A. flavus is the major producer of aflatoxin, which is responsible for millions of dollars in losses in the world and for significant health issues in developing countries, and is the second leading cause of aspergillosis in immunocompromised individuals. Sequencing of A. flavus NRRL3357 showed that its 36-Mb genome contains 13,488 genes including the aflatoxin gene cluster. Here we describe our efforts to use the RNA-Seq technology to characterize the entire transcriptome of the species under conditions conducive to aflatoxin production. To that end, we sequenced cDNA fragments obtained from Poly(A)-enriched total RNA samples extracted from fungal mycelium grown under 3 conditions: (i) PMS medium, 29 C, 24h, no toxin; (ii) GMS medium, 29 C, 24h, make toxin; and (iii) GMS medium, 37 C, 24h, no toxin. Two cDNA libraries from each treatment were sequenced using the Illumina (SOLEXA) short-read technology. Over 5 Million 100 nt reads were sequenced for each cDNA prep, which were combined to generate a powerful high resolution map of the A. flavus transcriptome. In addition, we used the RPKM analysis to determine transcript abundance in the 3 mRNA samples. The analysis detected expression in at least 50 % of the genes for each condition and contributed to our understanding of the genetic basis of the aflatoxin regulation.
Full conference title:
10th EUROPEAN CONFERENCE ON FUNGAL GENETICS
- ECFG 10th (2010)