摘要
A new method is presented with which we isolated milochondrial DNA from fresh carp liver usingdifferential centrifugation and DNase treatment that gave high yield of purified product with an easyand economical procedure. Highly distinct bands were displayed in agarose gel electrophoresls ofthe product digested with restrictlon enzymes, which were successfully used in constructingrestriction map and molecular clone of mitochondrial genes. With DNAs thus obtained, we havecloned cysteine tRNA gene (tRNA^(Cys) gene) of carp mitochondria, determined the nucleotide sequenceof it and the light strand origin, and depicted the cloverleaf secondary structure of tDNA^(Cya) and thelight strand origin. Analysis of nucleotide sequences of tRNA^(Cy) genes of 5 vertebrates has revealedunusual features of carp mitochondrial tRNA^(Cy) gene as compared with their cytoplasmic counter-parts, Altogether 36 bases were found in the light strand origin of carp mitochondriaf: 11 pairs in thestem; and 14 bases in the loop. As compared with those of other 11 vertebrate species, the sequenceof the stem is very conservative while both sequence and length of the loop are quite variable. Thestructure of the stem-loop may play an important role in light strand replication.
A new method is presented with which we isolated milochondrial DNA from fresh carp liver using differential centrifugation and DNase treatment that gave high yield of purified product with an easy and economical procedure. Highly distinct bands were displayed in agarose gel electrophoresls of the product digested with restrictlon enzymes, which were successfully used in constructing restriction map and molecular clone of mitochondrial genes. With DNAs thus obtained, we have cloned cysteine tRNA gene (tRNA^(Cys) gene) of carp mitochondria, determined the nucleotide sequence of it and the light strand origin, and depicted the cloverleaf secondary structure of tDNA^(Cya) and the light strand origin. Analysis of nucleotide sequences of tRNA^(Cy) genes of 5 vertebrates has revealed unusual features of carp mitochondrial tRNA^(Cy) gene as compared with their cytoplasmic counter- parts, Altogether 36 bases were found in the light strand origin of carp mitochondriaf: 11 pairs in the stem; and 14 bases in the loop. As compared with those of other 11 vertebrate species, the sequence of the stem is very conservative while both sequence and length of the loop are quite variable. The structure of the stem-loop may play an important role in light strand replication.
基金
This work was supported by grant from National Foundation of Natural Sciences of China.
