FIG. 2.

Characteristics of the norB-cypA region in different Aspergillus species. (A) Schematic diagram of the norB-cypA sequences of different aflatoxin biosynthesis gene cluster homologs. Thick arrows indicate coding regions and direction of transcription of norB and cypA. Gaps represent deletions of 32 and 854 bp in A. flavus NRRL3357 and AF13, and 1516 bp in A. flavus AF70 and A. oryzae ATCC12892, ATCC46244, and FRR2874 when the sequences are compared to the sequence of A. parasiticus in this region. Additional smaller deletions or insertions are marked by asterisks (11 bp in A. parasiticus NRRL2999 at bp 1166, 13 bp in BN008R, and 4 bp in A. nomius NRRL13137). The positions of oligonucleotide primers AP1729 and AP3551 are indicated by small arrows. (B) Agarose gel (1.0%) electrophoresis of PCR fragments obtained by amplification of different Aspergillus DNAs with primers AP1729 and AP3551. Abbreviations: AF, A. flavus; AP, A. parasiticus; AO, A. oryzae; AN, A. nomius.