Asexual fruiting body development in Aspergillus nidulans requires a precise spatial and temporal coordinated expression of many genes. Insertional mutagenesis was used to isolate and characterize a new mutant of A. nidulans in which hyphal growth was slightly reduced and conidiophore development was specifically blocked at the metula stage. In contrast to the uninucleate metulae of the wild-type, in the mutant these structures were elongated, multinucleate and septate. Further differentiation and production of phialides by a budding-like process was not observed. The mutant metulae thus resembled hyphae rather than metulae and the gene was therefore named hypha-like metulae (hymA). The hymA gene was mapped to linkage group VI. The integrated vector was rescued with border sequences from the integration site. The border sequences were used to isolate a cosmid from a wild-type library which was subcloned to a 5 kb fragment able to complement the mutation in trans. This fragment encoded a 1·8 kb transcript expressed in hyphae and throughout development. It is proposed that hymA is involved in budding processes, and is required for the formation of metulae and for their further differentiation.
AdamsT. H., BoylanM. T., TimberlakeW. E.1988; brlA is necessary and sufficient to direct conidiophore development in Aspergillus nidulans. Cell 54:353–362
AndrianopoulosA., TimberlakeW. E.1994; The Asperbillus nidulans abaA gene encodes a transcriptional activator that acts as a genetic switch to control development. Mol Cell Biol 14:2503–2515
AramayoR., AdamsT. H., TimberlakeW. E.1989; A large cluster of highly expressed genes is dispensable for growth and development in Aspergillus nidulans. Genetics 122:65–71
BoylanM. T., MirabitoP. M., WillettC. E., ZimmermanC. R., TimberlakeW. E.1987; Isolation and physical characterization of three essential conidiation genes from Aspergillus nidulans. Mol Cell Biol 7:3113–3118
ClutterbuckA. J., TimberlakeW. E.1992; Genetic regulation of sporulation in the fungus Aspergillus nidulans. In Development: The Molecular Genetic Approach pp. 103–120 Edited by RussoV. E. A., BrodyS., CoveD., OttolenghiS. Berlin: Springer Verlag;
FinkG. R., GimenoC. J.1994; Induction of pseudohyphal growth by overexpression of PHD1, a Saccharomyces cerevisiae gene related to transcriptional regulators of fungal development. Mol Cell Biol 14:2100–2112
FischerR., TimberlakeW. E.1995; Aspergillus nidulans aps A (anucleate primary sterigmata) encodes a coiled-coil protein necessary for nuclear positioning and completion of asexual development. J Cell Biol 128:485–498
GimenoC. J., LjungdahlP. O., StylesC. A., FinkG. R.1992; Unipolar cell divisions in the yeast Saccharomyces cerevisiae lead to filamentous growth: regulation by starvation and RAS. Cell 68:1077–1090
GoldmanG. H., MorrisN. R.1995; Extragenic suppressors of a dynein mutation that blocks nuclear migration in Aspergillus nidulans. Genetics 139:1223–1232
LebererE., LeeuwT., FourestlieuvinA., WuC. L., ChenevertJ., ClarkK., WhitewayM., ThomasD. Y.1995; Pheromone response in yeast - association of BEM1P with proteins of the MAP kinase cascade and actin. Science 270:1210–1213
MayorgaM. E., TimberlakeW. E.1992; The developmentally regulated Aspergillus nidulans wA gene encodes a polypeptide homologous to polyketide and fatty acid synthases. Mol Gen Genet 235:205–212
MillerK. Y., ToennisT. M., AdamsT. H., MillerB. L.1991; Isolation and transcriptional characterization of a morphological modifier: the Aspergillus nidulans stunted (stuA) gene. Mol Gen Genet 227:285–292
PradeR., TimberlakeW. E.1993; The Aspergillus nidulans brlA regulatory locus consists of two overlapping transcription units that are individually required for conidiophore development. EMBO J 12:2439–2447
StringerM. A., DeanR. A., SewallT. C., TimberlakeW. E.1991; rodletles, a new Aspergillus developmental mutant induced by directed gene inactivation. Genes Dev 5:1161–1171
WaringR. B., MayG. S., MorrisN. R.1989; Characterization of an inducible expression system in Aspergillus nidulans using ale A and tubulin coding genes. Gene 79:119–130
WieserJ., AdamsT. H.1995; flbD encodes a myb-like DNA- binding protein that coordinates initiation of Aspergillus nidulans conidiophore development. Genes Dev 9:491–502
XiongM., ChenH. J., PradeR. A., WangY., GriffithJ., TimberlakeW. E., ArnoldJ.1996; On the consistency of a physical mapping method to reconstruct a chromosome in vitro. Genetics 142:267–284