Messenger RNA in Dormant Cells of Sterkiella histriomuscorum (Oxytrichidae): Identification of Putative Regulatory Gene Transcripts

Tourancheau, Anne Baroin; Morin, Loı̈c; Yang, Tié; Perasso, Roland

doi:10.1016/s1434-4610(99)70017-9

Cited by 20 publications

(19 citation statements)

References 20 publications

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“…However, these spore transcripts may also have a more dedicated role. Stored mRNA is also found in a number of dormant biological systems, such as sporangiospores of the fungus Mucor racemosus, seeds of Arabidobsis thaliana, spores of the fern Onoclea sensibilis, and cysts (31,36,42,66). In these cases, the stored mRNA is rapidly translated upon activation and germination Alternatively, the stored late-sporulation transcripts have a regulatory role, similar to the case for the small regulatory RNA molecules identified in prokaryotic and eukaryotic cells (17,63,71,72).…”

Section: Resultsmentioning

confidence: 90%

Analysis of Temporal Gene Expression duringBacillus subtilisSpore Germination and Outgrowth

et al. 2007

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Bacillus subtilis forms dormant spores upon nutrient depletion. Under favorable environmental conditions, the spore breaks its dormancy and resumes growth in a process called spore germination and outgrowth. To elucidate the physiological processes that occur during the transition of the dormant spore to an actively growing vegetative cell, we studied this process in a time-dependent manner by a combination of microscopy, analysis of extracellular metabolites, and a genome-wide analysis of transcription. The results indicate the presence of abundant levels of late sporulation transcripts in dormant spores. In addition, the results suggest the existence of a complex and well-regulated spore outgrowth program, involving the temporal expression of at least 30% of the B. subtilis genome.A number of bacterial species such as bacilli and clostridia have the ability to form dormant spores. The spore has a specialized and complex structure, enabling the organism to survive for a long time under harsh environmental conditions and in the absence of nutrients. When triggered by specific nutrients, the spore is capable of breaking dormancy (germination) and initiating vegetative growth (34, 52). The Bacillus subtilis spore is composed of a dehydrated central compartment (the spore core) engulfed by two protective outer layers: a thick spore-specific peptidoglycan layer known as the spore cortex and a multilayered protein structure known as the coat (12).The process of endospore formation in Bacillus subtilis has been studied in great detail. Studies have revealed a highly ordered and strictly regulated program ensuring the correct coordination of various aspects of the sporulation process, such as asymmetric cell division, prespore engulfment, spore maturation, and mother cell lysis (22). The sporulation program involves the timed activation of several mother cell and forespore compartment-and sporulation stage-dependent RNA polymerase sigma factors that transcribe specific sets of sporulation genes. Eventually, the sporulation program results in the lysis of the mother cell and the release of a dormant spore (22).The process of spore germination and outgrowth has been studies in less detail. Spore germination is initiated when the spore senses the appropriate trigger molecules, often simple sugars and/or amino acids. The germinant molecules are sensed by germination receptors. This, by an unknown mechanism, leads to an irreversible commitment of a spore to germination. The germinating spore initially releases Zn 2ϩ and H ϩ (65). Simultaneously (and probably as a consequence), the pH of the spore core rises from 6.5 to 7.7. In a second stage, the germinating spore releases the spore core's large supply of dipicolinic acid (pyridine-2,6-dicarboxylic acid), and the spore core is rehydrated. Subsequently, cortex lytic enzymes are activated and the protective spore peptidoglycan cortex is degraded. This enables the germinating spore to hydrate the spore core further and to swell. These germination events coincide with a loss of...

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Section: Resultsmentioning

confidence: 90%

Analysis of Temporal Gene Expression duringBacillus subtilisSpore Germination and Outgrowth

et al. 2007

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“…Nevertheless, the accumulation of specific mRNA molecules associated with the cryptobiotic process has been reported in both prokaryotic (Albertson et al, 1990) and eukaryotic cells. In the ciliates Colpoda inflata (Benitez and Gutiérrez, 1997) and Sterkiella histriomuscorum (Tourancheau et al, 1999), mRNAs were found in resting cysts. Several fungal species produce dormant spores containing stored mRNA (Camonis et al, 1982) and, in Acanthamoeba, Byers et al (1991) managed to isolate mRNA from resting cysts that was capable of actin translation in vitro.…”

