Serpwidgets
05-21-2002, 10:17 PM
Since this has been a hot topic lately, I thought I'd explain the whole thing and clear up all the confusion.
Grab a deck of cards (or two if you have them) and get the 2s and 9s so you can play along with the illustration. :) Seriously.
Let's say cornsnake genes are playing cards. You have slots for Ace through King. We'll say spades is dominant, and the red "mutant" cards are "recessive" to the black cards.
First example, in 'slot 2' we have amelanism, the Two of Hearts. We also have it's Normal, non-amel counterpart, the Two of Spades.
Every cornsnake inherits a pair of deuces, one from each parent, and each card can be either the two of spades or the two of hearts. (the different twos are what are called "alleles" because they are different but both occupy the same corresponding slot or "locus")
Knowing the basics of inheritance, you know that since the two of hearts is recessive, the only way amelanism will be expressed is if a two of hearts is inherited from each parent. (If not, then a two of spades is going to be present, and it will override the other card) With me so far?
Now, you should also know that an animal that has the Two of Spades and the Two of Hearts is "heterozygous" because the pair of twos it has are different from each other.
It is important to understand that the definition of het is strictly: "the cards of the same number are of different suits" no matter what effect it might have on the animal's appearance!
Ok, let's move on to Motley/Striped. Motley and striped both occupy slot 9. So, unlike every other known cornsnake trait, there are three different cards here:
- 9 of Spades (the dominant wild type allele)
- 9 of Hearts (the Motley allele)
- 9 of Diamonds (the Striped allele)
A "Striped" corn has 2 9s of Diamonds.
A "Motley" corn has 2 9s of Hearts.
A "Striped Motley" has a 9 of Hearts AND a 9 of Diamonds.
A "normal het for striped" has a 9 of Spades and a 9 of Diamonds.
A "normal het for motley" has a 9 of Spades and a 9 of Hearts.
A "normal, not het" has both 9s of Spades.
Reading test: is a "Striped Motley" a Het? ;-)
Ok, so now that we've established that a striped motley is in fact heterozygous, we can move forward...
The surest way to get a "Striped Motley" is to breed a striped corn (pair of 9 of diamonds) to a motley (pair of 9 of hearts) corn. The offspring will all inherit a 9 of diamonds and a 9 of hearts and be what are called "striped motleys."
Remember, these are heterozygous. If you breed two of them together, you will get a result of 100% non-normally-patterned offspring. (25% striped, 25% motley, 50% het Striped/Motley)
I think I've rambled far enough on this, and you can use your playing cards to see the rest of the possibilities. The main point is that there are 3 alleles, so the usual "formulas" don't apply here.
Grab a deck of cards (or two if you have them) and get the 2s and 9s so you can play along with the illustration. :) Seriously.
Let's say cornsnake genes are playing cards. You have slots for Ace through King. We'll say spades is dominant, and the red "mutant" cards are "recessive" to the black cards.
First example, in 'slot 2' we have amelanism, the Two of Hearts. We also have it's Normal, non-amel counterpart, the Two of Spades.
Every cornsnake inherits a pair of deuces, one from each parent, and each card can be either the two of spades or the two of hearts. (the different twos are what are called "alleles" because they are different but both occupy the same corresponding slot or "locus")
Knowing the basics of inheritance, you know that since the two of hearts is recessive, the only way amelanism will be expressed is if a two of hearts is inherited from each parent. (If not, then a two of spades is going to be present, and it will override the other card) With me so far?
Now, you should also know that an animal that has the Two of Spades and the Two of Hearts is "heterozygous" because the pair of twos it has are different from each other.
It is important to understand that the definition of het is strictly: "the cards of the same number are of different suits" no matter what effect it might have on the animal's appearance!
Ok, let's move on to Motley/Striped. Motley and striped both occupy slot 9. So, unlike every other known cornsnake trait, there are three different cards here:
- 9 of Spades (the dominant wild type allele)
- 9 of Hearts (the Motley allele)
- 9 of Diamonds (the Striped allele)
A "Striped" corn has 2 9s of Diamonds.
A "Motley" corn has 2 9s of Hearts.
A "Striped Motley" has a 9 of Hearts AND a 9 of Diamonds.
A "normal het for striped" has a 9 of Spades and a 9 of Diamonds.
A "normal het for motley" has a 9 of Spades and a 9 of Hearts.
A "normal, not het" has both 9s of Spades.
Reading test: is a "Striped Motley" a Het? ;-)
Ok, so now that we've established that a striped motley is in fact heterozygous, we can move forward...
The surest way to get a "Striped Motley" is to breed a striped corn (pair of 9 of diamonds) to a motley (pair of 9 of hearts) corn. The offspring will all inherit a 9 of diamonds and a 9 of hearts and be what are called "striped motleys."
Remember, these are heterozygous. If you breed two of them together, you will get a result of 100% non-normally-patterned offspring. (25% striped, 25% motley, 50% het Striped/Motley)
I think I've rambled far enough on this, and you can use your playing cards to see the rest of the possibilities. The main point is that there are 3 alleles, so the usual "formulas" don't apply here.