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Ulrich Kück - One of the best experts on this subject based on the ideXlab platform.

  • genome wide identification of target genes of a mating type α domain transcription factor reveals functions beyond sexual development
    Molecular Microbiology, 2015
    Co-Authors: Kordula Becker, Christina Beer, Michael Freitag, Ulrich Kück
    Abstract:

    Summary Penicillium chrysogenum is the main industrial producer of the β-lactam Antibiotic Penicillin, the most commonly used drug in the treatment of bacterial infections. Recently, a functional MAT1-1 locus encoding the α-box transcription factor MAT1-1-1 was discovered to control sexual development in P. chrysogenum. As only little was known from any organism about the regulatory functions mediated by MAT1-1-1, we applied chromatin immunoprecipitation combined with next-generation sequencing (ChIP-seq) to gain new insights into the factors that influence MAT1-1-1 functions on a molecular level and its role in genome-wide transcriptional regulatory networks. Most importantly, our data provide evidence for mating-type transcription factor functions that reach far beyond their previously understood role in sexual development. These new roles include regulation of hyphal morphology, asexual development, as well as amino acid, iron, and secondary metabolism. Furthermore, in vitro DNA–protein binding studies and downstream analysis in yeast and P. chrysogenum enabled the identification of a MAT1-1-1 DNA-binding motif, which is highly conserved among euascomycetes. Our studies pave the way to a more general understanding of these master switches for development and metabolism in all fungi, and open up new options for optimization of fungal high production strains.

  • dicer dependent biogenesis of small rnas and evidence for microrna like rnas in the Penicillin producing fungus penicillium chrysogenum
    PLOS ONE, 2015
    Co-Authors: Tim A Dahlmann, Ulrich Kück
    Abstract:

    MicroRNAs (miRNAs) are non-coding small RNAs (sRNAs) that regulate gene expression in a wide range of eukaryotes. In this study, we analyzed regulatory sRNAs in Penicillium chrysogenum, the industrial producer of the β-lactam Antibiotic Penicillin. To identify sRNAs and microRNA-like RNAs (milRNAs) on a global approach, two sRNA sequencing libraries were constructed. One library was created with pooled total RNA, obtained from twelve differently grown cultures (RNA Mix), and the other with total RNA from a single submerged cultivation (∆ku70FRT2). Illumina sequencing of both RNA libraries produced 84,322,825 mapped reads. To distinguish between Dicer-dependent and independent sRNA formation, we further constructed two single dicer gene mutants (∆dcl2 and ∆dcl1) and a dicer double mutant (∆dcl2∆dcl1) and analyzed an sRNA library from the Dicer-deficient double-mutant. We identified 661 Dicer-dependent loci and in silico prediction revealed 34 milRNAs. Northern blot hybridization of two milRNAs provided evidence for mature milRNAs that are processed either in a complete or partial Dicer-dependent manner from an RNA precursor. Identified milRNAs share typical characteristics of previously discovered fungal milRNAs, like a strong preference for a 5' uracil and the typical length distribution. The detection of potential milRNA target sites in the genome suggests that milRNAs might play a role in posttranscriptional gene regulation. Our data will further increase our knowledge of sRNA dependent gene regulation processes, which is an important prerequisite to develop more effective strategies for improving industrial fermentations with P. chrysogenum.

  • members of the penicillium chrysogenum velvet complex play functionally opposing roles in the regulation of Penicillin biosynthesis and conidiation
    Eukaryotic Cell, 2013
    Co-Authors: Katarina Kopke, Birgit Hoff, Jens Kamerewerd, Sandra Bloemendal, Alexandra Katschorowski, Ulrich Kück
    Abstract:

