Testing for Stargazing

[Rich Z]

Well, all I can say is that if you see something like THIS someday, worrying about proper doses of an anesthetic is going to be real low on your priority list...

 

[Shiari]

I don't understand how people can be going "oh, you can't prove it isn't het!" here... but are capable in testing for desired hets in other instances and going "Well, I guess it most likely isn't het"?

Should I continue testing Vanay for caramel when he was bred to a homozygous caramel and produced NO caramel offspring in 18 eggs? Or can I comfortably say that he is unlikely to be carrying that gene?

Anyone want to do the math? If I've done it correctly, the odds of not getting *any* caramels.... is 0.00038%.

 

[iculatr]

I don't understand how people can be going "oh, you can't prove it isn't het!" here... but are capable in testing for desired hets in other instances and going "Well, I guess it most likely isn't het"?

Should I continue testing Vanay for caramel when he was bred to a homozygous caramel and produced NO caramel offspring in 18 eggs? Or can I comfortably say that he is unlikely to be carrying that gene?

Anyone want to do the math? If I've done it correctly, the odds of not getting *any* caramels.... is 0.00038%.

The possibility is always there, but the probability of it being there is "reduced" with each breeding to a homozygous Caramel that does not produce Caramel offspring. Same goes for stargazer testing. It "reduces" the probability, but it will always still have a possibility of being het for stargazer. It is inaccurate to say you have a stargazer-free line, no matter how much testing you do.

When our sunkissed anery stripe hatched out a few weeks ago, I stated in the following thread: http://www.cornsnakes.com/forums/showthread.php?t=122202 that...

I got this project from Jeff Mohr last year, and he said that the Sunkissed male that started this project (and a few others) never ended up with Stargazer hatchlings. Jeff is fairly certain he was SG free. Out of the sunkissed miami, sunkissed pewter, sunkissed anery motley and sunkissed anery stripe projects he started, he never saw stargazers in the F2's. We had no stargazers last year either. Even though the line was never officially tested, its seems to be clean.

The key is that it seems to be clean. The project group that was used to eventually get the sunkissed anery stripe has now bred for 5 years. Wouldn't you say that the possibility of stargazer showing up is always there, but the probability of it being there is "reduced" with each breeding season (which all have resulted in no stargazers showing up)?

 

[Shiari]

Say that male sunkissed WAS het. But the females he was matched to were *not*.

Now say you kept back two offspring. One is het, one is not. You breed them together: No stargazers. You keep back a couple of THOSE offspring... again, one het, one not. See where this goes? Half the animals are now carriers, but because you didn't match up the right two, you don't know it.

Is that not why most people prefer to test for hets by pairing with a homozygous example of the morph being looked for?

So what is the magic number for "reasonable to treat as most likely stargazer free"? How many zeros do I need after that decimal point if 3 are not enough. 5? 10? How many more eggs should I create from Vanay and homozygous caramels to get to say "he's not likely carrying the gene"?

 

[iculatr]

Say that male sunkissed WAS het. But the females he was matched to were *not*.

Now say you kept back two offspring. One is het, one is not. You breed them together: No stargazers. You keep back a couple of THOSE offspring... again, one het, one not. See where this goes? Half the animals are now carriers, but because you didn't match up the right two, you don't know it.

Is that not why most people prefer to test for hets by pairing with a homozygous example of the morph being looked for?

So what is the magic number for "reasonable to treat as most likely stargazer free"? How many zeros do I need after that decimal point if 3 are not enough. 5? 10? How many more eggs should I create from Vanay and homozygous caramels to get to say "he's not likely carrying the gene"?

As for the holdbacks, there will be plenty of cross breeding to see if stargazer shows up in the line. Not a bad project to work with, in my opinion, while trying to see if it ever shows up.

