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Co-dominant vs Recessive Traits

Blazing_Tiger

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Today was the first day i started trying to learn about genetics for breeding animals. I think i have the basics down. Let me know if i'm right.

1. Is a co-dominant trait just a "dominant recessive trait"? as oxymoron as that sounds? As in, a co-dominant trait is just a recessive trait that is visible?

2. What if you have homozygous recessive trait albino (aa), and cross it with a Super pastel(p*p*)? Will the offspring, according to punnett square, be 100% Super Pastel het for Albino?

3. Well, i know with co-dominant traits you can make supers. According to New England Reptile "Piebald" is a recessive trait in ball pythons. So what if you would cross a Piebald(pp) x Piebald(pp). Would you create a Super Piebald? Or is there something genetically with recessive alleles so that the offspring would just be Piebalds(pp)?

Thats all for now! But i'm sure ill have some more questions soon depending on how much time i have to expand my genetics knowledge.

Thanks for any help,

Travis Stewart

PS: I would like to hear from YOU guys! I've already looked at the New England Reptiles genetics pages(101,201,301), along with a the first three(101,201,301)VMSherps genetic pages. But if you know of any other sites that explain genetics better, they would be appreciated!
 
You're a bit off with co-dominance. Essentially, a recessive trait will only be shown if it is the only genes an animal has. A co-dominate trait will show, even if another dominate trait is inherited.

Example: Human blood groups: 'A' and 'B' are co-dominate, while 'O' is recessive. If I get an 'A' or a 'B' from either parent, I will show that blood group, and if I get an 'O' as well, the 'O' will be hidden. If I get both 'A' and 'B' then my blood type will be 'AB' as both genes get expressed.

2. For this cross, yes every single offspring would be p*a.

3. No. Recessive is recessive. You would need two of the recessive alleles to even show this trait (baring other things like epistasis, which I don't feel like typing up)
 
Okay. So the order of Dominance is:Co-Dominant, Dominant, Recessive? Where Co-Dominant trait will show over a Dominant trait, and a Dominant trait will show over recessive trait?

Also, is it true to say that Super Pastel could be thought of as Pure Pastel and/or 100% Pastel? Where as an animal with a Dominant trait and the co-dominant trait pastel is only 50% pastel and 50% dominant trait? Or does the dominant trait not show at all in the pastel? If the dominant trait doesn't show at all, then why do Super Pastels look different then Pastels?

If my way of thinking doesn't make sense to you, i completely understand! I have a way with losing people. Maybe i word it in a way that only i understand? i don't know. But if you need anything clarified, i would be happy to.

And again, i am pretty new to genetics and how they work so please excuse me if my ignorance frustrates you in any way.
 
So, I think you are separating co-dominate and dominate traits. They are the same thing. If you have multiple dominate alleles, then they are co-dominate. Both get expressed to some extent, and are shown in an individual.

So yes, a super pastel would be a pure pastel.

Now, the thing is, this is a very simplified start to genetics. Epistasis (which I mentioned earlier) is where a third gene has a factor in the expression of other ones; the most common example is in Labrador coat colour. (A dominate allele in one trait allows for black and chocolate in that it codes for a receptor of melanin, where if you have two recessive (mutations), then the gene for yellow/red coats will be expressed.
 
Alright cool. Thanks a lot. And i figured there was something more to genetics then what i was learning. But overall for 1 day of reading about it, i think i did pretty good at understanding it. And thanks for your help Scott, i really appreciate it.

And this is probably going to sound like a dumb question but does Epistasis pertain to breeding snakes also? Or is it generally not used in snake breeding?
 
Not sure on that, I don't breed snakes but I like genetics.

Interesting fact, a silkworm's silk glands have about half a million chromosome sets.
 
So could any snake breeders out there tell me if what i seem to understand about snake genetics is all there is to it? Or is there something else i would have to know as a snake breeder?

@Scott - If you feel like it, send me a PM explaining that interesting fact of yours. Besides what i said in this thread, i'm clueless when it comes to genetics.
 
So, I think you are separating co-dominate and dominate traits. They are the same thing. If you have multiple dominate alleles, then they are co-dominate. Both get expressed to some extent, and are shown in an individual.

That's not correct. They are not the same thing in the least.

Travis, take a look at this article. Toward the end of the article it discusses the different modes of inheritance, how they work and how to prove it out.
 
Lets simplify this

Recessive genes are only expressed homozygous
Dominant genes are expressed the same if is homozygous or heterozygous
Co-dominant are expressed as heterozygous but have another expressed phenotype when homozygous


Epistasis is most defiantly at play.
 
Sounds like a pain to figure out if a trait is co, incomplete or dominant. And is there a list somewhere that has all the recessive, dominant, co-dominant, incomplete dominant traits?
 
