Reptile & Amphibian Forums

i was wondering about the genetics on pastels. also, could anyone explain to me what a co-dominate, dominate, double hets, triple hets, why i see more ghosts as DH hets, and also, the genetics of ghosts. if anyone has any info on my questions, please post,
cheers
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1.2 leopard geckos1.0 jungle carpet python
1.1 columbian BCI

"i was wondering about the genetics on pastels. also, could anyone explain to me what a co-dominate, dominate, double hets, triple hets, why i see more ghosts as DH hets, and also, the genetics of ghosts. if anyone has any info on my questions, please post,
cheers"

As I understand it, Pastel is a specific line of Hypo.

Hypo is a dominant trait.

Het = heterozygous = having one gene within a gene pair, ie het for albino means having one albine gene and one normal gene. Also applies to dominant traits like hypo, het hypo woulod mean one hypo and one normal gene but since Hypo is dominant, the animal looks hypo.

Homozygous = having both genes within a gene pair the same. Hom for albino would have two albino genes and look albino. Hom for hypo would have two genes for hypo and look hypo.

Dominant = trait where there are not significant 100% distinguishable traits between the het and hom animals

Co-dominant = Trait wher the Het and Hom anaimals are 100% identifiable.

Ghost is Hypo/Anerythristic. Could be het for hypo/hom for anerythristic or hom for both and still look basically the same.

A "double het for ghost" would have one hypo gene and one anery gene and would look like a normal hypo.
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Thanks,

Dave "Rainbows-R-Us"

0.1 Wife (WC)
0.2 kids (CBB)
2.7 Brazilian Rainbow Boa (adult breeders)
2.5 Brazilian Rainbow Boa (sub-adult from 2004)
4.8 Brazilian Rainbow Boa (sub-adult from 2005)
2.1 Hypomelanistic BRB
0.1 Het for Hypomelanistic BRB
0.1 BCI "Elvira" normal from 1989
1.0 BCI albino / het-anery
0.1 BCI Hypo / het-albino
0.1 BCI Anery / het-albino
0.1 BCI Hypo (possible super)
1.0 BCI albino het stripe
1.0 BCI salmon hypo
0.1 BCI ghost

lots.lots.lots feeder mice and rats

Dave,

I answered this above, but Pastel is a polygenic trait...where you take two boas that are lacking black breed and take the best babies that are lacking black and breed them...to create boas with even less black....

Now you can find boas within this spectrum of ones lacking black...some have colors and some are void of color...just remember pastel does not mean color...it means lacking black...that is all.

There are many grades of pastels on the market...I believe that the pastel trait will compliment any line...they sort of clean them up.

Pastel traits can also be un-done by breeding to animals with more black...

I like to think of it as a string with many beads on it...and the pastel trait is like a bead...the more times you breed it toward that desired trait the more pastel beads you have on the string...which makes the pastel trait show up more radically in some animals.

Hope this helps , Andy Federico
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Thanks Andy, all this genetics stuff is wayyyyyyy deep and kinda overwhelming. Tick off one more learned trait.
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Thanks,

Dave "Rainbows-R-Us"

0.1 Wife (WC)
0.2 kids (CBB)
2.7 Brazilian Rainbow Boa (adult breeders)
2.5 Brazilian Rainbow Boa (sub-adult from 2004)
4.8 Brazilian Rainbow Boa (sub-adult from 2005)
2.1 Hypomelanistic BRB
0.1 Het for Hypomelanistic BRB
0.1 BCI "Elvira" normal from 1989
1.0 BCI albino / het-anery
0.1 BCI Hypo / het-albino
0.1 BCI Anery / het-albino
0.1 BCI Hypo (possible super)
1.0 BCI albino het stripe
1.0 BCI salmon hypo
0.1 BCI ghost

lots.lots.lots feeder mice and rats

Glad I could help. Andy
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I'd like to make a few modifications here.

>As I understand it, Pastel is a specific line of Hypo.

As I understand it, Pastel is a line of boas selectively bred for less than normal black pigment. There are probably many genes involved, with each gene having a small, additive effect. On the other hand, the salmon (hypo) mutant gene is a single mutant gene that produces a fairly obvious effect.

>Hypo is a dominant trait.

A trait is a difference from what we'd see in a wild type or normal boa constrictor, which is the type we'd expect to see in the pet trade. We can look at a snake that shows the hypo trait and say that it has less black pigment than a normal snake. Genes are inside the cells and are invisible to the naked eye.

A gene is a unit of heredity, made up of DNA. See

http://en.wikipedia.org/wiki/Gene

for a more complete definition of a gene.

The terms "dominant", "codominant", and "recessive" should be applied to the gene and not the trait. This can often be confusing because the trait and the gene have the same name.

By the way, "dominate" and "co-dominate" are common mispellings of "dominant" and "codominant".

