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Corn Snake Genetics

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Lirpa

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Oct 10, 1996, 3:00:00 AM10/10/96
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I crossed a pastel Hypomelanistic female corn snake (a "ghost" corn closely resembling the
picture at the website http://members.aol.com/guttata319/Hawkherp/pastel.GIF) with an
orange/red amelanistic male. It is her very first clutch (18 eggs), which she laid in
mid-July. I incubated the eggs at about 78-79 degrees and they finally started hatching
over the last weekend. 3 babies have yet to come out of their eggs but all 3 eggs are
slit. One egg went bad soon after it was laid. All 17 remaining eggs hatched on their
own. All emerged babies appear normal, without any kinks. I got 1 snow corn, 8
amelanistic corns and 8 anerythristic corns (all have a tiny amount of reddish brown color
near the top of the head however) but no wild types or hypomelanistic. Does any expert out
there know what the probable genetic makeup of the parent snakes might be? I am a bit
disappointed since there are no hypomelanistic corns (what I really wanted). Any
suggestions on how I may be able to produce pastel or normal hypomelanistic corns in the
greatest numbers in the future. Any help appreciated.


Randy Remington

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Oct 10, 1996, 3:00:00 AM10/10/96
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There seems to be some differing opinions on what a pastel is. I once bought
a pair from Ernie Wagner (I deeply regret that I later sold these beauties)
and if I remember right he told me that they were ghost motley's
(hypomelanistic, anerythristic, and motley). They did look motley but their
color seemed more than just ghost (hypomelanistic and anerythristic) so I'd
agree with the explanation at
http://members.aol.com/guttata319/Hawkherp/hypo.html that pastels are
particularly colorful ghosts. However the animal at
http://members.aol.com/guttata319/Hawkherp/pastel.GIF does not look motley to
me (but then again there seems to be a lot of variation in motleys). At any
rate it seems to be up for discussion if a pastel is motley or not.

Your pastel female is at least hypomelanistic and anerythristic (likely just
type A anerythristic). The fact that she produced a snow indicates that she
is also heterozygous for amelanistic. I would not be surprised if the motley
gene was also floating around also.

The Snow baby also tells us that in addition to being amelanistic, your male
must be heterozygous for anerythristic (most likely type A but could be
either type as your female could carry type B). It would appear that your
male does not carry the hypomelanistic gene (I've forgotten the formula to
figure the chance of producing the 8 for 8 non hypomelanistic babies which
are non amelanistic if your male did carry hypomelanistic). It is not
surprising that he would not carry the hypomelanistic gene because
amelanistic covers hypomelanistic so not too many people are crossing these
gene lines.

The surprising thing is that more snows were not produced and that no normal
were produced. If the male is heterozygous for the same type of
anerythristic as the female is homozygous for (most likely type A) they
should have produced about 1 in 4 snows (they also should have produced 1 in
4 normal’s).

If you want to produce all ghost's you should get a ghost male. If you want
to produce about 50/50 ghosts and just plain hypo's you should get a
homozygous for hypomelanistic and heterozygous for anerythristic (type A
assuming she is type A) male. If you want to produce all hypomelanistic’s
(but not ghosts) you should get a hypomelanistic male which does not carry
the gene for anerythristic. As I'm still confused about what a pastel is I
couldn't tell you what to do to produce pastels. If it's just the addition
of motley that turns a ghost into a pastel and your female is pastel (motley,
hypomelanistic, and anerythristic) then a pastel male would produce all
pastels with your female. If pastel is just a "particularly colorful ghost"
it might be that the "particularly colorful" part is inherited in a complex
way and might not breed 100% true (then again it would be up to the beholder
to decide what is "particularly colorful")

Rich Zuchowski

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Oct 11, 1996, 3:00:00 AM10/11/96
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In <53khg4$h...@news-e2b.gnn.com> Remin...@gnn.com (Randy Remington)
writes:
>
>There seems to be some differing opinions on what a pastel is. I once
bought
>a pair from Ernie Wagner (I deeply regret that I later sold these
beauties)
>and if I remember right he told me that they were ghost motley's
>(hypomelanistic, anerythristic, and motley). They did look motley but
their
>color seemed more than just ghost (hypomelanistic and anerythristic)
so I'd
>agree with the explanation at
>http://members.aol.com/guttata319/Hawkherp/hypo.html that pastels are
>particularly colorful ghosts. However the animal at
>http://members.aol.com/guttata319/Hawkherp/pastel.GIF does not look
motley to
>me (but then again there seems to be a lot of variation in motleys).
At any
>rate it seems to be up for discussion if a pastel is motley or not.

