Mannitol-1-phosphate dehydrogenase, MpdA, is required for mannitol production in vegetative cells and involved in hyphal branching, heat resistance of conidia and sexual development in Aspergillus nidulans

2021 ◽  
Author(s):  
Joo-Yeon Lim ◽  
Seung-Hyun Jang ◽  
Hee-Moon Park
Keyword(s):  
Heat Resistance ◽  
Aspergillus Nidulans ◽  
Sexual Development ◽  
Vegetative Cells ◽  
Hyphal Branching ◽  
Mannitol Production

scholarly journals Molecular Physiological Characterization of a High Heat Resistant Spore Forming Bacillus subtilis Food Isolate

2021 ◽  
Vol 9 (3) ◽  
pp. 667
Author(s):  
Zhiwei Tu ◽  
Peter Setlow ◽  
Stanley Brul ◽  
Gertjan Kramer
Keyword(s):  
Bacillus Subtilis ◽  
Heat Resistance ◽  
Dipicolinic Acid ◽  
Laboratory Strain ◽  
High Heat ◽  
High Heat Resistance ◽  
Vegetative Cells ◽  
Heat Resistant ◽  
Food Isolate ◽  
Wet Heat

Bacterial endospores (spores) are among the most resistant living forms on earth. Spores of Bacillus subtilis A163 show extremely high resistance to wet heat compared to spores of laboratory strains. In this study, we found that spores of B. subtilis A163 were indeed very wet heat resistant and released dipicolinic acid (DPA) very slowly during heat treatment. We also determined the proteome of vegetative cells and spores of B. subtilis A163 and the differences in these proteomes from those of the laboratory strain PY79, spores of which are much less heat resistant. This proteomic characterization identified 2011 proteins in spores and 1901 proteins in vegetative cells of B. subtilis A163. Surprisingly, spore morphogenic protein SpoVM had no homologs in B. subtilis A163. Comparing protein expression between these two strains uncovered 108 proteins that were differentially present in spores and 93 proteins differentially present in cells. In addition, five of the seven proteins on an operon in strain A163, which is thought to be primarily responsible for this strain’s spores high heat resistance, were also identified. These findings reveal proteomic differences of the two strains exhibiting different resistance to heat and form a basis for further mechanistic analysis of the high heat resistance of B. subtilis A163 spores.

scholarly journals Aspergillus nidulans wetA activates spore-specific gene expression.

1991 ◽  
Vol 11 (1) ◽  
pp. 55-62 ◽  
Author(s):  
M A Marshall ◽  
W E Timberlake
Keyword(s):  
Gene Expression ◽  
Cell Wall ◽  
Aspergillus Nidulans ◽  
Gene Activation ◽  
Regulatory Function ◽  
Specific Gene ◽  
Coding Region ◽  
Vegetative Cells ◽  
Mutant Strains ◽  
Late Stages

The Aspergillus nidulans wetA gene is required for synthesis of cell wall layers that make asexual spores (conidia) impermeable. In wetA mutant strains, conidia take up water and autolyze rather than undergoing the final stages of maturation. wetA is activated during conidiogenesis by sequential expression of the brlA and abaA regulatory genes. To determine whether wetA regulates expression of other sporulation-specific genes, its coding region was fused to a nutritionally regulated promoter that permits gene activation in vegetative cells (hyphae) under conditions that suppress conidiation. Expression of wetA in hyphae inhibited growth and caused excessive branching. It did not lead to activation of brlA or abaA but did cause accumulation of transcripts from genes that are normally expressed specifically during the late stages of conidiation and whose mRNAs are stored in mature spores. Thus, wetA directly or indirectly regulates expression of some spore-specific genes. At least one gene (wA), whose mRNA does not occur in spores but rather accumulates in the sporogenous phialide cells, was activated by wetA, suggesting that wetA may have a regulatory function in these cells as well as in spores. We propose that wetA is responsible for activating a set of genes whose products make up the final two conidial wall layers or direct their assembly and through this activity is responsible for acquisition of spore dormancy.

