scholarly journals Changes in Free and Membrane-bound Ribosomes during the Vegetative Growth of Neurospora crassa

1973 ◽  
Vol 79 (2) ◽  
pp. 181-187
Author(s):  
K. D. Grinwich ◽  
J. R. Trevithick
1997 ◽  
Vol 10 (9) ◽  
pp. 1075-1086 ◽  
Author(s):  
Shaohua Liu ◽  
Ralph A. Dean

Three G protein α subunit genes have been cloned and characterized from Magnaporthe grisea: magA is very similar to CPG-2 of Cryphonectria parasitica; magB is virtually identical to CPG-1 of Cryphonectria parasitica, to gna1 of Neurospora crassa, and to fadA of Emericella nidulans; and magC is most similar to gna2 of Neurospora crassa. Homologous recombination resulting in targeted deletion of magA had no effect on vegetative growth, conidiation, or appressorium formation. Deletion of magC reduced conidiation, but did not affect vegetative growth or appressorium formation. However, disruption of magB significantly reduced vegetative growth, conidiation, and appressorium formation. magB¯ transformants, unlike magA¯ and magC¯ transformants, exhibited a reduced ability to infect and colonize susceptible rice leaves. G protein α subunit genes are required for M. grisea mating. magB¯ transformants failed to form perithecia, whereas magA¯ and magC¯ transformants did not produce mature asci. These results suggest that G protein α subunit genes are involved in signal transduction pathways in M. grisea that control vegetative growth, conidiation, conidium attachment, appressorium formation, mating, and pathogenicity.


1975 ◽  
Vol 53 (7) ◽  
pp. 823-825 ◽  
Author(s):  
Charles E. Martin ◽  
Robert P. Wagner

Mitochondrial nuclease activity in Neurospora crassa occurs in membrane-bound and soluble forms in approximately equal proportions. These activities apparently are due to the same enzyme, which has an approximate molecular weight of 120 000. A portion of the insoluble enzyme appears to be associated with the inner mitochondrial membrane and is resistant to solubilization by detergent treatment as well as by physical disruption methods.


2008 ◽  
Vol 180 (2) ◽  
pp. 325-339 ◽  
Author(s):  
Fangfang Liu ◽  
Seng Kah Ng ◽  
Yanfen Lu ◽  
Wilson Low ◽  
Julian Lai ◽  
...  

Woronin bodies (WBs) are dense-core organelles that are found exclusively in filamentous fungi and that seal the septal pore in response to wounding. These organelles consist of a membrane-bound protein matrix comprised of the HEX protein and, although they form from peroxisomes, their biogenesis is poorly understood. In Neurospora crassa, we identify Woronin sorting complex (WSC), a PMP22/MPV17-related membrane protein with dual functions in WB biogenesis. WSC localizes to large peroxisome membranes where it self-assembles into detergent-resistant oligomers that envelop HEX assemblies, producing asymmetrical nascent WBs. In a reaction requiring WSC, these structures are delivered to the cell cortex, which permits partitioning of the nascent WB and WB inheritance. Our findings suggest that WSC and HEX collaborate and control distinct aspects of WB biogenesis and that cortical association depends on WSC, which in turn depends on HEX. This dependency helps order events across the organellar membrane, permitting the peroxisome to produce a second organelle with a distinct composition and intracellular distribution.


1970 ◽  
Vol 12 (4) ◽  
pp. 914-926 ◽  
Author(s):  
Dorothy Newmeyer

Neurospora crassa strains of opposite mating type are ordinarily heterokaryon-incompatible during vegetative growth. An unlinked mutant called tolerant (tol) is described, which suppresses the vegetative incompatibility of unlike mating types without affecting their ability to cross. The mutant tol was selected and studied by means of duplications heterozygous for mating type. Use of the duplication eliminates complications due to unlinked heterokaryon genes. The mode of action of tol has been confirmed by conventional heterokaryon tests. tol has been mapped in linkage group IV, close to tryp-4. A suppressor similar or identical to tolerant has been found in a wild strain from Panama, out of 14 different wild types which were tested. By using a different duplication which covers the unlinked heterokaryon-compatibility locus C, it was shown that tolerant does not suppress C/c incompatibility. The fact that tolerant suppresses only one of the two functions ascribed to mating type revives the question of whether 'mating-type' is one gene or two. However, the data strongly support Pittenger's (1957) conclusion that, if two genes are involved, they must be closely linked.


2015 ◽  
Vol 75 ◽  
pp. 30-45 ◽  
Author(s):  
Rosa A. Fajardo-Somera ◽  
Bastian Jöhnk ◽  
Özgür Bayram ◽  
Oliver Valerius ◽  
Gerhard H. Braus ◽  
...  

