Using BrUTP incorporation and statistical analysis, the authors investigated RNA transcription in the interphase nuclei in Physarum polycephalum Schw. The rRNA synthesis in the nucleolus continued actively throughout ...Using BrUTP incorporation and statistical analysis, the authors investigated RNA transcription in the interphase nuclei in Physarum polycephalum Schw. The rRNA synthesis in the nucleolus continued actively throughout the interphase, while in nucleoplasm hnRNA was transcribed at law levels in S phase and actively in G(2) phase. The rate of nucleoplasm RNA transcription was doubled between early S phase and late S phase, and a 5-6 folds increase was detected between the early S phase and G(2) phase.展开更多
The dynamic changes of nucleolar ultrastructure in the cell cycle of Physarum polycephalum Schw. were studied by an en bloc silver-staining method. The results showed that the nucleolus was large in size and situated ...The dynamic changes of nucleolar ultrastructure in the cell cycle of Physarum polycephalum Schw. were studied by an en bloc silver-staining method. The results showed that the nucleolus was large in size and situated in the center of the nucleus in late G(2)-phase, and the fibrillar centers, dense fibrillar components and granular components could be observed in the nucleolus. During prophase, the nucleolus moved towards the periphery of the nucleus and in late prophase disintegrated near the nuclear envelope. in metaphase, the disintegrated nucleolar components were dispersed in masses and located at the periphery of the chromosomal region of the nucleus. No specifically silver-stained area and argentophilic protein sheath were observed on the chromosomes, but there were some big dispersed silver particles within the chromosomes. During telophase the nucleolar components moved towards the two poles along with the chromosomes and co-existed with the decondensing chromatin in daughter nuclei. The nucleolar components then gradually converged with one another and separated from the chromatin. A big nucleolus was formed in the nucleus about 120 min after the completion of mitosis.展开更多
[Objective]The paper was to culture the plasmodia of Physarum pusillum for obtaining the optimal condition of sporophores and sclerotium,to reduce the agricultural diseases.[Method]Liquid culture combined with oat-aga...[Objective]The paper was to culture the plasmodia of Physarum pusillum for obtaining the optimal condition of sporophores and sclerotium,to reduce the agricultural diseases.[Method]Liquid culture combined with oat-agar culture was used to culture plasmodia of P.pusillum.Then plasmodium was induced to obtain Sporophores in lab by hunger and adjusting light（3 000,6 000,9 000,12 000 lx）and temperature（20,22,24,26 ℃）.[Result]Sporophores and sclerotium of P.pusillum were obtained from both oat-agar media and liquid media.The optimal conditions were 26 ℃,6 000 lx and 22 ℃,3 000 lx.[Conclusion]The result provided theoretical basis for reducing the loss of crops caused by myxomycete as much as possible in agricultural production.展开更多
Physarum polycephalum L., a naturally synchronized myxomycophyta, was demonstrated to contain a cyclin B1-like protein by Western blot and immunoelectron microscopy. The content and subcellular location of the protein...Physarum polycephalum L., a naturally synchronized myxomycophyta, was demonstrated to contain a cyclin B1-like protein by Western blot and immunoelectron microscopy. The content and subcellular location of the protein varied during the cell cycle. The cyclin B1-like protein was first detected in the plasmodia of S phase while it did not appear in the nuclei until late G2 phase. The content of the protein in both the plasmodia and nuclei rose gradually onwards, peaked at metaphase and disappeared abruptly at ana-telophase. The protein was found to be distributed in both the cytoplasm and nuclei in late G2 phase and metaphase. In nuclei, the protein was mainly located in the chromosomal and nucleolar areas. The results suggest that the cyclin B1-like protein of P. polycephalum begins to be synthesized at S phase, enters the nuclei at late G2 phase, accumulates in both cytoplasm and nuclei onwards and breaks down at ana-telophase. The results also suggest that the cyclin B1-like protein acts as a cytoplasmic-nuclear protein during certain phases of the cell cycle.展开更多
This paper introduces a novel application of bionic engineering： a bionic musical instrument using Physarum polycephalum. Physarum polycephalum is a huge single cell with thousands of nuclei, which behaves like a gia...This paper introduces a novel application of bionic engineering： a bionic musical instrument using Physarum polycephalum. Physarum polycephalum is a huge single cell with thousands of nuclei, which behaves like a giant amoeba. During its foraging behavior this plasmodium produces electrical activity corresponding to different physiological states. We developed a method to render sounds from such electrical activity and thus represent spatio-temporal behavior of slime mould in a form apprehended auditorily. The electrical activity is captured by various electrodes placed on a Petri dish containing the cultured slime mold. Sounds are synthesized by a bank of parallel sinusoidal oscillators connected to the electrodes. Each electrode is responsible for one partial of the spectrum of the resulting sound. The behavior of the slime mould can be controlled to produce different timbres.展开更多
