4. On an illegal wolf ranch in Wyoming, gray wolves are bred and sold illegally. A mutation was identified, generating a beautiful gray “speckled” coat color. The speckled wolves were particularly popular with buyers. The breeders struggled to keep up with demand. They noticed that when two speckled wolves were bred, their pups always contained some normal gray and some speckled gray pups. In one typical season of interbreeding the speckled wolves, they cumulatively generated 82 speckled and 38 gray pups. A. Use appropriate genetic symbols and give the genotype of a speckled wolf. (2 points) B. State a clear genetic explanation for the pattern illustrated Solution Merle is a pattern gene like the piebald gene and not a color gene. The effect of the merle gene is to change the base coat colorcausing lighter patches resulting in a speckled or mottled appearance to the base coat color. It may also affect the dark pigments of eyes and nose and it can occur with any color. The merle gene is not a dilution gene which dilutes the entire base coat color. A. Inheritance of Merle gene: Merle gene is dominant to non-merle (solid base coat). We know that dominant genes signified by a capital letters mask the effect of recessive genes signified by lowercase letters. Merle is signified by a capital M and non-merle by a lowercase m. A merle wolf only needs one merle gene (because it is dominant) to exhibit the merle pattern. The genotype of merle wolf would be written as Mm (heterozygous). A non-merle wolf would carry no merle genes and thus would “genetically” be mm. The major problems occur when two merle Mm are bred together. Mm (merle) × Mm (merle) M m M MM Mm m Mm m MM (homozygous) is double merle wolf. B. When two merle wolves (Mm) are bred together there is a 25% chance that they will produce a double merle wolves (‘lethal white’ MM) – a wolf that has two copies of the merle gene. The health consequences of these wolves vary from mild to severe. Some wolves may be born deaf, some born blind and some born deaf and blind. M M M MM MM m Mm Mm M m M MM Mm m Mm m.