what is het?

what is het and what does it stand for?

Het is short for heterozygous, which means the animal has one copy of a gene. Most corn mutations are the result of one or more recessive genes, where the animal would need 2 copies of a gene for it to be outwardly expressed. An albino is homozygous for albinism (2 copies), and a 'het' albino only has one copy of the albino gene. If bred to an albino, the offspring will be 50% albino, and 50% het albino.

Serpwidgets has a genetics tutorial on his site...he'll probably come post here later.

So if something is het it is guarantied to have 50% of it's babys to be what it is het for? So if I had a normal het for bloodred half of it's babys would be bloodred?

No.

The trick with recessives is that BOTH parents must contribute the recessive gene to any individual offpsring in order for that offspring to express the trait.

Bloodred is arguably a simple-recessive trait, but I won't go into that because it will only make things worse at this point. So we'll just assume for this discussion that it is.

Also, note that the outcomes quoted are only odds. It's like saying, "if you flip 100 coins you'll get 50% heads and 50% tails." You get the idea.

If you breed the normal het bloodred to a normal (not het bloodred) you will get all normals, and each of them will have a 50% chance of being het for bloodred. (You will also not know which ones are het and which aren't het.)

If you breed the normal het bloodred to another normal het bloodred, 25% of the offspring will be bloodreds, and the remainder of the clutch will each have a 2/3rds chance of being het for bloodred. (As above, you won't know which are/aren't het.)

If you breed the normal het bloodred to a bloodred, half the babies will be bloodreds, the other half will be normals, known to be het for bloodred.

Why?

I suggest that at some point you try the link (in my signature) to my tutorial, which will go into more detail about it, but the whole basis behind it is just a simple matter of how genetic material is inherited.

I'll explain in the next post (cuz there's a length limit and I'm sure I'll find it, hehe.)

Quick & dirty Inheritance explanation...

Genetic material is inherited in packages known as chromosomes. A chromosome is basically a big string of beads, where each bead is a gene.

You have 23 pairs of chromosomes. If you split those into two sets of 23 chromosomes (1 through 23) you will find that you inherited one complete set from your mother and one complete set from your father.

In other words, you actually inherited a complete human genetic blueprint from EACH of your parents. So you basically have two copies of all the genetic material that goes into making a human.

When you have kids, you will not pass down ALL of your genetic material to any of your kids. Instead, you will give each of your kids only one set of 23 chromosomes, and so will their mother. Thus, they will also (just like you) have a 23 pairs of chromosomes.

This is the first "trick" of inheritance. You are not "your mom + your dad." You are "half of your mom + half of your dad." It's important to know this.

(continued)

The second trick is: not all genes are the same all of the time. If they were, then all life on Earth would be exact clones of each other. There are variations within individuals. Within a species, the variations are not really "how many strings of beads (chromosomes) they have" as much as "the second bead on string 14 is blue instead of yellow." Which is why members of the same species are so similar, but can still be very different from each other.

Say at some place on chromosome #1 (in the human blueprint) there's a gene that normally produces a vital component for making Melanin (the black/brown/yellow pigment in humans, and in cornsnakes. And actually, just for trivia's sake, almost every known form of life on Earth produces melanin. )

This "Melanin" gene could be altered ("mutated") and so there would be another version ("allele") in some humans that doesn't contribute that vital component for making melanin.

Say you got that gene from one of your parents. But the thing is, you also got the "normal" gene from the other parent, and thus you're still able to produce pigment. The "normal" gene is not stopped from producing melanin, so you can't tell you're a "carrier" of that gene.

The "broken, non-functional" gene is not "expressed." Instead, it is masked by the normal gene. You could say that you are "het for albino" because the gene pair is not a matched pair.

You can also say--since this "albino" gene is not expressed when it is paired up with the "normal" gene--that the "albino" gene is "recessive" to its normal counterpart. Note that "het" doesn't always mean "there's a hidden gene." It just happens in this case that it is hidden, only because it is recessive. Remember, "het" truly means "the paired genes are different."

Notice that half of your kids (since they inherit one complete set of human blueprint from you) would also inherit that gene. And with those kids' kids, half of them would also be "hets." The gene can be carried through generations and generations without ever being noticed. It wouldn't be noticed because it's a recessive gene.

BUT, if you (being "het") were to have kids with someone who is also "het for albino" (a pair made up of one normal and one albino gene) then there's a chance with each of your kids that they could inherit the "albino" gene from you, and also the "albino" gene from their mother.

In that case, that individual will not have a working copy of all the genes needed to make melanin, so his body will not produce melanin. He would be an albino.

