Coat color and genetics

Rayn89

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So, this is sort of a long post but hopefully you can keep up. First of all, and most importantly I have read in several places that a male kitten's color can only be determined by the dam's coloration or a dilution thereof. In my own personal experience, I have seen otherwise, and I will explain why- I had a cinnamon pointed female cat give birth to a male tuxedo cat and his black is very black. I saw her with a male tuxedo cat that looked very similar to Binx (the baby). The fact that she had a dominate colored kitten tells me the color here must have come from the father because brown would have been the dominate color here not black. She also had one blue swirl pattern tabby male and two blue tortoiseshell females. If a dilute color (cinnamon) cannot produce a dominate color (black), then the black gene must have come from the father. This was years ago.

I have also recently had a brown tabby/tortoiseshell cat give birth to two blue babies that look exactly like the blue swirl tabby cat I mentioned earlier. They are both male and I presume him to be the father. She also had one male dark colored tabby (like her but without the tortie markings) and one blue tortoiseshell female. If anyone has similar experience or additional information on this topic, please feel free to share or tell me how I may be wrong.
 

goingpostal

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A dilute can produce black, two dilutes cannot. The male also carried for blue so that is why some kittens were dilute and some were not. By swirl pattern, do you mean classic tabby?
 
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Rayn89

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He has what I can only describe as faint rosettes. His underbelly is 'spotted'. He looks like a Bengal mix although it seems unlikely. I guess you never know.

That's what is confusing here. If a dam determines the color of a male kitten 100% of the time with no exceptions, then how does the father being or not being dilute have any influence on the outcome of the coloring on a male offspring?
 

StefanZ

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I dont know much about cinnamon coloration. I take your word cinnamon means ALSO to be a carrier of the dilute gene - I suppose doubled up.

Daddy, having black, is obviously ALSO a carrier of the dilute gene, because his childs are some black, and some dilute... Theorethically it should give half half.

Im not sure about this colors only from momma. Although kittes DO tend to get colors from momma.

Blue isnt a real color; its diluted black... And thus, the solid blue Russian Blue, if they are mixed out, their mixed kittens tend to be black....


Its common tabbies have spotted belly. So this doesnt hint anything.
But if the kitten has visible shadows of rosettes; real or even ghost, the probability is high he has an Ancestor.
 
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Rayn89

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Well, any information I can find states that male kittens only- get 100% of their color from their mother 100% of the time. Female kittens have a 50/50 chance to inherit colors or combinations thereof from either parent. It has to do with the X Y chromosomes and how may copies they get for coloration. It's hard to find super-in depth information on this subject but as another user stated that if the female carried for dilute but the male wasn't dilute then the male kitten could be a dominate. If so, then the male does to some extent influence color of ale offspring, at least at the dilute/non-dilute level.
 
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Rayn89

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Update- I also found this. 'A (non-silver) tabby must have at least one parent that is either a shaded or a tabby. A silver tabby must have at least one silver tabby, shaded or smoke parent' - Basic Feline Genetics – The Cat Fanciers' Association, Inc (cfa.org)

The torbie female that birthed the silver tabby male and the darker blue tabby male kitten is not silver but brown.

I hope someone with very comprehensive and in-depth knowledge on this subject will see this and hop on at some point..
 

LunarFlower

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LunarFlower LunarFlower - someting for you to bite on? :)
I’ll chew on it today and will chime in when I get a chance. In the meantime, it would be extremely helpful to have pictures of all of the cats in question (and littermates/parents if possible) and very clear distinction made as to the exact relationships among all of them.

Cinnamon is very much not common; there may be some confusion as to the parents’ base colors. I know at the very least there is confusion as to the concept of the color cinnamon going on; cinnamon is NOT a dilute, it’s a mutation of black that has nothing to do with dilute. The dilute of black is blue.

Clear photos in as neutral of light as possible would be helpful @Reyn89 .

Thank you!

Edit: by the way, the ONLY major part of cat coloration that is sex-linked is whether or not there is orange/cream. Dilute, tabby, silver, etc. are affected by both parents. I’ll go into more detail later.
 
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LunarFlower

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Okay, this might be long. I'm going to give a genetic breakdown of the cats described and the most likely way this could work; then I'm going to write up a short crash course on cat color inheritance. I can also talk about pattern inheritance if needed, but I'll leave that up to you.