The opal bloodred I purchased from Rich Hume last year is 50% phet caramel. When she is old enough to breed, I will most like breed her to a homozygous caramel male. If no Caramels are produced, I would probably not pursue trying to prove the phet out again. That is not saying that she is definitely not het caramel, but rather the probably is reduced. I don't make the rules and certainly cannot control nature. Things will happen when you expect them to and also when you don't expect them to. Surprise hets show up all the time.

 

[Shiari]

Doesn't answer my question.

And what point can we reasonably say that an animal is so unlikely to be carrying this particular gene that there's not really any point in bothering with it? Not just reduced but "the odds are so low that entertaining the idea at this point is rather silly"?

If I got 30 eggs total from Vanay to a homozygous caramel, and produced no caramels, the odds of that happening if he's het for caramel is 0.00000009%. Would it really be reasonable to keep going? Or would I be chasing fools gold?

 

[diamondlil]

Doesn't answer my question.

And what point can we reasonably say that an animal is so unlikely to be carrying this particular gene that there's not really any point in bothering with it? Not just reduced but "the odds are so low that entertaining the idea at this point is rather silly"?

If I got 30 eggs total from Vanay to a homozygous caramel, and produced no caramels, the odds of that happening if he's het for caramel is 0.00000009%. Would it really be reasonable to keep going? Or would I be chasing fools gold?

BY the same token, no snake should ever be sold at a premium price as het for a sexy genetic combo! As for outcrossing.............I crossed a bloodred produced by Vinman in the Bronx with one produced by Lexcorn in Scotland and discovered they were both het amel. They are generations away from any possible familial relationship but were both carrying the same unknown het (in this case a desirable one)
Accidents in breeding, prolapse, eggbinding, DIE are not the same as knowingly selling snakes with a very real potential for a genetic defect.

 

[cornmorphs]

Doesn't answer my question.

And what point can we reasonably say that an animal is so unlikely to be carrying this particular gene that there's not really any point in bothering with it? Not just reduced but "the odds are so low that entertaining the idea at this point is rather silly"?

If I got 30 eggs total from Vanay to a homozygous caramel, and produced no caramels, the odds of that happening if he's het for caramel is 0.00000009%. Would it really be reasonable to keep going? Or would I be chasing fools gold?

This was a similar argument to one I had this week. I hatched from a pair of anery motleys het for lavender, 20 eggs.. they were proved het lavender as I hatched moonstone motleys last year, and none this year from those 20 eggs.. yet 20 eggs is the number quoted for a snake to be 99.99% SG free with no SGs visually in the clutch.

 

[vetdebbie]

I guess some cant read or understand no matter how many times it been said, there is no test,not one that will give any reliable results...oke:

You're right - there isn't a test at the moment.

But what if there was? What if there was a genetic test that could be taken that would say definatively "your snake is carrying the stargazer gene" or your snake is not carrying the stargazer gene"? What would be people's stance be then?

I ask for 2 reasons.
1) Most of the negative stances or anti-test opinions revolve around the only current method of testing, which is of course by breeding with all it's potential complications and inaccuracy, plus the need to euthanase the babies. I understand why people don't like it. (While choosing personally to disagree with them).
2) Ive forgotten the other reason! Darn it - it's early here and clearly the caffeine hasn't kicked in! It was however, rest assured, a really good point....:bird:




I think the other reason may have been that although a genetic test at the moment sounds like a work of SciFi, it may be closer than you think.

Procorns (that is myself and my husband Adam) have for nearly the last year been trying to work towards the goal of a PCR test done on shed skin, that in it's ultimate extreme example could test for, well, any known het. We don't know If it happen, and if it does WHEN this might be, but we have to try!

At the moment we are helping a group at the University of Bangor by basically sending them shed skins from all our single homozygous gene animals to aid in their project to map the corn snake genome. This is phase one and is currently a PhD project underway. They also requested sheds from our homozygous stargazer animals. We haven't heard a lot from them recently but I guess we are getting into the exam/summer vacation time and so they are probably somewhat distracted.

