Basic Genetics: Tabby patterns

Gene group Ta, T, tb
TICKING Gene Ta Gene Ta is responsible that a coat gets ticked. It is dominant over its alleles. Therfore gene Ta must be present only once to see its expression that the coat appears ticked. But note: Ta shows incomplete dominance. Refer to our discussion about the Ocicat; for an explanation of incomplete dominance see here.	Alleles	MACKEREL Gen T (Tigre) Gene T is dominant to gene tb. Your cat must have either TT or Ttb that its coat shows a mackerel pattern.	Possible gene combinations TaTa homozygous ticked TaT heterozygous ticked Tatb heterozygous ticked TT homozygous mackerel Ttb heterozygous mackerel tbtb homozygous blotched tabby Note that cats with a blotched pattern must be always homozygous for tb.
		BLOTCHED Gene tb Gene tb is recessive to gen T. That means, a cat must carry gene tb twice (tbtb) to show the blotched pattern.
All cats have genes for tabby pattern. Look at new born black or chocolate kittens, they show very often the tabby pattern they are carrying. A cat must carry at least one agouti gene A to show its pattern, with the exception of the red/cream cats which can show the tabby pattern without carrying agouti.		If you are interested to know which tabby colours are possible then klick here.
		Have a look also on the Crossing table for Tabby.

And where is the gene for Spotted ?

There is no special gene for Spotted existent. One hypothesis says that the Spotting is derived from the mackerel pattern. That seems to be true if you look on the spotted cats commonly known, like the European Spotted, British Spotted or Oriental Spotted, and it seems to be true when you think about the Egyptian Mau.
But when you look at the Ocicat the spots are arranged as there would be underlying the blotched pattern. Even in the standard of the Ocicat you'll find the description that the spots should be arranged as they would sorround a bull eye. It is also known that still from the Ocicats one can get blotched tabby Ocicats. The coat between the spotting pattern is ticked. Also the spots themselves are ticked. On this breed you can see the incomplete dominance of the gene Ta, as the Ocicat is ticked and at the same time shows spots.
When you look at the Bengals, you will find the same phenomenon, there are existing spotted Bengals and so called Marble Bengals (classic tabby blotched).
There is also another theory that a special group of genes (not a single gene, but a group) influences the way how the spots are arranged, more following a mackerel pattern or more following a blotched pattern.

Where can I find a ticked tabby cat ?

Usually well known are the Abyssinians and Somalis. At those breeds in their standard the most points are allotted that they must have ticking. You think that Abyssinians are not tabby cats, you are wrong. They are. When you look in their face, you still see the typical tabby markings, the "M" on the front, their eyes and nose leather are rimmed. They should show these tabby markings, but not more. When their colour is very intense, you will find sometimes also the necklaces and faint stripes on the inner side of their front legs. Those stripes are of course not desirable, preferred are cats without any stripes neither on their neck nor on their legs. Careful selective breeding has diminished the stripes on the Abyssinians and Somalis.
Another breed are the Oriental ticked tabby cats. Those cats must show faint stripes on their legs and their tail, while their body should not show any stripes but their coat is ticked.
A phenomenon are the Ocicats which have ticking as well as spotting. Even in their spots you'll find the ticking. It is still not known how the gene Ta is working with the spotting pattern. But this breed would make the theory that a group of genes are responsible for the spotting pattern more plausible.

How can this theoretical knowledge be used for the breeding practice ?

You want to breed Red Tabbies.

There you should try to answer the following questions first:

• Which cats do I need ?
  At least one of the parents must be a red (or red tabby with or without agouti) cat.
• If you have a red or red tabby cat, is it with Agouti or without Agouti ?
  You should study the pedigree of your cat very carefully, if there are any black tabbies (which carry at least one agouti gene) behind your cat. That would increase the chances that you have a red tabby cat with agouti.

In the following examples I assume that none of the following cats carries chocolate. Of course the examples will also work with chocolate, you will only need more columns and rows, if the cats are heterzygous for chocolate, as you'll have more combinations.

