~~OPAL !?'s Genetic's Training~~

I am glad that you are enthusiastic about learning genetics! :) At times you may have trouble understanding what I am talking about and that is normal. But PLEASE tell me when you are having trouble because it will only get more confusing if you keep going without asking questions.

With that in mind though, this is going to be fun. :)

Okay, so here is my guide about genetics. If you are ever stuck you can refer to this to see if that helps.

https://docs.google.com/file/d…WxReEIyLU56V0E/edit?pli=1

So first things first. Skin color is controlled by pigments called Melanin. Everything has it. Melanin protects your skin from the sun.
"Melanin: The pigment that gives human skin, hair, and eyes their color. Dark-skinned people have more melanin in their skin than light-skinned people have. Melanin is produced by cells called melanocytes."

There are two different types of melanin cells in cats. Eumelanin and Pheomelanin. Eumelanin is the normal type and Pheomelanin is the mutated type.

Eumelanin is what makes a cat look black, chocolate, or cinnamon. When the cat has the mutated version called Pheomelanin, the cat loses the ability to produce melanin and the cat ends up looking red/orange.

So we are first going to focus on Eumelanin colors because those are the easiest to start with.

Okay, we will go over some basics. I will put key words in bold and I will provide a short key words list at the bottom of each lesson.

A Gene is a trait that is passed from parent to offspring. Number of toes and hair color are examples of different types of different genes.

In this case we will be talking about cats and for each gene, a cat will get two alleles (one from the mother and one from the father).

In this case, we have 3 different alleles that code for normal coat color. This gene is often referred to as the cat's Base Color. So if you see anyone talking about the Base Color of a cat, they are referring to the Eumelanin colors.

In cats, the Black Phenotype is the most dominant and will show up as the cat's color as long as they have at least one "B" allele. The Chocolate Phenotype is the second most dominant and will only show up if the cat doesn't have a "B" allele but DOES have at least one "b" allele. The Cinnamon Phenotype is recessive to both Black and Chocolate and will ONLY show up if the cat receives a "bl" from both parents.

Black = BB, Bb, or Bbl
Chocolate = bb or bbl
Cinnamon = blbl

So from looking at which alleles code for black, chocolate, and cinnamon, you should be able to see which allele is the most dominant and which allele is the most recessive.

Now when a cat has two of the same allele (ex: BB) the cat is said to be homozygous for that trait. And when a cat has two different alleles (ex: Bb) the cat is said to be heterozygous for that trait.

Each set of traits has two different ways of describing it. The phenotype and the genotype.

Phenotype refers to the the physical description of that allele.
Genotype refers to the genetic description of that allele.

For Base Color, the phenotype refers to the colors (black, chocolate, and cinnammon), and the genotype refers to the allele combination (ex: BB, bb, blbl).

To figure out what color the kittens will be when you cross two Eumelanin colored cats, you set up a punnet square using the genotypes of the parents. :)
Click Here for a Punnet Square reference PDF

For now we are going to assume that these cats are homozygous for Base Color. Since the base color isn't gender specific, it doesn't matter which is the male and which is the female, but I will let you know which is which.

So if we were going to do a cross of a male Black cat and a female Black cat, the punnet square would look like this:

B B

B BB BB

B BB BB

What does this mean? This means that when crossing two black cats that are both Homozygous for that trait, the phenotype of all of their offspring will be Black.

So if I were to write this out it would look like this:

Black x Black

Black

So when you do pairings, you will write out your answers like this: (replacing the male, female, and offspring with colors of course) When you are doing pairings for other people you don't have to write out the punnet square, but for practice I want you to write it out.

Male x Female

Offspring

Review Questions:

1) What does it mean for a trait to be dominant? recessive?

2) For base color, write out the colors (not alleles) in order of most dominant to recessive.

3) Based on the Genotypes, can you name the Phenotypes of the following cats?

BB =

blbl =

bbl =

4) Figure out the offspring of these cat pairings: (for these problems, assume that the parents are homozygous for their colors)

Black male, Black female:

Chocolate male, Black female:

5) Figure out the offspring for these cat pairings: (for these problems, assume that the dominant colored parent is heterozygous for the color of the recessive colored parent)

Cinnamon male, Chocolate female:

Black male, Cinnamon female:

**Make sure you follow the template that I used in the example above.** (You can copy and paste this template (below) if that helps - just replace the female with the female's color, and the male with the male's color)

Also, if you are like me and you learn well from visual examples you can watch this video. :)

[/spoiler]

So you already know how the 3 Eumelanin Base Colors are Black, Chocolate, and Cinnamon. And that the Base Color genes are B, b, and bl.

Next we are going to learn about a set of genes that alter the Base Color called Dilute but first we need to know how the Eumelanin pigments work.

Each pigment (black, chocolate, and cinnamon) is a slightly different shape, and this shape difference is what gives you the different color. Those pigments are compacted into each strand of hair.

The dilute gene alters this by spreading apart those pigments which causes the cat to appear lighter (and therefore diluted).

Ignore the middle (Caramelized versions) for now because we will learn about those later but these graphics are a pretty decent visualization of what I am describing.

