2 questions

[SnakeAround]

First; I've seen jungle albino corns being advertised as F1, that ain't possible I think, do you?

Second; see pic below, advertised as a chocolate phase corn. Doesn't exist I think? Only choc. emoryi's I think.....

tnx!

 

[Billybobob]

I think that the king snake amel gene is located at the same spot as the corn snake amel gene so it is possible.

As for the chocolate corn I have never heard of them.

 

[Preita]

That picture looks like a normal to me. Though I could be wrong :shrugs:

 

[thunder]

When they say F1 in referring to a hybrid, they don't mean that it is the first generation born in captivity, that the parents are wc. They mean that it is a first generation cross, in that it's parents were a corn and a king, not a pair of jungle corns.

 

[Tegucentric]

"Chocolate: A hybrid between a cornsnake and the Emory's' Ratsnake. Generally brown to coffee blotches on a paler background. Usually produced as a by-product of the Creamsicle."

Rick

 

[SnakeAround]

@thunder; i do knwo that F1 means it's the first hybrid cross, but as far as I know, a snake with an albino king gene and an albino corn gene, just looks like a normal. At least, that's with breeding creamsicles; they're never F1. First you'll breed some normal loking snakies and maybe chocolates! I cannot imagine 2 species more different from each other could produce a critter with codominant albino genes, 'cause that's what you're talking about when they are located on the same locus but different.

 

[paulh]

@thunder; i do knwo that F1 means it's the first hybrid cross, but as far as I know, a snake with an albino king gene and an albino corn gene, just looks like a normal. At least, that's with breeding creamsicles; they're never F1. First you'll breed some normal loking snakies and maybe chocolates! I cannot imagine 2 species more different from each other could produce a critter with codominant albino genes, 'cause that's what you're talking about when they are located on the same locus but different.

It's possible. As I recall, Bern Bechtel tested both amelanistic corn snakes and albino Cal kings. He found that both lacked melanin pigment because they produced a nonfunctional version of an enzyme named tyrosinase. The hybrid is also unable to produce tyrosinase so lacks melanin. That's also what happens when an amelanistic corn is crossed to a tyrosinase negative albino black rat snake.

As far as I know, Great Plains rat snakes used in making creamsicles were normals. They would pass a gene for the normal, functional version of tyrosinase to the F1 babies, and that normal gene would cause melanin to be produced.

Albino in the Cal king and amelanistic in the corn are not codominant mutant genes. They are alleles. That's what you're talking about when they are located on the same locus but different.

A genetics prof I used to work for crossed an albino pigeon and albino ringneck dove. The result was one albino baby that lived to adulthood (and was sterile) and many many dead embryos and infertile eggs. This indicates that albino in the pigeon and ringneck are allelic. And pigeons and doves are less alike than Cal kings and corns because unlike the snakes, few hybrids hatch and all are sterile.

 

[SnakeAround]

I do remember discussing creamsicle breeding before and really am convinced that an amel emoryi x albino corn only breed normal phenotypes het for both amel genes, on the same allele but not functioning like 2 corn genes or 2 emoryi genes together would. That's why I used the word co-dominant for 2 types of amel genes being on the same allele, but breeding phenotypically amels. It was more like a comparison but I do think it quite well decsribes what I mean.... But I don't hink they are alleles.

I do think breeding creams happens by normal emoryi x amel corn; F1 hatchlings all are het for (corn) amel. Breed those together; F2 hatchlings are either amels o(creamsicles)r normals het amel, spread fifty-fifty. This text is from Kat nad explains it with codes;

The emoryi ratsnake has an albino gene, we'll call it 'Ae'. The cornsnake has an albino gene, we'll call it 'Ac'. An animal with 'AeAe' appears as an albino. An animal with 'AcAc' appears as an albino. An animal with 'AeAc' appears as a normal. Furthermore, 'Ae' and 'Ac' probably aren't alleles, so... if 'We' and 'Wc' are the wildtypes, what you really have in the AeAc case is 'AeWe,AcWe'. The snake would be described as Normal het corn-albino, emoryi-albino.

As for the jungle albino cross; their genes are more different so I cannot imagine them 'working together'on 1 allele to produce an amel.

 

[Billybobob]

I do remember discussing creamsicle breeding before and really am convinced that an amel emoryi x albino corn only breed normal phenotypes het for both amel genes, on the same allele but not functioning like 2 corn genes or 2 emoryi genes together would. That's why I used the word co-dominant for 2 types of amel genes being on the same allele, but breeding phenotypically amels. It was more like a comparison but I do think it quite well decsribes what I mean.... But I don't hink they are alleles.

Amel emoryi x albino corn dose produce normal het for both traits, you are right they are not alleles.

As for the jungle albino cross; their genes are more different so I cannot imagine them 'working together'on 1 allele to produce an amel.

While corns and kings are different species there amel genes are alleles so they do produce amels. (After my first post I checked up on it)

 

[SnakeAround]

Wow, strange tric of mother nature! Two species further apart share loci for albino and another 2 species very close together won't.... I love to know such things, tnx!

 

[paulh]

When two independent mutant genes (genes found at different loci, which are different locations in the chromosome set) produce the same appearance, the two are called mimics, not codominant. Codominant refers to a specific pattern of phenotype production by two alleles at one locus.

Humans have 20,000-25,000 gene loci, according to the Human Genome Project. Corn snakes probably have a number in the same order of magnitude. On the other hand, people have only identified mutants at around a dozen loci in the corn snake. In other words, the corn snake almost certainly has the locus for the emoryi albino mutant gene. Because the corn snake can contribute a wild type (normal) gene when the albino emoryi is mated to an amelanistic corn. It's just than nobody has turned up a mutant gene at that locus in the corn snake. Yet. Just as nobody has turned up a mutant gene at the amelanistic locus in the emoryi. Yet.

It helps to keep the mutant genes straight if each has a single, unique name. If we call the corn mutant "amelanistic" and the emoryi mutant "albino", then crossing an amelanistic corn to an albino emoryi produces normal F1s that are heterozygous amelanistic and heterozygous albino.

Kat, I'll send you a file on standard gene symbols. If anyone else wants it, let me know by e-mail. I also have a file on the difference between dominant, recessive, and codominant genes that I can give to anyone who wants it, too.

 

[SnakeAround]

Tnx! So if a F1 hatchling of an alb. kingx amel. corn breeding turns out to be phenotypically an albino a.k.a amel, the genes are on different loci but working together to produce this color if I understand right? So a corn also has the loci for the king albino gene? Doesn't seen very logical to me.....

Let me think..... Does the combination of a corn amel gene with a normal king gene on the corn albino locus produce the F1 phenotype albino? Like the king normal gene is dominated by the amel corn gene at that locus? Is that the answer? Would be great cause that would really put me a step forward in understanding genetics on this....

It could also explain why an alb. emoryix amel. corn cross cannot produce phenotypical albino's; they are so closely related, that the emoryi can provide a normal corn gene on the 'empty' corn amel locus to prevent the corn amel gene to be dominating.... It's albino gene is put on the emory albino gene of the hatchling...

Only one question stays open; what 'happens' to the albino king gene the hatchling gets? Is it randomly put somewhere? Or could there be a king locus in the genetic make up of the corn? Does the occurence of mutual available loci 'decide' which species can be crossed?! Or am I ranting now?