FIG. 3.

Analysis of growth and expression of the nor-1 promoter in transformant D8D3 and control strains. (A) D8D3 (•) and control strains of A. parasiticus, NR-1 (▵), NR-1/pSL82 (▿), and NR-1/pGAPN2B (□) were inoculated into an aflatoxin-inducing growth medium (YES broth). Mycelia were harvested at 24, 48, and 72 h after inoculation. A portion of each sample was dried for weight determination (milligrams per 100 ml of culture). For the control strains, the points on the graph represent data from a single culture. D8D3 was grown in triplicate and the error bars indicate standard errors. (B and C) Northern hybridization analysis of nor-1 and uidA transcripts. Thirty micrograms of total RNA was loaded into each lane. Each autoradiogram represents RNA isolated from mycelia after growth for 24, 48, and 72 h in aflatoxin-inducing medium. Blotted RNA was hybridized with a PCR-amplified 780-bp nor-1 probe (B) or a 1.7-kb amplification product of the uidA gene (C). The nor-1 transcript is approximately 1.3 kb and the predicted nor-1::GUS transcript is approximately 2.2 kb. This estimate is based on the size of the uidA gene in nor-1::GUS and the nor-1 transcription initiation and polyadenylation sites which are also included in the fusion.