Reptile & Amphibian Forums

I'm trying to wrap my head around these genetics..
I know how the recessive genes work as far kind of..
what is the difference between a dominant and codominant gene. can you give me an example?
i know the mojave is codominant and the spider is dominant.
if both were bred to a normal some would look like spiders or mojaves and the rest would be wild type right? So what is the difference?

A Codominant gene is a gene that only needs 1 copy to be partially expressed, and 2 copies to create a Super form. Whereas a Dominant trait only needs 1 copy to be completely expressed, and a Recessive trait needs 2 copies to be completely expressed.

By definition, the homozygous form of the codominant trait looks different from the heterozygous form which also looks different from the wild type (Normal).

So a Heterozygous individual, let's say a Mojave, only has one copy of the "Mojave" gene. If bred to a Normal, each egg would have a 50% chance of receiving a copy of this gene and becoming a Mojave, and a 50% chance of NOT receiving it yielding a Normal.

A Homozygous individual, a Super Mojave (Blue eyed leucistic), have two copies of the "Mojave" gene. If bred to a Normal, each egg would have a 100% chance of receiving a copy of this gene yielding a clutch of all Mojaves.
-----
Lincoln, NE
0.1 Pastel, 1.0 Pastel het Pied, 0.1 Pied, 0.1 Cinn, 1.0 Black Pewter, 1.0 Woma (hidden gene?), 0.1 Yellowbelly
2.0 Normals, 1.0 Thayeri, 0.1 Thayeri X Alterna, 0.1 crazy cat, 1.0 husband

Dominant = no super form

Co-Dominant = there is a super form

i get that a spider is dominant because two spiders will still give you spiders
mojave co dominant because mojave to mojave gives super mojave (all white snake)
-----
This is courage.. to bear unflinching what heaven sends. -unknown

1.0 Basset Hound (Capone)
1.1 cats (San Quinton and Gracie)

Co-dom homozygous form and the heterozygous form look different.

Dominant homozygous form and the heterozygous form look the same.
-----
Tosha
JET Pythons
The Blog
nihil facimus sed id bene facimus

Great thread. I was confused too. I knew that a codom = Super. But I really understand the whole thing now.

Bill
-----
2.1 Tripple Het Caramel, Orange Ghost, Genetic Stripe
1.1 Het Lavenders
1.1 Het Caramel Albino
0.1 Het Albino
0.1 Spider Het Albino
0.1 Het Pied
1,1 Pastel Het for Orange Ghost
1.0 Albino
0.1 Spinner
1.1 Super Pastel
0.1 Jungle Pastel
1.0 Pied 50 percent White
0.1 Clown
0.3 Normal
1.1 Kids
0.1 Spouse
1.0 Chocolate Lab

okay so if you breed a codominate then a mojave and a mojave would produce mojaves and leucistics across the board or would you still get normals too?
-----
This is courage.. to bear unflinching what heaven sends. -unknown

1.0 Basset Hound (Capone)
1.1 cats (San Quinton and Gracie)

Mojave to a Mojave breeding results in each egg having:
25% chance of being a Normal (bb)
50% chance of being a Mojave (Bb)
25% chance of being a Super Mojave (BB)

The punnet square would look like:

Image from TangerineGecko.com

-----
Lincoln, NE
0.1 Pastel, 1.0 Pastel het Pied, 0.1 Pied, 0.1 Cinn, 1.0 Black Pewter, 1.0 Woma (hidden gene?), 0.1 Yellowbelly
2.0 Normals, 1.0 Thayeri, 0.1 Thayeri X Alterna, 0.1 crazy cat, 1.0 husband

Dom het and homo look the same. Does that mean that if i have a homo dom then it will hrow all "hets"? Homo spider = all spiders when bread to a normal. Or does that no occur? If that is the case would homo spider to super pastel throw all bees?

You pretty much have it. A Dominant trait will look the same whether the animal is Homozygous (HH) or Heterozygous (Hh). A Homozygous dominant bred to a normal will produce all Heterozygous babies of that phenotype. For example, the morph Champagne is *supposed* to be dominant. So a Homo Champagne bred to a Normal will produce all Champagnes, but they will be Heterozygous for that trait.

I think people mostly consider Spiders to be Codominant, but there is very little statistical or anecdotal evidence either way. I have never heard of anyone breeding a Spider to a Normal and producing all Spiders *every single time* which would essentially prove the animal to be a Homozygous dominant (or just extremely lucky).
-----
Lincoln, NE
0.1 Pastel, 1.0 Pastel het Pied, 0.1 Pied, 0.1 Cinn, 1.0 Black Pewter, 1.0 Woma (hidden gene?), 0.1 Yellowbelly
2.0 Normals, 1.0 Thayeri, 0.1 Thayeri X Alterna, 0.1 crazy cat, 1.0 husband

I don't think a gay spider would throw anything....haha. J/K yes. if you had a homo spider and super pastel, they would throw all bees.