Pied Theory

I think it has everything to do with the pattern of the snake combined with the pied gene.
Spieds have coloured heads and not much else, from what I've seen of Piebald Lessers, they have very little pattern if any.
Maybe it's the variance in the "Normal" pattern that determines the amount of white. Much like the contrast in albinos.
The theory backs up the claim that certain "lines" produce a higher percentage of High White Pieds.

-Steven

Russ, I have no doubt you may be right. But isn't the sequence of events that determine how the cells react based on the individual embryo? To me that would be random. It may be a good thesis study for someone. Science is not perfect and we are always finding new answers for questions we have already answered. It's based mostly on ideas and loosly on facts. My college biology prof told us that. lol.

Maybe if I think about it next season, I'll start keeping tabs on which girls and guys throw low, med, and hi-white kids. I have to say though I'll stick to my opinion as of now and stand behind the idea of it being random.

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Originally Posted by Russ Lawson

Agreed partially: Nature absolutely does do random - just usually not on purpose. Why do you think eukaryotes go to such lengths to protect the genes from mutation. Mutations are random for the most part, and are typically not something that is desired (at least from a molecular/cellular biology standpoint).

However, I don't think it can be said 100% for certain that the amount of white on a piebald is random. From a breeder's standpoint you can say it's random and that's enough, but having a basic understanding of molecular and cellular biology, I can tell you there is/are most likely some determinate factor(s) that is/are likely somewhat complex. What I believe is that there is a series of molecular events that occur in the development of the embryo which determine the extent to which the partial leucism of a piebald animal is expressed. I will see if I have time to look into this sometime this week to see if any studies have been done on the actual mechanism of the expression of piebaldism in any other species.

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Originally Posted by stevenkeogh

I think it has everything to do with the pattern of the snake combined with the pied gene.
Spieds have coloured heads and not much else, from what I've seen of Piebald Lessers, they have very little pattern if any.
Maybe it's the variance in the "Normal" pattern that determines the amount of white. Much like the contrast in albinos.
The theory backs up the claim that certain "lines" produce a higher percentage of High White Pieds.

-Steven

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Steven, which lines claim to produce high whites? I'm not sure what you mean by the "normal" pattern of the snake causing the amount of white. That to me is the random part. When you mix things such as pinstripe, spider, even cinnamon, in the mix the pattern is then disrupted. We have seen all of these combos produce mostly all white pieds with only colored heads. I produced 3 Pewter Pieds this season and all of them were white except for the heads. I believe this was caused by the cinny gene of the Pewter. All of the Pastel Pieds I've seen, and I have produced them, have had normal amount of random white and pastel pattern.

I think what I'm trying to say here is, if you look at the super form of some of the co-doms, or the doms with distinctly different patters, we are getting pieds with white bodies and the usual colored head. Those that do not affect pattern and are only color based are producing the normal looking pieds with different colors.

Color based morphs combined with pied where pattern is not affected. All of these morphs on their own continue to produce normal patterns even the super pastel.
Albino
Axanthic
Pastel
Ghost

Pattern based morphs combined with pied where patter is affected. All of these morphs produce a disturbance in patter, especially the super forms of cinny, mojave and lesser.
Pinstripe
Spider
Cinny
Clown
Mojave
Lesser

I'm not saying I know the cause of why the combos are high or low white ,but I have noticed a trend. At least we all have something to discuss. Any other ideas? Very cool topic!:)

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Originally Posted by steveboos

IT'S RANDOM.

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I don't 100% buy into the idea that our DNA has a random number generator encoded in it.. but I do think it's complex enough that we won't figure out the 'how' behind white % in pieds.

Ohhhkay.

Because I was curious, I had to look up what causes the piebald spotting in piebald mice. Apparently, it has been known for a long time to be due to a deficiency in neural crest cell derived melanocytes. (The "neural crest" is a group of cells that migrate along the embryo and produce lots of different cell types in the body.)

Recently, it was discovered that the exact cause of the deficiency is a mutation in a signal molecule that "turns on" the melanocytes. Without that signal molecule, most of the melanocytes don't turn on and therefore the animal has white patches in those areas. According to these researchers, the amount of white is directly correlated to the level of expression of the signal molecule. Animals with almost no signal molecule are all white (and also have other diseases), while animals with 25% normal functioning signal molecule are about 20% white.

However, in the mouse model, the amount of signal molecule was determined by different alleles -- in mice, there are apparently multiple different piebald alleles on the same locus. I don't think that can possibly be the case with piebald ball pythons since if it were, the amount of white would presumably have a very clear inherited component. Also, even normal piebalds have a pattern that is really distinct from normal ball pythons, which is kind of interesting and suggests to me that there may be more to it than "just" an ablation or lack of activation of melanocytes ...

Here's an article, for those interested (I'm not enough of a molecular geneticist to want to go all that crazy with most of it, but the abstract and discussion have some interesting points about the mechanism):

http://www.jbc.org/content/281/16/10799.full.pdf

This isn't the article in which they describe the original finding, but it's interesting nonetheless and I can't post that article in its entirety without violating copyright :colbert:

As far as the heritability factor, I thought I had heard tell of a few folks working with lines of extreme low-white pieds. Is this not the case after all?

When I refer to "Lines" of high white pieds I am only referring to the breeding stock.
The quotations are meant to imply that I do not consider them specific lines of Piebald.
I have not seen a lesser pied with colour. I am assuming other morphs with high varying amounts of white are similar in the respect that when combined with the piebald gene, the specimens end up being very high white.
So why can it not work the same way with the natural overall inherited pattern of the snake?
If a high white pied has another factor going on in it's pattern which determines the white, then you would be able to notice which het babies were more likely to pass on the high white trait.

Do you get what I am saying?

-Steven