% and het

[angelboa]

can an snake be 66% (or any other % other than 100) het? I was told on another fourm a while ago that its only 100% het for something because its either het or its not.

[trendkill]

From what I understand, saying 66% het is the same thing as saying it's a "possible het". Because there's a 66% chance that it is.

[bleeding_sarcasm]

Ill try to take this one. Het is short for heterozygous. That means an animal carries the gene, but doesnt show the gene, albino for example. Homozygous is an animal that carries the gene, and displays the gene.

to display a recessive gene [or to be homozygous], an animal needs 2 alleles for the same gene. a het will have an albino allele, and a normal, dominant allele, so the gene is not displayed. an animal gets 1 set of genes from one parent, and 1 set of genes from the other. They mix and match, and if the animal ends up having 2 copies of the same recessive allele, itll display the gene. Thats why if you breed an albino to an albino [animals that both already have 2 copies of the recessive allele] you will get all albinos, no matter how you mix and match it, if its the same "kind" of albino, then they will all be albinos.

When a homozygous [albino] animal, is bred to a "normal" animal, without the gene, you create 100% hets. Because Albino is a recessive trait, and normal is a dominant trait. You get 100% because ALL of the offspring look normal, and carry the albino gene.

when you take 2 100% het animals [animals, that you know for a fact, have the gene, but dont show it] and breed them together, you get 25% homozygous animals, or Albinos in our example. 50% are carry the gene and dont show it. and 25% dont have the gene at all.

Since you cant look at the offspring from het to het breeding, and see which ones carry the genes, and which dont, you average it out, to be a 66% het. there is 2/3 possibility that out of those non-homozygous "normal" animals, you will get an animal that carrys the gene, but 33% of those "normals" are just that. Normal.

A 50% het, is when you breed a het [100% het, has the genetics] to a normal [does not have the genetics] all of the offspring, of course look "normal" but only 1/2 of them carry the gene, and you cant tell which is which.
66% and 50% hets are also referred to as "possible hets" there is a CHANCE that you will end up with an animal that has the genetics, but its not guaranteed like it is with a 100% het. You KNOW you have it. there is no question.

Keep in mind also, that the % is not, from each litter. it is the % that the animal *should* produce over the course of its breeding life time. if you have 20 babies, you cant expect 5 to be albino, 10 to be het, and 5 to be non het. You could end up with crappy odds, and get 1, or zero albinos, and a bunch of possible hets. Or really great odds, like 1/2 of them albino, then the next year, have almost none. Thats why when breeding hets, people usually recommend breeding 2 years, to verify that it is a het.

recessive genetics, yey. I hope thats not too confusing.

[Allysen]

While it IS true that an individual snake either is or is not a het, the percentages refer to the statistical probability the litter has at being heterozygous for the given trait based on the parents.

For example, a 66% possible het comes from a litter where both parents are 100% hets. Out of the litter, statistically speaking, 25% of the babies will be homozygous, and 25% will be normal, with the remaining 50% percent being hets. So out of all the babies that are normal LOOKING, 2 out of 3 will be hets. If you breed a het to a normal, then you get litters where the babies have a 50% chance of being hets. There's no way to tell without breeding them out, of course, so that's where the percentages come in.

[angelboa]

thank you that makes sence i was told my male keni is het for albino but we have no idea if out female syda or our other male shenzy is het for anything we are going to breed keni and syda soon

[angelboa]

now i need to go take pix of my rats so you can see why genetics confuse me

[bleeding_sarcasm]

Rats? well, its hard to have a breeding project with something so prolific, unless you keep VERY specific records, and can be assured of the genetics of each animal. You could think you got a normal, and an albino, but the normal could be het, and you just do know. then dominant, co dom, and incomplete dominants are a whole different game Rabbits for example have like 7 or 12 genes that control what they look like