het

[cactus2u]

Hi can someone explain the het senario for me . If u had 100% het & if you were to cross with a normal what would the offspring be?
cheers

 

[Tsubakai]

The offspring would look normal - half would be het and half normal but you wouldn't be able to tell which was which just from looking at them.

 

[graffix]

Het is short for hetrozygous and is sometimes referred to as a split. Hets also only refer to recessive genes.

To put it as simple as I can ......

100% het means one of the parents visibly show a recessive trait.

66% hets come from both parents being 100% het but doesn't show the trait. This means normal looking offspring has a 66% chance of carrying that gene.Some siblings from this pairing should visibly show the recessive trait.

50% or possible het means one parent carried the recessive gene but was not visible, the other was normal.

 

[wokka]

What is left out of the 50% and 66% het is the words "chance of". Those animals may in fact not be hets. Some people think it is a deceptive description. To be correct 66% het should be described as a 66% chance of being hetrozygous( and therefor 33% chance of being normal); and 50% het, as 50% chance of being hetrozygous ( and therefore 50% chance of not being hetrozygous ie. normal)

 

[saximus]

Someone should make a sticky about this. Like you said Wokka, it can be deceiving when you are starting out and you hear about 66% and 50% hets.
Cactus the possibilities of the different scenarios are:
Albino-albino = 100% albinos
Albino-normal = 100% hets
Albino-het = 50% albino, 50% het so all non albinos are hets (100% hets)
Het-het = 25% albino, 25% normal, 50% het but again hets and normals look the same so of the normal looking ones 1/3 (33%) will be normal and 2/3 (66%) will be het.
Het-normal = 50% het, 50% normal but all look the same so there's a 50% chance any individual is het.

These are all just probabilities though so you could be really lucky and, for example, get all hets from an het-normal pairing or really unlucky and get none. From what I understand though, it usually comes pretty close to the expected ratios.

 

[dee4]

Someone should make a sticky about this. Like you said Wokka, it can be deceiving when you are starting out and you hear about 66% and 50% hets.
Cactus the possibilities of the different scenarios are:
Albino-albino = 100% albinos
Albino-normal = 50% het, 50% normal but all look the same so there's a 50% chance any individual in het
Het-het = 25% albino, 25% normal, 50% het but again hets and normals look the same so of the normal looking ones 1/3 (33%) will be normal and 2/3 (66%) will be het
These are all just probabilities though so you could be really lucky and, for example, get all hets from an albino-het pairing or really unlucky and get none. From what I understand though, it usually comes pretty close to the expected ratios.

Typo mate,
Albino-Het = 50% of the clutch will be Albino's and the remaining50% are 100% het( Look the same but carry the albino gene)

 

[saximus]

Cheers Dee I was fixing it as you wrote that haha

 

[graffix]

We should also add that the percentages given for each het and possible het are the percentage probability of EACH embryo and individual clutches will vary.

I have had pairs of hets that rarely produce color and others that absolutely nail it. The only certainty is uncertainty, that's what keeps it interesting.

 

[hugsta]

What is left out of the 50% and 66% het is the words "chance of". Those animals may in fact not be hets. Some people think it is a deceptive description. To be correct 66% het should be described as a 66% chance of being hetrozygous( and therefor 33% chance of being normal); and 50% het, as 50% chance of being hetrozygous ( and therefore 50% chance of not being hetrozygous ie. normal)

I agree with you, but it probably needs a more in depth explanation IMO. Out of a het to het breeding, lets say you get 12 animals, 3 of them will be the morph type animal, say albinos. The rest of the clutch, being 9 animals will be possible hets. If you break those animals up into what would be the other 3 parts of a 4punnet square and called it 100%, it is where you get your 33% and 66% from. So from the leftover animals, 66% will be hets and 33% won't be. This is not visible therefore you cannot differentiate between them, however 66% are still hets, it is just you cannot see them. I hope this helps a little more for those that don't understand this as well as others.

 

[hrafna]

i had no idea hets were a recessive only thing!

 

[MrBredli]

i had no idea hets were a recessive only thing!

It's not. Heterozygous means "Having different alleles at one or more corresponding chromosomal loci" which in layman terms means that for one particular gene/trait the animal in question has only one copy of the gene of a possible two (one comes from each parent - each gene has 2 alleles). Although this is not completely accurate and oversimplifies things, it will suffice for now.

With albinism being a recessive trait, for an albino to express the trait it needs both alleles to be the same (albino).

On the other hand, if you look at a co-dominant mutation such as the hypermelanistic bluetongues, you will find that animals that have just one copy of that gene (hets) will not look normal. They are visually distinguishable from both 'wild type' and the black beauties. This is because the two particular alleles that the hets have (wild type and hyper) both have an effect on the appearance of the animal as they are of equal strength (kind of). Replace the wild type alleles with another hyper alleles and you have a homozygous animal - a black bluey. Having two identical alleles makes this animal homozygous (like an albino). Being that this is a codominant trait, the resulting animal is referred to as the super form of the genetic trait, where the condition is is at full power, with no wild type alleles to compete with.

A dominant trait refers to a trait that is expressed even though the animal only carries only alleles for that trait. For example, if albinism were dominant, then all hets would actually be albino.

Hope this helps some and that it is presented in a way that is easy to comprehend. I did just wake up though...

 

[cactus2u]

OK Thanks to all posters have a better understanding now