# spider balls?



## mcdougle (Jan 20, 2009)

the spider ball is co-dom with the spider gene+ normal gene but is there a super form of spider with a spider +spider gene like with the pastel + pastel = super pastel


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## paulh (Sep 19, 2007)

mcdougle said:


> the spider ball is co-dom with the spider gene+ normal gene but is there a super form of spider with a spider +spider gene like with the pastel + pastel = super pastel


Quick answer: Nobody knows. The necessary breeding tests have not been done.

By the way, a snake with a spider gene paired with a normal gene is heterozygous. Just like a snake with an albino gene paired with a normal gene is heterozygous. A lot of herper genetics web sites claim that a heterozygous snake must look normal. This is true for recessive mutant genes, but not for genes that are either dominant or codominant to the normal gene. See the questions sticky in this forum. Addition: Also see the dominant, codominant, recessive page at http://www.corncalc.com.


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## mcdougle (Jan 20, 2009)

i thought the spider gene was always homozygous over the normal gene?


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## MadManc (Jan 9, 2011)

Im pretty sure i read somewhere that spider x spider = some normals, some spiders and some dead spiders?


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## Ssthisto (Aug 31, 2006)

mcdougle said:


> i thought the spider gene was always homozygous over the normal gene?


No.

"Homozygous" means "both genes of the pair are the same".

Most (if not _all_) Spider royals are heterozygous - they have only one copy of spider, inherited from only one of their parents.

What you might be thinking of is "dominant" - where if an animal has the gene it shows up (the animal doesn't look normal) and two copies of the gene (homozygous) looks exactly like one copy of the gene (heterozygous).

Spider may be dominant - but we won't know for sure until someone produces an animal that is homozygous for the spider gene, which looks like the heterozygous-spiders we are familiar with AND proves it to be homozygous by breeding trials. 

At this point, some evidence seems to be pointing towards Spider being codominant (one copy of the gene looks different to two copies, and both look different to normal) - with the homozygous form being an embryo that doesn't develop into a live baby snake ("Lethal homozygous"). But this hasn't been absolutely proven out, since breeders who are pairing spiders aren't releasing data about clutch numbers and eggs that fail to develop.


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## mcdougle (Jan 20, 2009)

i was sure that sake bytes tv said that the spider is a co-dom gene hence why you still get spiders from a spider+normal pairing and i was sure that homozygous ment visual gene and heterozygous ment non-visual gene? hence why you get nomal het albino where the mutation gene isn't visual


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## Magpye (Jan 26, 2007)

mcdougle said:


> i was sure that sake bytes tv said that the spider is a co-dom gene hence why you still get spiders from a spider+normal pairing and i was sure that homozygous ment visual gene and heterozygous ment non-visual gene? hence why you get nomal het albino where the mutation gene isn't visual



Snakes are diploid meaning they have 2 alleles for each gene, if both of these alleles are identical then they are said to be homozygous, if the copies are different they are said to be heterozygous. So in simple terms the genotype can either be 'AA', 'Aa', or 'aa' - with the first and last being homozygous states, and the middle being the heterozygous state.

If the trait of interest is recessive then it will only be visible if the genotype is homozygous recessive - aa. If the trait is dominant then it will be visible if the genotype contains a dominant allele - A. 

A codominant trait is one in which both alleles of the genotype are expressed equally regardless of which is dominant - in other words features that you would expect to only see in a recessive carrier would also be seen in a heterozygote.

If I remember rightly incomplete dominance is where in the heterozygous state both alleles are expressed but unequally. For example 75% of the appearance of the animal might exhibit the dominant trait, and 25% the recessive.

The reason the het albino isn't albino is because albinism is recessive, and so the appearance requires both alleles of the albino gene to be aa. A heterozygous individual would be Aa. The het albino would need to be crossed with another het albino, or a homozygote albino to have a chance of producing offspring that exhibit the albino appearance.


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## paulh (Sep 19, 2007)

Magpye said:


> Snakes are diploid meaning they have 2 alleles for each gene, if both of these alleles are identical then they are said to be homozygous, if the copies are different they are said to be heterozygous. So in simple terms the genotype can either be 'AA', 'Aa', or 'aa' - with the first and last being homozygous states, and the middle being the heterozygous state.
> 
> If the trait of interest is recessive then it will only be visible if the genotype is homozygous recessive - aa. If the trait is dominant then it will be visible if the genotype contains a dominant allele - A.
> 
> ...


