Photomorphogenesis in Physarum: induction of tubulins and sporulation-specific proteins and of their mRNAs.

Putzer, Harald; Verfuerth, Cornelia; Claviez, Michael; Schreckenbach, Thomas

doi:10.1073/pnas.81.22.7117

Cited by 25 publications

(30 citation statements)

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“…The induction of tubulin synthesis during light-induced differentiation has recently been reported [9] and we detect tubulin mRNA in starving, sporulation-competent as well as in sporulating plasmodia (unpublished results). We therefore asked whether the betB locus is also expressed in the differentiation process.…”

Section: Expression Of the Betb Genesupporting

confidence: 73%

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Cloning and expression of a β tubulin gene of Physarum polycephalum

Werenskiold

Poetsch

Haugli

1988

European Journal of Biochemistry

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A p tubulin gene of Physarum polycephalum has been isolated from a genomic library in the phage EMBL4.Southern-blot hybridization to genomic DNA indicates that the cloned DNA is derived from the betB1 locus of the p tubulin gene family. A tubulin-specific subfragment of the phage DNA was used as a hybridization probe to construct a restriction map of the betBI locus. The probe consisted of the almost complete coding region of the 5' half of the tubulin gene, interrupted by one intron. The derived amino acid sequence of this subclone deviates from the protein sequence for Physarum amoebal p tubulin (amino acids 4-207) in two of 207 amino acids. We used both recA and recBC sbcB bacterial host strains, which have been recommended for cloning of instability-conferring sequences of the Physarum genome, but were unable to subclone the 3' part of the gene from the phage DNA. Primer-extension analysis indicates that the betB gene is expressed in the vegetatively proliferating amoebal and plasmodia1 stages of the life cycle as well as in differentiating (sporulating) plasmodia.In uninucleate myxamoebae of Physarum polycephalum microtubuli serve varied functions as components of the cytoskeleton, of the flagella and in the mitotic spindle. In multinucleate plasmodia, on the other hand, microtubuli are used only in the closed mitotic spindle [l]. Surprisingly, twodimensional electrophoresis resolves tubulins into al and p1 isotypes in amoebae, and a l , a2, PI, pz isotypes in plasmodia [2]. Recent studies show that these electromorphs are composed of different subspecies [3, 41 at least some of which are encoded by distinct genes. While cloning and analysis of the LY tubulin genes and their expression are in progress [5], the analysis of p tubulin genes and their expression is hampered by a lack of cloned p tubulin sequences. The futility of attempts of various laboratories to isolate / 3 tubulin genes has been attributed to an instability of cloned p tubulin genes caused by internal repetitive sequences [6]. In spite of the considerable efforts of various laboratories, the number of cloned Physarum genes is still very limited. The problems encountered in the cloning of genomic DNA may be due to the occurrence of repetitive sequences throughout the genome that lead to the formation of hairpin structures. These can be visualized in the electron microscope at regular intervals of approx. 7 kb [7]. Formation of such hairpin structures might interfere with the replication of recombinant cloning vectors. Recently Nader and coworkers [8] demonstrated that part of the Physarum genome can be stably cloned only in recBC sbcB bacterial host strains. These authors identified a small fragment of 360 bp that conferred instability to a cloned actin gene, in recA host strains.Here we report the cloning of a Physarum p tubulin gene. recombinant EMBL4 phage. Southern-blot hybridization, DNA sequence and expression analysis suggest that the cloned DNA is derived from the betB locus. Subcloning and analysis of the 3' half of the gene has not...

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Section: Expression Of the Betb Genesupporting

confidence: 73%

“…Plasmodia of Physarum strains CL and MC,VIII were cultured and induced to sporulate as described [9]. Amoebae of strain MA185 were grown axenically in the same medium.…”

Section: Culture Conditionsmentioning

confidence: 99%

Cloning and expression of a β tubulin gene of Physarum polycephalum

Werenskiold

Poetsch

Haugli

1988

European Journal of Biochemistry

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“…Growth and starvation conditions were kept exactly as described (17). Sporulation was induced at the fourth day of starvation by illumination with fluorescent white light (17). studies, macroplasmodia were transferred with the paper support to 10 ml growth medium containing appropriate concentrations of the drug.…”

Section: Methodsmentioning

confidence: 99%

Specific nuclear elimination in polyploid plasmodia of the slime mold physarum polycephalum

