Paternal inheritance of mitochondrial DNA in mice

Abstract

FOR nearly 20 years it has been assumed on the basis of low-resolution experiments that mitochondrial (mt)DNA, in contrast to the genes in the nucleus, has an exclusively maternal mode of inheritance in animals¹. Using the polymerase chain reaction^{2, 3}, paternally inherited mtDNA molecules have now been detected in mice at a frequency of 10⁻⁴, relative to the maternal contributions. These mice were hybrids between two inbred strains (C57BL/6J and Mus spretus) whose mtDNAs can be distinguished easily. This new mode of inheritance provides a mechanism for generating heteroplasmy and may explain mitochondrial disorders exhibiting biparental transmission.