Genetics ◽  
1998 ◽  
Vol 148 (3) ◽  
pp. 1069-1079 ◽  
Author(s):  
Adlane V-B Ferreira ◽  
Zhiqiang An ◽  
Robert L Metzenberg ◽  
N Louise Glass

AbstractThe mating-type locus of Neurospora crassa regulates mating identity and entry into the sexual cycle. The mat A idiomorph encodes three genes, mat A-1, mat A-2, and mat A-3. Mutations in mat A-1 result in strains that have lost mating identity and vegetative incompatibility with mat a strains. A strain containing mutations in both mat A-2 and mat A-3 is able to mate, but forms few ascospores. In this study, we describe the isolation and characterization of a mutant deleted for mat (ΔmatA), as well as mutants in either mat A-2 or mat A-3. The ΔmatA strain is morphologically wild type during vegetative growth, but it is sterile and heterokaryon compatible with both mat A and mat a strains. The mat A-2 and mat A-3 mutants are also normal during vegetative growth, mate as a mat A strain, and produce abundant biparental asci in crosses with mat a, and are thus indistinguishable from a wild-type mat A strain. These data and the fact that the mat A-2 mat A-3 double mutant makes few asci with ascospores indicate that MAT A-2 and MAT A-3 are redundant and may function in the same pathway. Analysis of the expression of two genes (sdv-1 and sdv-4) in the various mat mutants suggests that the mat A polypeptides function in concert to regulate the expression of some sexual development genes.


1970 ◽  
Vol 42 (4) ◽  
pp. 483-488
Author(s):  
Md Nazrul Islam Bhuiyan ◽  
TIMA Mozmader ◽  
Siddiqur Rahman

Crude extract of leaves from Averrhoa carambola .L showed significant inhibition of growth and mutagenesis in Neurospora crassa. Result showed that 1 ml extract reacted with the test organism, N. crassa very much. During the period of 24 hours it gave only 2.4 cm linear vegetative growth of the mycelia. Whereas 0.5 ml and 0.25 ml extracts gave less reactions (1.75 cm and 2.25 cm respectively). The linear growth decreased with the increased of the concentration of the extracts. Conidia of Ema (5297) of N. crassa were treated for 3-4 hours separately in 100% and 50% concentration of the extracts. 100% extracts produced 4 types mutants namely ropy, albino, dirty and buff. 50% extracts produced 4 types of mutants namely- plug, vigorous, pigmented and conidial band. Key words: Neurospora crassa, Averrhoa carambola, mutants, ropy, albino, dirty, buff, plug, vigorous, pigmented and conidial band. Bangladesh J. Sci. Ind. Res. 42(4), 483-488, 2007


2001 ◽  
Vol 21 (4) ◽  
pp. 1045-1057 ◽  
Author(s):  
Jennifer Wu ◽  
N. Louise Glass

ABSTRACT The capacity for nonself recognition is a ubiquitous and essential aspect of biology. In filamentous fungi, nonself recognition during vegetative growth is believed to be mediated by genetic differences at heterokaryon incompatibility (het) loci. Filamentous fungi are capable of undergoing hyphal fusion to form mycelial networks and with other individuals to form vegetative heterokaryons, in which genetically distinct nuclei occupy a common cytoplasm. InNeurospora crassa, 11 het loci have been identified that affect the viability of such vegetative heterokaryons. The het-c locus has at least three mutually incompatible alleles, termed het-cOR, het-cPA , and het-cGR . Hyphal fusion between strains that are of alternative het-c specificity results in vegetative heterokaryons that are aconidial and which show growth inhibition and hyphal compartmentation and death. A 34- to 48-amino-acid variable domain, which is dissimilar in HET-COR, HET-CPA, and HET-CGR, confers allelic specificity. To assess requirements for allelic specificity, we constructed chimeras between the het-c variable domain from 24 different isolates that displayed amino acid and insertion or deletion variations and determined their het-c specificity by introduction into N. crassa. We also constructed a number of artificial alleles that contained novel het-cspecificity domains. By this method, we identified four additional and novel het-c specificities. Our results indicate that amino acid and length variations within the insertion or deletion motif are the primary determinants for conferring het-c allelic specificity. These results provide a molecular model for nonself recognition in multicellular eucaryotes.


1985 ◽  
Vol 40 (5-6) ◽  
pp. 421-426
Author(s):  
M. Hecker ◽  
A.-M. Dünger ◽  
G. Wachlin ◽  
F. Mach

Abstract Two-dimensional gel electrophoresis according to O’Farrell [6] was used to study synthesis of membrane bound proteins during outgrowth of Bacillus subtilis spores. Three major classes of membrane bound proteins were distinguished, depending on the time of onset and duration of their synthesis: Ia - a great amount of proteins typical of vegetative cells made throughout all stages of outgrowth and vegetative growth; Ib - vegetative proteins synthesized during middle and later outgrowth stages as well as during vegetative growth (sequential activation); II - outgrowth-specific proteins synthesized during early outgrowth but not in vegetative cells. A similar classification was made for total proteins [9]. In a temperature-sensitive mutant defective in early outgrowth the sequential activation of vegetative genes (group lb) is especially inhibited under restrictive conditions, whereas the syn­thesis of group Ia-proteins and outgrowth-specific proteins (II) could be detected during early outgrowth stages. We suggest that the expression of outgrowth genes, whose products might be found among the outgrowth-specific proteins, could be involved in the sequential reactivation of vegetative genes during outgrowth. The vegetative proteins of group la (continuous synthesis) are produced throughout growth and differentiation. On the other hand the synthesis of vegetative proteins, group Ib , is switched off during sporulation and switched on during outgrowth. The control mechanisms of the expression of these two groups of vegetative genes during growth and differen­tiation are discussed.


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