Genotypes and Punnett Squares
Building Your Genotype
A genotype is the genetic make up of a dog that creates its phenotype (outward
appearance), and knowing how to build one is just as important as how to read one. For the most part, genotypes are arranged
in alphabetical order to maintain consistency from person to person. The following breakdown is how I specifically build one.
I always start with the B Series:
Does the dog have a black nose? If yes, it is
annotated with a B for black. Does the dog have a chocolate parent or grandparent? If the dog
has a chocolate parent, the second position of the B series is annotated with a b (for chocolate)
because it is recessive to black. If the grandparent is chocolate, but not the parent, the second position would be annotated
with an * as unknown because there is only a possibility that the given dog received a chocolate
gene from the respective parent.
Does the dog have a liver/light brown nose? If yes, the B series of this particular
dog is annotated as bb because the dog is genetically chocolate and tan. For consistency purposes,
we will proceed with this example.
Bb
Now, move to the C Series:
Is the dog red, cream, or red with a cream parent (commonly referred to as blush)? In either case, these
examples are annotated as follows:
Red CC
Blush CC^ch
Cream C^chC^ch.
We will proceed with the cream example for maximum
annotation.
Bb C^chC^ch
Now, move to the A-Series:
Does the dog have cream points or is it cream?
If your dog is cream pointed, both A series
annotations are a^ta^t.
If your dog is cream, the first position of
the A series annotation is a^y, and the second position is contingent on the parents. If one
parent is pointed, the second position is annotated with an a^t, but if both parents are cream,
the second position can be either a^y or a^t; if the dog is shaded
the second position is a^t and if it is "clear" (no shading), the second position is
more than likely a^y.
*The exception to A series reds is ee reds. See Genetics Overview page for further
explanation.*
We will proceed with the a^ya^t annotation.
a^ya^t Bb C^chC^ch
This dog is an ASPS, black nosed cream that is recessively carrying chocolate.
Reading A Genotype
I'm presenting a variety of genotypes for
full understanding, and will be going into some symbols outside of the A,B,C's, but I will explain respectively.
a^ya^t BB CC dd EE K^brk
In following the B,C,A building pattern, we know that this dog is a black based/nosed red dog. So what is
the dd, EE, and K^brk? The receipt
of the two d's dilutes the black in the dog to blue, and we now know that this dog is a red
dilute. The E annotation verifies that the dog is not an ee/ESPS red, and the K^brk
annotation means that the dog is possessing and expressing brindle (K^br). So what is this dog in its entirety? A blue based
red brindle also known as a red dilute brindle.
a^ta^t bb C^chC^ch Mm
This example only addresses items of discussion
in this section and again follows B,C,A. We have a chocolate (bb) and cream (C^chC^ch)
pointed (a^ta^t) dog. So what is the Mm? M
is the annotation for the merle/dapple pattern. We know that this particular dog is only a single dapple because the second
position of the M series is a lowercase m. Collectively, it is a
chocolate and cream dapple.
So Who Cares About a Genotype?
Not many people, but some do for a variety of
reasons. Outside of all other considerations, such as disposition, conformation, etc, the genotypes are a means of predicting
litter outcomes in any given breeding. A breeder can use this info in an attempt to produce a particular color or pattern.
NOTE: Color and pattern should be the very least of concern to anyone planning a breeding. A fellow breeder once asked
me about a pup that she had produced; a comparable genotype to his is above (the red dilute brindle). She had a basic understanding
of dilutes, but was particularly interested in the variety of ways in which she could occasionally produce more without limiting
selected partners to decrease quality. As part of my discussion for her understanding, I built the following Punnett Squares
for her future reference.
Assuming that he carries points, his genotype would be like this: a^ya^t
B* dd K^brk. I'm not discussing C series, etc because we are only talking about red. The * is because I'm not
sure what he's carrying recessively.
When
bred to a plain jane black and tan carrying dilute (a^ta^t BB Dd kk), you can expect the following
offspring. His genes are vertical and hers are horizontal.
|
| a^t B D k
| a^t B d k
|
| a^y
B d k | a^ya^t BB Dd kk | a^ya^t BB dd kk |
|
a^y B d K^br |
a^ya^t BB Dd K^brk
| a^ya^t BB dd K^brk
|
| a^y
* d k | a^ya^t B* Dd kk | a^ya^t B* dd kk |
|
a^y * d K^br |
a^ya^t B* Dd K^brk
| a^ya^t B* dd K^brk
|
| a^t
B d k | a^ta^t BB Dd kk | a^ta^t BB dd kk |
|
a^t B d K^br |
a^ta^t BB Dd K^brk
| a^ta^t BB dd K^brk
|
| a^t
* d k | a^ta^t B* Dd kk | a^ta^t B* dd kk |
|
a^t * d K^br |
a^ta^t B* Dd K^brk
| a^ta^t B* dd K^brk
|
So in this case, you have the possibility
of getting the following:
Black and tans carrying d. (a^ta^t BB Dd kk, a^ta^t B* Dd kk )
Blue and tans (a^ya^t BB dd kk, a^ta^t B*
dd kk)
Black
and tan brindles carrying d (a^ta^t BB Dd K^brk, a^ta^t B* Dd K^brk)
Blue and tan brindles (a^ta^t BB dd K^brk, a^ta^t B* dd K^brk)
Red dilutes (blue) (a^ya^t BB dd kk, a^ya^t
B* dd kk)
Blue
based red brindles (what the male being discussed is) (a^ya^t BB dd K^brk, a^ya^t B* dd K^brk)
Red brindle carrying dilute (a^ya^t BB Dd
K^brk, a^ya^t B* Dd kk)
Red carrying dilute (a^ya^t BB Dd kk, a^ya^t B* Dd kk)
-This table is based on the same breeding, but with a blue and tan instead of a black
and tan carrying dilute.
| | a^t B d k |
a^t B d k |
| a^y B d k
| a^ya^t BB dd kk
| a^ya^t BB dd kk
|
| a^y
B d K^br | a^ya^t BB dd K^brk | a^ya^t BB dd K^brk |
| a^y * d k
| a^ya^t B* dd kk
| a^ya^t B* dd kk
|
| a^y
* d K^br | a^ya^t B* dd K^brk | a^ya^t B* dd K^brk |
|
a^t B d k | a^ta^t BB dd kk
| a^ta^t BB dd kk
|
| a^t
B d K^br | a^ta^t BB dd K^brk | a^ta^t BB dd K^brk |
|
a^t * d k | a^ta^t B* dd kk
| a^ta^t B* dd kk
|
| a^t
* d K^br | a^ta^t B* dd K^brk | a^ta^t B* dd K^brk |
In this case, you have a possibility
of getting the following:
Blue and tan (a^ya^t BB dd kk, a^ta^t B* dd kk)
Blue and tan brindles (a^ta^t BB dd K^brk, a^ta^t B* dd K^brk)
Red dilutes (blue) (a^ya^t BB dd kk, a^ya^t
B* dd kk)
Blue
based red brindles (what the male being discussed is) (a^ya^t BB dd K^brk, a^ya^t B* dd K^brk)
As you can see, genotypes and
Punnett Squares can be very valuable tools.
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