Gene or genome elements copy number is usually determined by the time consuming Southern blot analysis. In the study, a quantitative real-time PCR protocol was developed for the estimation of retrotransposon Cassandra copies number. Using the real-time PCR technique we have quantified the copies of internal domain of Cassandra in twenty-three Prunus domestica, L. accessions in a range from 25122 copies (Prunus domestica, L from Lipany region) up to the 188389 (Lutzelsachsenska). A conserved 18S rRNA gene was used for standard curve construction and for the calculation of the amount of DNA containing its single copy. Here, the absolute quantitation was prooved as to be suitable for routine analysis of retroelements number copies in plants. It provides fast, inexpensive and high-throughput alternative to the other used methods.
Key words: retrotransposon Cassandra, Prunus domestica, L., real-time PCR, number of copies