DNA was extracted using the DNeasy Blood and Tissue Kit (Qiagen, Hilden, Germany) following the supplier’s instruction. For each sample, approximately lysis buffer ATL with 20 ul proteinase K (12 h at 56 ๐C) the DNA solution was treated with 100 ug ml-1 RNase A (15 mim at 37๐C) and the pellet and the pellet discarded after centrifugation (14,000 rpm for 3 min). Bffering conditions were adjusted and DNA was loaded onto the DNeasy Mini spin column. Total genomic DNA was eluted with 120 ul buffer AE, and stored at –20๐C until used. The concentration and purity of DNA were estimated using both Na noDrop ND – 1000 Spectrophotometer (Thermo Scientific, Wilmington, Delaware, USA) and 3 per cent agarose gel electrophoresis.