The technical jargon is getting deep and gooey. Let's see if I can simplify it a bit.

Diploid simply means that genes come in pairs, like socks or gloves.

Alleles are slightly different genes that have the same location in the chromosome pairs. Alleles are not limited to two. If we use different colored socks for different alleles, one person can have only two socks, but those socks are not limited to two colors. Different people can have a (red/green/blue/black) sock paired with a (red/green/blue/black) sock. Pick one color from each list.

Homozygous = the two genes in the gene pair are the same. Sock analogy: the two socks are the same color (red/red or green/green or blue/blue or black/black).

Heterozygous = the two genes in the gene pair are NOT the same. Sock analogy: the two socks are not the same color (red/blue or green/black or etc.).

Gene A is dominant to gene a, and gene a is recessive to gene A if
AA --> full expression of gene A
Aa --> looks like AA creature
aa --> full expression of gene a

Gregor Mendel defined dominant and recessive genes this way. 

Gene A is codominant to gene a, and gene a is codominant to gene A if
AA --> full expression of gene A
Aa --> looks different from AA creature and aa creature
aa --> full expression of gene a

There are more details at the dominant, recessive, codominant page in the http://www.corncalc.com web site. 

Codominant, incomplete dominant, semidominant, partial dominant, overdominant and about a dozen other terms describe genes that do not fit the dominant vs. recessive gene pattern. For breeders' purposes, they can all be lumped together under the term "codominant", which has fewer characters than any of the other terms.


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## mcdougle (Jan 20, 2009)

so i guess my spider being co-dom of normal and spider and the genes being displayed equally is why he has normal front pattern and spider tail pattern


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## Ssthisto (Aug 31, 2006)

mcdougle said:


> so i guess my spider being co-dom of normal and spider and the genes being displayed equally is why he has normal front pattern and spider tail pattern image


Not at all. Because you're misusing the word "codominant".

His being heterozygous for Spider (and heterozygous for normal) doesn't affect his visual appearance compared to any other spider out there. 

He has a perfectly standard, expected Spider pattern, within the range of typical Spider patterns. Now, it's quite possible that the influence of his normal parent's pattern has resulted in his SPECIFIC spider pattern, but he definitely isn't "normal front half, spider back half"

*IF* Spider is a gene that is codominant to normal, then the homozygous (double-copy) appearance may be "embryo that dies in the egg", since no definite homozygous animal has ever been proved out.


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## mcdougle (Jan 20, 2009)

This is him normal lookin head end spider lookin tail end


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## Ssthisto (Aug 31, 2006)

See, his front pattern to me still looks *very *spider - thin black lining, high white sides.

And you could get a spider with the "alien heads" all the way down, which is still just as likely to be het spider/het not-spider as a spider with the jagged "barbed wire" pattern from neck to tail.

At this point ALL spiders are presumed to be het spider/het not-spider.


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## mcdougle (Jan 20, 2009)

Ssthisto said:


> See, his front pattern to me still looks *very *spider - thin black lining, high white sides.
> 
> And you could get a spider with the "alien heads" all the way down, which is still just as likely to be het spider/het not-spider as a spider with the jagged "barbed wire" pattern from neck to tail.
> 
> At this point ALL spiders are presumed to be het spider/het not-spider.


 
I thought the best spider didn't have any spots in the pattern?


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## Ssthisto (Aug 31, 2006)

That may be, subjectively speaking, but "best selectively bred trait" isn't exactly the same thing.

It may well be possible to breed for spiders that show more of the barbed-wire patterning (or, conversely, if you personally like the ones with the spots, to breed for the ones that are spots all the way down) ... but it won't have anything to do with whether the Spider is heterozygous or homozygous for the spider gene.

I suspect if you want more barbed-wire-patterned spiders, you should breed the most barbed-wire looking spider to the best BANDED normals you can get - because the "banded" pattern may well affect the expression of the Spider pattern.


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## mcdougle (Jan 20, 2009)

ok so back to the start sorry if it seems like going in circles but there's alot of new info to try and take in here lol.

so nobody knows whether there is a super spider?

if there was one what do you think it might look like so if i decide to breed two spiders i know what to look for in the babys?

i thought co-dom ment 2 dominent genes so whether it is a normal gene or a spider gene both types are domenent over eg albino so 2 dominent genes spider-dom +normal-dom = co-dom?


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## Ssthisto (Aug 31, 2006)

No, nobody knows *for sure* that there's a homozygous "super" spider. It's suspected that the homozygous "super" spider looks like an egg that doesn't hatch, but this hasn't been proven.

