cDNA synthesis

The cDNA synthesis was performed using SuperScript Double-Stranded cDNA synthesis kit (Invitrogen, Carlsbad, MA, USA) with added random hexamer primers (Thermo Fischer Scientific, Waltham, MA, USA). The RNA used was extracted simultaneous with DNA of Mat1 using the MasterPure™ Complete DNA and RNA Purification Kit (Epicentre, Madison, WI, USA). The MinElute PCR purification kit (Qiagen, Hilden, Germany) was used for sample clean-up and concentration. The cDNA protocol was implemented using triplicate samples that were later pooled and concentrated using Eppendorf concentrator 5301 (Eppendorf, Hamburg, Germany). In total, 673 ng of double stranded cDNA, as measured by SYBR-Green quantification (Roalkvam et al., 2011) was subjected to pyrosequencing at the Norwegian Sequencing Center (Oslo, Norway) using the 454 FLX sequencer (Roche, Basel, Switzerland) with Titanium chemistry.