Figure 1.

Intraspecies somatic cell cloning, in which the inheritance of allogeneic (homologous) mtDNAs stemming from genetically different nuclear recipient oocytes and nuclear donor cells is still incompletely recognized during preimplantation development of nuclear-transferred pig embryos. In the vast majority of intraspecies (porcine) cloned embryos, mitochondrial genome primarily arises from the nuclear recipient oocytes, whereas in their other counterparts, mtDNA copies appear to be inherited heteroplasmically (i.e., both from nuclear donor cells and from recipient ooplasm).