morph names and my opinions.

[crotaphytidae]

concerning the snows and their ability to become super snow when combined with the mack gene, I think they are similar to Ultramels in cornsnake where the alleles all sit in the same locus and when Gem is in the homozygous state it is still a gem, same with the Tugs and LBS but when they are place with the mack snow gene on the same locus this triggers a super snow phenotype even though the animals are the heterozygote genotype. This is what makes sense to me after learning this concept, that multiple alleles can be on the same locus.

 

[Gregg M]

Explain?

I have no stand on this just curious to why you say they are not.

Snows are not anery because they are not void of yellows, oranges, lav, or any other color... Maybe super snows can be called anery by definition but the mode in which it is expressed is not anery in the conventional sense...

Blizzards are not anywhere close to being leucistics... Color can be introduced easily and eye color is normal and not what you typically find in a true leucistic animal... If blizzards were truely leucistic, they would be no other color but white and their eyes would either be blue or black 100% of the time... There would be no variation at all...

 

[nevinm]

gregg i said the super snows are anery not regular macks.

and thats not true. leucistic animals have eather blue, black, OR normal colored eyes. and as i said befor. look at the first blizzards. they were all white and most still are. after line breeding and in breeding they started showing yellow. and lets not forget we are talking about animals that can change shades by mood and background colors. if a leucistic chamelion is ever produced i garentee it will change shades here and there. blizzards only got that bright yellow through line breeding

 

[herpencounter]

Not all Leucistic animals have black/blue eyes Gregg, some can have normal colored eyes. Look it up.
I do agree with you on the body color.

 

[Gregg M]

All I have to say is give me one example of a leucistic reptile that has "normal" eye pigmentation...

Nevin, true leucistic animals can not have color line bred into them no matter how bright of a blood line you introduce...
If there ever was a true leucistic cham, it would not change color or shade due to the skin cells inablility to produce color or shades... The leucistic gene does not allow skin cells to produce color at all...

Anyway, the first blizzards sold look identical to the blizzards on the market today... They vary from almost white to dark gray...

 

[GroovyGeckos.com]

In my case I also meant Super Snows. Those were basically the only things I agreed with in this thread, that could possibly be as Nevin stated. Not that I think that is the case, for certain.

Gregg makes a good point about Blizzards with color, I`ll have to retract that statement and say that I agree, SS may be anery. I do not think Blizzards are luecistic for that reason, but was not thinking. I was not yet ready to dismiss it as a possibility, is all.

Sorry for any confusion. I just did not know how else to say, these were the only two valid points(IMO) in this thread.

 

[nevinm]

so does that mean you refuse to admit that piebaldism is a form of leusism? so let me tweek my words a lil. maybe its not a leusistic, maybe the blizzard is accually some sort of piebald which would explain the color tints and even the "paradox" spots...... but i guess that would make it leusistic then because piebald is a form of leusism.

 

[crotaphytidae]

I would have to agree with Gregg that the blizzards are not Leucistic based on all the points he has already mentioned. I have yet to see any leucistic animal have color bred into it reptile or not, but I do think that the homozygous Super Snow is an anery/ axanthic animal.

 

[Ian S.]

Blizzards are not anywhere close to being leucistics... Color can be introduced easily and eye color is normal and not what you typically find in a true leucistic animal... If blizzards were truely leucistic, they would be no other color but white and their eyes would either be blue or black 100% of the time... There would be no variation at all...

Leucism does NOT define a solid white animal. There are huge HUGE variations in leucism. In both reptiles,birds and mammals alike. Staggering variations at that. So much so that folks can't even agree on a lackluster defintition without getting down to a cellular/molecular level.:main_laugh:
Blizzards don't have black eyes 100% of the time? and where are these blizzards with introduced patterns? Most you'll see is underlying hughes of yellow & carrot tail which is not affective melanin @ work. Striped blizzards? Jungle blizzards? Even hypos can be expressed double homos with stripes. Enigma blizzards.... dang still no pattern. Here's some food for thought. Where did the supersnows pattern go against the blizzard and the murphy's?
Also your saying an albino leucistic cannot be created?