Assuming that your descriptions of the cats are correct, we can infer the following:

Mom 1 is a Cinnamon Point, meaning she has two copies of Cinnamon, two copies of colorpoint, no orange, and no agouti.

Dad 1 is a black tuxedo, meaning he has at least one copy of black, at least one copy of white spotting, no orange, and no agouti.

Kitten 1 (Binx) is a male black tuxedo, meaning he has at least one copy of black (which he can get from dad) and one copy of white spotting (which he can also get from dad)... so far so good. He doesn't inherit orange because mom doesn't have orange to pass down, and dad's full color black is dominant to cinnamon, leaving him solid black with white - aka, a black tuxedo. Bingo. Believe it or not, this is the least problematic kitten out of the lot genetically.

Kitten 2 is a blue classic tabby male; this is where the problems start to come in. In order to have a tabby, at least one parent must have agouti. Neither mom nor dad has agouti, so this kitten cannot have come from our assumed parents. Either she had kittens from more than one male (which is extremely common if she had any access to multiple intact males) or the descriptions of the parents is not correct.

Kitten 3 and kitten 4 are blue tortoiseshell females. Here is the other problem; in order for the girls to be tortoiseshells, the cream (dilute red/orange) must have come from somewhere... and it's not mom and it's not our assumed dad. The fact that the girls are tortoiseshells proves that mom mated with multiple males or the descriptions of the parents is incorrect. In order to get blue tortoiseshells from a cinnamon point, the father must have been a red-based cat carrying dilute or a cream based cat, and mom must be at least a carrier of dilute (which is a possibility.) Dad's genetics must also carry at least one copy of black, which would be covered up by his orange.

In order for any of the kittens to be dilute, mom must be a carrier of dilute, though she is not dilute herself. This works well, but not with the male described. I believe there to be at least two fathers to the litter - one tuxedo and one orange.


Now the more recent litter:

Mom number 2 is described as a brown tabby tortoiseshell... this is a minor problem, because brown tabby is not a genetic term. What you are describing is either a black based tabby tortoiseshell or a chocolate based tabby tortoiseshell. The way to tell the difference is to look at the darkest area of fur on the cat; if it is black, it is a black-based tabby; if it is brown, it is a chocolate based tabby. For her to be tortoiseshell, she has one X coding for red/orange, and one X for non-red/non-orange.

If I'm reading your post correctly, dad number 2 is one of the blue classic tabbies from the first litter described? If so, he has one copy of black, one copy of cinnamon, two copies of dilute, one copy of agouti, and his tabby pattern is classic. Great; we have some genotypes and phenotypes to work with.

Kittens 1 and 2 are blue classic tabbies like dad. This works because they inherited the X chromosome carrying the "not orange" allele from mom, (but could just as easily have inherited the "orange" allele... it was random chance that they wound up with this one.) Mom must have also been a carrier of dilute, and they happened to both inherit her dilute allele alongside either of dad's dilute alleles, making them both blue. They could have inherited the agouti allele from either or both parents, because both parents are tabbies. They inherited the classic pattern, which means mom is either a classic pattern herself or is a carrier of classic.

Kitten 3 is a male tabby that looks like mom but without the tortoiseshell. This is good. He also inherited the X with the "not orange" allele, but did not inherit mom's dilute allele, making him a full color. He is a carrier of dilute, though. If his tabby pattern is not classic, then it would likely be mackerel and coming from mom, making her a mackerel carrying classic.

This litter makes total genetic sense to me.


Now, how does this all work? There is a misconception that male cats inherit ALL of their color from mom; this is not correct. The main thing they inherit from mom is the gene on the X chromosome that determines whether they have orange (generally called red) or not.

Color inheritance in cats follows a hierarchy of genes and effects that cover each other up or work together to make the cat's total appearance. There are more genes than I have time to list here, so I'll cover some highlights and you can ask questions if you need clarification. It's going to get technical, so I apologize in advance. If you are breeding cats, it is good to know this, even if it is a bit confusing.

