Chapter 12, Problem 18P

The first page of this chapter displays photos of Rainbow and her clone, CC. Both cats are tabby (their colored fur has a mottled pattern) and both have white regions, mainly on their bellies and legs. However, a major difference exists in their appearances. Rainbow is a calico tabby; she has black and orange spots controlled by alleles of the X-linked O gene, where the dominant trait is black (O-) and the recessive trait is orange (oo). However, Rainbow’s clone, CC, is a black tabby; she lacks the orange spots.

CC was made by transferring into an enucleated oocyte a single nucleus from one of Rainbow’s diploid somatic cells. That diploid oocyte, a mimic of a fertilized egg, was then implanted in the uterus of a surrogate mother. (The process of cloning by somatic cell nuclear transfer will be described in more detail in Chapter 18.)

a.	What is Rainbow’s (and CC’s) genotype for the O gene??
b.	Given that CC was made from a single one of Rainbow’s somatic cell nuclei, explain the difference between CC’s and Rainbow’s appearances.
c.	Would every clone of Rainbow’s c. be a black tabby like CC, or do other possibilities exist? Explain.