A known species, Physarum melleum, was found fruiting on living leaves of Dendrobium candidum, which was collected in China in 2004. Its morphological characters were revealed by light microscopy (LM), environmental s...A known species, Physarum melleum, was found fruiting on living leaves of Dendrobium candidum, which was collected in China in 2004. Its morphological characters were revealed by light microscopy (LM), environmental scanning elec- tron microscopy (ESEM) and scanning electron microscopy (SEM). Character variations were distinguished by its olive-yellow peridium and its always thinner capillitium containing globulose granular material between the large calcareous nodes. The cal- cium carbonate granules, deposited on stalks, peridium and hypothallus as well as within stalks, were globose and smooth.展开更多
The nuclei and chromosomes were isolated from plasmodia of Physarum polycephalum. The nuclear matrir and chromosome scaffold were obtained after the DNA and most of the proteins were extracted with DNase I and 2 M NaC...The nuclei and chromosomes were isolated from plasmodia of Physarum polycephalum. The nuclear matrir and chromosome scaffold were obtained after the DNA and most of the proteins were extracted with DNase I and 2 M NaCl. SDS-PAGE analyses revealed that the nuclear matrir and chromosome scaffold contained a 37 kD polypeptide which is equivalent to tropomyosin in molecular weight. Immunofluorescence observations upon slide preparations labeled with anti-tropomyosin antibody showed that the nuclear matrix and chromosome scaffold emanated bright fluorescence, suggesting the presence of the antigen in them.Immunodotting results confirmed the presence of tropomyosin in the nuclear matrix and chromosome scaffold. Immunoelectron microscopic obserwtions further demonstrated that tropomyosin was dispersively distributed in the interphase nuclei and metaphase chromosomes.展开更多
CDKs play key roles in controlling cell cycle progression in all eukaryotes. In plants, multiple CDKs are present,among which the best characterized CDKs are PSTAIRE CDKs. In this study, we carried out Western blot,im...CDKs play key roles in controlling cell cycle progression in all eukaryotes. In plants, multiple CDKs are present,among which the best characterized CDKs are PSTAIRE CDKs. In this study, we carried out Western blot,immunoelectron microscopy and antibody treatment with an anti-PSTAIRE monoclonal antibody to explore the subcellular localization and functions of PSTAIRE CDKs in Physarum polycephalum. The results of Western blot and immunoelectron microscopy showed that in P. polycephalum, a PSTAIRE CDK-like protein was 34 kD in molecular weight and located in both nuclei and cytoplasm. In nuclei, the protein was mainly associated with chromosomes and nucleoli. The expression of the PSTAIRE CDK-like protein in both the plasmodia and nuclei showed little fluctuation through the whole cell cycle. When treated with an anti-PSTAIRE monoclonal antibody at early S phase, the cells were arrested in S phase, and the mitotic onset of P. polycephalum was blocked for about 1 h when treated at early G2 phase.Our data indicated that the PSTAIRE CDK- like protein has a direct bearing on the mitosis.展开更多
Features of tectonin I and II expression in Physarum polycephalum cells were examined at both the protein and mRNA levels. Among the five cell cycle stages of P. polycephalum, the plasmodia, microplasmodia, and sclero...Features of tectonin I and II expression in Physarum polycephalum cells were examined at both the protein and mRNA levels. Among the five cell cycle stages of P. polycephalum, the plasmodia, microplasmodia, and sclerotia contained both tectonin I and tectonin II;the spores did not contain any of these;and the amoebae contained tectonin I, but not tectonin II. When the mating of amoebae formed plasmodia, the mRNA and protein levels of tectonin II increased with the growth of zygotes. In the early stage of differentiation from plasmodia to spores, the mRNA levels of tectonins I and II decreased. Tectonins I and II were associated with the membrane fraction that precipitated at 200,000 ×g and could be released only by urea treat-ment of this fraction. Furthermore, when the fraction was digested with proteinase K, tectonin II completely disappeared. Immunofluoromicroscopy indicated that tectonins I and II exist in the lamellipodia of plasmo-dia.展开更多
In this paper, we demonstrate that in Physarum polycephalum, a naturally synchronized slime mold, histone deacetylase (HDAC) inhibitor Trichostatin A (TSA), arrestes the cell cycle at the checkpoints of S/G2, G2/M and...In this paper, we demonstrate that in Physarum polycephalum, a naturally synchronized slime mold, histone deacetylase (HDAC) inhibitor Trichostatin A (TSA), arrestes the cell cycle at the checkpoints of S/G2, G2/M and mitosis exit, and influences the transcription of two ras genes Ppras1 and Pprap1, as well as the Ras protein level. Antibody neu-tralization experiment using anti-Ras antibody treatment showed that Ras protein played an important role in cell cycle checkpoint control through regulation of the level of Cyclin B1, suggesting that Ras protein might be a key factor for histone acetylation-mediated cell cycle regulation in P. polycephalum.展开更多
文摘Using BrUTP incorporation and statistical analysis, the authors investigated RNA transcription in the interphase nuclei in Physarum polycephalum Schw. The rRNA synthesis in the nucleolus continued actively throughout the interphase, while in nucleoplasm hnRNA was transcribed at law levels in S phase and actively in G(2) phase. The rate of nucleoplasm RNA transcription was doubled between early S phase and late S phase, and a 5-6 folds increase was detected between the early S phase and G(2) phase.
