Unstable dTMP auxotrophs in Neurospora crassa

An unstable allele of the am locus of Neurospora crassa.

The mutant strain am126 was isolated, using the direct selection procedure, after nitrous acid mutagenesis. It produced neither measurable NADP-dependent glutamate dehydrogenase (GDH) nor immunologically cross-reacting material. That the am126 strain produced some form of GDH product was shown by the fact that it complemented several other am mutant strains. The GDH formed by complementation be...

Quelling in Neurospora crassa.

Heterocaryosis in Neurospora Crassa.

T IS possible by means of X-ray or ultraviolet treatment to produce mutant I strains of Neurospora crassa that are deficient in their abilities to synthesize specific vitamins, amino acids, or other essential substances (BEADLE and TATUM 1941; TATUM and BEADLE 1g4zb). It occurred to us that it might be possible to determine whether the mutant genes concerned in such haploid strains are recessiv...

Size restriction on utilization of peptides by amino acid auxotrophs of Neurospora crassa.

Growth of an amino acid auxotroph of Neurospora crassa on oligopeptides is shown to occur by extracellular hydrolysis, with subsequent utilization of monomer amino acid residues, and by transport of peptides. Peptides with a hydrodynamic volume greater than that of trileucine are not transported, and this lack of transport is shown to be due to restriction by the oligopeptide transport system r...

Biotransformation of Hydrocortisone by Neurospora crassa

The ability of Neurospora crassa FGSC 4335 in the biotransformation of hydrocortisone was investigated. The microorganism produced two major metabolites after incubation with the substrate for seven days. Each microbial product was purified chromatographically and identified on the basis of spectral data. The products were identified as 11?,17?,20?,21-tetrahydroxypregn-4-en-3-one (II) and 11?-h...