Elevation of the Heat Resistance of Vegetative Cells and Spores of Clostridium perfringens Type A by Sublethal Heat Shock

1997 ◽  
Vol 60 (8) ◽  
pp. 998-1000 ◽  
Author(s):  
NORMA L. HEREDIA ◽  
GERARDO A. GARCÍA ◽  
RAMIRO LUÉVANOS ◽  
RONALD G. LABBÉ ◽  
J. SANTOS GARCÍA-ALVARADO
Keyword(s):  
Heat Shock ◽  
Heat Resistance ◽  
Clostridium Perfringens ◽  
Growth Temperature ◽  
Optimal Growth ◽  
Shock Treatment ◽  
Heat Shock Treatment ◽  
Optimal Growth Temperature ◽  
Vegetative Cells ◽  
Kinetics Of

The degree of heat resistance conferred on Clostridium perfringens by a heat shock, the kinetics of this development, and its duration were determined. A sublethal heat shock at 55°C for 30 min increased the heat tolerance of vegetative cells at least two- to threefold. The acquired tolerance was maintained for 2 h after the heat shock treatment. Heat shock applied for the first hour of incubation produced spores more tolerant to heat than the spores of the control. Acquired thermotolerance is of importance in the case of this organism because of its inherently high optimal growth temperature.

scholarly journals Transcriptional Changes in the Transition from Vegetative Cells to Asexual Development in the Model Fungus Aspergillus nidulans

2012 ◽  
Vol 12 (2) ◽  
pp. 311-321 ◽  
Author(s):  
Aitor Garzia ◽  
Oier Etxebeste ◽  
Julio Rodríguez-Romero ◽  
Reinhard Fischer ◽  
Eduardo A. Espeso ◽  
...  
Keyword(s):  
Gene Expression ◽  
Aspergillus Nidulans ◽  
Cell Types ◽  
Asexual Development ◽  
Primary Metabolism ◽  
Air Exposure ◽  
Vegetative Cells ◽  
Content Type ◽  
Zinc Cluster ◽  
Transcriptional Changes

ABSTRACTMorphogenesis encompasses programmed changes in gene expression that lead to the development of specialized cell types. In the model fungusAspergillus nidulans, asexual development involves the formation of characteristic cell types, collectively known as the conidiophore. With the aim of determining the transcriptional changes that occur upon induction of asexual development, we have applied massive mRNA sequencing to compare the expression pattern of 19-h-old submerged vegetative cells (hyphae) with that of similar hyphae after exposure to the air for 5 h. We found that the expression of 2,222 (20.3%) of the predicted 10,943A. nidulanstranscripts was significantly modified after air exposure, 2,035 being downregulated and 187 upregulated. The activation during this transition of genes that belong specifically to the asexual developmental pathway was confirmed. Another remarkable quantitative change occurred in the expression of genes involved in carbon or nitrogen primary metabolism. Genes participating in polar growth or sexual development were transcriptionally repressed, as were those belonging to the HogA/SakA stress response mitogen-activated protein (MAP) kinase pathway. We also identified significant expression changes in several genes purportedly involved in redox balance, transmembrane transport, secondary metabolite production, or transcriptional regulation, mainly binuclear-zinc cluster transcription factors. Genes coding for these four activities were usually grouped in metabolic clusters, which may bring regulatory implications for the induction of asexual development. These results provide a blueprint for further stage-specific gene expression studies during conidiophore development.

The roles of phosducin-like protein in sexual development of Aspergillus nidulans

2012 ◽  
Vol 3 (1) ◽  
Author(s):  
Sei-Jin Lee ◽  
Dong-Min Han ◽  
Keon-Sang Chae ◽  
Dae-Hyuk Kim ◽  
Tae-Boong Uhm ◽  
...  
Keyword(s):  
Aspergillus Nidulans ◽  
Sexual Development

STUDIES OF ASPOROGENIC MUTANTS OF BACILLUS CEREUS: PRELIMINARY INVESTIGATIONS WITH CALCIUM AND ZINC

1962 ◽  
Vol 8 (6) ◽  
pp. 823-833 ◽  
Author(s):  
J. J. Cooney ◽  
D. G. Lundgren
Keyword(s):  
Heat Resistance ◽  
Bacillus Cereus ◽  
Trichloroacetic Acid ◽  
Minimal Medium ◽  
Soluble Fraction ◽  
Dipicolinic Acid ◽  
Insoluble Fraction ◽  
Temperature Sensitive ◽  
Vegetative Cells ◽  
Culture Cycle

The physiology of spore formation was studied in Bacillus cereus and a temperature-sensitive asporogenic mutant. The parent organism sporulates when cultured in a minimal medium at either 28 °C or 37 °C while the mutant sporulates only at 28 °C. The blocking of sporulation at 37 °C has been referred to as "abortive" sporulation. Uptake of calcium and zinc was followed during growth and sporulation or "abortive" sporulation. Calcium and dipicolinic acid (DPA) levels in sporogenic cultures increased as the medium calcium was increased. The asporogenic mutant took up less calcium and synthesized little DPA. Heat resistance of spores increased as the calcium and DPA increased. Over 99% of Ca45or Zn65were released from labelled spores when autoclaved to release DPA. Chemical fractionations were made of cells labelled with Zn65and Ca45and harvested at different times during the culture cycle. Smaller percentages of calcium than of zinc were located in the cold trichloroacetic acid soluble fraction. The alcohol-soluble, ether-insoluble fraction of spores contained a greater percentage of calcium than was found in vegetative cells. Cells which had undergone "abortive" sporulation contained the same percentage of calcium in this fraction as homologous vegetative cells.