    A velvet multisubunit complex was recently detected in the filamentous fungus Penicillium chrysogenum, the major industrial producer of the β-lactam Antibiotic Penicillin. Core components of this complex are P. chrysogenum VelA (PcVelA) and PcLaeA, which regulate secondary metabolite production, hyphal morphology, conidiation, and pellet formation. Here we describe the characterization of PcVelB, PcVelC, and PcVosA as novel subunits of this velvet complex. Using yeast two-hybrid analysis and bimolecular fluorescence complementation (BiFC), we demonstrate that all velvet proteins are part of an interaction network. Functional analyses using single- and double-knockout strains clearly indicate that velvet subunits have opposing roles in the regulation of Penicillin biosynthesis and light-dependent conidiation. PcVelC, together with PcVelA and PcLaeA, activates Penicillin biosynthesis, while PcVelB represses this process. In contrast, PcVelB and PcVosA promote conidiation, while PcVelC has an inhibitory effect. Our genetic analyses further show that light-dependent spore formation depends not only on PcVelA but also on PcVelB and PcVosA. The results provided here contribute to our fundamental understanding of the function of velvet subunits as part of a regulatory network mediating signals responsible for morphology and secondary metabolism and will be instrumental in generating mutants with newly derived properties that are relevant to strain improvement programs.

  • two components of a velvet like complex control hyphal morphogenesis conidiophore development and Penicillin biosynthesis in penicillium chrysogenum
    Eukaryotic Cell, 2010
    Co-Authors: Birgit Hoff, Hubert Kürnsteiner, Claudia Sigl, Ivo Zadra, Jens Kamerewerd, Rudolf Mitterbauer, Ulrich Kück
    Abstract:

    Penicillium chrysogenum is the industrial producer of the Antibiotic Penicillin, whose biosynthetic regulation is barely understood. Here, we provide a functional analysis of two major homologues of the velvet complex in P. chrysogenum, which we have named P. chrysogenum velA (PcvelA) and PclaeA. Data from array analysis using a ΔPcvelA deletion strain indicate a significant role of PcVelA on the expression of biosynthesis and developmental genes, including PclaeA. Northern hybridization and high-performance liquid chromatography quantifications of Penicillin titers clearly show that both PcVelA and PcLaeA play a major role in Penicillin biosynthesis in a producer strain that underwent several rounds of UV mutagenesis during a strain improvement program. Both regulators are further involved in different developmental processes. While PcvelA deletion leads to light-independent conidial formation, dichotomous branching of hyphae, and pellet formation in shaking cultures, a ΔPclaeA strain shows a severe impairment in conidiophore formation under both light and dark conditions. Bimolecular fluorescence complementation assays provide evidence for a velvet-like complex in P. chrysogenum, with structurally conserved components that have distinct developmental roles, illustrating the functional plasticity of these regulators in genera other than Aspergillus.

  • Homologous recombination in the Antibiotic producer Penicillium chrysogenum: strain ΔPcku70 shows up-regulation of genes from the HOG pathway
    Applied Microbiology and Biotechnology, 2010
    Co-Authors: Birgit Hoff, Ivo Zadra, Claudia Sigl, Jens Kamerewerd, Ulrich Kück
    Abstract:

    In Penicillium chrysogenum , the industrial producer of the β-lactam Antibiotic Penicillin, generating gene replacements for functional analyses is very inefficient. Here, we constructed a recipient strain that allows efficient disruption of any target gene via homologous recombination. Following isolation of the Pcku70 (syn. hdfA ) gene encoding a conserved eukaryotic DNA-binding protein involved in non-homologous end joining (NHEJ), a Pcku70 knockout strain was constructed using a novel nourseothricin-resistance cassette as selectable marker. In detailed physiological tests, strain ΔPcku70 showed no significant reduction in vegetative growth due to increased sensitivity to different mutagenic substances. Importantly, deletion of the Pcku70 gene had no effect on Penicillin biosynthesis. However, strain ΔPcku70 exhibits higher sensitivity to osmotic stress than the parent strain. This correlated well with comparative data from microarray analyses: Genes related to the stress response are significantly up-regulated in the Pcku70 deletion mutant. To demonstrate the applicability of strain ΔPcku70, three genes related to β-lactam Antibiotic biosynthesis were efficiently disrupted, indicating that this strain shows a low frequency of NHEJ, thus promoting efficient homologous recombination. Furthermore, we discuss strategies to reactivate Pcku70 in strains successfully used for gene disruptions.

Birgit Hoff - One of the best experts on this subject based on the ideXlab platform.