However one of the last conversations that was had revolved around their desire to try and produce a PCR for stargazer and maybe one other gene as an end point to their project, but it required funding to achieve. Now they were banding around figures of roughly £30,000, and we did offer to help fundraise when the time comes. Personally I don't think that 30 grand is a lot of money to do this. Ok, it IS a lot of money, but surely as a worldwide community of corn snake lovers we could find 3,000 people that would donate £10 each to the cause? (This is an international forum - so £10 = 12.36 euros = $15.45). If we can get to this goal, (and please god we will), then to donate £10 to produce a test that could then be commercialised so we could know one way or the other would be truly an amazing thing to be part of.


So think about guys - if we could have this test, would you? If you would not I would really like to hear your reasoning. (please don't bring cost into this, we don't have a cost but assume it is going to fall into the "pricey but affordable" category).

 

[diamondlil]

Yep, I'd want that test if it was possible, Debbie.

 

[Kokopelli]

Well, I personally don't deal with Corns... but I think that I see something here that I don't see in other forums/communities... It stems from a rather evolved moral code, which is admirable, but I wonder if we lost perspective.

I'll try to explain since even to me my comment seems vague.

I recently realized that I'm a rather poor animal dealer- I doubt that huge facilities who would have had to face the same issue I have(an animal passing away) would ship the body for postmortem... and, as it did for me, come back positive for Crypto... how many would check the entire collection and euthanize those that were asymptomatic carriers? My guess is? few, very few.... and no one imposes strict enough hygene rules that he can be sure that this parasite did not infect others... how many of us use latex gloves as I do now? and I did so only after I learned what Crypto actually meant.
Do we even really know how common it is in collections? anyone really tested? Cause on Leopard geckos it possibly exists in over 50% of'em. Will we truy

At some point, if you are going to keep animals, you will need to stop thinking like a lab... and do what makes sense... there's an academic term called "Satisficing", which is a combination of Satisfying and Sufficient- it's not bulletproof, but it's reasonable.

At some point, the implications and price of the purist approach becomes too drastic... do I believe that every single het or homozygous stargazer needs to die? no. I don't really know how many there are out there, and I personally think that deliberately breeding while fully knowing that the entire clutch is going to be culled is simply too much. This test, as stated above, doesn't even fully remove the chance of the gene's presence completely.

If the animals are healthy, and it hasn't popped up, I think it should be enough... animals get sick and die, and animals can and will naturally develop genetic defects... it's part of how life works.

I think there's a distinction between a disease and a defect, and I also think that we may have gone a bit too far in trying to cleanse something which we don't know how common it is- what if 30% of cornsnakes have the gene? should they all be put down? in the long run, other defects will emerge... you can't line-breed without a glitch occurring.

IMHO, we keep animals... and we need to endure the good and the bad... and I don't think there's a person out there who isn't aware that there's only so much he can do in order to ensure that his animal is well and healthy.

I think that too much time had passed, and too few tools exist, for us to be able to truly remove the SG threat- at some point, I feel, we need to realize that this can occur... just as wobbling exists in BP's and Enigma Leopard Geckos, and and only when, a cornsnake that is homozygous for the trait pops- either euthanize or keep it, and give/sell the others as SG carriers.

People are not going to stop breeding corns, it would take a huge effort... and way too many euthanizes to remain moral, at least in my opinion, to truly remove its' existence from collections.

Crypto, IMHO, which is infectious and more common, I believe, than anyone would imagine, is a far bigger threat... and even here, the tests are not full proof.

We keep animals, they are imperfect, as we are... at some point the tests and trials trying to "strengthen" and "purify" the animals might cause us to lose sight of what's humane and what's not.

 

[diamondlil]

A disease and a genetic defect are a bit different though. If you buy a SG carrier and don't breed it, the defect never gets passed on. So it can potentially be stopped from spreading through any given breeding project by selecting animals to breed from that are as far as possible proven to be from SG free stock. Ok, maybe many people won't care, they'll see dollars signs or pretty snakes and ignore the risks. People who do care aren't necessarily more morally right, just more exacting in their standards. If I wanted to breed a sunkissed project I'd want to start of with clean genetics and I'd pay over the odds to do so from a breeder I trusted.

