First we need to just restate what is in fact not stated that often, that the wild cats have tabby coats. And the classic moggie tabby we see all time has the same gene that creates the tabby coat that is carried by the glamorous Bengal wild cat hybrid and the rare designer cat the Toyger (toy tiger).
I think it is also worth saying that genetics are very complicated and news items about genetics don’t explain things fully. Maybe it’s because they can’t. It is sensible to treat all this information with a bit of caution. That said….
Gestation (pregnancy) in domestic cats is 63-65 days. At about 49 days of gestation the hairs on the embryo start to form. At this time a recently identified gene that the scientists have called Taqpep dictates the pattern by working in tandem with another gene Edn3.
What might have been standard tabby stripes (mackerel tabby coat) are transformed into blotches and swirls which are called classic tabby coats by cat fanciers and breeders.
This happens when the Taqpep gene, which would have created a mackerel tabby coat, is turned off by a mutation. The result is the classic tabby pattern you see in the lower picture on this page.
It seems, then, that the “default tabby coat” is the mackerel (striped) pattern or perhaps the spotted tabby. When the gene that produces this pattern is not allowed to work the pattern turns to blotches. Of course the spotted tabby is a version of the mackerel tabby really. A broken line becomes spots.
You have probably guessed but a cat with the striped pattern is called a “mackerel tabby” after the mackerel fish. We have to admit, however, that most mackerel tabbies have broken stripes. They are rather faint and sometimes border on spots.
The mackerel tabby cat in the picture on this page is a heavily selectively bred designer cat called a “Toyger”. The Toyger is meant to have well defined stripes like a tiger. The Sunquists in their acclaimed book on wild cats Wild Cats of the World say the tiger is the only striped cat. I have always found that comment interesting because mackerel tabby domestic cats are around in their millions.
In respect of wild cats, it seems that what would have been cheetah spots are transformed into king cheetah type joined up spots which are in between spots and blotches.
Source: Newspapers! Science Mag and me.