  • members of the penicillium chrysogenum velvet complex play functionally opposing roles in the regulation of Penicillin biosynthesis and conidiation
    Eukaryotic Cell, 2013
    Co-Authors: Katarina Kopke, Birgit Hoff, Jens Kamerewerd, Sandra Bloemendal, Alexandra Katschorowski, Ulrich Kück
    Abstract:

    A velvet multisubunit complex was recently detected in the filamentous fungus Penicillium chrysogenum, the major industrial producer of the β-lactam Antibiotic Penicillin. Core components of this complex are P. chrysogenum VelA (PcVelA) and PcLaeA, which regulate secondary metabolite production, hyphal morphology, conidiation, and pellet formation. Here we describe the characterization of PcVelB, PcVelC, and PcVosA as novel subunits of this velvet complex. Using yeast two-hybrid analysis and bimolecular fluorescence complementation (BiFC), we demonstrate that all velvet proteins are part of an interaction network. Functional analyses using single- and double-knockout strains clearly indicate that velvet subunits have opposing roles in the regulation of Penicillin biosynthesis and light-dependent conidiation. PcVelC, together with PcVelA and PcLaeA, activates Penicillin biosynthesis, while PcVelB represses this process. In contrast, PcVelB and PcVosA promote conidiation, while PcVelC has an inhibitory effect. Our genetic analyses further show that light-dependent spore formation depends not only on PcVelA but also on PcVelB and PcVosA. The results provided here contribute to our fundamental understanding of the function of velvet subunits as part of a regulatory network mediating signals responsible for morphology and secondary metabolism and will be instrumental in generating mutants with newly derived properties that are relevant to strain improvement programs.

  • sexual reproduction and mating type mediated strain development in the Penicillin producing fungus penicillium chrysogenum
    Proceedings of the National Academy of Sciences of the United States of America, 2013
    Co-Authors: Julia Bohm, Hubert Kürnsteiner, Ivo Zadra, Birgit Hoff, Celine M Ogorman, Simon Wolfers, Volker Klix, Danielle Binger, Stefanie Poggeler
    Abstract:

    Penicillium chrysogenum is a filamentous fungus of major medical and historical importance, being the original and present-day industrial source of the Antibiotic Penicillin. The species has been considered asexual for more than 100 y, and despite concerted efforts, it has not been possible to induce sexual reproduction, which has prevented sexual crosses being used for strain improvement. However, using knowledge of mating-type (MAT) gene organization, we now describe conditions under which a sexual cycle can be induced leading to production of meiotic ascospores. Evidence of recombination was obtained using both molecular and phenotypic markers. The identified heterothallic sexual cycle was used for strain development purposes, generating offspring with novel combinations of traits relevant to Penicillin production. Furthermore, the MAT1-1–1 mating-type gene, known primarily for a role in governing sexual identity, was also found to control transcription of a wide range of genes with biotechnological relevance including those regulating Penicillin production, hyphal morphology, and conidial formation. These discoveries of a sexual cycle and MAT gene function are likely to be of broad relevance for manipulation of other asexual fungi of economic importance.

  • two components of a velvet like complex control hyphal morphogenesis conidiophore development and Penicillin biosynthesis in penicillium chrysogenum
    Eukaryotic Cell, 2010
    Co-Authors: Birgit Hoff, Hubert Kürnsteiner, Claudia Sigl, Ivo Zadra, Jens Kamerewerd, Rudolf Mitterbauer, Ulrich Kück
    Abstract:

    Penicillium chrysogenum is the industrial producer of the Antibiotic Penicillin, whose biosynthetic regulation is barely understood. Here, we provide a functional analysis of two major homologues of the velvet complex in P. chrysogenum, which we have named P. chrysogenum velA (PcvelA) and PclaeA. Data from array analysis using a ΔPcvelA deletion strain indicate a significant role of PcVelA on the expression of biosynthesis and developmental genes, including PclaeA. Northern hybridization and high-performance liquid chromatography quantifications of Penicillin titers clearly show that both PcVelA and PcLaeA play a major role in Penicillin biosynthesis in a producer strain that underwent several rounds of UV mutagenesis during a strain improvement program. Both regulators are further involved in different developmental processes. While PcvelA deletion leads to light-independent conidial formation, dichotomous branching of hyphae, and pellet formation in shaking cultures, a ΔPclaeA strain shows a severe impairment in conidiophore formation under both light and dark conditions. Bimolecular fluorescence complementation assays provide evidence for a velvet-like complex in P. chrysogenum, with structurally conserved components that have distinct developmental roles, illustrating the functional plasticity of these regulators in genera other than Aspergillus.

