What if... (this thread is brain food)

[Serpwidgets]

Imagine if you will:

The first person to discover amelanism doesn't publicise their discovery. Instead they selectively bred these, and line-breed them to produce a cornsnake with high-orange ground color, and no white flecks around the saddles. This person calls them "Sunglows."

This person then sells off all of these Sunglows. None of their ancestors are ever seen or documented.

The general public get their hands on this new morph, and it is discovered that they breed true.

Breeding to normals produces normals, so it is initially assumed that this is a recessive trait. Everyone is excited to see what happens in the F2.

When the F1s are crossed, some of the offspring show similarities to the original Sunglows, but white flecks appear around the saddles on almost all of them. Something has been "lost" in the process.

It is then assumed that Sunglow is not a simple trait, and people start to notice that some of the F1s show varying degrees of added brightness and other subtle hints of their ancestry. And a few of the F2s can look pretty much as "good" as the original lines.

Meanwhile, some people are selling F1 offspring that are "het for Sunglow" and others are selling F2s--with lots of white flecking--as "Sunglows." Since these do not totally resemble the originals, other people claim that these are not "pure" Sunglows. Those who have been testing the trait come out and say, "It's obviously not a simple trait. It appears to be the result of some sort of recessive and a few codominants. (?) So instead of 'het' they should be called 'Outcrossed Sunglows' to be more accurate."

The confusion grows. Nobody is really sure what exactly makes a Sunglow a Sunglow. Many people insist that anything from those lines that has pink eyes is a Sunglow, and refer to that "trait" as Sunglow. Others argue that Sunglow is NOT a "trait," but the result of selective breeding, and only those which have the pink eyes, a bright orange ground color, and no white flecks are "true" Sunglows.

Both sides are at least partially correct. As you know, there is a specific gene which is absolutely necessary in the making of Sunglows, and it is a simple-recessive. But there is also a distinct difference between the Sunglow "cultivar" (one which has been purposely cultivated to achieve specific results) and those expressing the simple Sunglow "gene."

By now you have surely seen through the analogy to the real situation that may or may not match this scenario. But when I came to this realization this weekend, it suddenly made sense to me... someone had opened the door to the fridge because the light just suddenly came on.

The question is, what do you think is a good solution to the problem presented above?

 

[kenster]

first off I have to know what you keep in the fridge, if opening the door made you think of that

I have no good answer for your question. I am sure that questions like that become more and more popular as more and more people breed snakes. Which in turn creates more morphs. Which in turn makes people sell them off for something that they really are not, or as something that will not produce that same trait ever again. Although you have given me something to think about for the next 3 hours i'm here at work bored out of my mind...

 

[Darin Chappell]

Way too long...but here goes

Ok, I'll play for a while...

Although I see exactly what you are saying concerning the difference between the Sunglow cultivar and the Sunglow gene, I would have to ask if those are the only two options available to us. What if sunglow is genetically recessive, but it is only shown as the cultivar when the multiple genes that come together to comprise sunglow are homozygous in a given animal?

For example, I would say that the sunglow cultivar has a gene that prohibits the production of melanin. However, I would also suggest that there needs to be another gene present that greatly reduces or eliminates completely the border around the saddles. Combine those two genes with one that enhances the orange background color of the body, and then I believe that you would have a sunglow cultivar.

Serp, you're the genetics wiz, so I'll not try to steal your thunder on this, but for some of you who have not fully studied mendelain genetics, an animal that is a sunglow cultivar might be expressed as being genotypically represented as mm, bb, oo. In this model, M=normal melanin production, B=normal border width, and O=normal orange levels of ground color; m=no melanin, b=no borders, and o=enhanced orange ground coloration.

A true sunglow (mm,bb,oo) bred to a normal (MM,BB,OO) will produce all hets (Mm,Bb,Oo) in the F1. When these animals are crossed, the F2 will statisically produce: 1/64 wild type het for nothing; 26/64 normals het for m,b,o or any combination thereof; 9/64 homo for m and possibly het for b and/or o, 9/64 homo for b and possibly het for m and/or o, 9/64 homo for o and possibly het for m and/or b; 3/64 homo for m and b and possibly het for o, 3/64 homo for b and o and possibly het for m, 3/64 homo for o and m and possibly het for b; and 1/64 homo for m,b, and o.

