Spotted tabbies

[caterpillar]

Cindy and Lucy, my two sibling kittens, are spotted and striped brown tabbies. (But they seem to be getting greyer looking with the growth of longer hairs on their winter coats) I posted some earlier messages that alluded to them as possibly being part Mau cat at the Breeder's forum. One poster responded that they looked like pixie bobcats.

Genetically, how do tabbies become "spotted?" Cindy has this beautiful pattern of arrowhead like black spots on her sides and some scattered random spots on her legs, chest and face. Lucy's spots appear to be more dilute on her winter coat. Both kittens have the broken necklaces that describe Mau cats. Their Momcat, Dolly, was also a spotted brown tabby.

I surfed to some pixie bobcat sites and some pictures look like them, but my kittens don't have the kinked, short bobcat tails, although Cindy has a noticeable kink at the tip of her tail. They also seem to have larger, more prominent ears than the pixie bobcats.

Are spotted tabbies related to bengals?

Sorry for all of the questions. I'm just curious as to why some tabbies are spotted and some aren't.

 

[elizabeth a.]

One of the big problems with coat color genetics is that we use different words for the same thing and the same word for different things. "Spotted" is one of those words! We use it for patches of color (e.g., a calico is spotted with white, and that is indeed the name we give to the gene). But you're obviously using it in the other way, to describe the tabby stripes breaking down into "spots".
This has a genetic basis, but there's no specific information on it. Current thinking is that modifier genes are acting on the stripes to prevent them being continuous and to break them up. I have a suspicion that in some breeds, like Bengals, which originate from a species cross of the domestic cat with another feline species not its direct ancestor, we might even have introduced some new genes. But no scientific studies have been done to analyze this possibility.
Modifier genes are found in most breeds and a tabby could be spotted for no other reason than that she ended up with a lot of modifiers. If you don't know her family history in too much detail, though, then who knows what might be in the background?! Modifiers are the kind of genes that have very small individual effects on the phenotype, they act in a cumulative way.
Don't let the tail kink distract you as this shows up in a lot of breeds, for a lot of reasons. I've even heard of the stress of shows producing transient kinks!