# Cinnamon and chocolate genetics



## Alaskacat (Aug 2, 2010)

Please can the genetics people give me some help as I am a bit confused on the cinnamon and chocolate genetics. I understand that they sit in the same place on the hair so are sort of the same - sort of. So you can't have both of them in one cat??

I have a cinnamon Siamese who I would like to mate with my lilac boy. I presumed that the kits would be choc or lilac and carry cinnamon but I am not sure. 

My confusion is that my girl is by a seal boy out of a chocolate girl, so the cinnamon must have been carried by chocolate (presuming the pedigree is correct). Also, my girls father, the seal point, has a chocolate father so must carry chocolate so how does she end up cinnamon?

I have a DNA sample for my girl already with Langfords so can easily test her (not sure what for though), but just wanted to clarify. She is definitely cinnamon.

Thank you


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## pipje (Jun 29, 2011)

cinnamon is recessive to chocolate. am typingthiswith my mobile so pardon the short reply


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## spotty cats (Jul 24, 2012)

Chocolate (or lilac) can carry cinnamon, a cat just can't carry both choc and cinn.

Lilac x cinnamon will give you lilac (if she carries dilute) or chocolate carrying cinnamon. 

Cinnamon as a recessive is 'forever'. Both your girls parents were carrying to produce her, or one parent was a carrier and the other cinnamon.


I have chocolate, lilac and blue that carry cinnamon. A tawny (seal) girl who could have carried chocolate or cinnamon, she carries chocolate.


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## lisajjl1 (Jun 23, 2010)

Hi,

I know how confusing the Cinnamon gene can be, has taken me over a year now to begin to understand how it works and particularly in relation to Chocolate! All those genes to contend with!!! There have been some ups and downs along the way...

I have found the following can happen....I have had what genetically proved to be Choc Point kittens who I would have sworn were Cinnamon from just looking at them and a cat who was just about a definite cert for Cinnamon carrying from her pedigree proving not to be!!! And thats only just the start of it...dont you just love recessives! 

Unless you can see the Cinnamon clearly running down in the pedigree on both sides, look for Oriental lines in there as in fact a real rarity in Siamese lines and may be a number of generations back so you might need to backtrack, then think it is always best to be absolutely sure she is Cinnamon by testing as this doesnt sound clear cut with no Cinnamon parent etc...if Langfords already have your swab I think is only a small fee for an extra test.

Can I just mention on subject of testing that as much testing as possible is needed to identify where PRA is present in Siamese and Oriental lines, a highly undesirable gene and accurately knowing a cats status may affect breeding plans once you know what you are working with. I have previously posted about PRA on other posts and always keen to raise awareness that testing is out there, easy to do and neccesary.....in fact a database is being collated to collect and record testing results and enable the data to be evaluated - if anyone has any PRA test results that havent already been submitted to this if you pm me will send you the email address they should be forwarded onto, confidentiality is assured. Sorry to deviate from original question from op but very important.

Hope this helps. : )


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## OrientalSlave (Jan 26, 2012)

You have one gene for the basic colour of the cat. It has three versions, black, chocolate and cinnamon. Black is dominant over choc & cin, and choc over cin. Could write it: B > b > b1 which is using the standard codes for these genes. B for black, b for chocolate and b1 for cinnamon.

All mammels have chromosones in pairs, so (except for XY) they have two copies of each gene, one on each chromosone. One from the father, one from the mother.

So, you start getting cominations. Bb, Bb1, bb1, bb and so on. It's not so clear as here I can't write b1 with the 1 as a superscript - a smaller raised number.

What matters are the colours of the different combinations - there are six of them:


BB = homozygous black. This cat will always have black/seal/brown kittens. Brown could be a brown tabby or brown burmese - both are genetically black.
Bb = black carrying chocolate
Bb1 = black carrying cinnamon (like my Lola)
bb = homozygous chocolate. Two of these cats will only every have chocolate kittens.
bb1 = chocolate carrying cinnamon
b1b1 = cinnamon

Your cinnamon MUST be b1b1. All her kittens will carry cinnamon, or be cinnamon.

Your lilac is either bb, or bb1. The Langford test should tell you which.

If he is bb then all kittens will be bb1 - chocolate carrying cinnamon. If he is bb1 then it gets more interesting...

You can draw a little square to help sort this out - it's called a Punnett squre:
Punnett square - Wikipedia, the free encyclopedia

You put the genes of one parent along the top in two columns, and of the other one down the left in two rows, then you fill in each of the four squares with the genes from the top and left, and you can see what colours you will get:


Capture by Sal Woo, on Flickr

(the red wiggly lines are Word complaining about the spelling!)

So *if* your lilac carrys cinnamon, you will get (on average - that gene fairy is always spinning her wheel of fortune) 25% homozygous chocolate, 50% chocolate carrying cinnamon, and 25% cinnamon.

Of course if the cinnamon carries dilute then lilac and fawn come into the equation...

I don't know what colour tests you have asked for. The ones I would do are for cinnamon for the lilac, and dilute for the cinnamon. I would have both tested for PRA (leads to blindness) as well which is a potential problem in some siamese and orientals. If you don't understand the results when you get them feel free to PM me or post them here.


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## OrientalSlave (Jan 26, 2012)

I see my post crossed with Lisa's. It was Lisa that alerted me to testing for PRA.


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## Alaskacat (Aug 2, 2010)

Thank you for all the replies. That makes sense about only carrying chocolate or cinnamon so one can be expressed and the other carried. I will take the advise and double check her colour and I can see if she carries dilute. I have attached a photo as she's not typey enough to show with GCCF so admit to having not had anyone else's opinion on her colour. 

My Siamese are already tested for PRA hence Langfords having her DNA on file. I have fed my results back.

I second the need to test. One of my cats has tested as a carrier so it is vital breeders test and mate accordingly. I do think breeders should be transparent about PRA and anyone buying a Siamese should ask for their status. Makes getting a Siamese from a BYB a very risky move, but I suppose that is the same for other breeds too. 

Thanks again for the clarification. Every day is a school day!!


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## we love bsh's (Mar 28, 2011)

Alaskacat said:


> Thank you for all the replies. That makes sense about only carrying chocolate or cinnamon so one can be expressed and the other carried. I will take the advise and double check her colour and I can see if she carries dilute. I have attached a photo as she's not typey enough to show with GCCF so admit to having not had anyone else's opinion on her colour.
> 
> My Siamese are already tested for PRA hence Langfords having her DNA on file. I have fed my results back.
> 
> ...


Shes pretty im glad I don't have to get my head around these colours just yet.


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