Marchantia polymorpha mitochondrial orf identifies transcribed sequence inangiosperm mitochondrial genome

Heterologous hybridizations performed using nine Marchantia polymorpha mito chondrial orfs and the sdh4 gene against angiosperm mtDNA suggested that th ree of them and the sdh4 gene have been conserved in the mitochondrial geno me of different angiosperm species. Solanum tuberosum mtDNA fragments, whic h hybridized to M. polymorpha orf207 and sdh4 gene, were cloned, sequenced. and their expressions evaluated by Northern and RT-PCR. Hybridizing fragme nts to sdh4 gene and orf207 from potato mtDNA were shown to be transcribed. but only in the case of sdh4 gene was there homology between the protein e ncoded by the DNA sequence from M. polymorpha and the potato mitochondrial genome. M. polymorpha orf207 showed little similarity to an open reading fr ame from potato mtDNA, named here orf78. The putative proteins encoded by b oth orf207 and orf78 were not related, indicating that these orfs do not co nstitute homologous sequences. (C) 2001 Elsevier Science B.V. All rights re served.