 

[Kokopelli]

A disease and a genetic defect are a bit different though. If you buy a SG carrier and don't breed it, the defect never gets passed on. So it can potentially be stopped from spreading through any given breeding project by selecting animals to breed from that are as far as possible proven to be from SG free stock. Ok, maybe many people won't care, they'll see dollars signs or pretty snakes and ignore the risks. People who do care aren't necessarily more morally right, just more exacting in their standards. If I wanted to breed a sunkissed project I'd want to start of with clean genetics and I'd pay over the odds to do so from a breeder I trusted.

You're absolutely right, they are different. I see less harm in SG than in diseases to be sure.
Point I was trying to make though, that since it's less severe, I think we have gone too far- culling a whole clutch just to test if that gene is present is a tad extreme. Every single one of us, I would imagine, would want to pay more for a better guarantee that the animal is defect-free. But isn't SG testing in the form of breeding and than culling an entire clutch is just too big of a price just for a less than perfect guarantee? Aren't we endorsing an inhumane act by doing so? I think we might be.

I can see merit in everyone's views... it's just me babbling after a very long self examination and criticism of my actions with the whole Crypto thing... Since it was Crypto, which is deadly and infectious, I could lay my conscience to rest... but I still am not sure if I have gone too far by euthanizing asymptomatic carriers when in fact it's entirely possible that tons of snakes out there are actually naturally carrying the parasite... too little is known.

So faced with SG, which to me seems less dangerous, I think that the act is very extreme... and when we don't know the scope...
Dunno. I think that in the act of trying to ensure the health of the animals, we have gone ahead and lost a bit of what it means to actually cherish their lives... it's a slippery slope.

Please don't take it as criticism, it's really me and my internal babbling.

 

[Susan]

It has been mentioned before that concentrating on Sunkissed and het Sunkissed corns only as being the target morphs that need to be tested for stargazing is, IMO, ludicrous. I have in my collection a female I purchased in 2003 from Rich Z as a normal het lavender (WWE's Valkyri, for those interested, and I have not changed her ACR record yet). She has been producing clutches since 2006, sometimes even double clutching and her offspring, and by now her grandchildren, may be found all over the country or beyond. I think it was her first year that I discovered she was het hypo. Last year, I only had one available male that was homo or het lavender so I bred her to that male. That male was an orchid and low and behold, it turns out my female is also het Sunkissed. It was by sheer accident I discovered more of her het genetics. I wonder what else could be in her...or ANY other snake in my collection?!! I had no idea I had dilute either until I happened to pair siblings together, and using het to ph pairings, was able to determine several other snakes carrying dilute, but in some cases, it did take several clutches to hatch out one dilute offspring.

 

[ZiggysMom]

I have been reading this thread with interest and carefully considering all the ideas and opinions shared.
I do agree that SG is probably much more widely spread than we all want to think about.
I do not think every het SG should be put down, but it would be nice if they were not bred again.
I have several SK het and momo snakes in my collection so I too face the question of whether or not to test. And like I just said, at this point we just don't know how far the gene has spread so I should be considering testing all my snakes. (20+ animals)
If one clutch would give a definitive answer, I would test at least my SK animals. If it would take three or more clutches to be fairly sure, not positive, that each animal is not a carrier and I face putting down all those normal acting babies while I wait for the test cycle to be complete, ... well ...honestly that is not happening. (I don't have the facilities to hold that many snakes for three or more years to wait out a long testing schedule in hopes that maybe I could sell them later if no SG was found.)

I am VERY excited to hear that someone is working on a test for SG! And if a shed could be tested instead of blood, even better! I was wondering just yesterday if some group like USARK could commission a test. When the group working on the SG test needs funds to move to the next step please let us all know. I for one WILL be donating to that cause. When a test is available, I would like to test all my snakes, without destroying years worth of babies.