  • Homologous recombination in the Antibiotic producer Penicillium chrysogenum: strain ΔPcku70 shows up-regulation of genes from the HOG pathway
    Applied Microbiology and Biotechnology, 2010
    Co-Authors: Birgit Hoff, Ivo Zadra, Claudia Sigl, Jens Kamerewerd, Ulrich Kück
    Abstract:

    In Penicillium chrysogenum , the industrial producer of the β-lactam Antibiotic Penicillin, generating gene replacements for functional analyses is very inefficient. Here, we constructed a recipient strain that allows efficient disruption of any target gene via homologous recombination. Following isolation of the Pcku70 (syn. hdfA ) gene encoding a conserved eukaryotic DNA-binding protein involved in non-homologous end joining (NHEJ), a Pcku70 knockout strain was constructed using a novel nourseothricin-resistance cassette as selectable marker. In detailed physiological tests, strain ΔPcku70 showed no significant reduction in vegetative growth due to increased sensitivity to different mutagenic substances. Importantly, deletion of the Pcku70 gene had no effect on Penicillin biosynthesis. However, strain ΔPcku70 exhibits higher sensitivity to osmotic stress than the parent strain. This correlated well with comparative data from microarray analyses: Genes related to the stress response are significantly up-regulated in the Pcku70 deletion mutant. To demonstrate the applicability of strain ΔPcku70, three genes related to β-lactam Antibiotic biosynthesis were efficiently disrupted, indicating that this strain shows a low frequency of NHEJ, thus promoting efficient homologous recombination. Furthermore, we discuss strategies to reactivate Pcku70 in strains successfully used for gene disruptions.

Ivo Zadra - One of the best experts on this subject based on the ideXlab platform.

  • sexual reproduction and mating type mediated strain development in the Penicillin producing fungus penicillium chrysogenum
    Proceedings of the National Academy of Sciences of the United States of America, 2013
    Co-Authors: Julia Bohm, Hubert Kürnsteiner, Ivo Zadra, Birgit Hoff, Celine M Ogorman, Simon Wolfers, Volker Klix, Danielle Binger, Stefanie Poggeler
    Abstract:

    Penicillium chrysogenum is a filamentous fungus of major medical and historical importance, being the original and present-day industrial source of the Antibiotic Penicillin. The species has been considered asexual for more than 100 y, and despite concerted efforts, it has not been possible to induce sexual reproduction, which has prevented sexual crosses being used for strain improvement. However, using knowledge of mating-type (MAT) gene organization, we now describe conditions under which a sexual cycle can be induced leading to production of meiotic ascospores. Evidence of recombination was obtained using both molecular and phenotypic markers. The identified heterothallic sexual cycle was used for strain development purposes, generating offspring with novel combinations of traits relevant to Penicillin production. Furthermore, the MAT1-1–1 mating-type gene, known primarily for a role in governing sexual identity, was also found to control transcription of a wide range of genes with biotechnological relevance including those regulating Penicillin production, hyphal morphology, and conidial formation. These discoveries of a sexual cycle and MAT gene function are likely to be of broad relevance for manipulation of other asexual fungi of economic importance.

  • among developmental regulators stua but not brla is essential for Penicillin v production in penicillium chrysogenum
    Applied and Environmental Microbiology, 2011
    Co-Authors: Claudia Sigl, Hubert Kürnsteiner, Hubertus Haas, Thomas Specht, Kristian Pfaller, Ivo Zadra
    Abstract:

    In filamentous fungi, secondary metabolism is often linked with developmental processes such as conidiation. In this study we analyzed the link between secondary metabolism and conidiation in the main industrial producer of the β-lactam Antibiotic Penicillin, the ascomycete Penicillium chrysogenum. Therefore, we generated mutants defective in two central regulators of conidiation, the transcription factors BrlA and StuA. Inactivation of either brlA or stuA blocked conidiation and altered hyphal morphology during growth on solid media, as shown by light and scanning electron microscopy, but did not affect biomass production during liquid-submerged growth. Genome-wide transcriptional profiling identified a complex StuA- and BrlA-dependent regulatory network, including genes previously shown to be involved in development and secondary metabolism. Remarkably, inactivation of stuA, but not brlA, drastically downregulated expression of the Penicillin biosynthetic gene cluster during solid and liquid-submerged growth. In agreement, Penicillin V production was wild-type-like in brlA-deficient strains but 99% decreased in stuA-deficient strains during liquid-submerged growth, as shown by high-performance liquid chromatography (HPLC) analysis. Thus, among identified regulators of Penicillin V production StuA has the most severe influence. Overexpression of stuA increased the transcript levels of brlA and abaA (another developmental regulator) and derepressed conidiation during liquid-submerged growth but did not affect Penicillin V productivity. Taken together, these data demonstrate an intimate but not exclusive link between regulation of development and secondary metabolism in P. chrysogenum.

