Theory on snow lines

[Sandra]

Intro

Recently I spent some time thinking about why snows from non Mack lines would produce Super snows and I found a way for it to be possible. Sorry if something like this has been posted before or if it was obvious to you all. And please, no bashing like "you have no proof" etc etc, I know, this is just to have some fun.

Premises

For those who are not familiar with snow lines, there are several snow lines out there apart from the Mack one. One of them are the Gem snows, thought to be dominant. Another one are the TUG snows, thought to be dominant too. There are several selective bred snow lines too.

Gems, TUGs and some selective bred snows, when bred to Mack snows, have produced super snows. Your first thought would be that those other lines are indeed Mack snows. But if they were Macks, when breeding Gem x Gem, TUG x TUG, Gem x TUG, etc... They would produce super snows. This is not the case.

Basics

Mack snow and super snow are the same mutation, just the Mack snow is the heterozygous form and super snow the homozygous form. This morph is incomplete dominant with regard to the normal morph, that's why the heterozygous has an intermediate appearance between a normal and the homozygous. The alleles would be located something like this in the gecko's genome:

Mack snow:

Gene 1: (normal)-----(normal)
Gene 2: (normal)-----(normal)
Gene 3: (mack)------(normal)
Gene 4: (normal)-----(normal)
Gene 5: etc.

Super snow:

Gene 1: (normal)-----(normal)
Gene 2: (normal)-----(normal)
Gene 3: (mack)------(mack)
Gene 4: (normal)-----(normal)
Gene 5: etc.

When we combine several morphs, the most common thing is that they affect diferent genes. For example, a Mack snow albino genome would look like this:

Mack snow albino:

Gene 1: (albino)------(albino)
Gene 2: (normal)-----(normal)
Gene 3: (mack)------(normal)
Gene 4: (normal)-----(normal)
Gene 5: etc.

In a dominant mutation, as some snow lines are supposed to be, the heterozygous and the homozygous form would look the same but their genotype would be different:

This...

Gene 1: (normal)-----(normal)
Gene 2: (gem)-------(normal)
Gene 3: (normal)-----(normal)
Gene 4: (normal)-----(normal)
Gene 5: etc.

...Would look the same as this...

Gene 1: (normal)-----(normal)
Gene 2: (gem)-------(gem)
Gene 3: (normal)-----(normal)
Gene 4: (normal)-----(normal)
Gene 5: etc.

...And that's why Gem x Gem only produces either Gems or normals.

Explanation

It sometimes happens that two mutations affect the same gene. When we say that a mutation is "recessive" or "dominant" or "incomplete dominant" we usually refer to how does it behave with regard to the normal morph. But if the second allele is not normal but another mutation, it doesn't have to act the same way.

My theory is that all the snowy morphs affect the same gene (which would make sense because they all consist in reducing the same kind of pigmentation) and the Mack snow gene is dominant over them, thus showing its full potential even in the heterozygous form. The genome of a super snow that comes from Gem X Mack breeding would look like this:

Gene 1: (normal)-----(normal)
Gene 2: (normal)-----(normal)
Gene 3: (mack)------(gem)
Gene 4: (normal)-----(normal)
Gene 5: etc.

Results

If this was true, then the results of breeding should be something like this:

(Het) Gem x (Het) Mack
25% normals
25% (Het) Gems
25% (Het) Macks
25% (Het) Gem / (Het) Mack (Super snow phenotype)

(Het) Gem x (Homo) Mack (Super snow)
50% (Het) Macks
50% (Het) Gem / (Het) Mack (Super snow phenotype)

(Homo) Gem x (Homo) Mack (Super snow)
100% (Het) Gem / (Het) Mack (Super snow phenotype)

(Het) Gem / (Het) Mack super snow x (Het) Gem
25% (Het) Gems
25% (Het) Macks
25% (Homo) Gems
25% (Het) Gem / (Het) Mack (Super snow phenotype)

(Het) Gem / (Het) Mack super snow x (Het) Mack
25% (Het) Macks
25% (Het) Gems
25% (Homo) Macks (Super snows)
25% (Het) Gem / (Het) Mack (Super snow phenotype)

(Het) Gem / (Het) Mack super snow x (Homo) Gem
50% (Homo) Gems
50% (Het) Gem / (Het) Mack (Super snow phenotype)

(Het) Gem / (Het) Mack super snow x (Homo) Mack (Super snow)
50% (Homo) Macks (Super snows)
50% (Het) Gem / (Het) Mack (Super snow phenotype)

I think I'm not forgetting anything, but could be...

It would be difficult to prove out because most of the time it acts like normal Mack crosses would act on the outside, even if the genotypes are different. I think the key is here:

(Homo) Gem x (Homo) Mack (Super snow)
100% (Het) Gem / (Het) Mack (Super snow phenotype)

A Mack x Super snow cross would NOT produce always supers (well, maybe if you are a hell of lucky guy, but more likely not).