Is anyone working on a more accurate test for crypto?

 

[Kokopelli]

Is anyone working on a more accurate test for crypto?

Yes,
http://www.killcrypto.com/

I personally have held back 3 Crypto positive asymptomatic carriers on which I am conducting a trial treatment via 2 possible cures... Once I have results I will share them.

Be it as it may, both are focused on a cure rather than an easy diagnosis. There are several diagnosing possibilities, they are simply not 100% foolproof.

 

[Nanci]

Am I saying what I did was right NO WAY!!! Will I do it again NEVER!!! But at the time and age of 18ish (some 13 years ago) I did what I had to do to try to save my snake. I do not regret it and if I had to do it all over again I still would of made the choice that I did. Did my snake survive and thrive yes, but I am sure that I was just luck that it did.

Just part of a lesson learned. Everyone's made mistakes in there past and all we can do to grow is learn from them. You can bet that in the future my snake would see a vet in a heart beat.

An 18 year-old without financial resources is different from a grown, educated, gainfully-employed adult. You stabilize the animal, put it in the car and drive to a vet. Even if it's a hundred miles.

At what point does inconvenience to the pet owner, who put the animal in this situation in the first place, outweigh the responsibility to seek appropriate medical care? Ever? I guess there are some people out there who believe breeding stock is to be treated like farm animals- if the cost of care outweighs the worth of the animal, kill it (not directed at you, Rich). I am not one of those people.

What if it was a dog or cat? Or your wife? Yup- medical professional, at whatever the cost in driving time, or money.

I'm sorry, I'm just not buying that in any but the GRAVEST emergency it is appropriate, or in the animal's best interest, or gives the animal the best chance at life, to cut it open yourself and hope it lives...

 

[stephen]

Back to the topic

I had a male Lavender 100% het for Amelanistic a LONG time ago when Lavenders were still quite rare,I bred him to alot of Homo Amelanistic females,I never had any baby Amels hatch out until the 4th year.So the breeding trials to test for Stargazing isnt something that will prove much.Also if someone pays top dollar for a Stargazer free animal and finds out years down the road, that this animal is actually a carrier what will that do to the breeders reputation....! Until there is a way of finding out 100% certainity that there animals are Stargazer clean,in my opinion the tests are a waste of time.

 

[Nanci]

Well, maybe they shouldn't be registered as SG-Free, but as the percent possibly free they are, based on the number of offspring they have hatched. That is a more meaningful number.

 

[MysticExotics]

Ok, so I have a question. Those that are adament about testing for SG, are you going to test for 3-4 years on the same animal(s) to see if the gene is present, or are you going to test once, then say the line is SG free if there are no SG in the clutch?

How many times have people paired the same snakes, year after year, only to have something pop out, three or four years down the road?
Those of you that know about Hekate, my "hot little motley", came from a Anery female & a Snow male. This pair was cohabbed from the time they were babies, & once they matured, they produced a clutch every year. At 7 years old, the owner needs to rehome them, & I help him find a home for the pair. In turn, he gives me a clutch of eggs, one of which ended up being a Motley. He told me he never got any babies like that before. So, thats 3-5 years of the same pair breeding, & the het for Motley doesn't show up until later.

If there was a definative test, that did not take 3-4 years to prove out, I would likely do the testing. It would be worth it to me to take one year out & test all the breeders. However, I am a hobby breeder, & I don't want to spend 3-4 years testing my breeders on the chance that they might carry the gene. I still do not think it is as big of a deal as it's being made out to be.
Like Oren said, there are bigger things to worry about.
If I had SG pop up in a breeding, then I would likely take the time to narrow down the culprit & retire that breeder, but with the extent of testing it would take to truely test each breeder for the SG gene, I personally feel that's a bit overboard for something that isn't as likely to show up.