brookcove
Posted : 3/14/2008 4:49:51 PM
Your geneticist is wrong, I'm sorry to say. This actually helps you out, of course, as it greatly broadens the breeds you can look to. The geneticist is also wrong about the ticking. I'll explain both below.
First, a recessive trait means both parents can carry the gene for the trait, but they won't have the characteristic (gene expressed) unless they are homozygous for it, or carry two genes (alleles, to be precise). So, you can have two dogs with a lower earset - say a pit bull type earset (or sighthound, or many other dogs which have the east-west type ears), but both of them have a single allele for erect ears. Their puppies can have many different earsets, because earset is controlled by many different factors (for instance, ear leather thickness is one of them). Erect ears can certainly result from this combination.
So there's lots of breeds that could have gone into your dog's genetics. Most natural random bred dogs in rural areas are something shepherdy, something retrievery, something herdy, something pittie/chowish, and something houndy. A shepherd would contribute two alleles for erect ears, allowing for a dropped ear parent (with a single erect ear allele) and a high probability that the pups would have erect ears.
All of these dogs are from a ***-eared/dropeared combination. In fact, both parents of the tri colored dog (the smallest one, to the left) were drop eared.
Now, the ticking is a bit more complicated. This is because ticking only expresses under certain circumstances. If your dog is genetically a "solid colored" dog, she can be genetically ticked, but since it only expresses in white areas, you wouldn't see any ticking. Add to that the fact that if one parent has a dominant gene, it doesn't mean all that parent's puppies will inherit the gene. It only means that any pup which gets the ticking gene, will have the potential to be ticked. But again, the gene requires white areas for expression and that's a seperate set of alleles.
I've seen cattle dog mixes that I knew were ACD mixes, that were solid colored. In the above picture, the dam of the three to the right, is as heavily ticked as the long haired pup to the far right. The sire of the tri colored dog was heavily ticked as well.