Mycosystema. 2013, 32(2): 253-260.
Two single spore unfruitful isolates, PYd21 and PYd15, were obtained from Volvariella volvacea CV. PY in Fujian Province. A hybrid heterokaryon, H15-21, was obtained by mating PYd21 and PYd15, and it could fruit normally. Using solexa genome analyzer platform, the genome of PYd21 was de novo sequencing; digital gene expression profiles of the mycelium including PYd21, PYd15 and H15-21 were sequenced respectively; a transcriptome containing equivalent mRNA of 8 samples including the mycelium samples of PYd21, PYd15 and H15-21, fruiting body samples of “pinhead” stage, and stipes of “button”, “egg”, “elongation” and “mature” stages from H15-21 were sequenced. Phosphofructokinase (PFK) genes were cloned and sequenced from both PYd21 and PYd15, and their structures were analyzed through paired-end mapping of transcriptional reads. Sequence alignment revealed both sequences to be identical, and PFK consists of 3,494bp with an open reading frame (ORF) of 2,457bp, encoding a polypeptide of 818 amino acids. PFK contained 12 exons and 11 introns, and the 5′UTR and 3′UTR were 281bp and 103bp long, respectively. One type of alternative splicing and 6 alternative splicing sites were identified during RNA processing. TPM (transcripts per million tags) values for PYd21, PYd15 and H15-21 were 71.08, 120.61 and 251.85, respectively, showing significant positive correlation to the growth rate of mycelium. The data indicated that the expression level of PFK gene in H15-21 had synergistic effect. The expression levels of PFK gene were confirmed by real-time quantitative PCR.
