The Experts below are selected from a list of 510 Experts worldwide ranked by ideXlab platform
Maria Kwiatkowska - One of the best experts on this subject based on the ideXlab platform.
-
Short Communication Effect of GA3 Treatment on the Number of Spermatozoids and Endopolyploidy Levels of Non-Generative Cells in Antheridia of Chara
2016Co-Authors: Vulgaris L, Maria Kwiatkowska, Agnieszka Wojtczak, Katarzyna Poptoriska, Key Antheridium, Chara EndoreplicationAbstract:The youngest nodes located under an apical bud of Chara vulgaris were isolated and cultivated in the presence or absence of 10~s M GA3 under laboratory conditions to form spermatozoids. GA3 increased the DNA C-value in manubria by 20 % and increased the number of spermato-zoids per antheridium over 2-fold
-
sitze variation in the antheridia and oogonia of Chara vulgaris under different experimental conditions
Acta Societatis Botanicorum Poloniae, 2014Co-Authors: Maria Kwiatkowska, Agnieszka Pala, Janusz MaszewskiAbstract:Changes in sizes and shapes of sex organs - antheridia and oogonia - were studied in wild populations of Chara vulgaris collected during summer, autumn, and from samples cultured in the laboratory under varying L:D and temperature conditions. Morphometric measurements indicate that the size variations refer mainly to male sex organs, while those evidenced for oogonia are much lower. Our observations are discussed in terms of changing morphogenetic preferences for antheridia and oogonia within the life-span of a plant.
-
effects of gibberellic acid and amo 1618 on the development of vegetative systems in generatively matured thalli of Chara vulgaris l
Acta Societatis Botanicorum Poloniae, 2014Co-Authors: Maria Kwiatkowska, Miroslaw GodlewskiAbstract:Effects of GA 3 (10 -11 -10 -4 M) and AMO-1618 (10 -6 -10 -4 M) on the development of generatively matured thalli of Chara vulgaris were investigated during 21-day culture of plants in axenic conditions. It has been found that in the main bud the divisions of apical cells of the thalli are not stimulated by GA 3 , whereas in the lateral buds the cell divisions are stimulated by higher GA 3 concentrations. Subsequent mitotic activity of the apical cells in the branches of the main axis is not stimulated by GA 3 , whereas the lateral buds of these branches are activated. The development of rhizoids in younger nodes is accelerated by high GA 3 concentrations. The elongation of the polynuclear, internodal cells of the main axis and that of pleuridia are inhibited proportionally to the GA 3 concentration. AMO-1618 stimulates the development of new nodes, elongation of internodes and delays the activation of lateral buds as well as the formation of rhizoids. These results suggest that the GA 3 -induced inhibition of elongation of the thalli and diminution of the apical domination is connected with a high level of endogenous gibberellins in the generatively matured thallus.
-
The effect of cadmium on growth of vegetative thallus and development of generative organs of Chara vulgaris L. after short time of cultivation
Polish Botanical Society, 2014Co-Authors: Aleksandra Gosek, Maria Kwiatkowska, Robert DuszyńskiAbstract:The effect of cadmium ions in two different concentrations (10-8M i 10-6M) on vegetative thallus, male (antheridia) and femele (oogonia) generative organs of Chara vulgaris L. was investigated. After 9 days of growth in a presence of cadmium the number of lateral branches decreased and the lengths of internodes of the main axis and pleuridia became shortened. The increase in oospores volume and decrease in antheridial volume (both total and internal) after 3, 7 and 9 days of cultivation were observed. The productivity of antheridium measured by the number of antheridial filaments and number of cells within filament is also lower in plants cultivated with cadmium in comparison with control ones
-
Size-variation in the antheridia and oogonia of Chara vulgaris under different experimental conditions
Polish Botanical Society, 2014Co-Authors: Maria Kwiatkowska, Agnieszka Pala, Janusz MaszewskiAbstract:Changes in sizes and shapes of sex organs - antheridia and oogonia - were studied in wild populations of Chara vulgaris collected during summer, autumn, and from samples cultured in the laboratory under varying L:D and temperature conditions. Morphometric measurements indicate that the size variations refer mainly to male sex organs, while those evidenced for oogonia are much lower. Our observations are discussed in terms of changing morphogenetic preferences for antheridia and oogonia within the life-span of a plant
Agnieszka Wojtczak - One of the best experts on this subject based on the ideXlab platform.