 

[nevinm]

thank you ian. i was going to thow out the thought of the white tigers. but you said everything i wanted to. white tigers are considered leusistic, white animals with blue eyes. but they also still have the black stripes. still considered leusistic

 

[Ian S.]

More observations / questions... are tangerine albinos we're working with not albino because they're line bred for yellow, pink, orange, red? is a paradox albino not an albino because the genes didn't correctly tell melanaphores where and when to turn off?

 

[nevinm]

i wouldnt call them a paradox albino. they are T+ albinos. which really means they are just like a normal animal with out any black pigmant. a paradox albino would be a real T- albino that has normal looking patches.

 

[Ian S.]

Nah bro they are still T- albinos with a defect within the defect.
T+ albinos are completely different type of mutation affecting the levels of tyrosinase not melanin. Tyrosinase levels are still produced in the T- albinos and is washed out when the melanophores are. Tyrosinase is still able to be produced and seen in leucism even though melanin isn't and can be controlled by hormones. (aka) Why do we have dark blizzards?

 

[nevinm]

got ya, i would like to see a paradox T+ albino

 

[Ian S.]

:main_laugh:LOL I had T+ and T- backwards lol
I'll take the title of idiocy.(can we call it a typing error) but I fixed it.:main_laugh:

 

[Ian S.]

In Greggs defence however it was believed that tyrosinase was always wiped out with the melanin in leucism. Tyrosinase co produces melanin by oxidization of amino acids. Just because the melanin isn't there, does not mean the tyrosinase is affected.

 

[paulh]

Thanks for the information. Just a couple more questions:

First, you're saying that for all practical purposes there is no need for us as reptile breeders to make any distinction between co-dominance and incomplete-dominance, correct?

Correct. Even if we wanted to, we seldom have the information needed to make such a distinction.

Second, what is the distinction between the two, and could you give us an example of each?

With incomplete dominance, the heterozygous type can be distinguished from both homozygous types, and one allele has a nonfunctional product. The phenotype depends on whether there is one or two copies of the allele producing a functional product. In codominance, the heterozygous type can be distinguished from both homozygous types, and both alleles have functional products. (The textbooks do not all have the same definitions, though.)

In the mouse, the albino mutant gene has been tested and found to be tyrosinase negative. As far as we know, that mutant gene does not produce a functional product. The mouse has several mutant alleles to the albino allele, including chinchilla and himalayan. Chinchilla and himalayan mice have melanin pigment, though less than the normal mouse. All of these mutants are recessive to the normal mutant. According to the books, all combinations of these mutant alleles are more or less intermediate in appearance between the two homozygous types. So a mouse with a himalayan gene paired with a chinchilla gene is an example of codominance, while a mouse with a chinchilla gene paired with an albino gene is an example of incomplete dominance.

Another example of codominance is the MN blood type system in humans.

Another example of incomplete dominance is sexlinked hemophilia in humans. The gene is usually classed as a recessive mutant gene, because heterozygous females do not have hemophelia. But it is an incomplete dominant mutant gene when the appropriate clotting factor is assayed.

The more sensitive the test, the more likely to change a dominant or recessive mutant into a codominant.

Finally, why do some in the reptile field insist on making a distinction if the distinction is not a profound one?

They are following a genetics textbook which does make a distinction. Most texts do, some texts do not, and sometimes there is a change between editions of the same text.

 

[preacherman]

Thank you for all the information, paulh. You've been very helpful and informative. Can I ask where your education in genetics comes from?

 

[hybrid]

Whats is a Co-dom Snow Blizzzard then? I'm lost and i recently got one from JMG. Please help.

 

[hybrid]

btw: my avatar is the gecko in question