Cloning of Brn1, a reductase gene involved in melanin biosynthesis in Cochliobolus heterostrophus.

Phylogeny of Bipolaris inferred from nucleotide sequences of Brn1, a reductase gene involved in melanin biosynthesis.

“…position is identical to that reported for the B. maydis Brn1 gene (Shimizu et al, 1997). The amino acid sequences deduced from exons showed high homology throughout the entire region.…”

“…This secondary metabolite is theorized to be important to the survival of these fungal groups (Sussman, 1968). Several genes involved in the melanin biosynthetic pathway have been analyzed, especially 1,3,8-trihydroxynaphthalene reductase genes: THR1 in Colletotrichum lagenarium (Perpetua et al, 1996), ThnR in Magnaporthe grisea (Vidal-Cros et al, 1994), Brn1 in Cochliobolus heterostrophus (ϭteleomorph of Bipolaris maydis) (Shimizu et al, 1997). Amino acid sequences of proteins encoded by these genes showed high homology through the entire sequence.…”

Melanin Biosynthesis in the Maize PathogenCochliobolus heterostrophusDepends on Two Mitogen-Activated Protein Kinases, Chk1 and Mps1, and the Transcription Factor Cmr1

“…Subsequent steps are thought to involve a dimerization of 1,8-DHN molecules, followed by polymerization catalyzed by p-diphenol oxidase (16,32). The BRN1 gene encoding T3HN reductase has been isolated in C. heterostrophus (28). Genes involved in melanin biosynthesis, including the polyketide synthase (PKS1), T3HN reductase (THR1), and scytalone dehydratase (SCD1) genes, have been isolated in B. oryzae, a rice pathogen closely related to C. heterostrophus, and in C. lagenarium (10,11,23,30).…”

Molecular analysis and characterization of the Cochliobolus heterostrophus .BETA.-tubulin gene and its possible role in conferring resistance to benomyl.

“…The locations of exons and introns were deduced from interruptions in aa sequence homology with the btubulin gene of Septoria nodorum (Cooley and Caten, 1993) and confirmed by sequencing PCR products amplified from cDNA. Template cDNA was synthesized previously (Shimizu et al, 1997). Two primers, 5Ј-ACACCCCAAACCGCCATCATGC-3Ј and 5Ј-TG-GAAACCCTGGAGGCAGTCGC-3Ј, were used in the PCR amplification for mapping introns.…”

“…Construction of the genomic DNA library of C. heterostrophus was described previously (Shimizu et al, 1997). DH10B cells carrying the cosmids were plated on LB agar medium containing 50 ppm (w/v) kanamycin and screened by colony hybridization (Sambrook et al, 1989).…”