  • two components of a velvet like complex control hyphal morphogenesis conidiophore development and Penicillin biosynthesis in penicillium chrysogenum
    Eukaryotic Cell, 2010
    Co-Authors: Birgit Hoff, Hubert Kürnsteiner, Claudia Sigl, Ivo Zadra, Jens Kamerewerd, Rudolf Mitterbauer, Ulrich Kück
    Abstract:

    Penicillium chrysogenum is the industrial producer of the Antibiotic Penicillin, whose biosynthetic regulation is barely understood. Here, we provide a functional analysis of two major homologues of the velvet complex in P. chrysogenum, which we have named P. chrysogenum velA (PcvelA) and PclaeA. Data from array analysis using a ΔPcvelA deletion strain indicate a significant role of PcVelA on the expression of biosynthesis and developmental genes, including PclaeA. Northern hybridization and high-performance liquid chromatography quantifications of Penicillin titers clearly show that both PcVelA and PcLaeA play a major role in Penicillin biosynthesis in a producer strain that underwent several rounds of UV mutagenesis during a strain improvement program. Both regulators are further involved in different developmental processes. While PcvelA deletion leads to light-independent conidial formation, dichotomous branching of hyphae, and pellet formation in shaking cultures, a ΔPclaeA strain shows a severe impairment in conidiophore formation under both light and dark conditions. Bimolecular fluorescence complementation assays provide evidence for a velvet-like complex in P. chrysogenum, with structurally conserved components that have distinct developmental roles, illustrating the functional plasticity of these regulators in genera other than Aspergillus.

  • Homologous recombination in the Antibiotic producer Penicillium chrysogenum: strain ΔPcku70 shows up-regulation of genes from the HOG pathway
    Applied Microbiology and Biotechnology, 2010
    Co-Authors: Birgit Hoff, Ivo Zadra, Claudia Sigl, Jens Kamerewerd, Ulrich Kück
    Abstract:

    In Penicillium chrysogenum , the industrial producer of the β-lactam Antibiotic Penicillin, generating gene replacements for functional analyses is very inefficient. Here, we constructed a recipient strain that allows efficient disruption of any target gene via homologous recombination. Following isolation of the Pcku70 (syn. hdfA ) gene encoding a conserved eukaryotic DNA-binding protein involved in non-homologous end joining (NHEJ), a Pcku70 knockout strain was constructed using a novel nourseothricin-resistance cassette as selectable marker. In detailed physiological tests, strain ΔPcku70 showed no significant reduction in vegetative growth due to increased sensitivity to different mutagenic substances. Importantly, deletion of the Pcku70 gene had no effect on Penicillin biosynthesis. However, strain ΔPcku70 exhibits higher sensitivity to osmotic stress than the parent strain. This correlated well with comparative data from microarray analyses: Genes related to the stress response are significantly up-regulated in the Pcku70 deletion mutant. To demonstrate the applicability of strain ΔPcku70, three genes related to β-lactam Antibiotic biosynthesis were efficiently disrupted, indicating that this strain shows a low frequency of NHEJ, thus promoting efficient homologous recombination. Furthermore, we discuss strategies to reactivate Pcku70 in strains successfully used for gene disruptions.

Maria Kempe - One of the best experts on this subject based on the ideXlab platform.

Hubert Kürnsteiner - One of the best experts on this subject based on the ideXlab platform.

