Rules are meant to be broken.....pattern "rules" of cornsnakes

[El Jefe]

There was a recent discussion on what defined a motley...clear belly, few belly checks, etc.

You can read more about it here:
http://www.cornsnakes.com/forums/showthread.php?t=103981

Intrigued and having some down time, I went through some of the 2010 hatchlings to take some pictures to illustrate some of the "rules" we know in cornsnakes are not always as clear as they seem.


The first set of pictures is from a Normal het sunkissed, blood, anery, amel X same breeding. I produced a bunch of neat critters--including a sunkissed blood or three--but also got some "different" results....

First up in the picture line are all the heads....with the real blood red being the last one.

 

[El Jefe]

Then the belly pics...with the real bloodred being the last one.

 

[El Jefe]

I know, I know....you can see differences in the three...especially when you look at the belly, but those bald heads are interesting. Some say they are markers for the het or maybe they are influenced by the blood and sunkissed? I don't know. What I do know is there were quite a few of these baldies that had belly checks with this type of sunkissed/blood het pairing....more so than I normally see in other blood combos.

 

[El Jefe]

Okay...big deal, bald heads. Sure that is a blood trait but the checkered belly gives it away that it is probably not a blood. Right?

Well, how about this critter.....as far as I know there is no blood, motley, or stripe anywhere in the ancestry and I bred 8 females--all sisters--for this project and did not see a single blood, motley or stripe.


Where are the belly checks?

 

[El Jefe]

I'll go through more and post other "different" corns when I find more time....

If you've got some, post away!

 

[Blue Apple Herps]

Jeff, in the last pic of the true blood in post #2, do you not consider those to be belly checks?

Just curious because, long story short, I had a sulphur/butter clutch hatch that either had 100% clear bellies (sulphur) or a zippered belly (butter het blood), and then I had one that had a belly like that one. He has the classic blood head pattern, but I've labeled him, and just sold him, as not a blood but a het due to what I thought were checkers.

 

[El Jefe]

First up in the picture line are all the heads....with the real blood red being the last one.

Then the belly pics...with the real blood red being the last one.

Jeff, in the last pic of the true blood in post #2, do you not consider those to be belly checks?

I should have added at the end of these sentances....."or is it"..... LOL

Jeff, in the last pic of the true blood in post #2, do you not consider those to be belly checks?

Just curious because, long story short, I had a sulphur/butter clutch hatch that either had 100% clear bellies (sulphur) or a zippered belly (butter het blood), and then I had one that had a belly like that one. He has the classic blood head pattern, but I've labeled him, and just sold him, as not a blood but a het due to what I thought were checkers.

That is exactly it....what really defines a pattern mutation? Is that "true" blood that have really a blood red? It has a bald head, fairly uncheckered belly and diffused sides....but wait, there are some belly checks. Interesting....

 

[wstphal]

Well, many so-called Mendelian genes show intermediate levels of expression. For example, cystic fibrosis in people. Homozygotes get the big, bad disease. Heterozygores are carriers and allegedly don't have any problems, but the incidence of pancreatitis, inflammation of the pancreas, is MUCH higher in heterozygotes than in non-carriers. So there is a "little bit" of expression in heterozygotes. So could diffused show less-than-100%-obliteration of belly checkers? Or a known heterozygote for diffused show reduced belly checkers? I would suspect it occurs occasionally.

One more reason why I want to see someone do the corn snake genome. There are no snakes that have been sequenced, only 1 species of anole.

 

[crackerhead]

The zipper belly is something I see pretty regularly in animals that are 100% Het Blood. Of course just to throw a wrench in the mix I get the same pattern on animals with no blood in the genetic soup. I used to think the split belly was a sure sign of an animal being Het Blood because whenever it showed up in my collection that was the case. I was corrected by bigger breeder that has seen more animals in a day than I ever will see in my life time. It's easy to make assumptions based on small sample size. Which, of course, is what we tend to do given that we desperately want a neat and ordered world. Rules make life sooo much easier. It's a shame none of my animals can read. :nope:
Thanks Jeff, for sharing the anomalies and making me once again realize how much there is to learn. And I was just starting to feel secure....:eek1:

Terri

 

[Iflln2fntsy]

I can say from experience that tackling the molecular genetics of corn snake color, will be an exciting but difficult task. I am currently finishing my PhD in molecular genetics and part of my project looked at the genetics of strangely colored pigs in my population (pigs breaking the rule of pigmentation )...i can sum up my project in 4 words..."coat color is complex". And mammals only have one type of pigment producing cell, so I can only imagine the genetic complexity of snake coloration!

I also cannot wait until they sequence a snake genome to see what kind of information will come from it

P.S. - Something else to think about when looking at "rule breaking" is the interaction between alleles at different genes, especially those unknown/unproven hets.

 

[Nanci]

Jeff, have you done much reading about the masque gene? Split belly checkers and the bald head, especially with the gray band between the eyes being wide, are two of the characteristics. It is much more noticeable in males. It may or may not be present in bloodreds- depends on the snake! It has occurred in combination with many genes, and by itself in normals.

 

[wstphal]

I can say from experience that tackling the molecular genetics of corn snake color, will be an exciting but difficult task. I am currently finishing my PhD in molecular genetics and part of my project looked at the genetics of strangely colored pigs in my population (pigs breaking the rule of pigmentation )...i can sum up my project in 4 words..."coat color is complex". And mammals only have one type of pigment producing cell, so I can only imagine the genetic complexity of snake coloration!

