but most of these genes are recessive. This means that longhaired hybrid breeds usually have to have two longhair or longhair carrier parents, and the gene can also be passed on for many generations without being expressed. Wire Hair There are lots of variations of allele that would affect the dog's hair. The allele that causes bristles is actually dominant. Dogs with both the longhair and line coat genes will be "coarse," which means longer line coats of fur. Examples of such coats include the Korthals Griffon, and possibly the Irish Wolfhound. Nose colours The most common colour of dog nose is black. However, a number of genes can affect nose colour. A blue dog nose is genetically impossible. But greyhounds without the blue dilution gene are sometimes found. Therefore, a dog that appears to be "blue" may have a black nose and black eyes because it is actually a black dog with the gray gene, not a proper blue diluent. Sometimes the blues can also be so dark that their coats and noses look almost black. It's hard to tell if these dogs are black or blue. A "butterfly" nose is a bright pink patch lacking pigment on the skin of a dog's nose. The patches are randomly positioned and can cover any number of noses, from a tiny pink blob to almost the entire nose. Butterfly noses are sometimes seen on dogs with extreme white spotted patterns, but usually they are associated with meteorite coloration. The meteorite gene diluted the random portion of pigment in the hair and nose, forming gray areas in the hair and pink areas in the nose. Liver and Isabella's nose are usually very light, sometimes completely pink or bright pink, so the butterfly nose may not appear in the liver or Isabella meteorite color. "Dudley nose" is a dog with a loss of pigment on its nose. Typically, the pigment loss on Dali's nose is in the middle and spreads outward, covering almost the entire nose of some dogs. Dudley's nose will never completely lose its pigment, nor will it be as bright pink as a butterfly's or even a liver dog's. Dudley noses are common in blacknosed dogs and are particularly associated with the recessive red gene. Eye Colours The genes also affect the eye colours of dogs. There are two main types of eye colours patterns. Amber eyes All hepatic dogs