Induction of sporulation inBlastocladiella emersonii: Influence of nutritional variables

Corrêa, Luiz Carlos; Lodi, Wilson Roberto Navega

doi:10.1016/0147-5975(86)90012-5

Cited by 7 publications

(18 citation statements)

References 21 publications

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“…The effect of subinhibitory concentrations of glucose and tryptophan on gene expression during the sporulation phase was also analyzed, and data obtained suggest that these nutrients affect the sporulation process differently, even though both nutrients can block zoospore biogenesis when added in large amounts (3). The presence of 1% glucose in the sporulation solution led to the overexpression of genes involved in cytoskeleton composition and function.…”

Section: Resultsmentioning

confidence: 99%

“…In Saccharomyces cerevisiae, it was reported that cells overexpressing the cofilin gene were unable to survive, indicating that expression of cofilin should be appropriately regulated for normal cell growth (13). Since the actin cytoskeleton is involved in various cellular processes such as cell motility and division and since cofilin is the unique actin-regulatory protein essential for cell viability in S. cerevisiae (12,25), Dictyostelium discoideum (1), Drosophila melanogaster (11), and Caenorhabditis elegans (24), it is possible that the transcriptional rise observed for cofilin and profilin genes during B. emersonii sporulation in the presence of glucose could explain the block in sporulation that was shown to occur at higher concentrations of this carbohydrate (3).…”

Section: Resultsmentioning

confidence: 99%

“…In the presence of high glucose concentrations (Ն2%), B. emersonii cells induced to sporulate fail to progress to the empty-zoosporangium stage even 320 min after induction (the half-life [T 50 ] of normal sporulation control for empty zoosporangia is 210 min) (3). In the presence of 2% glucose, significant delays in basal septum formation and especially in the appearance of papillated zoosporangia are observed (3). To investigate the effect of glucose on global gene expression during sporulation of B. emersonii, cells were induced to sporulate in the presence of a subinhibitory concentration of glucose (1%) and microarray experiments were carried out.…”

Section: Resultsmentioning

confidence: 99%

“…The process culminates in the production and release of a number of motile zoospores to the medium. This synchronized sequence of events can, however, be disturbed by nutritional variables such as (i) Casamino Acids, which promote the return of the cells to the growth phase when added to cultures together with the sporulation solution and before septum formation; (ii) certain amino acids that either prevent (tyrosine, phenylalanine, tryptophan, histidine, and threonine) or delay (valine, serine, arginine, and methionine) septum formation when added to early sporulation cultures; and (iii) sugars such as glucose, which can block zoospore biogenesis (3).…”

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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: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

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

Vieira

Gomes

2010

Eukaryot Cell

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“…The aquatic fungus B. emersonii possesses a life cycle with synchronous growth and cellular di¡erentiation phases easily manipulated in the laboratory [13]. Although sporulation can be induced by changing growth media to a bu¡ered calcium chloride solution, the importance of calcium has not been properly evaluated yet.…”

Section: Discussionmentioning

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

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An analysis of developmental timing in Blastocladiella emersonii sporulation

Peralta¹,

Lodi²

1988

Developmental Biology

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Induction of sporulation inBlastocladiella emersonii: Influence of nutritional variables

Cited by 7 publications

References 21 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 fungus Blastocladiella emersonii is dependent on extracellular calcium

An analysis of developmental timing in Blastocladiella emersonii sporulation

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