Basic genetics question

PaysonHobbyist

New Member
Messages
10
Hello,

I thought I had a pretty good handle on the genetics of leopard geckos but am now second guessing myself and feel confused.

Is there a good place to understand the basic genetics of leopard geckos?

Let me explain what I am understanding currently, please tell me if I have anything wrong and if there is anything else really important to understand.

There are dominant genes. There are only a few of them. (Does anyone know where I can find a complete list?) They all have a super form, or two copies of the gene, which means that if I breed the super to anything else then all. the offspring will always be visual. An example would be breeding a super mack snow to a normal, then all the babies will be mack snow.

There are recessive genes such as the albino strains, which means that you need two copies of the gene in order for them to become visual. If you breed them to something that does not contain that gene then they become a 100% HET and for the recessive to appear you need another that is HET to breed them together. If you breed two HETs and they do not become visual then the offspring will have a 66% chance of being HET. If you breed a HET to something that does not contain the HET then the offspring will not show the trait at all and will have a 50% chance of being HET. Any breeding after that will just have a possibility of being HET but that possibility is pretty slim. The only way to know for sure if they are HET is if they come from a visual recessive or if they produce a visual recessive when bred to another that is also HET. Is there a list of all recessive genes? I know you do not breed across the albino lines. Can anyone explain that and what happens if you do? I only ask to understand, I would never breed them together.

All other traits will only have a possibility to become visual but they have to have a copy of the gene to show up. This is where I get confused. How likely are they to show up if bred? Is there any way to increase the possibility? Are more than one copy needed to show up? Is there a term for these? Is there a complete list of these? Knowing that these are only possible. How did someone breed to get an almost completely black leopard gecko (black night for example)?

Please help me know if I am understanding correctly and if I am missing anything important. Thank you for your help.
 

acpart

Geck-cessories
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You have a lot of it right. Here are a few corrections:
Dominant: you're right that you need only 1 copy of the gene for the trait to be visible. You're getting co-dominant mixed up in there as well. A simple dominant will look the same whether the gecko has 1 or 2 copies of the gene. With a co-dominant trait like Mack snow, a gecko with one copy of the gene looks different from a gecko with 2 copies of the gene. The co-dominant trait with the 2 gene copies is called the "super" form.

Your description of "recessive" is correct, but the next to the last paragraph (the one that starts "all other traits . .. ") is confusing. The description sounds like recessive again. I think you're trying to describe what we call "line bred" or "polygenetic". This means that there are a variety of genes that contribute to the "look" and if you breed geckos with these traits, you'll get a range of how much the traits are displayed. Usually breeders try to pair the geckos that have the best looking outcomes for the desired trait and some of the offspring may be even more gorgeous.

Here are some resources for gecko genetics, from which you may be able to extract a list of dominant, co-dominant and recessive characteristics:

leopardgeckowiki.com
reptilecalculator.com

Aliza
 

LoveReps

Member
Messages
133
Location
Tennessee
Also albino strains cannot be crossed due to underlying or obvious birth defects that can be created. Due to the lack of pigmintation already being a defect itself, disrupting the strains by crossing them will cause issues which is why it is important to breed all the strains separately. You'd basically be stacking the defects to create a more problematic defect so to speak.
 

PaysonHobbyist

New Member
Messages
10
Thank you both very much for the explanations and your help. I finally understand the albino strains so that helps a lot. The other description helps a lot as well. I am now just wondering what traits are Recessive, dominant and co-dominant. Is there a good list?

Thank you.
 

LoveReps

Member
Messages
133
Location
Tennessee
Here is a good list you might find helpful. It has just about every morph you can think of and gives descriptions. It also explains genetics along with what morph has what traits so I hope you find this useful enough.


 

acpart

Geck-cessories
Staff member
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Location
Somerville, MA
I have not heard that crossing albino strains can cause some genetic problems (it could well be the case, just not something I've heard). Another issue is that it muddies the water for future breeders. A gecko that's het for 2 different strains of albino makes it difficult to know what is being produced if anyone uses it as a breeder. There are lots of people who just aren't that discriminating about what geckos they'll breed together.

Aliza
 

LoveReps

Member
Messages
133
Location
Tennessee
A couple of years ago I didn't think that crossing them would have any effect other than not being able to tell them apart. I have spoken to a few breeder about this situation as I was curious myself as I've always been fascinated with the albino strains but i knew that they were not meant to be mixed. Alot of breeders have told me that mixing two different strains of albino would not only make it harder to tell the offspring apart, but it could also cause genetic defects due to the stacking of mutations, which made sense considering the morphs have certain physical defects that make them what they are. I have found an article explaining this if you would like to know more. It is not a huge topic but it is worth mentioning in case someone decides to get playful with genetics. It's quite interesting.
 

acpart

Geck-cessories
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I would love to know more, and depending on how extensive the article already is, would really like to have someone write an article for Gecko Time (yes, we'll still publish if someone wants to write --geckotime.com/archives) about it.

Aliza
 

acpart

Geck-cessories
Staff member
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Thanks. I sent Dillon a message to see if I can learn more. The theory makes sense to me but I'm wondering if there are any studies.

Aliza
 
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