FIG. 4.

Gene expression and FB₁ biosynthesis in the wild type and FT536. (A) Northern blot analysis of the wild type and FT536 grown on cracked-corn medium for 8 days. Total RNA (15 μg) was electrophoresed in 1.2% agarose-formaldehyde gels, transferred to a nylon membrane, and hybridized with radiolabeled FCC1, FUM5, AREA, and TUB2. The molecular sizes of the transcripts are indicated on the right. rRNA, photograph of the ethidium bromide-stained gel. (B and D) FB₁ production by the wild type (♦) and FT536 (▪) grown on cracked-corn (B) and DL (D) media. Values are means and standard errors from three replicates. For points lacking error bars, the standard error was less than 10% of the value. (C and E) RT-PCR analysis of FCC1, FUM5, AREA, and TUB2 in the wild type and FT536 grown on cracked-corn (C) and DL (E) media. Day zero samples were from uninoculated corn (C) and wild type and FT536 grown for 4 days on YPD medium (E). The total RNA used as template for each RT-PCR was standardized before the reactions (2 μg/reaction). RT-PCR products were electrophoresed in a 1.2% agarose gel, transferred to a nylon membrane, and hybridized with radiolabeled FCC1, FUM5, AREA, and TUB2.