Reptile & Amphibian Forums

Can anyone list the different breeding combinations that result in this morph?

Thanks.

I don't think all the combinations of suspected alleles (different mutations of the same gene) in this complex have been tried yet and there are probably a few more alleles to name and add to the group.

However, my _guess_ is that all combinations of the following:

lesser, butter, mojave, phantom, Vin Russo, and mocha

will produce a blue eyed leucisitic except for two copies of the phantom which is a dark enough (but very neat) snake that most wouldn't call it a leucistic.

There also appears to be another allele that is sometimes called the hidden gene (I like dilute but it's not mine to name) that combines with lesser or butter to make a platy daddy or platy butter and with phantom to make the phantom 44 but none of those are considered leucistics.

I wouldn't be surprised if whatever makes the crystal with mojave is also an allele of this group but crystal probably isn't white enough to be considered leucistic either.

A breeder near me produced blue eyed leucistics with a new line female bred to a lesser last summer but I don't think he has completely confirmed that this female is not the same as any of the established line (she is somewhat subtle, maybe like a Vin Russo or maybe more toward mojave like a mocha but could well be a distinct new mutation). I don't believe he has named this new line yet and of course finding out what its homozygous version looks like (i.e. maybe very distinct like the super phantom) will be important. I've heard there may be other new white snake makers in this group too. Why there are so many different mutations of this same gene I don't know.

Thanks a lot. I appreciate your effort. You came up with some I couldn't find. While researching this I came across the ruby red eyed Pied Lesser of Ralph's. I think that's the one I'd like to make now. I'd like to get some super lessers to work with.

Do you think that may be these different lines are just markers for the leucistic gene?
And that there may be the possibility that during meosis, the gene for the color/pattern of these lines could crossover on the homologous chromosome; and end up making an animal that looks like a mojave/lesser/etc., yet doesn't carry the ability to produce a leucistic?

Might the only true way to know that your getting a heterozygous for leucistic animal be to by an offspring of one?

>Do you think that may be these different lines are just markers for the leucistic gene?

I think it is unlikely. I might change this opinion in the following scenario -- A lesser platinum and a mojave mated and produced a leucistic. This leucistic was mated to a normal. Their babies showed a range of appearances from lesser on one end to mojave rather than being divisible into lessers and mojaves.

>And that there may be the possibility that during meosis, the gene for the color/pattern of these lines could crossover on the homologous chromosome; and end up making an animal that looks like a mojave/lesser/etc., yet doesn't carry the ability to produce a leucistic?

I think you mean a crossover in the middle of the gene. It's possible, but if there was only one base pair difference in the sequence of the two genes, then the results of the crossover would be no different from the original genes. A real difference would require a difference of two base pairs and a crossover between them. And then the results might be no more than other genes in the list of alleles that Randy gave.

>Might the only true way to know that your getting a heterozygous for leucistic animal be to by an offspring of one?

By pedigree will do it. A leucistic from a mojave x lesser platinum has a lesser mutant gene paired with a mojave mutant gene. The two genes are different, which makes a heterozygous snake that is leucistic. Though I'd probably be more likely to call it a lesser platinum//mojave.

Heterozygous means that the two genes in a gene pair are different. This can mean that one gene is a normal gene and the other is a mutant gene. Or it can mean that the two genes are different mutant genes, such as lesser platinum//mojave.

Paul Hollander

Hello Paul,
Thank you so much for your informative response!
It’s been years since biology, so I broke out one of my ol’ books last weekend for fun. The experiments by Thomas Hunt Morgan on his fruit flies started the wheels turning !

I’m definitely no genetics expert, and it is not kind to my impatience to look up dead ends on the net.
It’s nice to find a forum where people are willing to share their knowledge!
May be you are available to clear-up one more thing?
.........Or 2?

>"I think you mean a crossover in the middle of the gene. It's possible, but if there was only one base pair difference in the sequence of the two genes, then the results of the crossover would be no different from the original genes. A real difference would require a difference of two base pairs and a crossover between them. And then the results might be no more than other genes in the list of alleles that Randy gave."

I was actually thinking of the point where a diploid set becomes haploid, and the pair of homologous chromosomes already exchanged broken fragments while they were still attached; Joining the leucistic allele on the end of the chromosome that carries normal color/pattern.

Then one chromosome takes the leucistic causing allele along with the normal color/pattern allele to one pole, and the sister chromosome takes the morph pattern/color gene to the opposite pole w/o the leucistic gene.

I guess I am basing this on the assumption of there being 2 separate alleles for leucisim and pattern/color morphs; and that the gene for color/pattern or leucism is located more towards the end of a chromosome vs. the middle?

Otherwise, how could there be black and blue eyes? Or even those wicked eyes with the red stripe down the middle? The existing pattern/color showing through where it can? So I wondered that leusism is existing somewhere else, and not linked to color/pattern. Or may be, the leusistic gene occurs so close to pattern/color; that they rarely ever cross w/o eachother?

And I guess, at this point, NEVERMIND!!!! That’s probably what you were getting at, LOL!!!!!!!!!!!!!!!

