Testing for Stargazing

I have SK's from two sources: Walter & PJ. I plan on testing my SK's from Walter for SG once they're big enough to breed, & the ones I have from PJ come from Chuck & Connie's lines, so they've already been tested.

I also got the impression that the basis of this thread implied that very few breeders actually test their SK's. I know a number of people who work with SK's who have or will be testing their SK lines.

I think for the most part, many of the breeders here are very trustworthy, & the number of those that are not, is much smaller. I've seen pretty good self policing in the herp community, & either calling out irresponsible breeders, or making others aware of irresponsible breeders.

Many of us know who we can trust, & who we can't. We offer assistance to those who are new to the community & might not know who to avoid, & which breeders are highly recommended.

I like the topic of testing SK lines for SG, but to say that "most breeders" don't bother to test, is definitely incorrect.

Originally Posted by Tara80

I know Don has sent quite a few of his sunkisseds, if not all of them, up to Chuck and Connie for testing and some have proven positive and most not.

That is good to know. I used Don's loaner Sunkissed to start 3 of my projects, but unfortunatly I didn't get a ID with it so there is no way to know for sure which one it was

I just have to test all my breeders that came from that particular SK.

Walter
BOUT' CORNS !!

I _do_ believe registration and documentation of gazer-free individuals at ACR is important. Even for those of you who don't register all your stock, it would be helpful to register the SKs. Obviously, as Susan says, some individuals are rumored to not represent snakes truthfully (not speaking of the stargazer gene specifically) but at least it would be a starting point.

At this point the gazer gene is most likely not confined to sunkissed lines. Sunkissed has been mixed with so many morphs that the gazer gene really could be anywhere. I know when Chuck and Connie started testing that they felt that snakes (not from sunkissed lines) hatched prior to a certain year (might have been 2004?) were probably unaffected but anything after, unless you knew the snakes ancestry, was probably fair game. That is probably more true today since the gene has been spread more and more. And dont forget that the gazers came from Okeeteees so it is possible that some Okeetees are carriers and spreading the gene.

I definitely think that starting to test sunkisseds is a positive beginning but it is definitely not the end. The gazer gene will remain dormant and hidden for a long time.

Chuck has posted how many hatchlings you need to hatch to say that a snake is >98 or 99% gazer free depending on whether one parent is homo or het gazer. The numbers were not as high as you might expect so even het gazers are worth using. Someone who knows statistics could probably easily figure it out.

Originally Posted by Reptilekyle64

To Quote tara:
For the record gazer is tested by only a few people and I would not put that number over 20 in U.S For the hundreds of sunkissed and sunkissed morphs produced every year...

I highly doubt that. There are a good number in this thread alone. I would put the number a fair bit higher than 20. I can count 4 in my area of NC alone, and that's a tiny area. Yes, there is a large number being produced, but only 20 testers in entire US? Not likely.

Susan, I agree. The ACR is only as good as the honesty used to enter data. It is however, a fairly decent reference point. People do need to register the stock somewhere and being able to trace SK lines is handy.

Yeah now we are getting into some good stuff. I love all the opinions and the real number of who is testing. Their are a ton of garage breeders pumping these thongs out meaning SK untested. I was just saying there should be a group where you are a trusted member to make sure people who say they are testing are testing.

Susan as far as ACR one of the SG males I use to test is a registered SG. He pedigree shows he originated from kathy love stock and is in fact a SG. That's where I was going with that.

I think if a group can be created like the BOI so folks know who they are buying snakes from then there could easily be a group with proof they have tested and are actually selling gazer free SK. Anything can be falsified look the did it for Obama.

If you are breeding a gazer to test a snake you need 7 eggs to show that the snake being tested has a >99% chance of not carrying the gene. If you are using a het gazer you need 17 eggs to have the >99% chance of being gazer free. Of course you will never reach the 100% definite het gazer free point and there will always be the breedings that defy the odds.

The year in which sunkisseds were started to be bred to other lines was 1999. I don't know how many morphs it was bred into or when but it all started in 99.

Originally Posted by JoannaD

Chuck has posted how many hatchlings you need to hatch to say that a snake is >98 or 99% gazer free depending on whether one parent is homo or het gazer. The numbers were not as high as you might expect so even het gazers are worth using. Someone who knows statistics could probably easily figure it out.

Here is a list that Joe Pierce got from a breeder over the pond. I believe this is pretty much the same as what Chuck came up with.


Number of eggs needed.......

Here a list for people who test for Stargazer.
If you breed with:

het Stargazer X Unknown and you don't get any Homo Stargazer, than the chance that the corn is free from Stargazer is by

1 egg 25%
2 eggs 43.75%
3 eggs 57,81%
4 eggs 68.36%
5 eggs 76.30%
6 eggs 80.20%
7 eggs 86.65%
8 eggs 89.99%
9 eggs 92.49%
10 eggs 94.37%
11 eggs 95.77%
12 eggs 96.83%
13 eggs 97.62%
14 eggs 98.22%
15 eggs 98.66%
16 eggs 98.99%
17 eggs 99.24%
18 eggs 99.43%
19 eggs 99.57%
20 eggs 99.68%

And if you breed with Homo Stargazer X Unknown

1 egg 50%
2 eggs 50%
3 eggs 62.50%
4 eggs 75%
5 eggs 84.37%
6 eggs 90.62%
7 eggs 94.53%
8 eggs 96.87%
9 eggs 98.24%
10 eggs 99.02%
11 eggs 99.46%
12 eggs 99.70%
13 eggs 99.84%
14 eggs 99.91%
15 eggs 99.95%
16 eggs 99.97%
17 eggs 99.98%
18 eggs 99.99%

I hope that you will see that test for 100% sure free from Stargazer isn't possible, but like you see we can come very close.

Walter
BOUT' CORNS !!

How much does it cost to gentically test? I know you test out morphs by breeding but I wouldn't want to test out stargazing and create more possibly! How do you test them?

Walter the numbers for the het gazer crossing look right but they are not right for the homo gazer according to what I understand from Chuck. According to him with a homo gazer at 7 eggs the per cent is 99.2187 and with 6 eggs it is 98.4375.

Again, if I understand the formula from Chuck correctly this is how it goes.

With a gazer there is a 0.5 chance the egg gets the gazer gene. So 100(0.5^x) , where x is the number of eggs you have, gives you the percent chance that you are getting a false negative result, i.e that your snake fooled the odds and really is carrying the gene. if you then subtract that number from 100 it gives the % that your snake does not carry the gene.

So 0.5^6 X 100 = 1.5625, 100-1.5625=98.4375 or 98.4375% the snake does not carry the gene.

With 7 eggs the equation is 0.5^7=0.7813, 100-.7813=99.2187 or 99.2187% the snake is free of the gazer gene.

With a het gazer the 0.5 changes to 0.75 because 0.75 times the snake will not get the gazer gene.

With that my brain is fried and I need to go clean the kitchen!