Dominant/Recessive Genes in Canines

[Erinesque]

I started thinking about this topic yesterday; I have a chug (chihuahua/pug), who looks like a small pug. I was bored last night, and started browsing on a pet finder website, looking at all dogs, of all ages, all over the country, and saw several other chugs, and noticed that some look like pugs, while others look like chihuahuas.

I had always assumed that the pug was a dominant gene, and chihuahua was recessive, hence why my chug, Emrys, looks the way he does. However, seeing other dogs with the same breeding as he has, has discombobulated me. Does anyone know the answer to this, when dealing with dog breeds, are any particularly dominant or recessive? This has got me wondering now!

[Nunavut Pants]

The breed characteristics are determined by a whole lot of genes, some dominant and some recessive, and more that are kind of both or neither. In fact, individual characteristics (e.g., size, or perky ears or floppy ears) can be determined by many genes, and the interactions between several others!

So it's not quite as simple as "chihuahua == dominant; pug == recessive". I've done some reading on cat colors on Wikipedia; there may be good reading on dog breed characteristics there as well.

[Seshat]

Despite the classic 'dominant/recessive' teaching we all get in science class in school, it's very rarely that clear-cut.

Look at skin colour. Human skin colours range from the near-transparent 'classic' Irish colouring, to near-pure-black.

But the 'in between' colours can be a near milky white, or a pink, a beige, an ivory. near-black shades are chocolate, reddish, dusty brown. Skin has so many varied hues - if we take the tint that's halfway between near-white and near-black we can see everything from a definitely reddish colour to very yellow colours to clearly neither - clearly brown, but not reddish or yellowish.

You just can't make that range with 'you have red or you have yellow'.

As it happens, we have genes that state how much we have of each of yellow-brown and red-brown melanins. And that doesn't include such things as piebalds ...

[Kittish]

Even in cases where it is a simple dominant/recessive gene pairing, you can get expression from both genes. Sweet peas are a good example. Red is the dominant gene for flower color, white is recessive. In plants with both genes, the flowers are pink.