#tabby patterns

Aiming to improve silver bengals, in this program an outcross line was created with egyptian mau and american shorthair. It's a great opportunity to analyse the inheritence of rosettes!

Half-bengal Aeon (bengal x mau) on the left has some rosetting effect: i'd say he has blurry, multicolored spots. (However, I notice that the arrangement of the spots is closer to that of a bengal than to mau.)

Fusion (american x (bengal x mau)) has a very interesting pattern, but decidedly not rosetted.

The rosettes are back! They are a little full, formless and inorderly, but indeniably rosettes.

The two alleles of the ticked gene are ticked (Ta) and not ticked (ta), with ticked being dominant. As a cat isn’t solid, this supersedes any other tabby pattern a cat could have. Mackerel is actually a dominant trait (Mc) over classic (mc), but because that’s a different gene, a ticked cat can have the genetics for mackerel without actually carrying mackerel (as I consider carrying to refer only to recessive alleles being covered by their dominant counterpart.)

Sorry if I'm asking for too much, but my brain just doesn't get it. It's always better when someone explains something directly to me rather than just some random article that uses confusing terms for beginners.

(Also, are there some letters for some of these?? For example, MC/mc, D/D, etc. Or are all of them polygenetic?? I just need a simple explanation. You don't have to worry about it.)

1. Charcoal

Charcoal comes from the agouti allele of the leopard cat (Prionailurus bengalensis) called APb, so it's allelic with tabby A (Felis catus agouti) and solid a. For this reason i usually reserve the term 'tabby' for A_ cats, and call Apb_ just 'charcoal' (as opposed to 'charcoal tabby').

A is pretty much dominant over Apb, so A/Apb cats look regular tabbies.

A standard, dark faced, dark patterned charcoal is usually Apb/a genetically, but even Apb/Apb can and usually does look darker than A/_, sometimes even as dark as an Apb/a - these homozygous cats are sometimes called 'double charcoals'. Another, rarely used but in my opinion more fortunate terminology is 'midnight charcoal' for Apb/a and 'twilight charcoal' for Apb/Apb. (It reflects the level of darkness more intuitively.)

Apb/Apb, Apb/a, a/a (vö rosetted tabby below)

Charcoal is simply an agouti allele and as such, it's independent of any other gene, and can be combinated with all cat colors, including every patterns from blotched to servaline.

2. Rosetted, braided, marbled

I haven't found actual proof of this, but very likely these are all caused by the same modifier(s), from respectively the spotted, mackerel and blotched pattern. This hypothetical modifier is sometimes called the bengal modifier because rosetted and marbled are both bengal-specific patterns, and braided is the characteristic of toygers, a breed originating from bengal/domestic cross. The fourth installment of the series would be servaline (modified ticked).

servaline, ticked, rosetted, spotted, braided, mackerel, marbled, blotched

There's no gene yet associated with this modifier. I'm thinking it's probably fairly intermediate (and/or additive polygenic), because bengal crosses are often 'kind of' rosetted.

3. Sokoke

Sokoke is a rare breed with an unique pattern: very overticked blotched tabby. (This means there's little-to-no true solid black in the coat, even the darker parts have some agouti banding.) I don't think there ever were any genetic explanation for this pattern (although i think it can be an extreme form of the chaos polygenes (which themselves are hypothetical too, but you know. It makes sense to me)).

Yes, every kind of tabby pattern exists with reds. The orange-agouti epistasis just reveals what a nonagouti cat carries, doesn't affect the pattern itself.

I think right now there is no real consensus on the interaction of spotted and blotched. For example Kaelin & Barsh vote for "no effect all", and puts down mackerel as the tabby (Taqpep/LVRN) genotype of spotted:

Hartwell (of messybeast) thinks it does affect it, or at least a spotting modifier which does exists: "Spotted tabbies can be due to broken mackerel stripes (in which case the spots are not so rounded) or to a spotting gene. The spotting gene breaks up the underlying mackerel or classic tabby pattern into spots."