OK, so what modifiers to eumelanin occur in pigs? I know the basics of mouse & cat color genetics at the expression level, and a tiny bit about horses....

 

[TandJ]

That last one sure looked like a cinder or an emoryi cross or both.. *LOL*

This guy has no blood influence, Ashey or Emoryi in him at all..

I am to the point of where I could care less about what anyone else sells there stuff as, I just don't care.. I know think I have a pretty good idea of my own personal choices and what I am more than willing to let lay on my conciousness.. *shrugs*

Regards... Tim of T and J

 

[wstphal]

Tim, that's a nice looking snake, good eater too!

 

[Iflln2fntsy]

OK, so what modifiers to eumelanin occur in pigs? I know the basics of mouse & cat color genetics at the expression level, and a tiny bit about horses....

Melanogenesis is pretty much the same across most mammalian species. I am not sure what you mean by modifiers to eumelanin, but there are several major genes that come into play with pigmentation. The first is KIT, this determines if you have cells that are able to produce color, dominant mutations cause an absence of color due to a lack of melanocytes in the skin. The next big player is MC1R, mutations in this gene will result in either red(recessive) or black(dominant) being produced by the melanocyte (wild type color for many mammals is brown which is a result of equal amounts of red and black pigmentation). There is also the Agouti gene which turns pigmentation on and off, you see the result expression of this gene in the hair color of mice with the "striped" hair shafts. Another gene, EDNRB is responsible for spotting (at least in mice, nothing has been found in pigs yet). Mutations in tyrosinase causes an albino phenotype....and this list goes on. I usually go to the Mouse Genome Informatics website to look at expression stuff since coat color in pigs is still an ongoing project (mutations associated with a certain phenotype have only been found in KIT and MC1R so far in pigs). My project is currently looking at the occurrence of solid white F2 piglets from a cross between a black breed of pigs and a red breed of pigs. Right now I know it is recessive and that there are at least 4 genes at play (could be more ).

Sorry for the long post, not sure i answered your question...i get excited about genetics and start to ramble sometimes...

 

[wstphal]

Well, there are the modifiers of distribution of melanin along the hair shaft (agouti, dilutes in mammals), the modifiers of red/brown balance (brown/black/red selfs), the modifiers that prevent melanin synthesis, ie, white spotting or the temperature sensitive mutant (it's called Himalayan in mice and Siamese in cats). So you are working with solid white piglets in the F2 of a cross between a black & a red line of pigs. Let's see -- if this were simple, you'd get 1/4 one color & 3/4 the other and instead you got WHITE! Are they leucistic whites or albino whites?

Sorry, I know NOTHING about pig color except that they do come in various breeds & colors, but I love genetics! Can't you tell? And yeah, you answered my question, only you opened up MORE questions! Isn't that the way of things?

 

[Cornparadise]

wow that's a lot of genetic material to sink in. But definately interesting Anyway, just to add some oil to the fire...I have a Ultramel Bloodred female with the clear white belly, diffusion and coloration from the bloodred gene. BUT she also has about 5 or 6 checkers on het belly right after her neck.....

 

[Cattsy]

Oh I'm LOVING this... I love genetics too... Makes my hubby cross-eyed LOL

 

[Iflln2fntsy]

And yeah, you answered my question, only you opened up MORE questions! Isn't that the way of things?

Opening more questions is always what happens, but that is what makes science interesting . Knowing stuff about the coat color in other animals is like knowning about coat color in pigs. Most of the genes controlling coat color in all mammals are the same it just depends if mutations in those genes have been seen/found in every species. I would bet that these same genes are partially controlling coloration in snakes also, but there would be more genes at work since snakes have xanthophores, erythrophores, and iridiophores in addition to melanocytes.

To answer the question about my white pigs, they have normal colored eyes so they are not albino, but their lack of color is not due to any of the genes known to cause leucism. But mutations in the gene I am investigating has been known to cause the exoskeleton of fruit flies to turn white (I know pigs are evolutionarily a ways off from flies, but this gene hasn't really been researched very much). Hopefully I will have the answer about my gene soon and I can add to the list of genes known to change skin/hair/other color...thus making everything just a little more complicated

 

[wstphal]

Opening more questions is always what happens, but that is what makes science interesting . Knowing stuff about the coat color in other animals is like knowning about coat color in pigs.

Yes, that's why I love it, and why I thought I was going to do research although I wound up in health care. But questions are the driving force. Why? Why? Why? Those were my 3 favorite words as a child, and not "Why can't I...?" but "Why is the...?"

To answer the question about my white pigs, they have normal colored eyes so they are not albino, but their lack of color is not due to any of the genes known to cause leucism. But mutations in the gene I am investigating has been known to cause the exoskeleton of fruit flies to turn white (I know pigs are evolutionarily a ways off from flies, but this gene hasn't really been researched very much). Hopefully I will have the answer about my gene soon and I can add to the list of genes known to change skin/hair/other color...thus making everything just a little more complicated

Oh, that is so cool. That would be a great connection if the gene is the same or a close homologue. I love it when we can connect Drosophila genetics to mammal genetics. Drosophila are kinda nasty but such a cool model!

Do you do molecular biology? Or what? More details please!

Oh, and does your user name indicate you are a science fiction/fantasy fan?