Cells recovered from mating spots were resuspended in ice-cold DEPC-treated water, centrifuged at 1'000 g for 1 minute, the supernatant removed and cells snap-frozen in liquid nitrogen. Pellets were resuspended in 750 μL of extraction buffer (10 mM Tris-HCl, pH 7.5; 10 mM EDTA, pH 8.0; 0.5% SDS), mixed with an equal volume of acid-equilibrated phenol, and incubated at 65°C for 1 hour. The samples were cooled on ice and centrifuged at 16'000 g for 15 minutes at 4°C. The aqueous phase was sequentially extracted with phenol:chloroform:isoamyl alcohol (125:24:1; 77617-100ML, Merck, Darmstadt, Germany) and chloroform:isoamyl alcohol (24:1; 25666-100ML, Merck, Darmstadt, Germany), each using centrifugation at 16'000 g for 5 min at 4°C. RNA was precipitated at -20°C overnight using three volumes of absolute ethanol and 0.1 volumes of a 3M sodium acetate pH 5.2 solution, and recovered by centrifugation at 16'000 g for 10 min  at 4°C. The RNA pellet was washed with 70% ethanol pre-chilled to 4°C and re-suspended in DEPC-treated water. The RNA samples were further purified and subjected to DNAse treatment using the Monarch RNA purification kit (T2010S, New England Biolabs, Ipswich, USA), following manufacturer instructions. RNA samples were stored at -70°C until use. Truseq Stranded RNA