Studies on Morphological Mutant “<i>cut</i>” in <i>Neurospora crassa</i>

Abstract

Cytological and biochemical studies on the red bread mold, Neuro spora crassa, have been carried on by many investigators, and their numerous fruits have been accumulated (Horowitz 1950, Bonner 1951, etc.). On the studies of morphological mutants, however, only their structures and the modes of inheritance have been described and there have been few literatures in which explanation was given on the mechanism of inducing their mutant structures. The present report will add some knowledge to us in such a field.

Turgor regulation in the osmosensitive cut mutant of Neurospora crassa

“…The osmosensitive mutant cut is one example. The cut mutant was originally isolated as a morphological mutant which exhibits a flat, as if it had been cut, conidiation zone when grown in slants (Kuwana, 1953). Temperature, pH and carbon source do not affect the mutant, but growth is affected by humidity (normal morphology is observed at 100 % relative humidity) and osmotic pressure (it is unable to grow at high osmolarity) (Kuwana, 1953).…”

Light-dependent regulation of the gene cut-1 of Neurospora, involved in the osmotic stress response

“…We focused our attention on cut-1, the only one associated to a formerly mapped genetic marker with a known phenotype (Kuwana, 1953;Banks et al, 1997;Youssar et al, 2005). The outstanding features of the expression of this gene, up-regulated by certain stressing conditions and down-regulated by light and by proteins related with light signaling, and the lack of information on the function of the HAD proteins in fungi, led us to start a preliminary investigation on the regulation of two further HAD genes found in the Neurospora genome.…”

“…In addition to the os strains, two further Neurospora osmosensitive mutants are known, ovc (Youssar et al, 2005) and cut (Perkins, 1974). These mutants exhibit a typical growth alteration in slant cultures, not shown by the os mutants, consisting of a premature interruption of aerial development and the formation of a dense mycelial top surface (Kuwana, 1953;Youssar et al, 2005).…”

Studies on a Temperature-sensitive Irreparable Mutant of <i>Neurospora Crassa</i>

“…The location of os (B135) is shown in Perkins (1956). The morphological mutant cut (Kuwana 1953) looks like os in its growth form in a test tube (also see Emerson and Emerson 1958), but it was not allelic to os as shown in Fig. 1.…”