An analysis of developmental timing in Blastocladiella emersonii sporulation

Peralta, Rosane Marina; Lodi, Wilson Roberto Navega

doi:10.1016/0012-1606(88)90269-2

Cited by 8 publications

(5 citation statements)

References 29 publications

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“…Vegetative cells were then induced to sporulate by filtering the cells through a Nitex cloth; rinsing them, resuspending them in sporulation solution (1 mM Trismaleate, pH 6.8, containing 1 mM CaCl 2 ) with or without 1% glucose at a density of 5 ϫ 10 5 cells per ml, and incubating them with agitation at 27°C. The progress and synchrony of sporulation were monitored by taking samples at different times and by examining the cellular phenotypes (vegetative cell, septate zoosporangium, papillate zoosporangium, cleavage zoosporangium, and empty zoosporangium) under a light microscope as described previously (28). Aliquots (100 ml) of cell cultures were taken at each time point (0, 60, 120, 150, and 180 min).…”

Section: Methodsmentioning

confidence: 99%

Global Gene Expression Analysis during Sporulation of the Aquatic Fungus Blastocladiella emersonii

Vieira

Gomes

2010

Eukaryot Cell

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The Blastocladiella emersonii life cycle presents a number of drastic biochemical and morphological changes, mainly during two cell differentiation stages: germination and sporulation. To investigate the transcriptional changes taking place during the sporulation phase, which culminates with the production of the zoospores, motile cells responsible for the dispersal of the fungus, microarray experiments were performed. Among the 3,773 distinct genes investigated, a total of 1,207 were classified as differentially expressed, relative to time zero of sporulation, at at least one of the time points analyzed. These results indicate that accurate transcriptional control takes place during sporulation, as well as indicating the necessity for distinct molecular functions throughout this differentiation process. The main functional categories overrepresented among upregulated genes were those involving the microtubule, the cytoskeleton, signal transduction involving Ca 2؉ , and chromosome organization. On the other hand, protein biosynthesis, central carbon metabolism, and protein degradation were the most represented functional categories among downregulated genes. Gene expression changes were also analyzed in cells sporulating in the presence of subinhibitory concentrations of glucose or tryptophan. Data obtained revealed overexpression of microtubule and cytoskeleton transcripts in the presence of glucose, probably causing the shape and motility problems observed in the zoospores produced under this condition. In contrast, the presence of tryptophan during sporulation led to upregulation of genes involved in oxidative stress, proteolysis, and protein folding. These results indicate that distinct physiological pathways are involved in the inhibition of sporulation due to these two classes of nutrient sources.The life cycle of Blastocladiella emersonii, an aquatic fungus of the class Blastocladiomycetes, involves a series of complex morphological and biochemical events, which involve transcriptional, posttranscriptional, and posttranslational mechanisms of control, especially during two stages of cell differentiation, the germination and the sporulation of the fungus (21). Germination starts with the zoospore, a motile uninucleated wall-less nongrowing cell, which is responsible for the dispersal of the fungus. In the presence of appropriate stimuli, the zoospore germinates, undergoing a number of biochemical and morphological changes. The early events of germination, which include retraction of the single polar flagellum, construction of a cell wall rich in chitin, and cleavage of a giant mitochondrion into normal-size ones, do not require concomitant RNA and protein synthesis and involve posttranslational regulatory events (17,20,30,31,35,36). Major changes in the pattern of RNA and protein synthesis are observed only at the late events of this stage, when the germ tube begins to branch, giving rise to a rhizoidal system through which nutrients are absorbed, and when the cells enter the vegetative growth phase (17,20...

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Section: Methodsmentioning

confidence: 99%

Global Gene Expression Analysis during Sporulation of the Aquatic Fungus Blastocladiella emersonii

Vieira

Gomes

2010

Eukaryot Cell

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“…Under starvation, the cells present an orderly and synchronized sequence of physiological and morphological transitions that culminates in the formation and release of zoospores in about 210–240 min at 27±1°C [6,10]. The half‐times ( T 50 in minutes) to emergence of the phenotypes are: septate zoosporangia (63±3); papillated zoosporangia (104±2), clivated zoosporangia (164±3) and empty zoosporangia (178±3) [11]. Another type of sporulation, named resistant sporulation, is induced by non‐defined environmental conditions and has not been well studied yet.…”

Section: Methodsmentioning

confidence: 99%

The induction of sporulation in the aquatic fungusBlastocladiella emersoniiis dependent on extracellular calcium

Coutinho

Corrêa

1999

FEMS Microbiology Letters

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Induction of sporulation in Blastocladiella emersonii is absolutely dependent on extracellular calcium. Vegetative cells grown in media with or without calcium do not sporulate in media devoid of calcium or in CaCl(2) with EGTA. Calcium channel blockers, CoCl(2) and nifedipine, and ionophore A23187 inhibited the induction of sporulation. The calmodulin antagonists trifluoperazine and chlorpromazine inhibited the sporulation when present in the cultures at least 60 min after induction. So, calcium that is accumulated during growth is not sufficient or is not mobilized to initiate sporulation, and a calcium influx is likely to occur by type II calcium channel functions, essential for the response to nutritional starvation. A calmodulin-like protein has been suggested to mediate calcium events in sporulation.

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“…Under starvation, the cells present an orderly and synchronized sequence of physiological and morphological transitions that culminates in the formation and release of zoospores in about 210^240 min at 27 þ 1³C [6,10]. The half-times (T 50 in minutes) to emergence of the phenotypes are: septate zoosporangia (63 þ 3); papillated zoosporangia (104 þ 2), clivated zoosporangia (164 þ 3) and empty zoosporangia (178 þ 3) [11]. Another type of sporulation, named resistant sporulation, is induced by non-de¢ned environmental conditions and has not been well studied yet.…”

Section: B Emersonii's Life Cyclementioning

confidence: 99%

The induction of sporulation in the aquatic fungus Blastocladiella emersonii is dependent on extracellular calcium

Coutinho¹

1999

FEMS Microbiology Letters

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Induction of sporulation in Blastocladiella emersonii is absolutely dependent on extracellular calcium. Vegetative cells grown in media with or without calcium do not sporulate in media devoid of calcium or in CaCl 2 with EGTA. Calcium channel blockers, CoCl 2 and nifedipine, and ionophore A23187 inhibited the induction of sporulation. The calmodulin antagonists trifluoperazine and chlorpromazine inhibited the sporulation when present in the cultures at least 60 min after induction. So, calcium that is accumulated during growth is not sufficient or is not mobilized to initiate sporulation, and a calcium influx is likely to occur by type II calcium channel functions, essential for the response to nutritional starvation. A calmodulin-like protein has been suggested to mediate calcium events in sporulation. ß

show abstract

An analysis of developmental timing in Blastocladiella emersonii sporulation

Cited by 8 publications

References 29 publications

Global Gene Expression Analysis during Sporulation of the Aquatic Fungus Blastocladiella emersonii

Global Gene Expression Analysis during Sporulation of the Aquatic Fungus Blastocladiella emersonii

The induction of sporulation in the aquatic fungusBlastocladiella emersoniiis dependent on extracellular calcium

The induction of sporulation in the aquatic fungus Blastocladiella emersonii is dependent on extracellular calcium

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