There certainly *hasn't* been any indication that a live hatched animal is homozygous spider at this point, and the only way you'd know for sure is if you bred the adult to normals/non-spiders and NEVER got a non-spider baby out.

Here are the definitions:

*Homozygous:* The two halves of the gene pair are the same (like "homosexual"). 
*Heterozygous: *The two halves of the gene pair are different (like "heterosexual").

A gene that is* recessive *to normal requires two copies of the gene to show up - Albino is an example of this. An animal with only one copy (_heterozygous_) of the recessive gene (and one "normal" copy) looks like a normal - the animal must be _homozygous _albino to look like an albino.

A gene that is *dominant* only requires one copy of the gene to show up. An animal with only one copy (_heterozygous_) of a dominant gene looks the same as an animal with two copies of the gene (_homozygous_). "Normal" is dominant to albino - an animal that is "het normal/het albino" looks the same as an animal that is "homozygous normal".

A gene that is *codominant *has three different visual possibilities. A homozygous non-carrier ("normal") looks different to a heterozygous animal, and a heterozygous animal looks different to a homozygous animal. Mojave is a good example of this one - a homozygous not-mojave is a normal. A _het mojave/het not-mojave _is a Mojave. And a _homozygous _mojave is a white snake with dark eyes and a dark head.

Oh, and you wouldn't compare Spider to Albino (for purposes of "dominance") because they don't exist on the same gene pair.
Dominance is established between genes that share the same gene pair - so, for example, Albino is recessive to "Not-Albino" but it ISN'T recessive to Spider.


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## mcdougle (Jan 20, 2009)

[QUOTE 
Oh, and you wouldn't compare Spider to Albino (for purposes of "dominance") because they don't exist on the same gene pair.
Dominance is established between genes that share the same gene pair - so, for example, Albino is recessive to "Not-Albino" but it ISN'T recessive to Spider.[/QUOTE]

i thought albino was recessive to most dominent genes els how do you get spider albinos i know as far as:
spider + albino = spider het albino
spider het albino + albino = spider albino

i dont know how the genes align with this or what the chances are but this is what i'm hoping to do in my future breeding plans


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## Ssthisto (Aug 31, 2006)

mcdougle said:


> i thought albino was recessive to most dominent genes els how do you get spider albinos i know as far as:
> spider + albino = spider het albino
> spider het albino + albino = spider albino
> 
> i dont know how the genes align with this or what the chances are but this is what i'm hoping to do in my future breeding plans


Albino is recessive ONLY to "not albino".

Spider acts on a different gene pair, and acts completely independently to the albino gene, just like "having a tail" is part of a different gene pair and acts independently to the albino gene.

If Albino was recessive to Spider *and *existed on the same gene pair, you wouldn't be *able* to get an Albino Spider - if you need two copies of albino for it to show, and your one copy of Spider takes up half of the two available gene "slots" then you can never have Spider AND albino show visually on the same snake.

Because it DOESN'T work that way, we know that albino and spider aren't on the same gene pair - they're on two separate gene pairs.

For an example:
I'm using *S** to indicate a copy of "Spider".
I'm using *S* to indicate a copy of "Not-Spider".
I'm using *a* to indicate a copy of "Albino"
I'm using *A* to indicate a copy of "Not-Albino"

So your Spider would be *S*/S* (het Spider, het normal)* A/A* (homozygous not-albino).
Your Albino would be *S/S* (homozygous not-spider) *a/a* (homozygous albino).

Cross the two, and you get:

*S*/S A/a* (Spider het albino)
*S/S A/a* (Normal het albino)

Cross a Spider het Albino to a Normal het Albino, and your possibilities are:

*S*/S a/a *(Albino Spider)
*S*/S A/a* (Spider, het albino)
*S*/S A/A* (Spider, not het albino)
*S/S A/A* (Normal, not het albino)
*S/S A/a* (Normal, het albino)
*S/S a/a *(Albino)


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## mcdougle (Jan 20, 2009)

so does this then come under quad genetics because were dealing with 4 genes not just 2?


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## Ssthisto (Aug 31, 2006)

No, it's just two gene *pairs* - the critical thing to remember is that, for the purposes of most morphs, *all genes come in pairs* like socks.