Personally, when this topic comes up, I always have to think of bengals.

Look at that curve of spots on the first one next to the spine, and that one long rosette on the next in the same position. I can't help but feel like the lines of the blotched pattern are there. Auh, I don't know. "Every bengal is genetically blotched but some have a spotted modifier thus rosetted" and "every bengal has the spotted modifier but some are homozygous blotched thus aren't affected" are both equally valid and sound models, but something pulls me toward the former.

I found some statistics in the supplementary materials of this paper: the authors tested 16 bengals for taqpep alleles and found one at 0.5 frequency.

...All right, that's a little confusing. 50% feels too much compared to the prevalence of marbled (although they didn't disclose the pattern of the cats, so it's possible they just had that much marbleds and carriers by accident or by choosing related animals), and too little for "every bengal is blotched under the rosettes". Maybe there are more, unkown and untested alleles?

AND WAIT A MINUTE!

"Pattern phenotype of F. nigripes, which resembles the atypical swirled pattern observed in domestic cats that carry the T139N allele (Fig. S2). Nine of nine F. nigripes individuals were fixed for 4 species-specific variants (T82K, H87P, E488K, F950V)." Black-footed cats seem to be genetically kind of blotched and phenotypically spotted! So a blotched-type pattern breaking up into spots is indeed possible.

A few more remarks: famously spotted breeds egyptian mau and ocicat both have a relatively high taqpep mutation frequency here (0.32 and 0.6 respectively). To me this suggest their spotting gene affects genetically blotched cats too.

...And now i looked into ocicats and found they have a sister-breed called aztec with a classic tabby pattern according to GCCF. If ocicat, too, has 60% allele frequency of blotched, that suggests the main difference between ocicat and aztec isn't mackerel vs blotched but a spotting modifier. (What's more, this ocicat breeder says not only the spotted modifier of ocicats affects blotched, but actually the mackerel allele has been completely eliminated from the breed.)

Ocicat. If you want to, you can imagine the blotched "bullseye" into the arrangement of the spots. At least I can 😆

All right, this starts to get long, and i know i won't be able to draw any real conclusions in the end. So.

Blotched is complicated*, spotted is even more complicated**, we don't know.

*several alleles that don't necessarily have the same interaction with spotted;

So, according to Carol W. Johnson who coined these terms in her article (Genetics of the shaded american shorthair (and striped tabbies, too!) - certainly a very interesting summary, i recommend reading it if you're interested in the topic), they are both (theorised) modifiers that determine the "clearness" of the tabby pattern.

According to this, the chaos gene(s) would be responsible for the sharpness of the division between agouti and colored hairs: background and pattern; to my understanding this is what could cause the difference between these two cats, for example:

Both of them are black blotched tabbies.

Patterned tabbies are bred for least possible chaos; for shaded and presumably non-wideband ticked too, chaotic pattern is desirable to obscure any breakthrough ghost markings.

The confusion gene(s) on the other hand would make the agouti banding on individual hairs unpredictable. Some hairs have one band, some have three, some none (either being completely dark or completely light).

Illustration from the article, and some agouti fur - this one seems pretty even, "not confused".

Standard ticked tabbies are bred for the least possible amount of confusion, but for shaded, a more "confused" banding is usually desirable: gives the cat a "sparkling" effect and an overall lighter impression.

Eh, i'm not sure there's a 'proper' definition here. It probably just means a kind of speckled pattern: small dots, somewhere between spotted and ticked, without taking into account how that pattern is produced. It has been seen mostly in hybrids, but i'm sure if a pattern like that would turn up in a 100% Felis catus cat, it'd be called servaline too. (Like i'm pretty sure marble tabby is used for plain blotched sometimes, and then let's not even start to get into what's being called golden. Cat breeding is not exactly always scientifically accurate and that's just how it is.)

Poljun is a mix breed between bengal and chausie. It's servaline pattern is likely the result of the bengal modifier.