So, out of 64 hatchlings, you would only expect to have 1 true sunglow *IF* the definition of a sunglow is to be genotypically AND phenotyipically m,b,o (amel, no white, and bright orange). There would undoubtedly be LOTS of amels that had too much white but were very orange in coloration. There would also be some amels with little or no white, but too red to be called true sunglows. There would even be some very orange normals with tiny thin borders around their saddles, but they produce melanin and cannot be called true sunglows. These animals could be called outcrossed sunglows or "sunglow wannabees," but real sunglows are just too rare to be confused with the masses of near-misses.

Now, (assuming there are no amels from which to draw breeding trial subjects) if I were to want to prove that each one of these characteristics were controlled by individually genetically recesive genes, I suppose I would take true sunglows and breed them to a snow corn (to see if amelanism is simple recessive), a hypo (to see what those border widths look like, assuming for the sake of argument that this is the effect of hypo), and a clean background Miami phase (to see if the orange can be reintroduced).

Assuming that all of these tests proved true, I would know that I had three simple recessive genes in one animal homozygous for them all that come together in that unique combination to create an effect in the cultivar which is really greater than the sum of its parts. All of the animals produced by my triple homozygous snake would be het for sunglow, but because it would be impossible to prove which genes were present in the F2 produced by those hets (unless they were homozygous in those individual animals), it would please many people to call them outcrosses rather than simple hets.

Of course if ANY of these sunglow genes were co-dominant, all bets would be off and the F1 and F2 would be completely unpredictable. However, if they could be shown to be simple recessive genes working in tandem, I think "sunglows" could be much better understood.

Here's an idea, what if we bred bloodreds to motleys (then crossed the F1s back to both morphs to see what happens in the F2s), bloodreds to sunglows (to see what happens to the border widths), and bloods to clean Miami phases (to see what happens to the stark contrast between saddles and ground color)? Maybe there would be better morphs to choose from, or maybe other aspects of the bloodreds ought to be examined, but surely we can come up with a series of tests that could be undertaken so as to determine which of the genes that control a bloodred's "look" are really simple recessives working in tandem with one another.

 

[tschofie]

Nice!

Ohhh... Lovely piece of reasoning there. Makes a very great
deal of sense -- maybe what we've been calling "pure"
bloodreds are analgous to high-end sunglows, nothing more
special that a particularly nice example of a normal recessive.

But there is a codominance element, isn't there? F1 Bloods
do show shades of their ancestry, unlike F1 sunglows.
And the belly check trait does seem to sort independantly,
which should mean that "blood" is a combination of at least
two separate and discernable chromosomal traits, unlike
sunglows, which are largely just nice examples of one recessive.

And yet... the sunglow trait is obviously genetic -- two sunglow
parents produce sunglows -- so just as Darin suggests, there
must be other traits at work there, too, that reduce the rings,
etc. They must not be too major, or you'd expect the "normal"
looking babies from an F2 cross to show highly reduced rings
in some cases (homo for no-ring), increased orange (homo
for orange), etc.

I like your musing very much, though. Makes a heck of a lot
more sense than anything I'd thought of.

(A way to find out for sure -- just got a rough estimate for the
price tag on sequencing an unstudied species' genome. Ready?
25 to 35 million, USD, at Myriad genetic laboratories. Hmm.
Not in this lifetime. Anyone know how to develop primers in
the kitchen sink?)

Cheers,
TS

 

[Tim Madsen]

tschofie, you said "But there is a codominance element, isn't there? F1 Bloods
do show shades of their ancestry, unlike F1 sunglows. "

I've done some experimenting with Sunglows. When I breed mine to a normal Amelanistic, that is one that has a lot of white. The F1 offspring almost all more closely resemble the Sunglow parent, some are identical to the Sunglow parent. So I would say that there is a codominance factor in Sunglows, at least in my line. I've never bred my Sunglows to a normal to see what effect they would have on that F1. I might try that next. IMHO

 

[Serpwidgets]

Hehe...