So you've got the "Albino gene pair" to work out which has the possibility of being *albino/albino *(looks albino), *albino/not-albino *(het albino, looks normal) or *not-albino/not-albino* (normal, not het albino) AND you have to calculate the "Spider gene pair" which has the possibility of being *spider/spider *(which might be "dead in egg" as there's never been a proven one), *spider/not-spider* (looks like a Spider) or *not-spider/not-spider* (normal).


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## mcdougle (Jan 20, 2009)

*S*/S A/a* (Spider het albino)
*S/S A/a* (Normal het albino)

Cross a Spider het Albino to a Normal het Albino, and your possibilities are:

*S*/S a/a *(Albino Spider)
*S*/S A/a* (Spider, het albino)
*S*/S A/A* (Spider, not het albino)<-
*S/S A/A* (Normal, not het albino)<-
*S/S A/a* (Normal, het albino)
*S/S a/a *(Albino)

ok so if these are two hets bred together if i was to use a full albono these would be reduced by theese <- two? is that right?


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## mcdougle (Jan 20, 2009)

also see that you can get spider het normal looks spider can you have a normal het spider looks normal?


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## Ssthisto (Aug 31, 2006)

mcdougle said:


> *S*/S A/a* (Spider het albino)
> *S/S A/a* (Normal het albino)
> 
> Cross a Spider het Albino to a Normal het Albino, and your possibilities are:
> ...


That's right, you wouldn't get any "not het albino" offspring, because the albino parent can't contribute anything "not-albino".



mcdougle said:


> also see that you can get spider het normal looks spider can you have a normal het spider looks normal?


No, because "spider" is not a recessive gene; it's at least codominant and may be dominant, and therefore if an animal carries the spider gene (single copy OR double copy) it will show the spider gene's affects on its appearance.


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## mcdougle (Jan 20, 2009)

but isn't normal also a dominent gene? this i take it would mean that the spider gene is really powerfull in the fact it can always over ride its counter part but i would have thought co-dominence would have had an equal chance of displaying ether one of the dominent genes or evan displaying the qualitys of both?


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## Ssthisto (Aug 31, 2006)

mcdougle said:


> but isn't normal also a dominent gene? this i take it would mean that the spider gene is really powerfull in the fact it can always over ride its counter part but i would have thought co-dominence would have had an equal chance of displaying ether one of the dominent genes?


Codominance actually means that the genes *both *affect the appearance of the animal, not that "one gene shows and the other doesn't".

For example:

If Red is dominant to White, an animal with one copy of Red and one copy of White is visually Red.

If Red is recessive to White, an animal with one copy of Red and one copy of White is visually Red.

If Red is codominant to White, an animal with one copy of Red and one copy of White may be Pink, or White with Red patches, or Red with White Spots - the two genes *share* the visual appearance of the animal in some way.

So, if the "spider" trait is codominant to "not-spider", then the *shared *appearance is "Spider". Now, we don't know what an animal that DOESN'T have a "shared" appearance looks like - because we've never proven that an animal with two copies of Spider exists.


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## mcdougle (Jan 20, 2009)

If Red is dominant to White, an animal with one copy of Red and one copy of White is visually Red.

If Red is recessive to White, an animal with one copy of Red and one copy of White is visually Red.

did you make a mistake here if red is recesive to white the animal would be white?

but any how this is one reason i thought spiders were co dominent because surly a spider with a spoted pattern is picking up the trait from the normal gene and the black stripping pattern is picked up from the spider gene i know this comes in different quantity's in the different individuals but i guess this is mostly just a theory


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## Ssthisto (Aug 31, 2006)

mcdougle said:


> did you make a mistake here if red is recesive to white the animal would be white?


Sorry about that, you're absolutely right!



> but any how this is one reason i thought spiders were co dominent because surly a spider with a spoted pattern is picking up the trait from the normal gene and the black stripping pattern is picked up from the spider gene i know this comes in different quantity's in the different individuals but i guess this is mostly just a theory


Not really, no. 
As I said, we don't KNOW what a homozygous-spider looks like (because there aren't any proven ones), so we don't know for sure what effects "normal" has on the visual Spider trait. A homozygous-spider might be solid white for all we know!


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## mcdougle (Jan 20, 2009)

right like with the fires and russos? do you think that maybe super spider aggs dying may have summin to do with the fact most if not all spiders have head wobble and maby the double dose of this em what would you call it a dissability, or just say flaw is whats killing them?


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## Ssthisto (Aug 31, 2006)

mcdougle said:


> right like with the fires and russos? do you think that maybe super spider aggs dying may have summin to do with the fact most if not all spiders have head wobble and maby the double dose of this em what would you call it a dissability, or just say flaw is whats killing them?


