Neuronal Genomics Using Mouse Cloning with the Single Neuronal Nucleus

Brain system is composed of enormous numbers of diversified single neurons. Therefore assessing epigenetic and genetic regulation in the nucleus of single neurons is a new challenge for understanding neuronal commitment, differentiation and maturation. As differentiated neurons are, in nature, postmitotic, neither the genome nor its epigenetic modifications are easy to evaluate fully. The cloning of mammalian cells, which has been used mainly in the fields of assisted reproduction and regenerative medicine, can be applied to propagating the entire genome of single neurons. In addition, embryonic stem (ES) cells derived from embryos cloned from single neuronal nuclei provide an “eternal” resource for assessing the genetic content of individual neurons. Here, we discuss the possible genetic/epigenetic regulation of gene expression in the nuclei of single neurons, and the utility of cloning by neuronal nuclear transfer to assess the genomic constitution of the single nucleus of differentiated neurons during development. This use of cloning technology may be a fruitful approach for analyzing the entire genome of individual single neurons.