Now, (assuming there are no amels from which to draw breeding trial subjects) if I were to want to prove that each one of these characteristics were controlled by individually genetically recesive genes, I suppose I would take true sunglows and breed them to a snow corn (to see if amelanism is simple recessive), a hypo (to see what those border widths look like, assuming for the sake of argument that this is the effect of hypo), and a clean background Miami phase (to see if the orange can be reintroduced).

Heh, I like that, there's no other source of amelanism but you breed it to a snow.

In the example I'm saying there is one known "simple" component, and several other components that are not simple... the remainder of that phenotype requires specific, directed breeding in order to achieve the "true" look. The "pink eyes" (amel) trait behaves like a standard simple-recessive, the rest defy definition as simple traits.

Assuming that all of these tests proved true, I would know that I had three simple recessive genes in one animal homozygous for them all that come together in that unique combination to create an effect in the cultivar which is really greater than the sum of its parts. All of the animals produced by my triple homozygous snake would be het for sunglow, but because it would be impossible to prove which genes were present in the F2 produced by those hets (unless they were homozygous in those individual animals), it would please many people to call them outcrosses rather than simple hets.

I disagree on this point. I think the term outcross denotes a lack of known traits, not an unknown genotype. I wouldn't call snow motley X normal -> F1 X F1 -> F2 "outcrossed snow motleys." I would call them "amel poss het anery and motley" or whatever.

Of course if ANY of these sunglow genes were co-dominant, all bets would be off and the F1 and F2 would be completely unpredictable.

I think this would actually make for an easier time predicting what's happening. With simple codominants there aren't any unknown hets or "possible" hets.

 

[Darin Chappell]

I agree with every point you made, Serp:

I also laughed when I suggested breeding to a snow because of no amels in existence! However, because in your initial example all of the ancestors of the sunglow were out of the reach of testing, I thought that this would be the only way to see a analogous situation in which we now find ourselves. What if bloodreds (br) and motleys share an identicial gene that controls the lack of ventral markings? Is that any different from an amel and a sunglow sharing the gene for lack of melanin? Now, what if there was a common ancestor to both morphs that had this genotypic (if not phenotypic) mutation, but because of the breeding trials that have long sense separated themselves, there is no way to prove the connection. If so, then we have "no amels to breed to and must use a snow instead!" We cannot go to a phenotypical ancestor, so we have to go to the genetic "first cousin once removed" instead.

Second, I'm not saying that a sunglow x normal F1 ought to be called an outcrossed sunglow. What I am saying is that, if we did not yet understand the genetics, and the F1s crossed to snows did show animals that were somewhere in between the parents (and we know they would be interpreted that way as regular amels), then would not many people be all for calling these animals outcrosses rather than hets? I suppose that when we more fully understand the br combinations that make true brs, we might stop using the term outcrosses for their F1 too.

Finally, I also agree that if the genes for br are (one or more of them) codominant, then the outcomes of the F1 are more predictable. What I meant by "completely unpredictable" concerning the F1 and F2 generations was that the codominance would make all of the simple recessive/punnett square figures I had listed above moot. I know, I know...it was a poor choice of wording, but I was only up because of a bad headache and it was late !

However, I'm not 100% certain about the codominancy of certain bloodred genes. I mean, in a single clutch of outcrosses, it is entirely possible to get all normal looking babies, babies with a partial belly checkering, and babies with no belly checkering at all. Further, some of those babies will also exhibit the "not quite a motley" look of the saddles that is common to many outcrosses, but those animals appear to be randomly selected apart from the belly checkering. So, there are separate genes that comprise the "look" of a bloodred which are inherited independently from one another, in my estimation, AND these genes may or may not be codominant because they express themselves fully in some hatchlings, partially in others, and not at all in the rest. If we bred a sunglow to a snow (having no amels from which to test! ) and the breeding resulted in the wide array of amel possibilities we now all take for granted, would we not then marvel at the codominancy of the sunglow gene? I think we would.