文摘The dynamic changes of nucleolar ultrastructure in the cell cycle of Physarum polycephalum Schw. were studied by an en bloc silver-staining method. The results showed that the nucleolus was large in size and situated in the center of the nucleus in late G(2)-phase, and the fibrillar centers, dense fibrillar components and granular components could be observed in the nucleolus. During prophase, the nucleolus moved towards the periphery of the nucleus and in late prophase disintegrated near the nuclear envelope. in metaphase, the disintegrated nucleolar components were dispersed in masses and located at the periphery of the chromosomal region of the nucleus. No specifically silver-stained area and argentophilic protein sheath were observed on the chromosomes, but there were some big dispersed silver particles within the chromosomes. During telophase the nucleolar components moved towards the two poles along with the chromosomes and co-existed with the decondensing chromatin in daughter nuclei. The nucleolar components then gradually converged with one another and separated from the chromatin. A big nucleolus was formed in the nucleus about 120 min after the completion of mitosis.
基金Supported by National Natural Science Foundation of China(70670015,71070012)~~
文摘[Objective]The paper was to culture the plasmodia of Physarum pusillum for obtaining the optimal condition of sporophores and sclerotium,to reduce the agricultural diseases.[Method]Liquid culture combined with oat-agar culture was used to culture plasmodia of P.pusillum.Then plasmodium was induced to obtain Sporophores in lab by hunger and adjusting light（3 000,6 000,9 000,12 000 lx）and temperature（20,22,24,26 ℃）.[Result]Sporophores and sclerotium of P.pusillum were obtained from both oat-agar media and liquid media.The optimal conditions were 26 ℃,6 000 lx and 22 ℃,3 000 lx.[Conclusion]The result provided theoretical basis for reducing the loss of crops caused by myxomycete as much as possible in agricultural production.
文摘Physarum polycephalum L., a naturally synchronized myxomycophyta, was demonstrated to contain a cyclin B1-like protein by Western blot and immunoelectron microscopy. The content and subcellular location of the protein varied during the cell cycle. The cyclin B1-like protein was first detected in the plasmodia of S phase while it did not appear in the nuclei until late G2 phase. The content of the protein in both the plasmodia and nuclei rose gradually onwards, peaked at metaphase and disappeared abruptly at ana-telophase. The protein was found to be distributed in both the cytoplasm and nuclei in late G2 phase and metaphase. In nuclei, the protein was mainly located in the chromosomal and nucleolar areas. The results suggest that the cyclin B1-like protein of P. polycephalum begins to be synthesized at S phase, enters the nuclei at late G2 phase, accumulates in both cytoplasm and nuclei onwards and breaks down at ana-telophase. The results also suggest that the cyclin B1-like protein acts as a cytoplasmic-nuclear protein during certain phases of the cell cycle.
文摘This paper introduces a novel application of bionic engineering： a bionic musical instrument using Physarum polycephalum. Physarum polycephalum is a huge single cell with thousands of nuclei, which behaves like a giant amoeba. During its foraging behavior this plasmodium produces electrical activity corresponding to different physiological states. We developed a method to render sounds from such electrical activity and thus represent spatio-temporal behavior of slime mould in a form apprehended auditorily. The electrical activity is captured by various electrodes placed on a Petri dish containing the cultured slime mold. Sounds are synthesized by a bank of parallel sinusoidal oscillators connected to the electrodes. Each electrode is responsible for one partial of the spectrum of the resulting sound. The behavior of the slime mould can be controlled to produce different timbres.
