title: Genetic control of phosphorus assimilation in Neurospora crassa: dose-dependent dominance and recessiveness in constitutive mutants.
abstract: Mutants called nuc-1c, constitutive for alkaline phosphatase synthesis, were isolated and mapped very close to nuc-1 mutants in which this enzyme is not expressed. nuc-1 is epistatic to nuc-1c. nuc-1c acts only if it is cis to normal nuc-1 function. The preparation of partial diploids heterozygous for various nuc-1 alleles is described; nuc-1c is dominant to nuc-1+, which in turn is dominant to nuc-1. In heterocaryons with nuc-1+, nuc-1c is dominant when it is present in high proportion, but essentially recessive if it is present in low proportions. In heterocaryons with nuc-1, nuc-1c is again dominant when present in high proportions, but in low proportions it "complements" to give essentially normal repressibility. A model of regulation consistent with these findings is presented.
mesh_terms: D000469:Alkaline Phosphatase / Q000235:genetics*; D002467:Cell Nucleus; D004843:Epistasis, Genetic; D005796:Genes; D006579:Heterozygote; D009154:Mutation; D009491:Neurospora / Q000235:genetics*; D009492:Neurospora crassa / Q000166:cytology / Q000235:genetics*; D010758:Phosphorus / Q000378:metabolism
chemical_list: D010758:Phosphorus; D000469:Alkaline Phosphatase