Synthesis of cDNA was carried out in 20 l reaction using Revert Aid TMH minus first Strand cDNA Synthesis kit (Fermen-tas, USA) following manufacturer’s instructions. Briefly, 11 l of the purified RNA were added to a mixture containing 4 l RTbuffer (5×), 1 l of random hexamer, 2 l 10 mM dNTP, 1 l RNa seinhibitor and l l of Moloney murine leukaemia virus reverse transcriptase.