 

[SilverTongue]

I only partialy understand what you are all talking about. But just one question

If we bred a sunglow to a snow (having no amels from which to test! ) and the breeding resulted in the wide array of amel possibilities we now all take for granted, would we not then marvel at the codominancy of the sunglow gene? I think we would.

How did we get a snow w/o any amels???

 

[Darin Chappell]

This whole "using sunglow in place of bloodred" thing has made it more muddied than I think anyone had suspected! LOL

In Serp's original scenario, the ancestors that brought about the "sunglow" (read that as standing in for bloodred) morph had been lost to us because those in between morphs were not propigated. So, I simply extended that to say that no amels (other than the sunglows) were available any longer, and, if that were true, then sunglows would appear to us to be something completely different than what we understand them to be: a line- bred enhanced amel.

However, just because we do not have the actual in between morphs that were used to create the bloodred, it is possible that there are other descendants of those same ancestors, carrying similar genes which are not identified as being bloodreds or even related to them.

In our little "what if" scenario, I simply applied the same logic to the sunglows. What if, in the making of the sunglows, the snows were brought about as well. However, because they did not match what the original breeder of the sunglows was looking for, they were sold off as culls with no explanation of their genetics. Later, after all of the amels had dissapeared into the mix of normals and sunglows, the only animals that still showed a lack of melanin would be the snows that (in our scenario) would be considered completely unrelated to the sunglow line, but were actually just long-lost cousins exhibiting the same gene in a different morph.

So, to answer your question (finally), we would not have the snows without the amels, we simply would have had the snows without having kept the amels that produced them. IF the white checker-free belly of the bloodred is controled by the same gene as that of the motley, it may very well be that BOTH morphs share a common "in between" morph ancestor that was unacceptable as a bloodred, but carried the gene for ventral patternless offspring nonetheless. Those in between morphs are now lost to us, so we assume that bloodreds and motleys have no common genetics beyond simply being cornsnakes, but they too could be long-lost cousins sharing the same genetic marker (or is that un-marker) where their ventral scales are concerned.

This is just TOO fun! I wish I was better with the genetics to have a real answer to all of the questions popping up in my thoughts from this thread! Please, everybody feel free to poke as many holes in my reasoning as you can find. I'm just having fun with this and will in no way take any offence

 

[Kat]

My guess is that bloodred and motley are unrelated. Why?

They behave differently...

Bloodred traits include fading side patterns and no belly pattern.
Partial effects of bloodred traits occur in animals which are NOT bloodred, but are decended from bloodred, ergo bloodred seems to be co-dominant with 'normal' if you will...

Motley, however, seems to affect dorsal patterns in a different way, by creating more connectivity between the saddles. Motley does produce plainbelly as well, but of a different form. And while Motley is co-dominant with Stripe, you can't really tell a normal het motley from a normal not het motley.

I think the main question and the main line of reasoning the original post was meant to provoke was... how would you go about separating the gene from the phase in the example, in terms of the herp community? Obviously something needs to be done, but it needs to be done in such a way that the cornsnake breeders will accept it and not reject it completely.

 

[Darin Chappell]

However Kat,

You say that motley produces plain belly of a different form, but how do you KNOW that? I mean we all assume they're unrelated because of the differences in the dorsal patterns you noted, but what if those patterns are simply the product of genes that do differ from bloodreds, while the controlling belly genes are identical, having descended from a common ancestor?

Also, motley can appear to have a bit of a codominant effect on its F1 het offspring as well. In Rich Z's line of milksnake x motley morph (so-called because they aren't quite either, if I understand correctly), there are animals with varying degrees of reduced belly checkering much the same as you would find in outcrossed bloodreds. I know that Clint Boyer said on the "other" forum (as if there really is another one) that he had seen this effect in his milksnake x motley animals.

