In this article, we will talk mainly about the genetics of Wideband I will talk about what's called Nifty-silver or recessive shaded in another article.

Wideband is like silver a dominant trait, with dominant means that the cat only needs ONE copy of the trait for it to be seen. Simply explained if you see it, it's there if you do not see it it's not there, and there is nothing to be inherited by offspring either. But as with everything there are exceptions. Wideband will not show on a non-agouti, we will get into that later.

In this article, I will talk about the genetics of Silver shaded, Silvershell, Golden tabby, Goldenshaded, and Golden shell, as we know them from other breeds! I will also talk about some of my thoughts.

Let's first talk about the names, since this has been changed lately.

Chinchilla, the old designation for all cats with 1/8 tipping who were not red, it’s now called shell for all colors, earlier only red was called Shell.
Shell = WbWb (ems code: 12)
Shaded = Wbwb (ems code: 11)

For many years, a theory of an incompletely dominant wideband gene has been put forward, at least in our neighborhoods, as the cause of these colors. 
However, this theory has begun to be questioned by both researchers and breeders.

One of our most persistent researchers, regarding the color genetics of cats, Leslie Lyons, says that today the wideband gene is suspected to be recessive, so two copies of it are required for the trait to appear. But then we get to the question, IF now the wideband gene is recessive, then what makes chinchilla/shell? The theories are that we are talking here about polygenes and the selective breeding of the brightest cats. This theory might been triggered by the now-discovered Copper in BRI/BRL, which was in the beginning called recessive golden, now it's discovered that this is not wideband, but a completely different trait. This might also be the case in our MCO and might very well be the whole reason for people, including myself for a short while, believing that shaded/shell was caused by a recessive gene.

I have recently discovered that this is likely wrong, that shaded/shell in the MCO after all actually are dominant. What might cause us to believe otherwise is that there seems to be another trait in our MCO a fairly new trait. I will talk more about this in another article. 

What does all this mean? What is this really?
Well, wideband is a trait that widens the agouti bands on the hair, hence the cat must be agouti for this trait to show. You cannot see any bands on a solid black cat, right? 

From what it seems we have the wideband trait that turns wideband on or off, on = wider bands on the hairs, off = normal width on the bands on the hair.
But it's very, very likely, I would even say more or less certain that we also have to do with polygenes. Polygenes are present all the time giving our cats all kinds of different variations of the same trait. Just look at a classic tabby for example, with the same trait but we got classics with an extremely clear and vibrant pattern, others who are OK, and then we got terrible, terrible classics where we can see they are classics by the method of exclusion more or less. I strongly believe that polygenes will affect many aspects of the wideband cats some examples:

  • How pale or dark is the tipping
  • Visibility of the pattern
  • Spots on the belly
  • Unbroken rings on the legs
  • Uneven tipping

More or less any fault that we can see or any flaws in the wideband cats.


So then, what do we need to be able to get a silvershaded/shell or a goldenshaded/shell? 
Let's do some examples down below, if you have not already learned about agouti and silver, please go to those articles and make sure to learn about those two traits first.

AA or Aa Agouti The cat must be heterozygous or homozygous agouti for the trait to show
Wbwb or WbWb Wideband The cat must be heterozygous or homozygous for wideband (heterozygous gives shaded, homozygous gives shell).
II or Ii Inhibitor If also the inhibitor gene is involved the cat will be silvershaded or silvershell.

Let's show some examples, I will not go into test matings since this might complicate the understanding for those who are not very familiar with genetics.
Since it's not just one trait or even two traits but up to three different traits to take into consideration but I will show a couple of examples
I will use cats heterozygous for agouti in all examples but of course, it's the same with homozygous cats, I also use heterozygous silver in the silver examples, but of course, the color is the same if the cat is homozygous for the inhibitor gene, it's just the outcome of the offsprings that will be different.

Aa Ii Wbwb Silver shaded, heterozygous for agouti and heterozygous for silver and heterozygous on wideband
Aa Ii WbWb Silver shell, heterozygous for agouti and heterozygous for silver, and also homozygous on wideband
Aa ii Wbwb Golden shaded alternatively Golden tabby, heterozygous for agouti, without silver, but heterozygous on wideband
Aa ii WbWb Golden shell, heterozygous for agouti, without silver, but homozygous on wideband
Aa Ii wbwb Silver tabby, heterozygous for agouti and heterozygous for silver but do not have any wideband and will not be able to give that to any offspring.
Aa ii wbwb Non-silver tabby, heterozygous for agouti, without silver and do not have any wideband and will not be able to give that to any offspring. 
aa Ii Wbwb Non-agouti - Smoke, heterozygous silver, and heterozygous on wideband, this cat IS shaded but will not show since it's smoke.
aa ii Wbwb Non-agouti - solid black, red, cream, etc. heterozygous for wideband which means this cat IS in fact shaded it just won't show that since it's a solid cat.
aa Ii WbWb Non-agouti - smoke, heterozygous on silver and homozygous on wideband, this cat is a shell but will not be showing and will not be mentioned as such.


Now I'm certain some of you are thinking, what about golden tabby? Why are there golden tabbies and not any equivalent in the silver variations?
Well, this is a very good question. I got a theory but it's just my personal theory, but to me, it seems very logical and quite likely. 
That a golden tabby is just a Wbwb (wideband) with a very low amount of the polygenes that pushes the bands on the hair apart, and which would break the rings on the legs, the necklaces, and give the look of a shaded/shell.

Thinking this way we might realize something about the silver variations.

In a golden tabby we will see the bands on the hair all the way down to the root, in a silver tabby the first part from the root and up is hidden by the silver. Is it possible, that we do have a "hidden" wideband out there? It very well is!!!

Though I would like to issue a strong warning!!!

Please, remember those cats above will likely not give a clear, pale, nice good shaded if they would be wideband with a very low amount of polygenes.
If there would be wideband cats who are wideband but not really showing because of a lack of polygenes, those would give very poor shaded cats themselves, of course, they are a good start if you like to breed shaded/shell and you do have a lot of patience, since they do have the wideband gene and you would just need to slowly select for more silver, less pattern, less unbroken rings and so on. But also, please remember this is a theory!

I hope this makes it a little bit clear regarding shaded/shell in both silver and non-silver cats when it comes to genetics.


By: Malin Sundqvist

Dagdrivarn (