Could well be. Rain's mentioned in the past that it looks like "Spider" is a neural tube/neural crest defect (affecting the development of the animal while it's creating the spinal column/brain) and it might be that a double dose of Spider creates a neural tube problem *so* bad that it just doesn't develop into a live hatchling at all.


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## mcdougle (Jan 20, 2009)

see i'm lucky with my spider he's get next to no wobble at all you have to really concentrate on him to notice it and then its only really when he's feeding :2thumb:


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## mcdougle (Jan 20, 2009)

was just thinkin if the death is caused by the development of the nural tube going wrong then the embryo is still developing to a certain age before actually dying isn't it? but how far is it developing? i think is the question couldn't somebody do some test on the dead egg take out the unborn baby and use that to find out exactly whats going wrong? or evan to see (if its far along enough) if the babys that are dying are infact super spiders at all?


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## Magpye (Jan 26, 2007)

mcdougle said:


> was just thinkin if the death is caused by the development of the nural tube going wrong then the embryo is still developing to a certain age before actually dying isn't it? but how far is it developing? i think is the question couldn't somebody do some test on the dead egg take out the unborn baby and use that to find out exactly whats going wrong? or evan to see (if its far along enough) if the babys that are dying are infact super spiders at all?




It's not that simple. Genes are expressed at different times and levels during development, and many genes interact with other genes. So whilst there may be a theory that a given appearance is the result of a particular developmental problem, there could be several genes involved in that developmental problem. And without a sequenced genome it can be both difficult and expensive designing primers that amplify sequences genes that might be involved to work out what is happening. Some genes are conserved relatively well across species, which gives a starting point for the research but it is still expensive and time-consuming. 

There are alternative methods such as next-gen sequencing and RAD sequencing which can also be used to generate sequence data for much of the genome, but these are also very expensive to perform. Even then you would require a cluster of PCs, to analyse the enormous amount of data generated using such an approach.


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## Ssthisto (Aug 31, 2006)

You have a wonderful idea there - and I'd extend it to testing actual spiders to determine exactly what it is about them that makes them wobble, and whether the amount of wobble can be predicted based on any cues, physical or chemical, in the snake...

But, it'd require:

1. Someone who is medically trained and knows what they're looking at
2. Breeders who are willing to supply eggs from spider/spider pairings - WHOLE clutches, not just parts of clutches
3. Someone with some biochemistry/genetics background who'd like to sequence the royal python genome and identify where the "spider" gene allele lives - and which version is actually "spider" and which version is "normal" so that animals that are homozygous can be identified.


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## Magpye (Jan 26, 2007)

Coincidently Bangor University were considering to sequence the royal python genome:

http://www.reptileforums.co.uk/forums/snakes/644958-corn-snake-genome-project.html


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## mcdougle (Jan 20, 2009)

cool that sounds really good lets hope for some good results


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## Ssthisto (Aug 31, 2006)

mcdougle said:


> cool that sounds really good lets hope for some good results


I think the good results will only occur if they get some good financial investment to do it....


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## mcdougle (Jan 20, 2009)

i would give a big donation if i won the lottery but i dont actualy play but will one day lol


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## Royalmad (Aug 19, 2009)

*am i missing some thing here*

so at the moment if iam right the spider is a het no a co-dom or dom
but why do you get spiders when breed to normals this has gone right over my head


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## Ssthisto (Aug 31, 2006)

Royalmad said:


> so at the moment if iam right the spider is a het no a co-dom or dom
> but why do you get spiders when breed to normals this has gone right over my head


Ok, "het" is apples, and "dom or co-dom" is oranges. Try to disconnect them, don't compare apples and oranges, they don't refer to the same thing even if they're all genetics terms.

A recessive gene can be "het" (and will look normal)
A dominant gene can be "het" (and will not look normal, or different to homozygous)
A codominant gene can be "het" (and will not look normal)

Het (short for Heterozygous) only means "the two alleles at the same gene location are not the same".

So far as anyone knows, most if not all spider royals are "het" for the spider gene (they generally had one spider parent and one non-spider parent, therefore they can only have gotten ONE copy of Spider). Because you only need one copy of spider to be a spider, that means the gene is at least codominant and may be dominant.


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## Royalmad (Aug 19, 2009)

*ok*

thanks for the reply i understand a little more now not much but a bit more


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