new to bloodred..

paulh

You seem to know a great deal about genetics and the co-dominant gene. Please write up something that is better than what I posted and I will be happy to delete it. Leave out all the Gecko stuff.


I have a question about this test for Darrin. Which Hets for Bloods are we considering. Depending on whether Bloods are recessive or co-dominant, the offspring from a Blood may not be Het Blood at all. When we consider Bloods as co-dominant, are we considering them to all be Homo Blood and not Het Bloods. Are we saying that a Homo Blood and Het Blood will look different. If this is the case, why? They should look very similar. Other co-dominant genes in snakes, cause the offspring in Homo or Het form to look almost a like and easily detectable. A Het Salmon and Normal Boa are as different as night and day. A Homo Salmon and Het Salmon are so close that you can not tell without test breeding.

If Bloods are recessive all offspring will be Het Blood. If Bloods are co-dominant, half of the offspring will be normal and not be Het Blood at all, unless we are trying to say that all Bloods are Homo Blood and then all offspring would be het Bloods and none of them would look normal at all. This may explain why some offspring that are considered hets have the checkered belly. They are not hets at all. This is if the Blood gene is co-dominant.

If someone assumes that the Blood gene is recessive and that all offspring are Het Bloods, but the gene is co-dominant, this pattern recognition won‘t work. When we save these normals from the Blood X normal breeding, assuming they are hets (recessive) and we breed them back to a Blood, the resulting offspring will be half Bloods as if we were breeding a Blood X Het Blood(recessive), but a Blood (co-dominant) X Normal would produce half Bloods as well.

This is the same mistake people make with my Spotted Donkeys. They save a solid from a Spotted, assuming that it is recessive, and breed it to a Spotted. When they get a Spotted foal, they think it is because the solid was het(recessive) spotted when in fact that the Spotted foal came from the co-dominant Spotted parent. If they breed two solids from spotted parents until the end of time they will never get a spotted foal, because the gene is co-dominant and if the foal is not spotted it does not carry the gene.

It would seem that enough people have bred Bloods to know if it was co-dominant or recessive. Has anyone bred two Hets(recessive) for Bloods together and got Bloods? If so then it is recessive. If it is co-dominant then, when people bred a Blood to a normal, like my Blood X Lava which are from a wild line, I will get half Bloods. If we are trying to say that we are going to get something less than a Blood, an in between animal, it is not acting like other co-dominant genes in snakes, and it must be something else. .

Not all hets are hidden! The very definition of a gene being a co-dominant gene is that it shows a phenotypical change in the animals that are merely het for it.

A homozygous bloodred is not HET for the gene, therefore it is 100% the case that all bloodred outcrosses are going to be het for the pattern mutation because they all (by definition) had one parent that could throw nothing but the mutant gene into the mix.

If the bloodred pattern (episkiastism) is a co-dominant gene, and you breed a homozygous snake to a normal snake, all of the babies will be het for "epi," and they will all show the effects phenotypically. Whether the gene is co-dominant or not, is irrelavant to whether Bloodreds pass on their genes to their offspring. All the issue of co-dominance addresses is whether the phenotype is altered by the animal being het for the gene.

Hey Darin,

Is 'episkiastism' the official technical term for the pattern? If so, perhaps we ought to name the trait that. (I mean, we have Amelanistics, Anerythristics, etc...) It may be easier for some people to swallow than 'Diffuse', 'Suffuse', 'Faded', or whatever. Besides, 'Epi' corn kind of has a nice ring to it...

-Kat

"Episkiastic" is an English derivation of a Greek term that means basically the same thing that we have all been trying to describe with terms like "diffuse, faded, muted, etc." I just offered it as a suggestion in this thread earlier, but it is certainly not "official" by any means.

I like it too. I agree with you that "epi" is cute nick-name for the pattern.

Er... and my guesses are...

a, b, e, g, and k for het bloodred, and the rest are not.

(I'm probably wrong, but hey...)

I should make up a test list as well... Just for grins. Unless Serp's gotten more snakes that I don't know about, any snake he's got that's het for bloodred pretty much came from the same mother (Mary).

On a different note, it looks like my amel bloodred is pretty much a dud. The snow stripe I'd housed him with seems to be reabsorbing her eggs. Given this is his second year of non-performance, I think I'm going to have to send him to a new home.

