Cloning and Analysis of Reverse Transcriptase of Ty1-copia-like Retrotransposons in Petunia

Using degenerate oligonucleotide primers corresponding to conserve domains of Ty1-copia retrantranspon reverse transcriptase,fragments about 260 bp were achieved by PCR amplification from petunia( Petunia hybrida Vilm.),the amplicons were sequenced and analyzed to obtain twenty-four sequences of reverse transcriptase. The result showed that the lengths of twenty-four sequences of reverse transcriptase varied from 260 to 272 bp,homology ranged from 49. 8 % to 97 %,and these sequences were classified to seven families by using nucleotide cluster method. Ty1-copia retrantranspon reverse transcriptases exhibited high heterogeneity on its sequence length and nucleotide composition,which was translated into amino acids,eighteen sequences were integrated,while stop codon and frameshift mutation appeared in other six sequences. Stop codon mutation and frameshift mutation were importantly heterogeneouse performances of Ty1-copia retrotransposon in pentunia. The homology analyses result of reverse transcriptase from petunia with other plant species' indicated that some of them had high homology and probably had same origin.