So as you can see, the diluted versions are as follows:

Dense --> Dilute
Black --> Blue
Chocolate --> Lilac
Cinnamon --> Fawn

The dilute alleles are represented by "D" and "d". Dense (D) is dominant over Dilute (d).

Dense = DD or Dd
Dilute = dd

Now when we write out the genotype of cats we will also be including the dense/dilute alleles as well. So each cat will now be written with 2 pairs of alleles.

Example:

Black = BB DD

I want you to guess the genotypes for the following phenotypes:

Chocolate =

Fawn =

Blue =

Black =

Now guess what the phenotype is based on these genotypes:

Bb dd =

bb dd =

blbl Dd =

bbl dd =

So now we have two punnet squares to do. Now in the genetics test you will need to assume that unless there is a dilute parent, that both parents are homozygous for dense. And that is how we are going to learn it. Just know that when you are doing pairings for people, you will always assume that a dense colored cat is heterozygous for the gene. That way they can get more variety of kittens.

BUT in this thread, a dense cat will ALWAYS be homozygous for dense unless there is a dilute parent, in which case the dense parent will be Heterozygous for the gene.

Example:

Black x Chocolate

Black, Chocolate

B b D D

b Bb bb D DD DD

b Bb bb D DD DD

Try these pairings:

Black male, lilac female:

Fawn male, blue female:

Cinnamon male, chocolate female:

Blue male, Black female:

Okay, so next we will be talking about Tabbies. The tabby gene is referred to as the "Agouti" gene.

Agouti actually refers to the banding pattern of the hair. There are two different types of hair on tabbies. The Solid hairs are what produce the actual tabby markings, and the Agouti banding hairs are the "background" hairs. The Solid "striped" hairs show what color the cat actually is.

The neat thing about these agouti banding is that the stripes alternate between Pheomelanin and Eumelanin pigments. (As seen in the picture photo below).

Here is a closeup of the Agouti hairs on a Brown Tabby.

[img width=510 height=337]http://img.photobucket.com/alb…my%20kitties/Malibuah.jpg[/img]

The normal coloration of cats is to be Tabby. The solid gene is actually a mutation that blocks the production of these Agouti bands.

What this means is that the tabby banding is actually still there. Even though you cannot see it in Adult solid cats, you can actually get a glimpse of what tabby markings kittens would have if they didn't have the mutated copy of the Agouti gene (which made them solid).

This tends to go away when they get older (not sure of the mechanics of why you can see the markings sometimes). BUT there are breeds that take advantage of this and have bred their cats to maintain the ghost markings. You can see this in Egyptain Maus.

Anyway, so the genotype of Agouti is "AA or Aa" and the genotype for solid is "aa" and Agouti is Dominant over Solid.

Agouti = AA or Aa
Solid = aa

There are 4 different tabby patterns (3 of them are on separate loci - this means that they are seperate genotypes and are completely independent of each other).

Classic and Mackerel are on the same locus. Mackerel Tabby is dominant over Classic Tabby. Mackerel Tabbies have thin stripes, and Classic Tabbies have thick stripes that swirl into a bulls-eye pattern.

Mackerel Tabby = McMc or Mcmc
Classic Tabby = mcmc

Spotted Tabby is on a serarate locus and affects the Mackerel/Classic tabby pattern by chopping up the pattern into spots. Mackerel Spotted Tabbies tend to have smaller spots than Classic Spotted Tabbies. This is not important for predicting litters here on Feral Front because people tend to not care or understand this so we just don't complicate it too much. However, I think it is really neat so I am teaching it to you anyway. Just know that when doing litters, you won't distinguish between Mackerel or Classic Spotted Tabbies. You will just refer them all as Spotted Tabbies.

Since Spotted Tabby modifies the Mackerel/Classic Tabby markings, it is dominant over them. It is a gene that is either "ON" or "OFF".

Spotted Tabby = SpSp or Spsp
Normal Tabby = spsp

Now when the cat is heterozygous for Spotted Tabby (Spsp) the spotting gene cannot completely break up the Mackerel or Classic tabby pattern and can show a broken mackerel or classic tabby pattern. In the cat show world, they still refer to these cats as just Mackerel or Classic Tabbies since the spotting pattern typically isn't clear enough for them to be considered Spotted Tabbies and there isn't a category for specifically Broken Mackerel or Classic Tabbies.

Ticked Tabby is on a separate locus as well and also affects all tabby markings by blocking the production of tabby stripes. This gene only allows the agouti banding to be produced (except on the head - there is still the signature "M" marking that the tabby stripes produce).

Since ticked tabby stops all production of the tabby stripes, this means it is dominant over all other tabby markings. This pattern is also an "ON" or "OFF" gene.

Ticked Tabby = TaTa or Tata
Normal Tabby = tata

HOWEVER, when the cat is heterozygous for Ticked Tabby (Tata) there can sometimes be banding produced on the legs. This is not important for predicting litters but is still cool. With litters you will not distinguish between banding on the legs or not. They will all just be referred to as Ticked Tabbies.