You would also know, since he's actually expressing the "albino" trait (and since you know it's a recessive trait) that he has the gene pair "albino and albino." (This is known as "homozygous for albino," as compared to "het for albino.")

From that, you can also go on to say that:

-If he has any "normal-looking" kids, that they would also be "het for albino." Why? Because he cannot pass down the "normal" gene to them, he's going to give them one of his two copies of the "albino" gene. So they're pretty much guaranteed to be het for albino.

-If he marries another albino and they have kids together, all of their kids will inherit an "albino" gene from each parent. Thus, all of their kids would be albinos, too, because they won't get the "normal" gene from anywhere.

I think I get it....

So if I were to have a snake het for blizzard, and a normal, half of the babys would be het for blizzard, but not show blizzard cause it's recessive? But if I got a normal het for blizzard and another normal het for blizzard I would get some blizzards?
dang this genetics stuff aint that easy

Actually...

Blizzard is a combination of two independent traits: Amel (which removes the black) and Charcoal (which removes the red)

So, if a corn is "het for blizzard" it's actually carrying both of those traits. (Technically it is het for amel and het for charcoal, but people abbreviate that.)

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If you bred it to a normal, the offspring would each have a 50% chance of being het amel, and (regardless of whether or not they're het amel) a 50% chance of being het charcoal. As you have already picked up, they'd all be normals because both traits are recessive.

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If you bred it to a blizzard, then the amel trait would be picked up in the same way as crossing "amel to het amel" (50% of the babies will be amels) and same goes for charcoal.

So half of the babies are amels, and half of the babies are charcoals. From that you can also say that half of the amels will also be charcoals, and vice versa.



So half of a half (one quarter) of the babies would pick up both traits, and be blizzards.

Also...

If you breed a normal het blizzard to a normal het blizzard, this is easier to look at as "het amel to het amel" plus "het charcoal to het charcoal." Each trait has a 1 in 4 chance of being picked up, so the chance of any one baby picking up both traits is: 1/4 X 1/4 which is 1 in 16.

To figure out the outcomes (until you have them all memorized, hehe) you can use a lot of different methods.
Here's one way:

(Notice that I'm using a capital A for "Amel" and a small a for "het amel" and that the empty square is just a normal not even het amel.)






(The gray ones are normals, red ones are amels, black ones are charcoals, and the white one is a blizzard.)

So if I had an het for amel and an het for charcoal, 1/4 of the cluch would be blizard? When i was reading through this I was eating grapes and I had to go back 3 times for more grapes lol

Hehe, ya, I tend to be long-winded. And don't worry, it'll sink in eventually, hehe.

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The genetic blueprint for cornsnakes is made up of tens of thousands of genes, so there are tens of thousands of "pairs" in each cornsnake. We are only focusing on a handful of them here and there.

These two traits (amel and charcoal) are controlled by genes which are located in different parts of the blueprint. The one trait controls black production, the other controls red production. Since these two pigments are not part of the same process, the production of one is independent from the production of the other.

So, they are as different and independent as, for example, an imaginary trait which makes them have no tail, and some other imaginary trait which makes them have no eyes.

Say the gene for one is on the 3rd chromosome, and the gene for the other is on the 5th chromosome. This is how you end up with more than "one pair" and how we can breed them to produce combinations of traits like snow and blizzard and pewter. It's like having a pair of Aces and a pair of Jacks.

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Remember, amel and charcoal are recessive traits. This is why the hets look just like normals.

In order to express amel, it has to get the amel gene from its father and from its mother. In order to express charcoal, it has to get the charcoal gene from its mother and the charcoal gene from its father.

All in all, to be a blizzard, it has to have a pair of charcoal genes, AND a pair of amel genes. It has to get one amel + one charcoal from the mother, and one amel + one charcoal from the father. So in order to produce blizzards, both parents must carry both genes.

With "het for amel X het for charcoal" notice that only one parent even carries the amel gene. So...

How many babies will get the amel gene from the parent who's only het for charcoal? (none)

How many babies will express amel? (none)

Same goes for charcoal: none of them will express it, because there's no way for them to inherit charcoal from the parent that doesn't carry that gene.

In the end, all of the babies from that clutch would be normals, each with a 50% chance of being het for amel, and a 50% chance of being het for charcoal.

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If you want to produce blizzards, any of the following parents would work:
-Normal het blizzard (normal, double het amel and charcoal)
-Amel het blizzard (amel het charcoal)
-Charcoal het blizzard (charcoal het amel)
-Blizzard

Pair any of these two together, and they will be able to produce blizzards.

(You could add other traits in there, but if both parents don't at least fit one of those 4 descriptions, the pair will not produce blizzards.)

I'am not trying to produce blizzards or anything, it's just that when i was using my example blizzard was the first morph that popped