Position-dependent and -independent mechanisms regulate cell-specific expression of the SpoC1 gene cluster of Aspergillus nidulans

1987 ◽  
Vol 7 (1) ◽  
pp. 427-434
Author(s):  
B L Miller ◽  
K Y Miller ◽  
K A Roberti ◽  
W E Timberlake
Keyword(s):  
Aspergillus Nidulans ◽  
Gene Cluster ◽  
Regulatory Mechanism ◽  
Specific Expression ◽  
Vegetative Cells ◽  
Transcript Levels ◽  
Cis Acting ◽  
Chromosomal Position

Many genes that are expressed specifically in the differentiating asexual spores (conidia) of Aspergillus nidulans are organized into clusters. We investigated the effects of altered chromosomal position on expression of a gene from the conidiation-specific SpoC1 gene cluster. The gene became deregulated when integrated at nonhomologous chromosomal sites, in that transcript levels were elevated in vegetative cells (hyphae) and variably altered in conidia. We also investigated the effects on expression of insertion of the nonregulated argB gene into the SpoC1 region. Levels of argB transcripts were markedly reduced in hyphae. The results suggest that a cis-acting regional regulatory mechanism represses transcription of SpoC1 genes in hyphae. They also indicate that expression of individual SpoC1 genes is modulated during conidiation by trans-acting factors. We propose that the two types of regulation act together to produce the major differences in transcript levels observed in hyphae versus conidia.

The MpkB MAP kinase plays a role in post-karyogamy processes as well as in hyphal anastomosis during sexual development in Aspergillus nidulans

2011 ◽  
Vol 49 (3) ◽  
pp. 418-430 ◽  
Author(s):  
Sang-Cheol Jun ◽  
Sei-Jin Lee ◽  
Hyun-Joo Park ◽  
Ji-Young Kang ◽  
Young-Eun Leem ◽  
...  
Keyword(s):  
Map Kinase ◽  
Aspergillus Nidulans ◽  
Sexual Development ◽  
Hyphal Anastomosis

scholarly journals FigA, a Putative Homolog of Low-Affinity Calcium System Member Fig1 in Saccharomyces cerevisiae, Is Involved in Growth and Asexual and Sexual Development in Aspergillus nidulans

2013 ◽  
Vol 13 (2) ◽  
pp. 295-303 ◽  
Author(s):  
Shizhu Zhang ◽  
Hailin Zheng ◽  
Nanbiao Long ◽  
Natalia Carbó ◽  
Peiying Chen ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Aspergillus Nidulans ◽  
Sexual Development ◽  
Calcium Uptake ◽  
Fluorescent Protein ◽  
Calcium Influx ◽  
Hyphal Growth ◽  
Uptake System ◽  
Content Type ◽  
Green Fluorescent

ABSTRACTCalcium-mediated signaling pathways are widely employed in eukaryotes and are implicated in the regulation of diverse biological processes. InSaccharomyces cerevisiae, at least two different calcium uptake systems have been identified: the high-affinity calcium influx system (HACS) and the low-affinity calcium influx system (LACS). Compared to the HACS, the LACS in fungi is not well known. In this study, FigA, a homolog of the LACS member Fig1 fromS. cerevisiae, was functionally characterized in the filamentous fungusAspergillus nidulans. Loss offigAresulted in retardant hyphal growth and a sharp reduction of conidial production. Most importantly, FigA is essential for the homothallic mating (self-fertilization) process; further, FigA is required for heterothallic mating (outcrossing) in the absence of HACSmidA. Interestingly, in afigAdeletion mutant, adding extracellular Ca2+rescued the hyphal growth defects but could not restore asexual and sexual reproduction. Furthermore, quantitative PCR results revealed thatfigAdeletion sharply decreased the expression ofbrlAandnsdD, which are known as key regulators during asexual and sexual development, respectively. In addition, green fluorescent protein (GFP) tagging at the C terminus of FigA (FigA::GFP) showed that FigA localized to the center of the septum in mature hyphal cells, to the location between vesicles and metulae, and between the junctions of metulae and phialides in conidiophores. Thus, our findings suggest that FigA, apart from being a member of a calcium uptake system inA. nidulans, may play multiple unexplored roles during hyphal growth and asexual and sexual development.

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