基金Project (No. 2001BA744C) supported by the 10th Five-year National Key Technologies R & D Program, China
文摘A known species, Physarum melleum, was found fruiting on living leaves of Dendrobium candidum, which was collected in China in 2004. Its morphological characters were revealed by light microscopy (LM), environmental scanning elec- tron microscopy (ESEM) and scanning electron microscopy (SEM). Character variations were distinguished by its olive-yellow peridium and its always thinner capillitium containing globulose granular material between the large calcareous nodes. The cal- cium carbonate granules, deposited on stalks, peridium and hypothallus as well as within stalks, were globose and smooth.
文摘The nuclei and chromosomes were isolated from plasmodia of Physarum polycephalum. The nuclear matrir and chromosome scaffold were obtained after the DNA and most of the proteins were extracted with DNase I and 2 M NaCl. SDS-PAGE analyses revealed that the nuclear matrir and chromosome scaffold contained a 37 kD polypeptide which is equivalent to tropomyosin in molecular weight. Immunofluorescence observations upon slide preparations labeled with anti-tropomyosin antibody showed that the nuclear matrix and chromosome scaffold emanated bright fluorescence, suggesting the presence of the antigen in them.Immunodotting results confirmed the presence of tropomyosin in the nuclear matrix and chromosome scaffold. Immunoelectron microscopic obserwtions further demonstrated that tropomyosin was dispersively distributed in the interphase nuclei and metaphase chromosomes.
基金This work was supported by the National Natural Science Foundation of China(No.39870389)the Supported by the Excellent Young Teachers Program of MOE,P.R.C.
文摘CDKs play key roles in controlling cell cycle progression in all eukaryotes. In plants, multiple CDKs are present,among which the best characterized CDKs are PSTAIRE CDKs. In this study, we carried out Western blot,immunoelectron microscopy and antibody treatment with an anti-PSTAIRE monoclonal antibody to explore the subcellular localization and functions of PSTAIRE CDKs in Physarum polycephalum. The results of Western blot and immunoelectron microscopy showed that in P. polycephalum, a PSTAIRE CDK-like protein was 34 kD in molecular weight and located in both nuclei and cytoplasm. In nuclei, the protein was mainly associated with chromosomes and nucleoli. The expression of the PSTAIRE CDK-like protein in both the plasmodia and nuclei showed little fluctuation through the whole cell cycle. When treated with an anti-PSTAIRE monoclonal antibody at early S phase, the cells were arrested in S phase, and the mitotic onset of P. polycephalum was blocked for about 1 h when treated at early G2 phase.Our data indicated that the PSTAIRE CDK- like protein has a direct bearing on the mitosis.
文摘Features of tectonin I and II expression in Physarum polycephalum cells were examined at both the protein and mRNA levels. Among the five cell cycle stages of P. polycephalum, the plasmodia, microplasmodia, and sclerotia contained both tectonin I and tectonin II;the spores did not contain any of these;and the amoebae contained tectonin I, but not tectonin II. When the mating of amoebae formed plasmodia, the mRNA and protein levels of tectonin II increased with the growth of zygotes. In the early stage of differentiation from plasmodia to spores, the mRNA levels of tectonins I and II decreased. Tectonins I and II were associated with the membrane fraction that precipitated at 200,000 ×g and could be released only by urea treat-ment of this fraction. Furthermore, when the fraction was digested with proteinase K, tectonin II completely disappeared. Immunofluoromicroscopy indicated that tectonins I and II exist in the lamellipodia of plasmo-dia.
基金This work was supported by the National Natural Science Foundation of China(Grant No.30370316)National Basic Research Program of China(Grant No.2005CB522404)Young Teacher Foundation of Northeast Normal University(Grant No.111494025).
文摘In this paper, we demonstrate that in Physarum polycephalum, a naturally synchronized slime mold, histone deacetylase (HDAC) inhibitor Trichostatin A (TSA), arrestes the cell cycle at the checkpoints of S/G2, G2/M and mitosis exit, and influences the transcription of two ras genes Ppras1 and Pprap1, as well as the Ras protein level. Antibody neu-tralization experiment using anti-Ras antibody treatment showed that Ras protein played an important role in cell cycle checkpoint control through regulation of the level of Cyclin B1, suggesting that Ras protein might be a key factor for histone acetylation-mediated cell cycle regulation in P. polycephalum.