1988

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In growing plasmodia of the myxomycete Physamm polycephalum (G2-phase), three distinct classes of nuclei with a relative DNA content of lx, 2x, and 4x are observed in the presumed haploid strain CL. The 2x and 4x species comprise up to 35% and 5% of the nuclei. Quantitative cytofluorometric studies of nuclei isolated in either G2-or S-phase or after FUDR treatment (G1 arrest) show that the three nuclear populations undergo a synchronous mitotic cycle and that the relative DNA content of the nuclear fractions in G-2 phase reflects the 2c, 4c, and 8c state.The heterogeneity of the nuclear population does, however, seem to be restricted to the growth phase. During a starvation period of 4 days that always preceeds sporulation (and also meiosis), the 4c nuclear population is reduced to 7%, 8c nuclei are no longer detected. These results suggest that a mechanism exists in Physarum for the selective detection and elimination of polyploid nuclei.Key terms: Macroplasmodia, myxomycete, heploid stain, starvation, cell growth Plasmodia of the myxomycete Physarum. polyce phalum are unicellular, multinucleate organisms. The plasmodia1 cell cycle is characterized by synchronous nuclear divisions (6,9,15) and the lack of a G1-phase (21). After nutrient deprivation for 3 to 5 days, plasmodia are induced to sporulate by light (4). The formation of spores is accompanied by meiotic divisions (11). Germinating spores release single uninucleate amoebae, which, upon fusion with amoebae of different mating type, reform plasmodia,The colonia (CL) isolate differs from heterothallic P h y sarurn strains in that plasmodium formation occurs without amoeba1 fusion. CL plasmodia are therefore haploid in contrast to the generally diploid heterothallic strains (1,131. A low degree of diploidization, however, appears to be essential for the formation of viable spores in the CL strain (12). It has recently been reported that haploid strains, which were kept for extended periods in submerse culture, revealed a high degree of mixoploidy (10).A specific elimination of nuclei has been observed in Physarum heterokaryons. In a genetic analysis, Dee and Anderson (5) reported the elimination of diploid nuclei from haploid/diploid heterokaryons during growth phase; a similar effect was observed under starvation conditions (14).In this report we show that polyploidization in the strain CL may occur at a high level in plasmodia during growth and that the polyploid nuclei are gradually reduced to a minute amount during a prolonged starvation period. Thus we extend earlier findings of nuclear d e g radation in Physarurn heterokaryons to a naturally polyploidized strain, suggesting that a selective mechanism exists to include polyploid nuclei from meiosis. MATERIALS AND METHODSPlasmodia1 Culture Plasmodia of the colonia strain (CL) were generated by plating spores on agar made from dilute (33%) semidefined growth medium (3). Surface plasmodia were scraped from the agar, transferred to shake flasks containing growth medium, and cultured as microplasmodia at 24...

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“…During fruiting body formation of fungus Physarum polycephalum , the most prominent syntheses of an actin decreased while two tubulins T1 and T2 were strongly increased (Putzer et al 1984; Poetsch et al 1989). Increased tubulins suggest the cellular reconstruction is active during fruiting body formation.…”

Section: Proteins Involved In Cell Reconstructionmentioning

confidence: 99%

Potential molecular mechanisms for fruiting body formation of Cordyceps illustrated in the case ofCordyceps sinensis

et al. 2017

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The fruiting body formation mechanisms of Cordyceps sinensis are still unclear. To explore the mechanisms, proteins potentially related to the fruiting body formation, proteins from fruiting bodies, and mycelia of Cordyceps species were assessed by using two-dimensional fluorescence difference gel electrophoresis, and the differential expression proteins were identified by matrix-assisted laser desorption/ionisation tandem time of flight mass spectrometry. The results showed that 198 differential expression proteins (252 protein spots) were identified during the fruiting body formation of Cordyceps species, and 24 of them involved in fruiting body development in both C. sinensis and other microorganisms. Especially, enolase and malate dehydrogenase were first found to play an important role in fruiting body development in macro-fungus. The results implied that cAMP signal pathway involved in fruiting body development of C. sinensis, meanwhile glycometabolism, protein metabolism, energy metabolism, and cell reconstruction were more active during fruiting body development. It has become evident that fruiting body formation of C. sinensis is a highly complex differentiation process and requires precise integration of a number of fundamental biological processes. Although the fruiting body formation mechanisms for all these activities remain to be further elucidated, the possible mechanism provides insights into the culture of C. sinensis.

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Photomorphogenesis in Physarum: induction of tubulins and sporulation-specific proteins and of their mRNAs.

Cited by 25 publications

References 25 publications

Cloning and expression of a β tubulin gene of Physarum polycephalum

Cloning and expression of a β tubulin gene of Physarum polycephalum

Specific nuclear elimination in polyploid plasmodia of the slime mold physarum polycephalum

Potential molecular mechanisms for fruiting body formation of Cordyceps illustrated in the case ofCordyceps sinensis

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