-Kat

Amel Okeetee Blood X Amel Okeetee

I picked up a few Blood adults last year so I could start working them into my other morphs. This Amel Blood is out of the line of Amel Bloods that came from Amel Okeetees. He has the Blood pattern, but is much too orange. Hopefully, this Amel Okeetee female will put some more red into the offspring.

I can’t wait to see the offspring so I can see what Darin is talking about.

"Fire" Amel X Amel

I wish this male "Fire" Amel was a female, so I could breed him into the bloods. I am hoping to get some more like him out of this breeding to his grandmother. His red is extremely intense and very dark. An amel Blood with his dark red color would be nice! I might get him bred to a Blood female for her second clutch.

Codominance versus dominance

Joe, (and anyone else who gets recessives but is lost on codominants) I think you're missing the most important point here:

(I'm not trying to sound mad here, just trying to stress the important stuff, so don't read it as if I'm being short or yelling, hehe.)

Codominant is NOT the same as dominant. DNA does not care whether or not the allele humans designate as "wild type" is the dominant one. DNA does not cause one allele to become "dominant" just because it is more common in the population of that species. It seems that many people are so used to mutants being recessive that they can't accept a mutant allele being fully dominant... thus they apply "codominant" to it, which is simply not true.

The real reason that mutant alleles are more often recessive is because changes to the phenotype are unlikely to give them an advantage... they're already well-adapted and shaped by generations of hardcore selection. Mutations usually reduce the survival chances of the animal expressing that trait. They're usually "bad." Therefore if it's dominant, those born with even a single copy of it will express it... they're screwed, and are quickly killed off. A "bad" mutant that is dominant has a much harder time propagating through the wild gene-pool because so few carriers ever survive long enough to reproduce.

-----

Let's go back to the rose thing to more easily illustrate what I'm saying about codominance...

Our theoretical rose has two alleles at the "red" locus. One of them (the "white" allele, or "W") produces no red pigment. The other (the "red" allele, or "R") produces red pigment.

It's absolutely vital to note that (with two alleles) there are ++always TWO homozygous genotypes, and ONE heterozygous genotype. (Homozygous dominant is still homozygous. It isn't "double homozygous," it is just plain homozygous. You don't say normals are double homozygous for non-amel, double homozygous for non-charcoal, etc...)

With any two alleles, there are always exactly three possible genotypes that can be inherited:
WW (HOMOzygous because like genes are paired)
WR (HETerozygous because different genes are paired)
RR (HOMOzygous because like genes are paired)


----- With me so far? -----


If White were dominant, then red would HAVE to (by definition) be recessive to it. In this case, we'd get these genotypes/phenotypes:
WW = White
WR = White
RR = Red

And vice versa, if red were dominant, then white would HAVE to (by definition) be recessive to it, and it would be:
WW = White
WR = Red
RR = Red

In a codominant relationship, (by definition) white is not completely dominant over red, nor is red completely dominant over white. (And by definition, neither of them are recessive, either.) In this case, you get the following phenotypes:
WW = White
WR = Varying shades of pink*
RR = Red

*In some cases, the amount of codominance can vary wildly. As a result of "other" influences ranging from genetic factors which produce precursors to the red pigment, or environmental factors such as temperatures, or the nutritional content of the soil, etc. Remember, by definition the "WR" genotype is ALWAYS heterozygous, regardless of outward appearance. Because of this possible variability, the heterozygotes may actually visually pass for the "white" phenotype, and in other cases, they may actually pass for the "red" phenotype.

Notice that in a codominant relationship, there are not two phenotypes, but three. In the case of many (but not all) "diffuse patterned" corns, this is what is observed. That is, the heterozygotes will not look like either of the types of homozygotes. They will not look completely normal, nor will they look completely "patterned" like the homozygous mutants.

Also, notice that completely regardless of which is dominant, codominant, or recessive, the Punnett squares for any genotypes do not change. That is:
WW X WW = WW
WW X WR = WW and WR
WR X WR = 1/4 WW, 1/2 WR, 1/4 RR
WR X RR = WR and RR
RR X RR = RR
WW X RR = WR

These outcomes do not change. WW X RR always produces WR offspring.

-----

So, back to your cornsnakes, if you use "D" for the normal allele and "d" for the "patterned" allele, you would be doing these crosses:

DD X dd = Dd

These "Dd" F1s might be visually different from normals. They are hets no matter how you slice it, and no matter what they look like.

For the F2, Dd X Dd is the same exact cross (gene-wise) as you do with F1 of Amel X Normal.