Incomplete dominance and co-dominance are incredibly hard to distinguish, and in a lot of creatures look the same on the surface, and you can only tell on the microscopic level. Even that article you linked is misleading. A co-dominate flower for red and white will look the same as one with incomplete dominance more often that not.

I guess I did misspeak when I said all dominate alleles are co-dominate; Some can be strong enough to completely mask another genes expression.

I don't know if epistasis is a factor or not in snakes, but remember, it is not different alleles, but different genes. For the Labradors I mentioned, you look at 3 different genes total, writing the genotype as b/b;e/e;y/y where the b gene affects melanin amount, the e gene affects if they have the receptor to begin production of melanin, and y gene affects another pigment that is only noticed if melanin is not produced will make the coat either red or yellow.
 
Ok, I can't edit my above message, but after looking at that cornsnake morph gallery, the ones listed as double and triple recessive are most likely due to epistasis, in that they had to be recessive in multiple genes to have that morph expressed.
 
Incomplete dominance and co-dominance are incredibly hard to distinguish, and in a lot of creatures look the same on the surface, and you can only tell on the microscopic level. Even that article you linked is misleading. A co-dominate flower for red and white will look the same as one with incomplete dominance more often that not.

I guess I did misspeak when I said all dominate alleles are co-dominate; Some can be strong enough to completely mask another genes expression.

I don't know if epistasis is a factor or not in snakes, but remember, it is not different alleles, but different genes. For the Labradors I mentioned, you look at 3 different genes total, writing the genotype as b/b;e/e;y/y where the b gene affects melanin amount, the e gene affects if they have the receptor to begin production of melanin, and y gene affects another pigment that is only noticed if melanin is not produced will make the coat either red or yellow.

My article is not misleading. It is citing fact. I think you need to step away from the Labrador comparison, its adding to the confusion, very poor comparison with what the OP is asking. A single species of snake can have dozens of different mutations that can effect color and pattern (Ball Pythons and Cornsnakes being the top two), all using different modes of inheritance and physical expression.

Ok, I can't edit my above message, but after looking at that cornsnake morph gallery, the ones listed as double and triple recessive are most likely due to epistasis, in that they had to be recessive in multiple genes to have that morph expressed.

We don't use the terminology "epistasis," you are just causing more confusion. When more then one morph is expressed it's simply called a combination. It clearly states what makes up each one of those combination morphs on each individual page.



Travis, I noticed something else with your initial post...

Super Pastel x Albino = Pastels het Albino

This is because you're breeding Homozygous Incomplete Dominant to Homozygous Recessive. To produce Super Pastels that are het Albino, both parents must be expressing Pastel in some way (whether Pastel or Super Pastel).

Piebald x Piebald = Piebalds

This is because you are breeding Homozygous Recessive to Homozygous Recessive.
 
@Scott - Although some parts were mildly confusing (due mainly to my ignorance in the subject), you did help me understand a good bit. And thank you.

@Stephanie - The links were very helpful and i know they will be useful! It really seems like you know your stuff! Thanks for all your help. And if you don't have an issue with it, you mind being my go-to geneticist haha? It will be long before i start breeding though.
 
@Stephanie - The links were very helpful and i know they will be useful! It really seems like you know your stuff! Thanks for all your help. And if you don't have an issue with it, you mind being my go-to geneticist haha? It will be long before i start breeding though.

I got into genetics because I feel in love with the large variety of inheritable traits and combination's in Cornsnakes. Disgustingly enough, you can name a Cornsnake pairing and I can spit out the results from memory. Ball Pythons I can get about 2/3 right without assistance, they have way too many trade names. ;)

Something to short cut your Ball Python morph troubles...This link has a wizard that automatically calculates pairings.
 
Haha thats so cool (the morph wizard, and that you can name the results from memory). Im guessing you have been breeding corns for awhile then huh? I'm looking at getting a corn soon in May. Only 5 weeks left of college (wow that sounds nice). I'm really looking for any age below 1.5 yrs. I seen on your website that you will be having some corns available soon. Whats pricing like for your corns? And im only a 1 hour drive away from hanover what would shipping cost? This will be my first corn, but i have been doing my research.
 
Haha thats so cool (the morph wizard, and that you can name the results from memory). Im guessing you have been breeding corns for awhile then huh? I'm looking at getting a corn soon in May. Only 5 weeks left of college (wow that sounds nice). I'm really looking for any age below 1.5 yrs. I seen on your website that you will be having some corns available soon. Whats pricing like for your corns? And im only a 1 hour drive away from hanover what would shipping cost? This will be my first corn, but i have been doing my research.

I'm going to PM you with information on my Cornsnakes. I'll get kicked in the butt by a mod if I post it here. :D

I'm in Lancaster frequently, so if you do see something you like, I can always meet you up at TFP or somewhere else up that way.
 
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