>Het = heterozygous = having one gene within a gene pair, ie het for albino means having one albine gene and one normal gene. Also applies to dominant traits like hypo, het hypo woulod mean one hypo and one normal gene but since Hypo is dominant, the animal looks hypo.

You can't have only one gene in a gene pair. There are two genes in a gene pair. A gene pair is heterozygous whenever the two genes are different. Most commonly, one gene is a normal gene, and the other gene is a mutant gene. But sometimes both genes are mutant genes, as long as they are different mutant genes.

>Homozygous = having both genes within a gene pair the same. Hom for albino would have two albino genes and look albino. Hom for hypo would have two genes for hypo and look hypo.

This is correct, though it's best to stop after "Homozygous = having both genes within a gene pair the same."

>Dominant = trait where there are not significant 100% distinguishable traits between the het and hom animals

Change the first "trait" to "gene", and the definition is right. In salmon (hypo) boas, it is often hard to tell the difference between a snake with two salmon genes (homozygous salmon) and a snake with a salmon gene paired with a normal gene (heterozygous salmon). This makes the salmon gene a dominant mutant gene.

>Co-dominant = Trait where the Het and Hom animals are 100% identifiable.

Codominant. Change "trait" to "gene", and the definition is right.

Recessive = A mutant gene that produces a detectable effect only when homozygous. The heterozygous animal looks normal.

In practice, sometimes the heterozygous animal can be identified when it isn't expected to identifiable. In these cases, the gene is assigned to the category where there is the best fit, even if not an exact fit. Salmon (hypo) is one of the mutants that doesn't exactly fit either the dominant or codominant category. That's why you might see one person call it a dominant mutant and another call it a codominant mutant. In my opinion, it fits the "dominant" category better than the "codominant" category.

>Ghost is Hypo/Anerythristic. Could be het for hypo/hom for anerythristic or hom for both and still look basically the same.

Yes.

>A "double het for ghost" would have one hypo gene and one anery gene and would look like a normal hypo.

Better would be as follows: A "double het for ghost" would have one hypo gene paired with a normal gene and one anery gene paired with a normal gene. This boa would look like a hypo because the anerythristic mutant gene is recessive to the normal version of the gene and the salmon (hypo) mutant gene is dominant to the normal version of the gene. By the way, the normal version of the salmon gene is not the same as the normal version of the anerythristic gene. The two normal genes have different DNA structure and different locations in the chromosomes.

A DH het ghost isn't really a ghost. It's pretty easy to get a DH het ghost by mating a salmon to an anerythristic. To get a ghost, both parents must have at least one anerythristic mutant gene, and at least one parent must be a hypo, too. Matings that would produce ghosts:
DH het ghost x het anerythristic --> 1/8 ghost
DH het ghost x anerythristic --> 1/4 ghost
DH het ghost x DH het ghost --> 3/16 ghost
DH het ghost x ghost --> 1/4 ghost
ghost x het anerythristic --> 1/4 ghost
ghost x anerythristic --> 1/2 ghost
ghost x ghost --> 3/4 ghost
If price is a measure of rarity, compare the prices of the parents in these seven matings against the price of a hypo and an anerythristic.

A triple het has three gene pairs that are heterozygous. As humans have something like 20,000 gene pairs, and snakes can't be terribly far behind, there is a lot of opportunity to have heterozygous gene pairs. When I was breeding ringneck doves, five heterozygous gene pairs was fairly common, and sometimes I got up to eight.

everyones been so helpful. i've been taking notes on my computer because i am going to start breeding in the very near future, and want to (sooooo badly) get into hypos, pastels, and ghosts) those are my 3 absolute favorite morphs. i'd take a top of the line pastel over a top of the line sunglow anyday.
cheers.

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1.2 leopard geckos1.0 jungle carpet python
1.1 columbian BCI

We could be here all day talking about all that!! But to answer the Pastel question....Jeff Ronne is the man...here is an piece from his page....

First, what is a "Pastel"? I have explained this many times in the past. Including in my 1998 video, which I completed and sent the first copies out nearly four years ago. A Pastel is this: A Boa that has an odd overall wash lacking the normal amount of black and a reduction in black pigmentation in particular throughout the pattern. This is particularly apparent in babies, which have the same kind of washed out pattern as Hypos. The saddles as well as the side blotches have less black than "normal". In fact, often the side blotches have no black whatsoever. That's it, no more no less. Now it is unfortunate that this leaves a lot to interpretation. Identifying Pastels can be and is subjective. It is very much a matter of opinion. There are definitely degrees of "Pastelism". How much Pastelism is required to label an animal "Pastel"? I don't know what measure others may use, but I know what I look for in babies. I look for nearly no black in the side pattern.

You can get the rest here....

http://www.boaconstrictor.net/forums/showthread.php?t=386

Hope this helps, Andy Federico
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