I have both the 'pastels' and the 'pastel motleys' and am convinced
that they are not the same animal. The motley trait is pretty evident
in any animal that it is homozygous in.

Rich Zuchowski
SerpenCo
rz...@ix.netcom.com


Rich Zuchowski

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Oct 11, 1996, 3:00:00 AM10/11/96
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It appears pretty evident that your amelanistic male was not
heterozygous for hypomelanism. To get the greatest number of hypos
from your female, you need to use a male that is hypomelanistic. Since
your female is a ghost, the offspring would also be heterozygous for
anerythrism (probably type 'A'). The reason I say 'probably' is
because I am growing up some of the 'pastels' that I got from Marvin
Fowlkes and he is not sure of the genetic makeup of them. They look
much different from standard 'ghosts' so there may be a wild card in
them.

Rich Zuchowski
SerpenCo
rz...@ix.netcom.com


Nathan Tenny

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Oct 11, 1996, 3:00:00 AM10/11/96
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In article <53khg4$h...@news-e2b.gnn.com>,
Randy Remington <Remin...@gnn.com> wrote:
[...]

>It would appear that your
>male does not carry the hypomelanistic gene (I've forgotten the formula to
>figure the chance of producing the 8 for 8 non hypomelanistic babies which
>are non amelanistic if your male did carry hypomelanistic).

If the female is homozygous for hypomelanistic, and the male heterozygous,
each baby has a 50% chance of turning out hypomelanistic. So the chance of
getting 8 of 8 non-hypomelanistic is (1/2)^8 = 1/256---pretty unlikely, though
not completely outlandish.

NT
--
Nathan Tenny nte...@qualcomm.com
Qualcomm, Inc., San Diego, CA http://www.qualcomm.com/~ntenny/

The rec.pets.herp FAQ lives at http://www.qualcomm.com/~ntenny/herps/FAQ.html

D. Tracer

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Oct 11, 1996, 3:00:00 AM10/11/96
to

In article <53ldf7$k...@dfw-ixnews11.ix.netcom.com>,
Rich Zuchowski <rz...@ix.netcom.com> wrote:

>because I am growing up some of the 'pastels' that I got from Marvin
>Fowlkes and he is not sure of the genetic makeup of them. They look
>much different from standard 'ghosts' so there may be a wild card in
>them.
>
>Rich Zuchowski
>SerpenCo
>rz...@ix.netcom.com

I have a male pastel that I bought from Ernie Wagner almost 4 years ago
and it's virtually identical to the photo on Marvin Fowlkes' web page. Do
you know if his came from Ernie?

By the way, I outcrossed him (to a candycane amel) a couple of years ago
and will breed him back to one of those het babies next year ('97), so
I hope to produce some pastels (hopefully).

-DT

Randy Remington

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Oct 12, 1996, 3:00:00 AM10/12/96
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That's the way I figured it the first time then I tried to figure out the
chance of not producing any normals out of 17 given that 1/4 should have
been, (1/4)^17=1/17,179,869,184 and that didn't sound right at all so I
started doubting that formula. I should have paid more attention to the
lessons in statistics rather than getting distracted by the beautiful Iranian
Ph.D. who taught it.


Paul J Hollander

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Oct 12, 1996, 3:00:00 AM10/12/96
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In article <53nh9i$4...@news-e2d.gnn.com>,

If I remember my stat course right, the probability of not getting any
normals is (3/4)^17 = 0.0075. Small, but not impossible. Your formula
gets the probablility of getting all normals (or all of one genotype).

Paul Hollander phol...@iastate.edu
Behold the tortoise: he makes no progress unless he sticks his neck out.


Randy Remington

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Oct 12, 1996, 3:00:00 AM10/12/96
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Thanks,

I got off track with the 50/50 example and didn't realize that it was the .5
chance of not getting one and not the .5 chance of getting one. Your quite
right. The formula in this case would use .75 and not .25. 1 in 133 sounds
much more likely than 1 in 17 billion.


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