Silver Genetics
101
“ONE
IS SILVER, ONE IS GOLD”
An
Experiment about the Inhibitor Gene in Feline Genetics
By:
Tatyana Kalani
John
Adams
Elementary School
4th
Grade

INTRODUCTION
AND QUESTION
What
makes a cat silver or not?
What
is genetics?
-the study of hereditary transmission of characteristics in
organisms
What
is a gene?
-a hereditary unit that occupies a location on a chromosome and has
a specific influence on type, such as the color of your hair
How
can you get a silver cat and can silver cats be male or female?
HYPOTHESIS
What
is a hypothesis?
Something that I think will happen, an educated guess.
My
hypothesis is:
There must be a silver parent for a cat to be silver. If
you breed a brown and silver cat, you will get 50% silver kittens. Silver
cats can be either male or female.
PROCEDURE
How
will I test my hypothesis?
I
am going to test my hypothesis by doing the following:
1.
Learn and study
the
Punnett
Square
and
create a table as it relates to the inhibitor gene affecting the cat’s
color.
2.
Look at the
litters of kittens raised, comparing the colors of both parents and the
colors of the kittens.
Record
and review the data to reach a conclusion.
OBSERVATIONS
AND DATA
Punnett
Square
i
= brown gene
I = inhibitor (silver) gene
(The
inhibitor gene blocks the color pigment making the cat silver.)
Parent Colors:
Brown/Brown
|
i
|
i
|
i
|
ii
|
ii
|
i
|
ii
|
ii
|
Results:
100%
Brown Kittens
|
Parent
Colors:
Brown/Silver
|
I
|
i
|
i
|
Ii
|
ii
|
i
|
Ii
|
ii
|
Results:
50%
Silver Kittens
50%
Brown Kittens
|
Parent
Colors:
Silver/Silver
|
I
|
i
|
I
|
II
|
Ii
|
i
|
Ii
|
ii
|
Results:
75%
Silver Kittens(25% Homozygous)
25%
Brown Kittens
|
Parent
Colors:
Homozygous
Silver/Brown
|
i
|
i
|
I
|
Ii
|
Ii
|
I
|
Ii
|
Ii
|
Results:
100%
Silver Kittens
|
Actual
Results
Brown
to Brown
Litter
Date
|
Sire’s
Name
|
Sire’s
Color
|
Dam’s
Name |
Dam’s
Color |
Brown
M |
Kittens
F
|
Silver
M
|
Kittens
F |
Other
M
|
Kittens
F |
Total
|
1/15/02
|
Topaz
|
Brown
|
Amber
|
Brown
|
- |
2
|
- |
- |
- |
- |
2
|
8/2/02
|
Corey
|
Brown
|
Monika
|
Brown
|
3
|
- |
- |
- |
1(Blue)
|
1(Blue)
|
5
|
3/15/03
|
Garth
|
Brown
|
Baby
|
Brown
|
- |
4
|
- |
- |
1(Snow)
|
- |
5
|
4/1/03 |
Garth
|
Brown
|
Raindrops |
Brown
|
2
|
- |
- |
- |
2(Snow)
|
1(Snow)
|
5
|
5/2/03
|
Garth
|
Brown
|
Safari
|
Brown
|
1
|
- |
- |
- |
2(Snow)
|
1(Snow)
|
4
|
2/7/04
|
Ischiron
|
Brown
|
Spirit
|
Brown
|
2
|
1
|
- |
- |
- |
- |
3
|
2/23/04
|
Fireball
|
Brown
|
Lucy
|
Brown
|
3 |
2 |
- |
- |
- |
- |
5
|
Brown
to Brown produced 100% Brown or Non-Silver Kittens.
Both
male and female kittens were brown or non-silver.