Aa X Aa =
1/4 AA (Normal)
1/2 Aa (Normal, het)
1/4 aa (Mutant/Amelanistic)

The outcome for two hets for a codominant trait is the identical ratio of GENOtypes as with recessives or dominants. The difference is in the PHENOtypes:
1/4 DD (normal-looking)
1/2 Dd (possibly outcrossedy-looking, possibly almost mutant-looking... these are the "varying pink" roses.)
1/4 dd (mutant pattern)



++ (Sometimes one of the homozygous genotypes is fatal, or "incompatible with life." In those cases, you will only be able to work with the other two genotypes. This is true of the dominant gene for dwarfism in humans... all human dwarves are heterozygous, none of them are homozygous, because those "homozygous for dwarfism" embryos/fetuses die. IIRC the Merle gene in Aussies is fatal, and these things occur in mice/rats/horses, and fruit flies too. LOL one fruit fly "death" gene is named "Kenny.")

For those wanting to keep up with the genetics talk...

For the spotted donkeys, the crosses Joe is talking about go like this:

Where S = Spotted and s = Normal,

SS = Spotted
Ss = Spotted
ss = normal

Breed a Spotted to a normal:
Ss X ss = Ss and ss

Half the babies will be spotted (Ss)
The other half will be normal (ss)

People assume the normals are carriers. (Again, because they only learned the "rules of genetics" as they apply to recessives... if it came from a "mutant" it's gotta be het. But that is only true if the mutant is recessive.)

They breed the normal offspring to a spotted:
ss X Ss = Ss and ss

And then say, "see? It's het and that's why it produced spotted babies!"

However, if they breed two normal offspring from a spotted parent

ss X ss = ss

they will never get any spotted offspring.

The pic I posted does not carry any Bloodred as far as I know. I posted that pic to show that there may be other variations resembling the het Blood gene.
Here's the full pic:

Well, I picked Clint's example correctly, but I'm afraid I didn't do too well with Serp's. Now, there were some extenuating circumstances, in my defense, but even so, I put my "money" where my mouth was and came up short!

Serp, feel free to post the actual answers to this little quiz, or I can, if you like. If you're waiting to see if anyone else posts some answers, that's fine too ... whatever you decide.

At any rate ... I still believe that, most of the time, you can tell a het bloodred from a normal because there is SOME sort of a co-dominant variable working there. It may indeed be difficult to to tell a het bloodred from other plain belly morph variants (some het motlies or het stripes, and possibly animals with Rosy rat in their back ground), but against normals, I believe the pattern is seen 95% of the time.

Well,

Just for the fun of it. If I were to guess by the belly patterns, my guesses would be B, C, E & I for het bloodred - I am back and forth on K.
I am sure I am probably way off but thought I would give it a try.

Answer Key

I agree with Darin. You can't always ID a non-motley by the dorsal either, but it doesn't make motley "null and void" as a genetic pattern trait. By the same token, just because some non-hets can mimic the look, it doesn't mean hets can't have the look as a result of being het. It just means that it's not a "for sure" method of identification, similar to identifying "light anerys" as ghosts. I thought it would be worthwhile to point that out.

Here's the picture again, since it may be on another page for some people:


A = Crimson from normals both het amel/anery/hypo/blood. (Hmm... actually that makes her a poss het, but we always assume she's for sure het... doh!)

B = Amel het Blood (from Mary)

C = Normal (bunch-o-poss hets, but not het "bloodred")

D = Normal Het Blood (B, D, E and H are direct siblings)

E = Anery het Blood

F = Normal het ghost (very "rosy rat" looking, I knew she'd trip people up, hehehe)

G = Phantom NOT het (bred her to the Blood last year)

H = Snow Het Blood (got a pair of them, can't wait to see if they'll go this year!)

I = Normal het Anery (The anery mom threw some odd (striped-looking) head patterns and some odd bellies. She was unlikely to be het for motley or stripe.)

J = Anery poss het hypo/motley/amel. Half-sibling to I.

K = Charcoal het hypo pewter. Half-sibing to B, D, E and H. (same mom, the bloodred)

Also of interest is that, out of 40 siblings BDEH came from, only 1 showed any obvious "outcrossed" signs. In 2003 with the same bloodred but a different male, all of the boys (normals and charcoals alike) have the wide white stripe, and the females look like K. (shrug...)

