[The nucleotide sequences of the heavy and light strand replication origins of the Rana catesbeiana mitochondrial genome].

The nucleotide sequences of the D-loop region, the light (L) strand replication origin and the seven tRNA genes of the Rana catesbeiana mitochondrial genome were determined and compared with their counterparts of other higher vertebrate mitochondrial genomes. The results obtained are as follows: 1) The D-loop region consists of 2,187 nucleotides and is flanked by the cyt b gene on the 5' end and by the genes for tRNA, tRNA, tRNAPA and tRNA on the 3' end. These genes are distinctly different in their organization from those in other higher vertebrates. 2) The overall sequence homology between the D-loop regions of Rana catesbeiana and other higher vertebrates is rather low. The sequences known as CSB-1, 2 and 3, and TAS, however, are found to be conserved also in the Rana catesbeiana mitochondrial genome. 3) The origin of the L-strand replication, which consists of 27 nucleotides, occurs in the middle of the five-tRNA gene cluster that is located between the genes for URF2 and CO I. The nucleotide sequence and potential secondary structure of this origin is very homologous to those in other higher vertebrates. 4) The seven mitochondrial tRNA genes of Rana catesbeiana show many structual features common to those of other higher vertebrates.