Interorganellar gene transfer in bryophytes: the functional nad7 gene is nuclear encoded in Marchantia polymorpha.
The nad7 gene, encoding subunit 7 of NADH dehydrogenase, is mitochondrially encoded in seed plants. In the liverwort, Marchantia polymorpha, only a pseudogene is located in the mitochondrial genome. We have now identified the functional nad7 gene copy in the nuclear genome of Marchantia, coding for a polypeptide of 468 amino acids. The nuclear-encoded nad7 has lost the two group II introns present in the mitochondrial pseudogene copy. Instead, a typical nuclear intron is found to split an exon encoding the presumptive mitochondrial targeting signal peptide and the mature subunit 7 of NADH dehydrogenase. These results suggest that RNA-mediated gene transfer from the mitochondrial into the nuclear genome occurs not only in seed plants but also in bryophytes.
Kobayashi
Y
Y
Department of Agricultural Chemistry, Faculty of Agriculture, Kyoto University, Japan.
Knoop
V
V
Fukuzawa
H
H
Brennicke
A
A
Ohyama
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002467:Cell Nucleus / Q000235:genetics; D002478:Cells, Cultured; D008928:Mitochondria / Q000235:genetics; D008969:Molecular Sequence Data; D009245:NADH Dehydrogenase / Q000235:genetics*; D010944:Plants / Q000201:enzymology* / Q000235:genetics; D017386:Sequence Homology, Amino Acid
D009245:NADH Dehydrogenase