Serial analysis of gene expression in Monascus aurantiacus producing citrinin.

OBJECTIVE: To construct a tag expression library of Monascus aurantiacus that could produce citrinin maximally on the thirteenth (0.966 mg/mL) day in the submerged culture. METHODS: Total RNA was extracted from the mycelium, cDNA was synthesized using the SuperScript choice system, and then, a SAGE library was successfully constructed according to the MicroSAGE method. RESULTS: Five hundred and ninety eight clones were obtained in SAGE library, and 120 clones were picked out randomly for identification and sequencing purpose. Eighty nine clones had positive inserts, 26 clones had no inserts and the remaining 5 clones had no site of NlaIII enzyme in inserts. There were seven repeated clones. CONCLUSION: With the aid of SAGE2000 software, 901 tags were obtained from 89 clones, representing 686 unique transcripts. Six unique tags of them belong to highly expressed genes (Number of tags > or = 10) and 143 unique tags to moderately expressed genes (repeat tags > or = 2).