  • sexual reproduction and mating type mediated strain development in the Penicillin producing fungus penicillium chrysogenum
    Proceedings of the National Academy of Sciences of the United States of America, 2013
    Co-Authors: Julia Bohm, Hubert Kürnsteiner, Ivo Zadra, Birgit Hoff, Celine M Ogorman, Simon Wolfers, Volker Klix, Danielle Binger, Stefanie Poggeler
    Abstract:

    Penicillium chrysogenum is a filamentous fungus of major medical and historical importance, being the original and present-day industrial source of the Antibiotic Penicillin. The species has been considered asexual for more than 100 y, and despite concerted efforts, it has not been possible to induce sexual reproduction, which has prevented sexual crosses being used for strain improvement. However, using knowledge of mating-type (MAT) gene organization, we now describe conditions under which a sexual cycle can be induced leading to production of meiotic ascospores. Evidence of recombination was obtained using both molecular and phenotypic markers. The identified heterothallic sexual cycle was used for strain development purposes, generating offspring with novel combinations of traits relevant to Penicillin production. Furthermore, the MAT1-1–1 mating-type gene, known primarily for a role in governing sexual identity, was also found to control transcription of a wide range of genes with biotechnological relevance including those regulating Penicillin production, hyphal morphology, and conidial formation. These discoveries of a sexual cycle and MAT gene function are likely to be of broad relevance for manipulation of other asexual fungi of economic importance.

  • among developmental regulators stua but not brla is essential for Penicillin v production in penicillium chrysogenum
    Applied and Environmental Microbiology, 2011
    Co-Authors: Claudia Sigl, Hubert Kürnsteiner, Hubertus Haas, Thomas Specht, Kristian Pfaller, Ivo Zadra
    Abstract:

    In filamentous fungi, secondary metabolism is often linked with developmental processes such as conidiation. In this study we analyzed the link between secondary metabolism and conidiation in the main industrial producer of the β-lactam Antibiotic Penicillin, the ascomycete Penicillium chrysogenum. Therefore, we generated mutants defective in two central regulators of conidiation, the transcription factors BrlA and StuA. Inactivation of either brlA or stuA blocked conidiation and altered hyphal morphology during growth on solid media, as shown by light and scanning electron microscopy, but did not affect biomass production during liquid-submerged growth. Genome-wide transcriptional profiling identified a complex StuA- and BrlA-dependent regulatory network, including genes previously shown to be involved in development and secondary metabolism. Remarkably, inactivation of stuA, but not brlA, drastically downregulated expression of the Penicillin biosynthetic gene cluster during solid and liquid-submerged growth. In agreement, Penicillin V production was wild-type-like in brlA-deficient strains but 99% decreased in stuA-deficient strains during liquid-submerged growth, as shown by high-performance liquid chromatography (HPLC) analysis. Thus, among identified regulators of Penicillin V production StuA has the most severe influence. Overexpression of stuA increased the transcript levels of brlA and abaA (another developmental regulator) and derepressed conidiation during liquid-submerged growth but did not affect Penicillin V productivity. Taken together, these data demonstrate an intimate but not exclusive link between regulation of development and secondary metabolism in P. chrysogenum.

  • two components of a velvet like complex control hyphal morphogenesis conidiophore development and Penicillin biosynthesis in penicillium chrysogenum
    Eukaryotic Cell, 2010
    Co-Authors: Birgit Hoff, Hubert Kürnsteiner, Claudia Sigl, Ivo Zadra, Jens Kamerewerd, Rudolf Mitterbauer, Ulrich Kück
    Abstract:

    Penicillium chrysogenum is the industrial producer of the Antibiotic Penicillin, whose biosynthetic regulation is barely understood. Here, we provide a functional analysis of two major homologues of the velvet complex in P. chrysogenum, which we have named P. chrysogenum velA (PcvelA) and PclaeA. Data from array analysis using a ΔPcvelA deletion strain indicate a significant role of PcVelA on the expression of biosynthesis and developmental genes, including PclaeA. Northern hybridization and high-performance liquid chromatography quantifications of Penicillin titers clearly show that both PcVelA and PcLaeA play a major role in Penicillin biosynthesis in a producer strain that underwent several rounds of UV mutagenesis during a strain improvement program. Both regulators are further involved in different developmental processes. While PcvelA deletion leads to light-independent conidial formation, dichotomous branching of hyphae, and pellet formation in shaking cultures, a ΔPclaeA strain shows a severe impairment in conidiophore formation under both light and dark conditions. Bimolecular fluorescence complementation assays provide evidence for a velvet-like complex in P. chrysogenum, with structurally conserved components that have distinct developmental roles, illustrating the functional plasticity of these regulators in genera other than Aspergillus.