Silver
to Brown
Litter
Date
|
Sire’s
Name
|
Sire’s
Color
|
Dam’s
Name |
Dam’s
Color |
Brown
M |
Kittens
F
|
Silver
M
|
Kittens
F |
Other
M
|
Kittens
F |
Total
|
11/18/01
|
Splendor
|
Silver
|
Bernett
|
Brown
|
2
|
- |
- |
2
|
- |
- |
4 |
3/10/02 |
Splendor |
Silver |
Lace |
Brown
|
1
|
1
|
- |
1
|
- |
- |
3
|
3/12/02
|
Splendor |
Silver |
R
ena |
Brown
|
1
|
2 |
- |
2
|
- |
- |
5
|
3/26/02 |
Splendor |
Silver |
Saka
|
Brown
|
- |
1
|
4
|
- |
- |
- |
5
|
4/20/02 |
Splendor |
Silver |
Dehleon
|
Brown
|
1
|
- |
1
|
- |
1(Gold)
|
- |
3
|
7/15/02
|
Slate
|
Silver |
Cosette
|
Brown
|
- |
1
|
2
|
- |
- |
- |
3
|
3/12/03
|
Slate
|
Silver |
Sahara |
Brown
|
1
|
2
|
1 |
1
|
- |
- |
5
|
4/24/03
|
Silverado |
Silver
|
Monet
|
Brown |
1 |
- |
- |
- |
1(Smoke) |
1(Smoke) |
3 |
5/13/03
|
Matalica |
Silver
|
Mirage
|
Brown |
- |
- |
1
|
2
|
- |
- |
3 |
6/21/03 |
Splendor |
Silver
|
Mary
|
Brown |
1
|
1
|
1
|
1
|
- |
- |
4
|
8/21/03
|
Slate |
Silver
|
Lace |
Brown |
- |
2
|
- |
3
|
- |
- |
5
|
8/27/03 |
Splendor |
Silver
|
Katanga
|
Brown |
- |
2
|
2
|
3
|
- |
- |
7 |
12/2/03 |
Jean
Luc |
Silver
|
Sahara
|
Brown |
- |
1 |
2
|
2
|
1(Snow)
|
- |
6
|
1/28/04
|
Silverado
|
Silver
|
Silk
|
Brown |
- |
2
|
- |
1
|
3(Smoke)
|
- |
6 |
2/05/04
|
Samurai
|
Silver
|
Katanga |
Brown |
1
|
2
|
2
|
2
|
- |
- |
7
|
2/09/04 |
S
late |
Silver
|
Tara |
Brown |
1
|
3
|
|
- |
- |
- |
4
|
2/15/04
|
Samurai
|
Silver
|
Pearl
|
Brown |
1
|
- |
1
|
- |
- |
- |
2
|
Silver
to Brown produced 50% Silver and 50% Brown or Non-Silver.
Both
male and female kittens were silver, brown, or non-silver.
Silver
to Silver
Litter
Date
|
Sire’s
Name
|
Sire’s
Color
|
Dam’s
Name |
Dam’s
Color |
Brown
M |
Kittens
F
|
Silver
M
|
Kittens
F |
Other
M
|
Kittens
F |
Total
|
11/4/03
|
Silverado |
Silver |
Polar
|
Silver |
1 |
- |
1 |
- |
1(Smoke)
|
1(Smoke)
|
4
|
Results
were not conclusive as there was only one litter available.
ANALYSIS
OF DATA
What
I learned:
When
both parents are brown, the kittens were 100% brown or non-silver. Of the
29, or all of the kittens born in this group, none were silver. This
proves that a cat must have a silver parent in order to be silver. Silver
is a dominant gene so if a cat is brown it can not carry silver.
In
the silver to brown group, 75 kittens were born. Of the kittens, 38 were
brown or non-silver and 37 were silver.
Thus, 49.33% or approximately 50% of the kittens were silver. Of
the 37 silver kittens, 16 were male and 21 were female. This showed that
silver cats can be male or female and the inhibitor gene is not sex
linked.
CONCLUSION
Was
my hypothesis correct?
My hypothesis was correct!
There must be a silver parent for a cat to be silver.
If you breed a brown and silver cat, you will get 50% silver
kittens. Silver cats can be either male or female.
INFORMATION
AND CREDITS
Webster’s
II
New
Riverside
University
Dictionary
The
Bengal
Bulletin
Volume 17 Number 2 Summer 2003
The “New” Silver
Bengal
by:
Dr. Linda Evans, M.D., M.P.H.
Stevens,
Gloria. Legacy of the Cat. Raincoast Books.
Vancouver
,
British
Columbia
2001
Also:
Thank
you to the following people who submitted litter results for my
experiment:
Earl
Shropshire, Natalie Sullivan, Rhonda Hauffe, Chuck and Connie Pealer, and
Christina Dahleen. . . I LOVE YOU ALL!!!
A
special thanks to my mom for helping type set my project.
Thank
you to my dad and sister, Natasha, for helping paste my results on my
board.
Thank
you to all of the wonderful people at TICA and the shows for helping me
learn and experience the wonderful world of
Bengal
Cats!!!!
|