Well... Does this all sound logical to you? Let's have some fun over analyzing things as we always do

 

[Halley]

I have wondered for a while how this might work but have to say I haven’t put any real thought into it. Your explanation seems to make the most sense for me with both TUG snow, and the Gem snow. And I think you are right that the cross of:

(Homo) Gem x (Homo) Mack (Super snow)
100% (Het) Gem / (Het) Mack (Super snow phenotype)

Would be the one to answer this theory. I think the other crosses in theory should produce what you have predicated, but we don’t know how the genes in the genome line up with each other (meaning maybe they don’t combine in expected ration, much like the Bell Blazing Blizzard, Bell Patty, etc.)

However I think this theory doesn’t work for Line Breed Snows, for the reason that they are polygenetic. 6% of the offspring from a LBS x Mack Snow are phenotypic Supers. But… saying that I believe your theory to be correct for both TUG and Gem snow (if in fact they are both dominate), but believe that it simply cannot apply to a polygenetic trait.

 

[Sandra]

The only way this would work for line bred snows is that some of them are indeed mutatant animals that appeared in the line bred snow colonies without the breeders noticing it. But I can't count on that.

I'll have to keep thinking on it, hahaha.

 

[Gazz]

The only way this would work for line bred snows is that some of them are indeed mutatant animals that appeared in the line bred snow colonies without the breeders noticing it. But I can't count on that.

I'll have to keep thinking on it, hahaha.

That is my opinion i think that original LB-snow ancestor was infact a dominant snow type.Coz as we have seen with all the snows the whiteness can be polluted.So in my IMO with Albey LB? snows where there yellowing out there not reverting back to be normals.There just yellower snows like what we are seeing more and more with mack snow.If i had my way there would only be SNOW that's-(GEM/TUG/ALBEY) all i the same boat just keeping (GEM/TUG/ALBEY) as strain names all being dominant.SNOW-HET super snow-(MACK) also dominant but HET super snow.SUPER SNOW-dominant.IMO would make life esayer.But we would need to know if.
Snow het super snow X snow = SNOW 100% HET SUPER SNOW,normal,super snow.With all the snow strains.

 

[paulh]

Good thoughts.

Simplified question: Are the Mack snow and GEM mutant genes variants of the same normal gene? If so, they would have the same location in the genome. If not, they would have different locations in the genome.

To test this would require a first generation mating to produce babies with a Mack snow mutant gene and a GEM snow mutant gene. Ideally, this would be from a super Mack snow mated to a super GEM snow, but even a heterozygous Mack snow X heterozygous GEM snow could produce what we want.

Second generation is a test cross -- a first generation baby mated to a normal. If Mack and GEM are variants of the same normal gene, all babies would have either a Mack snow or a GEM mutant gene paired with a normal gene. If any normals appear, then Mack and GEM cannot have the same location in the genome and cannot be variants of the same normal gene.

Super snows from Mack X line bred are most likely additive effects from the combination of the Mack and the line bred genes.

 

[Gazz]

Would be a interesting project to breed a.

SUPER SNOW-(male).

To a.

GEM-(female) = 100% snow ??.
TUG-(female) = 100% snow ??.
Abley-(female) 100% snow ??.

If all share the same genes and throw 100% snows also by such a breeding would all the snows be super snow throwers.Then it would be interesting to see how meny super snows you get when you back breed all the snow offspring.Would it still work on a 25%Super snow,50%Snow,25%Normal basis like mack snow ??.

 

[fallen_angel]

I get so confused when it comes to trying to figure it out.. but we will be taking our Super Snow from our Line Bred Snow X Mack Snow pairing, and breeding him back to the Line Bred Snow, as soon as he is old enough, sometime next year, to see what happens. We are more than happy to share our results, but cannot help much when it comes to explaining them! But I think after giving it a few years, we (as a community) will be able to figure this stuff out.

 

[Sandra]

Simplified question: Are the Mack snow and GEM mutant genes variants of the same normal gene? If so, they would have the same location in the genome. If not, they would have different locations in the genome.

'nuff said!!

Second generation is a test cross -- a first generation baby mated to a normal. If Mack and GEM are variants of the same normal gene, all babies would have either a Mack snow or a GEM mutant gene paired with a normal gene. If any normals appear, then Mack and GEM cannot have the same location in the genome and cannot be variants of the same normal gene.

I'm not sure I understand what you mean. The Mack/Gem het with super snow phenotype supposedly would throw 100% snows (50% Gems and 50% Macks, which would be very difficult if not impossible to tell apart) but any other normal super snow would do the same (100% Macks). I don't get the point...

Super snows from Mack X line bred are most likely additive effects from the combination of the Mack and the line bred genes.

I've always wondered where do you draw the line between line bred trait and
mutation. If the selective breeding affects the animal so badly that a mutation acts different with him than with the normal allele, wouldn't that stop being just a line bred trait?

Would be a interesting project to breed a.

SUPER SNOW-(male).

To a.

GEM-(female) = 100% snow ??.
TUG-(female) = 100% snow ??.
Abley-(female) 100% snow ??.

If all share the same genes and throw 100% snows also by such a breeding would all the snows be super snow throwers.Then it would be interesting to see how meny super snows you get when you back breed all the snow offspring.Would it still work on a 25%Super snow,50%Snow,25%Normal basis like mack snow ??.

