a very bad algorithm for such a program because of all the adding. I used the FOIL technique for each locus and then nested loops to make the combinations, the way an automobile odometer works.


Can you pm me an example of the algorithm please Paul or maybe I could help you with the interface, I normaly program in VB.net or ASP.net :smile:

Thanks


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