Section: Discussionmentioning

confidence: 99%

Stress gene (hsp70) sequences and quantitative expression inMilnesium tardigradum(Tardigrada) during active and cryptobiotic stages

Schill

Steinbrück²,

Köhler

2004

Journal of Experimental Biology

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SUMMARY The eutardigrade Milnesium tardigradum can undergo cryptobiosis,i.e. entry into a reversible ametabolic stage induced by dehydration, cooling and, probably, osmotic and anoxic stress. For the first time in tardigrades,we described partial sequences of three heat-shock protein (hsp70family) genes and examined gene expression on the way from an active to a cryptobiotic and back to an active stage again. Results showed different patterns of gene expression in the hsp70 isoforms. All three isoforms seem to be true heat-shock proteins since transcription could be clearly enhanced by temperature elevation. Isoform 1 and, at a lower level, isoform 3 do not seem to have a specific function for cryptobiosis. By contrast,transcription of isoform 2 is significantly induced in the transitional stage between the active and the cryptobiotic stage, resulting in a comparatively high mRNA copy number also during cryptobiosis. This pattern of induction implies that isoform 2 is the most relevant hsp70 gene for M. tardigradum individuals entering the cryptobiotic stage.

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“…The three chromosomes AY883853, AY883855, and AY883856 have been recovered from recombinant clones of a partial genomic ordered library constructed as follows: macronuclear DNA molecules 1-3 kb long were blunt-ended by removing telomeric 3′ overhangs using a T4 DNA polymerase, ligated with EcoRI linkers, and cloned at the EcoRI site of the pBluescriptSK + plasmid (Stratagene, France). Southern and Northern blot hybridizations were done as described by Baroin-Tourancheau et al (1999) and Villalobo et al (2001) using α-dATP( 32 P)-labeled probes.…”

Section: Molecular Analyses Of Dna and Cdna Moleculesmentioning

confidence: 99%

“…The analysis of gene expression during the encystmentexcystment cycle of S. histriomuscorum gave us the opportunity to isolate hundreds of expressed sequence tags (ESTs) through differential screening of cDNA libraries (Baroin-Tourancheau et al 1999), construction of timespecific libraries (Villalobo et al 2003), and messenger ribonucleic acid (mRNA) differential display analyses (Villalobo et al 2002;Lescasse et al 2005). Here, we describe the corresponding macronuclear chromosome structure of a subset (18 cDNAs) of our S. histriomuscorum EST database.…”

Section: Introductionmentioning

confidence: 99%

Gene structure of the ciliate Sterkiella histriomuscorum based on a combined analysis of DNA and cDNA sequences from 21 macronuclear chromosomes

et al. 2005

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Macronuclear deoxyribonucleic acid (DNA) in hypotrichous ciliates consists of a set of linear molecules ranging in size from 0.5 to several tens of kilobases and typically carrying a single gene. Each minichromosome is present at a ploidy of >or=1,000 per macronucleus. These molecules are known as gene-sized molecules. Multigene molecules are also present, but are still poorly described. In analyzing the encystment-excystment cycle of Sterkiella histriomuscorum, we have characterized a set of 21 macronuclear molecules both at the DNA and complementary DNA (cDNA) levels. On a total of 23 validated coding sequences, we mapped the 5' and 3' untranslated regions for a subset of 10 and 18 transcripts, respectively. A combination of DNA and cDNA data allows us to precisely determine several structural features of macronuclear chromosomes, such as the organization of multigene molecules, an intron content higher than expected, and a conserved sequence surrounding the initiation transcription site. It also reveals one coding sequence containing a transcribed 10-bp element that displays the characteristic features of internal eliminated sequences (IES). Its presence in a fraction of the minichromosomes carrying this gene raises the possibility of an incomplete IES excision process during the development of the S. histriomuscorum macronucleus.

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Messenger RNA in Dormant Cells of Sterkiella histriomuscorum (Oxytrichidae): Identification of Putative Regulatory Gene Transcripts

Cited by 20 publications

References 20 publications

Analysis of Temporal Gene Expression duringBacillus subtilisSpore Germination and Outgrowth

Analysis of Temporal Gene Expression duringBacillus subtilisSpore Germination and Outgrowth

Stress gene (hsp70) sequences and quantitative expression inMilnesium tardigradum(Tardigrada) during active and cryptobiotic stages

Gene structure of the ciliate Sterkiella histriomuscorum based on a combined analysis of DNA and cDNA sequences from 21 macronuclear chromosomes

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