So, while I agree with you that we all have accepted that bloodred and motley are different and share no common genetic makeup, I would suggest that our acceptance of this "fact" in no way makes it so. There could be absolutely no connection what so ever, but I think it needs to be proven one way or the other via test breeding rather than simply throwing it out as a "common sense" issue.

 

[Darin Chappell]

One more thing,

If I bred a bloodred to a motley and all of the F1 had clear bellies, I then took multiple individuals of this clutch and bred them all to different bloodreds and/or motleys, and ALL of the F2s were white bellies as well, would this not be proof that bloodreds and motley shared a common gene in respect to their ventral coloration?

Now, we all know that no one is going to tie up that many bloodreds or motlies for a simple genetics test. However, this is the same way that we proove that any two supposedly different morphs either are or are not carrying the same gene.

 

[Kat]

I was under the impression that motleys and bloodreds had already been tested before...

However, I don't think a test as extensive as you've proposed would be necessary...

All you'd need would be for someone to breed a bloodred to a motley. If all offspring had solid bellies, then it's the same gene. If all offspring had the typical F1 bloodred belly, then it's not the same gene.

However, I doubt they're the same, as the effect they have on the lateral and dorsal patterns are different...

 

[HomeBreeder]

I have an adult that I'm fairly certain is one of Rich's motley X milksnake phase. She has no ventral markings for several inches behind her chin, but they pick up, and become more dense toward her tail... Here is a pic showing her belly and back:

I don't proclaim to have any answers when it comes to poly genetic and or codominant factors, but I do think I picked an exciting time to "get involved". There certainly seems to be a near limitless potential in corn snake morphs. It's going to be interesting to see what we communally learn in the coming years/decades. Of course if history is a good indicator were going to just have more questions to ask everytime we find one more answer!

^Curtis

 

[Darin Chappell]

Kat,
Normally, I would agree that such extensive testing would be wasteful, but because we all agree that at least some parts of the "bloodred cocktail" appear codominant, I would want to have the more exhaustive route simply to exclude further the possibility of the bloodred genes masking the normals. Overkill, I agree, but if I was going to tie up a bunch of bloodreds and motlies, I would want to be as sure as possible of my conclusions!

Curtis, you are absolutely right! Every time I hear someone say something about the corn morph possibilities being played out, I have to catch myself from chuckling in their face.

 

[Clint Boyer]

OK guys, what's in this one?

From what I've absorbed from the thread above, I don't think the Sunglow is a good analogy to Bloodreds. I believe the Bloodreds were originally developed from wild caught snakes that showed a more uni-color but were still considered normal. There was no original simple recessive gene to start the seletive breeding with. I would venture to guess that inbreeding the group produced the plain belly affect and that there may be no simple recessive gene in the Bloodred line.

Now this guy has some interesting aspects.

Here's a ventral shot, anyone care to guess what is in it's genetic background?

 

[Darin Chappell]

If that's the animal I saw you describing elsewhere Clint, I won't say anything right now because it would be unfair. Let's just say that when the tide turns, you'll know I knew what it was once the guessing is over.

Darin

 

[SilverTongue]

I know I am wrong but I am guessing anyways...

Motly/Milksnake Phase???

 

[Serpwidgets]

Bloodred and Motley are not alleles...

It explicitly states in the Corn Snake Manual that this was tested and all of the offspring had normal ventral patterning.

Even if bloodred were an allele of Motley... so is Striped. But Striped has its own name. Why would this other "trait" not have the same consideration?

The biggest point is that, at the point where the "Sunglow" story ends, it is obvious to anyone who looks at the evidence that Amelanism is its own trait, independent from the Sunglow morph as much as it is independent from Snow and candycane. If that is true, then I think it's obvious that something should be done about the names to avoid further confusion of the issue.

Imagine in your original scenario that the sunglow made of 3 independent simple recessive traits is the actual case.

• When outcrossing to an Okeetee, ~25% the F2s would express one particular trait and have NO borders, in stark contrast to the rest of the clutch.
• Outcrossing to a Miami, ~25% of the F2s would have extremely bright orange ground color, in contrast to the rest of the clutch.
• And outcrossing to anything, ~25% of the F2s would express amelanism, in contrast to the rest of the clutch.