……Just dawned on me. HA HA! I think I’m going to post this sorry answer to my own question anyways!

>"Heterozygous means that the two genes in a gene pair are different. This can mean that one gene is a normal gene and the other is a mutant gene. Or it can mean that the two genes are different mutant genes, such as lesser platinum//mojave."

I thought that Lucy’s had to be homozygous for the leucistic gene, in order to be white?, And basically, if a lucy is bred to a normal, the offspring are all hets for leucism? Why is it incorrect to call a Mojave a het for leusism?

Thank you so much!

ARGGHHHHH,,,,, I always think after I post.

I realize you did not say it was incorrect to call a mojave a het!!!

It does help to type out one's own thoughts in order to process others'. Go figure.

Heterozygous means that the two genes in a gene pair are different. This can mean that one gene is a normal gene and the other is a mutant gene. Or it can mean that the two genes are different mutant genes, such as lesser platinum//mojave.

A mojave ball python has a mojave mutant gene paired with a normal gene. Therefore a mojave ball python is heterozygous.

Most of the herper genetics web pages say that a heterozygous snake looks normal. The appearance of the heterozygous animal has nothing to do with whether an animal is heterozygous. The appearance of the heterozygous animal determines whether a mutant gene is dominant, codominant or recessive to the normal gene.

When a heterozygous snake looks normal, then the mutant gene is recessive to the normal gene. When a heterozygous snake does not look normal, then the mutant gene is not recessive to the normal gene.

When a heterozygous snake looks like the homozygous mutant type, then the mutant gene is dominant to the normal gene. When a heterozygous snake does not look normal and does not look like the homozygous mutant type, then the mutant gene is codominant to the normal gene. This is the ideal classification. Nature can be sloppy, though. Sometimes a heterozygous individual can look like the homozygous mutant type and sometimes abnormal but not like the homozygous mutant type. In these cases it is probably better to call the mutant dominant to the normal gene.

I'll get back on the other questions.

Paul Hollander

The link gives a good overview of some of the biology.

Mice have at least 50 genes that affect color and/or pattern. These are scattered over most of the mouse's chromosomes. And many of those genes have more than one mutant allele. Snakes probably have considerably more than 50 genes that work as a team to make normal coloration. One mutant gene disrupts the work of the team, and the snake no longer looks normal.

>I thought that Lucy’s had to be homozygous for the leucistic gene, in order to be white?, And basically, if a lucy is bred to a normal, the offspring are all hets for leucism?

It depends on the mutant gene. In the Texas rat snake, the leucistic mutant gene is recessive to the normal gene. When a leucistic Texas rat is mated to a normal, all the babies have a leucistic mutant gene paired with a normal gene and look normal. A dominant white cat has white fur and blue, green, or orange eyes. Such a cat may have either a pair of dominant white mutant genes (homozygous) or a dominant white mutant gene paired with a normal gene (heterozygous). Mating a heterozygous dominant white cat with a normal is expected to produce 50% dominant white cats (heterozygous) and 50% normal. And then we've gone over the leucistic ball pythons that are heterozygous because they are lesser platinum//mojave.

>Why is it incorrect to call a Mojave a het for leusism?

Technically, a ball python would be het leucistic if it had a mutant gene named leucistic paired with a normal gene. A mojave is certainly heterozygous. But as far as I know, there is no mutant gene named leucistic in ball pythons.

Even if we are pretty relaxed about the naming, het leucistic is a confusing term. It could refer to a mojave, a lesser platinum, a lesser platinum//mojave, or several other genotypes. Unique names are best.

Paul Hollander

genes and chromosomes

Thank you so much for your detailed responses. Very generous of you!
Thanks from myself, and I'm sure from many others who read these posts!

">Do you think that may be these different lines are just markers for the leucistic gene?

I think it is unlikely. I might change this opinion in the following scenario -- A lesser platinum and a mojave mated and produced a leucistic. This leucistic was mated to a normal. Their babies showed a range of appearances from lesser on one end to mojave rather than being divisible into lessers and mojaves. "

I also think it is unlikely that the mojave and lesser and other visible phenotypes in this group aren't caused by the same exact gene that when no normal copy is present causes the blue eyed leucistic appearance. Lots of people have now created leucistics from crossing these lines and I've not heard of reports of people breeding say lesser to mojave and consistently not producing leucistic like you might expect if the leucistic mutation where a separate recessive mutation from lesser or mojave and a crossover could separate them. I think the black eyed leucistic and the yellow belly just happen to be two other gene locations that can also produce white snakes.

Morph King dissolved and stopped posting here about the time they where producing lots of offspring from lesser//mojave leucistic X normal so I don't have the direct report from them that I hoped but I've heard 2nd hand that they produce distinct lesser and mojave around the expected 50/50 ratio and no normals or leucistics which is all consistent with the theory that lesser and mojave are alleles and single mutant gene traits.

However, it is also true that there is some overlap in appearance between lesser and mojave. While each line has it’s own distinctive typical look there have been cases posted where the lightest colored mojaves from lines not related to lesser are nearly as light as some of the darker lesser from lines with no possibility of actually being mojave.