Expression of imprinted genes in cloned mice

Genomic imprinting is a mammalian specific epigenetic modification of the genome. Assessment of the integrity of the imprinting memory in somatic cell cloned animals is important not only for understanding of the "reprogramming" process during cloning by nuclear transfer, but also for the applications of this technique for therapeutic cloning in the future. In this chapter, we summarize the analytical methods for assessment of monoallelic expression of imprinting genes and expression analysis. From a practical point of view, the authors suggest the use of intersubspecific F1 hybrids between the laboratory mouse (Mus musculus musculus) and the JF1 strain (Mus musculus molossinus). We also list the sequence for PCR primers to detect the polymorphism of imprinted genes between musculus and molossinus.