That could be interesting but not decissive evidence. A normal super snow theorically should throw 50% snows 50% supers in that situation. The het super snows should produce 75% snows and 25% supers.

(Het) Gem / (Het) Mack super snow x (Het) Gem
25% (Het) Gems
25% (Het) Macks
25% (Homo) Gems
25% (Het) Gem / (Het) Mack (Super snow phenotype)

But this things never happen exactly as you predict :main_rolleyes:

we will be taking our Super Snow from our Line Bred Snow X Mack Snow pairing, and breeding him back to the Line Bred Snow, as soon as he is old enough, sometime next year, to see what happens. We are more than happy to share our results,

Please do

 

[paulh]

I'm not sure I understand what you mean. The Mack/Gem het with super snow phenotype supposedly would throw 100% snows (50% Gems and 50% Macks, which would be very difficult if not impossible to tell apart) but any other normal super snow would do the same (100% Macks). I don't get the point...

"Supposedly" is the key word here. My original question was, "Are the Mack snow and GEM mutant genes variants of the same normal gene?" This can be rephrased as "Do Mack/Gem hets with super snow phenotype throw 100% snows?" Maybe not all the babies are snows. That sort of thing has happened in other species. The mating I suggested is designed to find out whether or not all the babies are snows.

If a Mack/Gem het (one gene pair) is mated to a normal (two normal genes in the gene pair), then all the babies will have a normal gene from the normal parent and either a Mack or Gem mutant gene from the het parent. They will all be snows, and none will look normal. By normal, I mean looking like most of the geckos running around in the wild.

If a Mack and Gem double het (two gene pairs) is mated to a normal (two gene pairs, each with two normal genes), then here are the expected progeny:
1/4 Mack and Gem double het (super snow?)
1/4 Mack snow (snow)
1/4 Gem snow (snow)
1/4 normal (not snow; looks like the geckos running around in the wild)

Getting normal-looking babies is impossible if there is only one gene pair involved. The only way to get normal babies is to use two gene pairs. If normal babies show up, then the Mack and Gem snow mutant genes are not different variants of the same normal gene. That would answer our question. On the other hand, if only snows show up, then we have other questions.

 

[Sandra]

I understand now Paul. Sorry, I'm being thick today, lol.

 

[godzillizard]

Maybe all the snow lines came from fasciolatus originally? Could macks be a mutt created from all the line bred snow lines on the market?

 

[boutiquegecko]

A little ot-I keep seeing the whole gene location thing in discussions. Is there a link some where to show where they are located? How was this figured out?
Has anyone else considered a morph mutation from the fasciolatus and how it might have something to do with our snow outcomes?
Brian here's Albey's take on it.
http://www.geckoforums.net/showthread.php?t=3825

 

[godzillizard]

Marlo, thanks for that link...very interesting

 

[bohannbj]

From what it sounds like I have to say that the inheritance pattern sounds more like Co-Dominance. Intermediate phenotypes are more of a blending of the two and the F2 generations can yield all three phenotypes. It could be incomplete but due to the lack of breeding records and the attempt of "het" selling has made the mack difficult to discern. I really wish we had a breeding results forum where people would post their results.
Brent

 

[boutiquegecko]

Brian I've added a fasciolatus/mack to our collection, but will be doing some outcrossing this year. It's just time/space to add in all the snow lines for test breeding. If I can get my hands on some gems I may see what outcomes from that cross will produce.
It is too bad we have no solid records of all the snow crosses and crossed with fasc. But then who knew we'd be trying to figure out if they are some how related years after they came out. Anyone have a rich friend or genetics friend who could do a test on each strain like they did with the albinos?

 

[liljenn]

Maybe all the snow lines came from fasciolatus originally? Could macks be a mutt created from all the line bred snow lines on the market?

I agree. ^^ IMO, since the current "leopard gecko" is the combo of the E. Macularius subspecies, I believe the "snow" morph shows more of the fasciolutus traits. Also, according to what I have read from Jim at Reptilian Gems, the Gem Snow is actually incomplete dominant, not dominate. (read: http://www.geckoforums.net/showthread.php?t=4951) Where as the TUG snow gene is claimed to be dominate. (although I do not know much about the TUG snow line. I know others have done some breeding with them.)

If I can get my hands on some gems I may see what outcomes from that cross will produce.

Hopefully, I will hatch some pure gem snows this next season. I am very fascinated by the Gems and will be doing some breeding with them over the next few years. I have been trying to read as much as possible about what other breeders already have done. I know that other than Reptilian Gem - Kelli (Hiss), Paul (Bright Albino), Shaun (Leggomygecko) & Chris (Palmetto Gecko) have done some work with them (probably others I am unaware of too!).

I am very much looking forward to seeing what I find.

 

[ReptilianGems]

Sandra,

I agree with your conclusions in you first post. Well thought out. I have thought the same thing for some time, but haven’t too the time to share. Thanks for doing so.

 

[Sandra]

I'm glad to see you here! I thought you had vanished off the face of the Earth...

If you have any other thoughts on it please share