<qa>  What is the approximate gene abundance assessed using real time PCR?12 The relative gene abundance will be assessed using real time PCR. Conventional PCR reactions will be used to generate gene-specific amplicons used as template DNA standards for qPCR. Amplicons will be purified using a gelPCR extraction kit QIAquick PCR Purification Kit Qiagen, USA and quantified fluorometrically using a Quant-iTTM PicoGreen dsDNA Assay Kit Invitrogen. The number of DNA molecules will be calculated based on the size and mass of the amplicons. Tenfold serial dilutions of the amplicons will be prepared and used following the procedure by Yu et al. 25. 