Example 1
You have a red female and you are searching for a male which would fit to get red tabbies. You don't know wether your red female carries agouti or not.
You can do a test mating with a black male. If your red (tabby) female gets tortie tabby kittens you are lucky that your female carries at least one agouti gene.

That was the worst case, because you still don't know if your female carries agouti or not. The little red/cream boys in this litter don't tell you anything more about your female, as they might be red/cream self or red/cream tabby with or without agouti.
Now you should mate the female with a black tabby male. In this litter at least you will get tortie tabby girls which carry at least one agouti gene and you should continue with your breeding program with one of the tortie tabby girls to come to red tabbies with agouti.

Here you are more lucky, as you get tortie tabby girls in this litter. Therefore you know that your female carries at least 1 agouti gene.
Now you can continue your breeding program in several ways:

1. You can mate your female with a black tabby male. In this 2nd litter you will get red tabby males with agouti and without agouti with the ratio 3:1. You can keep now one red tabby boy from that litter to back cross him to his mother. The chance is quite high that you kept a red tabby son with agouti and you will get now in this 3rd litter red tabby females with agouti.
2. You can keep a tortie tabby girl from your 1st litter (see above our Case 2) and cross this daughter with a black tabby male. The ratio of the red tabby boys you'll get from this 2nd litter is the same 3:1, 3 parts red tabby boys with agouti, 1 part red tabby boys wihtout agouti. You can keep here also a red tabby boy to use him to back cross him with his mother or to cross him with his grandmother - your red tabby female.
3. You keep a tortie tabby girl from the 1st litter to use her in a later crossing. You cross your female also with a black tabby male (like in alternative 1) and keep a red tabby boy out of this 2nd litter. This red tabby boy you may cross with his half sister the tortie tabby girl from the 1st litter or cross him back with his mother.
4. You can mate your female which turned out to carry at least one agouti gene with a red tabby male. But keep in mind that you might face here the same difficulties as with your female, that you don't know for sure, if the red tabby male carries agouti or not. You'll get out of this litter of course also red tabbies of both sexes, males and females.
   
   • If the red tabby male doesn't carry agouti only half of the red tabby boys and only half of the red tabby girls you get in this litter will carry agouti.
   • If the red tabby male carries agouti already 3 parts of the red tabby boys as well as of the red tabby girls you get in this litter will carry agouti.

These alternatives should demonstrate how you can increase the level of agouti, that you have more and more red tabby cats with agouti. It depends on you, which alternative you want to go.
In the 1st alternative you have to keep one cat and do inbreeding between mother and son.
In the 2nd alternative you have to keep two cats, but can use the boy from the 3rd litter twice, once to make an inbreeding between grandmother and grandson, second to make also an inbreeding between mother and son.
In the 3rd alternative you also keep two cats and can use the boy from the 3rd litter here also twice, once to make an inbreeding with his half sister (the black tortie tabby girl from the 1st litter) and second to make an inbreeding between mother and son.
In the 4th alternative you might reach your goal quicker, if the red tabby male you have chosen carries agouti.
How to testmate a red tabby male to find out if this male carries agouti or not leads us to our second example.

Example 2
You have a red tabby male, but don't know if he carries agouti or not.
We will cross him with a black female.

This was the worst case, but it shows immediately that your male doesn't carry agouti and you rather should use him for breeding red cats instead of red tabby cats.

In that case you know for sure that your red tabby male must carry at least one agouti gene, because you get black/blue tabby males and black/blue tortie tabby females in the litter.
To continue here with your breeding program to breed red tabby cats is easier than in Example 1 because less cats are involved. Now you can keep a black/blue tortie tabby girl and backcross her with her father. You will get red tabby cats (males and females) with agouti and without agouti in the ratio 3:1.

I've used the blotched pattern to show how to breed red tabby cats, but of course this will work with the other patterns ticked - gene Ta - and mackerel - gene T, too. But if the cats are not homozygous for one of those tabby patterns - as they must be for the blotched tabby pattern to show this recessive gene in their outfit - you will have various tabby patterns in the litter, mackerel, ticked and blotched.

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Last modified on  99-01-16