SO lets Recap:

Agouti = AA or Aa
Solid = aa

Mackerel Tabby = McMc or Mcmc
Classic Tabby = mcmc

Spotted Tabby = SpSp
Broken "Mackerel or Classic" Tabby = Spsp
Not Spotted = spsp

Ticked Tabby = TaTa
Ticked Tabby w/Banding = Tata
Not Ticked = tata

1) Guess the phenotypes of the cats below:

BB dd AA McMc spsp tata

bb Dd aa mcmc Spsp Tata

blbl dd Aa Mcmc spsp TaTa

BB Dd Aa mcmc spsp tata

bbl dd Aa mcmc Spsp tata

2) Predict the kittens: (These will just be generic tabby patterns - you don't have to do the pattern punnet squares. Just write "color" Tabby. Ignore the pattern for these ones)
~~Always assume the agouti gene is "Aa". This will be assumed on the test.
~~Always assume that solid colored cats would normally be Mackerel Tabbies (McMc spsp tata) if they had the agouti gene

Brown Tabby male, Blue female:

Chocolate male, Cinnamon Tabby female:

Fawn male, Blue Female:

Lilac Tabby male, Fawn Tabby female:

3) Predict the kittens: (Until you understand the tabby markings, do the punnet squares for all tabby markings. You may skip the punnet squares for base color and dilute if you feel you understand them)
~~Always assume the agouti gene is "Aa". This will be assumed on the test.
~~Always assume that solid colored cats would normally be Mackerel Tabbies (McMc spsp tata) if they had the agouti gene.
~~Always assume that spotted tabbies are Mackerel Spotted Tabbies (McMc Spsp tata)

Chocolate Classic Tabby male, Chocolate Mackerel Tabby female

Brown Ticked Tabby male, Black female

Blue Spotted Tabby male, Chocolate Mackerel Tabby

Cinnamon male, Fawn Classic Tabby

Remember how there are two types of pigments, eumelanin and pheomelanin? We already covered how Eumelanin colors are Black, Chocolate, and Cinnamon. Now we will discuss what colors you get from Pheomelanin.

The dense version of pheomelanin is called "Red". This is sometimes called Orange, but in the cat genetics world, it is called Red.

This red gene is a mutation that blocks the cat's ability to produce eumelanin colors. This means that it doesn't matter if a cat has "BB" or "blbl", if a cat has the red gene, it will look Red. So cats who are genetically black, chocolate, or cinnamon will look red.

Now if the cat has the dilute coloration, the red color turns into cream. So cats who are genetically blue, lilac, or fawn will look cream.

Red Tabby = DD or Dd
Cream Tabby = dd

Now remember how the solid gene is a mutation that stops the cat from being able to produce those agouti banded hairs? Well, the interesting things about the red gene is that the solid mutation cannot function properly when the cat has the red gene. This means that a red cat may be "aa" but will still look like a tabby.

Red Tabby = AA, Aa, or aa

Here on this site whenever you see a pairing that involves a red tabby, you are always going to assume that that cat is genetically solid. Which means that cat is "aa".

Now there are subtle ways of telling whether or not a red cat is genetically solid or tabby. A common thing that the tabby gene does it create a white ring and a white chin. So a genetically solid red tabby typically doesn't have this.

Unlike the other genes we have learned about, the red gene is located on the X-Chromosome. All mammals have two Sex chromosomes that determine if they are born with male genitalia or female genitalia. (XX or XY)

XY = Born with Male Genitalia
XX = Born with Female Genitalia

For the red gene, the X-chromosome is replaced by either a "O" for red, or "o" for non-red.
Since the red gene is on the x-chromosome, female must have two copies to be fully red, while a male only needs one copy to be red.

This also means that a female cat can have one red gene and one non-red gene. This is called a tortie and the cat ends up being partially red and partially non-red.

Red Female = OO
Tortie Female = Oo
Non-Red Female = oo

Red Male = OY
Non-Red Male = oY

This video helps explain torties quite nicely.

A tortie is always a Black Tortie, unless they specify a color in front of it. Also, a tortie is always a solid cat. We will get into tabbies later. For now, all of these cats in this lesson are genetically solid.

Examples:

Tortie = BB DD Oo aa
Cinnamon Tortie = blbl DD Oo aa
Lilac Tortie = bb dd Oo aa
Dilute Tortie = BB dd Oo aa

**Last thing to remember, a blue tortie is called a "Dilute Tortie"**

Guess the genotypes of these cats:
~~Always assume that red tabbies are genetically black solid cats, and cream tabbies are genetically blue solid cats.

Red Tabby male:
Cream Tabby female:
Brown Tabby male:
Tortie female:
Cinnamon female:

Guess the phenotypes of these cats:

BB dd OO aa:
bb Dd Oo aa:
blbl DD oY Aa:
BB DD OY aa:
bb dd oo AA:

Predict the kittens:

Black male, Red Tabby female
Red Tabby male, Cream Tabby female
Cream Tabby male, Fawn female
Red Tabby male, Red Tabby female
Red Tabby male, Cinnamon Tortie female