I also have a normal from pewter X F, and he has a HUGE white belly stripe and a funky head pattern. edit: fixed link http://www.cornsnakes.com/forums/showthread.php?s=&threadid=10263

Darin, I agree with you that you will often notice a het
diffuse/blood/episkiwhat?sic snake's heritage on its belly,
but I also acknowledge that that isn't a sure fire way to tell.
The below picture is of 6 clutchmates. I apologize for the
quality of the pics, but I was trying to get you a large
segment while not stressing them as they just ate yesterday.
Granted there is a lot of variability within this clutch, here
are the 6 I still have...



They all have at least a tiny white line on their bellies,
ranging from barely existant to 3/4 of the width of the
belly at some points. Normal dorsals and sides.

These guys come from generations of nothing but
normals/anerys/amels/snows. That's it. No motleys,
no stripes, no bloodreds, no aztecs hidden in the
backgrounds for generations.

I see what you both are saying, and I do not disagree at all. However, it seems that the trend is that it is much easier to have a "false positive" ID than a "false negative" one (though that can also happen at a lesser rate, it seems).

Serp's analogy of the light anery versus the darker ghost is a good one. I had actually considered the comparison between the charcoal and anery A as another good example of what I am referring to. One may have difficulty in telling these morphs apart (some more than others), but they are easily identifiable from normals. The fact that separate genes cause similar effects in animals does not take away fromt he fact that there IS a genetic effect taking place, which is discernable from the wild type phenotype.

Thanks for the pics everyone!

Co-dominant belly pattern?

I am curious to know if anybody thinks it is possible to recognize the het bloods if it is not known that bloods are in their background (Het bloods sold wholesale or as normals) A normal X het Blood breeding, may not be known to the breeder that one of the parents is het blood.

I have been looking at the belly patterns of most of my corns much more that I use to since I became involved in this thread. I use to only pay attention to the Motleys and Stripes, since I didn‘t have Bloods. I was surprised to find that one of my lines has a very similar belly pattern to the het bloods we are talking about. So if the blood pattern is co-dominant, a pairing of a Normal X het Blood would result in 50% het bloods I believe.

I started finding these corns with a belly pattern resembling the het bloods in my Lava and Ice Ghost line, amel Okeetees included. About half of them had a similar belly pattern to the het bloods, which is consistent with what would be expected from a Normal X het Blood breeding. The Wild caught Okeetees and the Lavas from the wild caught line have normal checkered bellies, but the Amel het Snow that I used to begin this project has a belly pattern similar to the het bloods. She was purchased from Lloyd Lemke, who had a lot of bloods at the time, but that is the only possible connection to bloods that I know of.

So either, the Amel het Snow that I used to start this project was a het blood, or has a belly pattern that is acting like a co-dominant belly pattern similar to the het bloods. I will get some photos and see what opinions I can get about the belly pattern in this group of corns that I have. Normally, I would not have held onto so many from one breeding and would not have seen this 50% belly pattern emerging.

No Change to bloodred

I dont think we should change any of the names of the older morph corns especially bloodreds,heck alot of the names dont match Snow (should be pure white)blizzard (dang charcoal sure got them close) Ghost ( wow they come in so many colors) and so on! And just another one of my opions,I hear so very often wow that corn has some zigzag pattern ( my money is that its het lavender) not! Or look at the belly pattern on that corn, man I bet its het bloodred! (not!) I am not saying that these morphs cant influence patterns of a cornsnake,but so can all the other genes influence them the same way! The only real way to know what your corn is, especially now a days, is through breeding trials. Theres way too many breeders out there breeding for numbers and not carring about what breeds to what,or caring to really know what hidden genes your cornsnake carrys,even getting any corn from another breeder. (my 2 cents!) bloodred pic included :grin01:

Now that's a blood red deserving the name!

Lavender with Bloodred

ecreipeoj said:

. Rich Z’s Lavenderblood, may be called an Amethyst Corn like was suggested or something completely different, but it will still be a Lavenderblood Corn.

Click to expand...

Don't any gay men read this forum? Lavender and Bloodred would get you MAUVE. Not "maaav" as in Mom: "Mowv" as in "mow the lawn" Good god, if I couldn't remember that they'd throw me out of the union. Faerie Local 512 would be down a member!

paulh said:

But with variable expressivity, one can't RELIABLY distinguish the heterozygotes from one of the two homozygotes. I think someone will have to do a fair amount of breeding to decide about the bloodred pattern gene.

Click to expand...

Wouldn't that make it either an incomplete dominant or an incomplete recessive?