You would then be able to say with some semblance of certainty (and even more so after the test is repeated again and again with the same results) that there are in fact 3 individual traits at work. At that point, it seems a logical conclusion that these known traits should be labeled so that when you are talking to someone else about them ("this snake is expressing or het for blahblahblah") they know what it is you're referring to.

The $64,000 question is, what would you name these traits? One of them is already going by the name Sunglow, as well as the morph which goes by the same exact name. Would you name any or all of these traits "Sunglow?"

Or--knowing that these traits will be used in many other combinations of morphs such as Candy Canes, Borderless Okeetees and Orange Miamis--would you think it better to name them something more like "Amelanism" and "hypo-border-ism" and "hyper-orange-ism?"

As far as the 'real life' scenario goes, it seems like the same thing may be happening.

I won't claim to be an expert or authority on Bloodreds or the bloodred "trait," but my understanding, based on everything I've read over the last couple years, is that the trait which causes plainbelly and varying degrees of dorsal pattern changes is in fact in independent simple trait.

Based on the many other genes at work on the pattern in a given "het" animal, it may have more or less of an effect on the pattern in each individual, giving it varying degrees of apparent codominance. But there seems to be an undeniable dividing line between anything that is het versus anything that is homozygous for this trait. In my understanding, in a clutch resulting from a "het" X a Bloodred there are two distinct phenotypes. I am also under the impression that the outcome when breeding Bloodred X Normal and breeding the F1s together--as far as the expression of the plainbelly trait in the F2s is concerned--is pretty much the same as any other simple trait.

Clint, you recently posted a photo showing bloods and non-bloods from the same clutch. Assuming it really is polygenic, I don't think anyone can explain why it is so easy to identify which ones are fully expressing that "one" trait which causes a gray head/ground color and the brick red saddles, and which are not. And why do we not see an entire range of "normal to bloodred" with lots of "gray area of unknowns" in any of these clutch pictures? (Or do we, and nobody ever posts those pictures?)

Also, I've yet to hear of a generation of bloodreds so outcrossed that it is impossible to recover that one trait, either. I personally don't think it will happen, any more than if you keep outcrossing every amelanistic generation to normals and then back to each other to recover the amelanism. If it's a multiple-gene trait, there is a point at which one or more of the components would be lost, and eventually it would become impossible to recover the original trait anymore. My guess (and it still is only a guess) is that my own "bloodred" (the motor-oil colored one) is one of those that has been outcrossed so far as to remove everything except the simple pattern trait.

I do plan on actually testing this over the long run, basically by keeping the least-bloodred-looking offspring from Mary, then crossing them to each other to recover "the trait" (and keeping the ones showing that the least) and then outcrossing again, etc. It should be interesting to see how much removed it can get.

So (I'm not saying it is, but) IF my theory is right, then--regardless of how many other components make up the "pure" bloodred cultivar and no matter how simple/polygenic/dominant/codominant/recessive ANY of the rest of the "true bloodred" components are--IMHO the one trait which can be shown as an independent simple trait should deserve its own label, completely separate from the morph in which is was originally discovered.

 

[Clint Boyer]

Well........

I agree with most of the hypothetical situations represented BUT, I'm not so sure it's as easy to prove as separating 3 simple recessive genes. There are going to be things that leave you scratching your head.

I'm also curious just how the 'offical' group will classify Sunglows, those with hypo used and those without.

Serp, as you already know, the pics I posted of Bloods were Bloods and hypo Bloods.

The snake in the pic above has Milksnake phase, Motley and Bloodred in it's ancestry. All three of these cultivars have an odd or patternless ventral, each one is different. I crossed a Classic female het Motley, possible het Blood to a Milksnake phase het Motley. It had a clutchmate that was completely patternless on the ventral but appeared normal in every other way, that one died. I'm not sure just what is going on, I still have this male and haven't decided if I'll use him in any projects.