OCCURRENCE AND TRANSCRIPTION OF GENES FOR NAD1, NAD3, NAD4L, AND NAD6, CODING FOR NADH DEHYDROGENASE SUBUNIT-1, SUBUNIT-3, SUBUNIT-4L, AND SUBUNIT-6, IN LIVERWORT MITOCHONDRIA

The genes encoding subunits 1, 3, 4L, and 6 of NADH dehydrogenase (nad 1, nad3, nad4L, nad6) in the mitochondrial genome of a liverwort, Marc hantia polymorpha, were characterized by comparing homologies of the a mino-acid sequences of the subunits with those of other organisms. The nad3 and nad4L genes are split by single and double group 11 introns, respectively. The 5'-half portion of the nad6 gene was repeated at an identity of 89% to form a reading frame consisting of 100 amino-acid residues. The Northern hybridization analysis showed that all four gen es are transcribed in the liverwort mitochondria.