1.) Dominant white. Like the name suggests, dominant white makes for completely white cats if they carry a single copy of this allele. It doesn't matter if mom has it or if dad has it, as long as one copy is inherited, the kitten will be white. (In some cases they can have a tiny smudge of color on their heads, but generally it blocks all color completely. It also can cause deafness, so breeding these cats should either not be done at all or only be done by someone who is responsible and can take care of the kittens if they are born deaf).

2.) White spotting. This is a gene that causes patches of white to appear on the body. It does not cause deafness. If one copy is inherited, the kittens usually have less than 50% of their body white, if two copies are inherited, the kittens usually have more than 50% of their body white. There are lots of genes and alleles, some of which probably aren't known yet, that affect the distribution and amount of white. It is possible for there to be a solid white cat that is "completely white-spotted", as well as a cat that seems to not have any white but is secretly a white-spotting cat that just doesn't show it. Usually, the white is noticeable, though.

3.) Other white. There are some polygenic and developmental things that can cause small amounts of white to appear on cats that don't carry the white spotting gene. Usually this is a small white locket on the chest, though that can also be from white spotting, so care must be taken when trying to determine the cause of small amounts of white.

4.) X-linked red. THIS is the one you are probably looking for and thinking of. There is a gene on the X chromosome that determines if the cell is going to show a red- based color (orange and cream) or not be able to show a red-based color (showing whatever color is underneath). Red/orange/cream takes precedence over all non-white base colors. It can cover up black, chocolate, cinnamon, blue, lilac, etc. Because male cats inherit their only X chromosome from mom, it is one of HER X chromosomes that determine if he can produce red or not. IF he gets an X that can produce red, he will be some orange-based color (orange,cream,flame-point, etc.) If he inherits an X that does not allow production of red color, he will be one of the black-based colors (black,blue,chocolate,cinnamon,lilac,seal point, etc.)
Female cats inherit their father's only X chromosome, plus an X from their mother. If both match, they will be non-tortoiseshell. If they do not match (one red and one not-red), they will be a tortoiseshell-based color (tortoiseshell, calico, tortie point, etc.) This is because during development there is a process called X-inactivation; basically, each cell during a certain period of development randomly shuts off one of the X chromosomes, leading to a patched appearance.
Calico is caused by the interaction between tortoiseshell and the white-spotting gene. In cats that show a large amount of white, the patches of black and red are usually broken up into larger patches and are less mixed together; this is what people commonly call calico. There is no known genetic difference between a tortoiseshell with white and a calico, however, so this distinction is merely descriptive of appearance and not genetics.

5.) Black. Black is what you can think of as the default for most cat colors. Some cats carry a mutated version of black that changes the appearance of the coat to a dark brown instead of black - this is Chocolate. Some cats carry yet another mutated version of black that causes an even lighter appearance - this is Cinnamon. All three colors are alleles of the same gene. Black is dominant to Chocolate which is dominant to Cinnamon. In order to have cinnamon, both inherited copies must be cinnamon. In order to have chocolate, at least one copy must be chocolate and the other copy must be chocolate or cinnamon, and in order to have black, at least one copy must be for black. Black is by far the most common version of this gene, with chocolate and cinnamon being very uncommon in the general population (but still there.)

6.) Dilute. Dilute is a completely separate gene location that modifies the vibrance of the other coat colors. It turns black into blue, chocolate into lilac, cinnamon into fawn, and orange into cream. It also turns black tortoiseshells into blue tortoiseshells, etc.

7.) Other tone modifiers: There are a LOT of other genes and polygenes that modify the fine-tuning of the coat's exact color and different effects that can be seen. I'm not going to cover them, but they are interesting if you want to do the digging. Some examples of these effects are caramelization, amber, russet, etc. They are mostly seen in rare purebreds, so they don't appear in the general population often. Just be aware that they exist in case you ever get something really *weird* color-wise. There are some genes and coat color effects that are not identified yet. New mutations can also crop up from time to time, leading to entire new colors and patterns we currently are unaware of.

Those are the color basics; let me know if you want me to go into patterns like colorpoints, tabbies, silvers, or any other specific genes or alleles. I'll be happy to elaborate if I can. I am also happy to answer any questions you may have. I know this was a lot of jargon, so feel free to ask for clarification.
 

LokiLamia

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I am fascinated. Thank you for taking the time to do a TED Talk for us. I will surely attend the next. 😃
 
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