The walls of Aspergillus nidulans conidia contain a green pigment that protects the spores from d... more The walls of Aspergillus nidulans conidia contain a green pigment that protects the spores from damage by ultraviolet light. At least two genes, wA and yA, are required for pigment synthesis: yA mutants produce yellow spores, wA mutants produce white spores, and wA mutations are epistatic to yA mutations. We cloned wA by genetic complementation of the wA3 mutation with a cosmid library containing nuclear DNA inserts from the wild-type strain. The wA locus was mapped to an 8.5-10.5-kilobase region by gene disruption analysis. DNA fragments from this region hybridized to a 7500 nucleotide polyadenylated transcript that is absent from hyphae and mature conidia but accumulates during conidiation beginning when pigmented spores first appear. Mutations in the developmental regulatory loci brlA, abaA, wetA and apsA prevent wA mRNA accumulation. By contrast, yA mRNA fails to accumulate only in the brlA- and apsA- mutants. Thus, the level of wA transcript is regulated during conidiophore dev...
By reconstruction and expression of the full-length WA (NWA) polyketide synthase ofA. nidulans ba... more By reconstruction and expression of the full-length WA (NWA) polyketide synthase ofA. nidulans based on the revised wA gene sequence, its product was re-identified to be a naphthopyrone compound YWA1 instead of citreoisocoumarin and its derivatives, which were found to be products of C-terminus truncated WA polyketide synthuse. YWA1 shows yellow color and is considered to be a true intermediate ofA. nidulans asexual spore pigments. Thus, the wA gene is identified to code for a polyketide synthase of heptaketide naphthopyrone YWA1.
The WA gene cloned from A. nidulans which was assumed to code for polyketide synthase involved in... more The WA gene cloned from A. nidulans which was assumed to code for polyketide synthase involved in conidial spore pigment biosynthesis was expressed in a heterologous host fungus A. oryzae using starch inducible fungal expression plasmid pTAex3. The A. oryzae transformant produced starch inducible compounds, whose structures were identified to be citreoisocoumairn and its derivatives. Apparent heptaketide nature of these
The walls of Aspergillus nidulans conidia contain a green pigment that protects the spores from d... more The walls of Aspergillus nidulans conidia contain a green pigment that protects the spores from damage by ultraviolet light. At least two genes, wA and yA, are required for pigment synthesis: yA mutants produce yellow spores, wA mutants produce white spores, and wA mutations are epistatic to yA mutations. We cloned wA by genetic complementation of the wA3 mutation with a cosmid library containing nuclear DNA inserts from the wild-type strain. The wA locus was mapped to an 8.5-10.5-kilobase region by gene disruption analysis. DNA fragments from this region hybridized to a 7500 nucleotide polyadenylated transcript that is absent from hyphae and mature conidia but accumulates during conidiation beginning when pigmented spores first appear. Mutations in the developmental regulatory loci brlA, abaA, wetA and apsA prevent wA mRNA accumulation. By contrast, yA mRNA fails to accumulate only in the brlA- and apsA- mutants. Thus, the level of wA transcript is regulated during conidiophore dev...
By reconstruction and expression of the full-length WA (NWA) polyketide synthase ofA. nidulans ba... more By reconstruction and expression of the full-length WA (NWA) polyketide synthase ofA. nidulans based on the revised wA gene sequence, its product was re-identified to be a naphthopyrone compound YWA1 instead of citreoisocoumarin and its derivatives, which were found to be products of C-terminus truncated WA polyketide synthuse. YWA1 shows yellow color and is considered to be a true intermediate ofA. nidulans asexual spore pigments. Thus, the wA gene is identified to code for a polyketide synthase of heptaketide naphthopyrone YWA1.
The WA gene cloned from A. nidulans which was assumed to code for polyketide synthase involved in... more The WA gene cloned from A. nidulans which was assumed to code for polyketide synthase involved in conidial spore pigment biosynthesis was expressed in a heterologous host fungus A. oryzae using starch inducible fungal expression plasmid pTAex3. The A. oryzae transformant produced starch inducible compounds, whose structures were identified to be citreoisocoumairn and its derivatives. Apparent heptaketide nature of these
Uploads
Papers by Maria Mayorga