-
blocking the bromodomains function contributes to disturbances in alga Chara vulgaris spermatids differentiation
Cells, 2020Co-Authors: Agnieszka WojtczakAbstract:Bromodomain containing (BRD) proteins play an essential role in many cellular processes. The aim of this study was to estimate activity of bromodomains during alga Chara vulgaris spermatids differentiation. The effect of a bromodomain inhibitor, JQ1 (100 µM), on the distribution of individual stages of spermatids and their ultrastructure was studied. The material was Feulgen stained and analysed in an electron microscope. JQ1 caused shortening of the early stages of spermiogenesis and a reverse reaction at the later stages. Additionally, in the same antheridium, spermatids at distant developmental stages were present. On the ultrastructural level, chromatin fibril system disorders and significantly distended endoplasmic reticulum (ER) cisternae already at the early stages were observed. Many autolytic vacuoles were also visible. The ultrastructural disturbances intensified after prolonged treatment with JQ1. The obtained data show that JQ1 treatment led to changes in the spermatid number and disturbances in chromatin condensation and to cytoplasm reduction. The current studies show some similarities between C. vulgaris and mammals spermiogenesis. Taken together, these results suggest that JQ1 interferes with the spermatid differentiation on many interdependent levels and seems to induce ER stress, which leads to spermatid degeneration. Studies on the role of bromodomains in algae spermiogenesis have not been conducted so far.
-
Short Communication Effect of GA3 Treatment on the Number of Spermatozoids and Endopolyploidy Levels of Non-Generative Cells in Antheridia of Chara
2016Co-Authors: Vulgaris L, Maria Kwiatkowska, Agnieszka Wojtczak, Katarzyna Poptoriska, Key Antheridium, Chara EndoreplicationAbstract:The youngest nodes located under an apical bud of Chara vulgaris were isolated and cultivated in the presence or absence of 10~s M GA3 under laboratory conditions to form spermatozoids. GA3 increased the DNA C-value in manubria by 20 % and increased the number of spermato-zoids per antheridium over 2-fold
-
immunocytochemical and immunogold analyses of histone h4 acetylation during Chara vulgaris spermiogenesis
Micron, 2016Co-Authors: Agnieszka WojtczakAbstract:Abstract Histone acetylation is one of the epigenetic modifications which play a significant role in chromatin remodeling during spermiogenesis. Acetylation of the histone H4 makes the exchange of nucleoproteins easy. Research on mouse spermatogenesis showed that H4 histone acetylated at Lys 12 (H4K12ac) was specific only to spermatids. Immunocytochemical studies of Chara vulgaris spermatids with the use of antibodies against the histone H4K12ac revealed positive reactions in spermatid nuclei at stages I-VII. This reaction, connected with nuclear condensation, was much stronger at the early stages of spermiogenesis than later on. Moreover, it showed that at the stages V-VII in spermatid nuclei the presence of the histone H4K12ac corresponded with DNA double-strand breaks. Electron microscopy studies with the use of immunogold technique revealed an almost twofold difference between the mean total numbers of gold grains in the examined chromatin in both stages. This study showed nearly equal distribution of gold grains on condensed and non-condensed chromatin of spermatids at the stage III/IV (48.11% and 51.89%, respectively). In the later stage-VI, when chromatin condensation proceeded, labeling of condensed chromatin reached 57.27%, while in the case of non-condensed chromatin it dropped to 42.73%. The percentage analysis also revealed an increase (above 9%) in condensed chromatin labeling in relation to the stage III/IV. Intensive acetylation of histone H4 at the early stages is correlated with DNA DSBs and transcriptional activity. It facilitates chromatin loosening, which enables the correct course of chromatin remodeling at a later stage. Histone γH2AX also influences chromatin structure in many biological processes in different cell types. Current studies reveal other similarities regarding histone H4 acetylation, not only between Chara and mammals but between invertebrates (molluscs) and vertebrates (bony fishes) as well.
-
immunogold evidence suggests that endoplasmic reticulum is the site of protamine type protein synthesis and participates in translocation of these proteins into the nucleus during Chara vulgaris spermiogenesis
Biology of Reproduction, 2009Co-Authors: Katarzyna Poplonska, Maria Kwiatkowska, Agnieszka Wojtczak, Justyna Teresa PolitAbstract:Abstract During spermiogenesis of an alga Chara vulgaris, which in many aspects resembles that of animals, histones are replaced by protamine-type proteins. Our earlier immunocytochemical studies showed that this replacement started during the short stage V of spermiogenesis, when electronograms revealed an extensive system of cisternae and vesicles of endoplasmic reticulum (ER). The present studies revealed at stage V intensive incorporation of labeled 3H-arginine and 3H-lysine quickly translocating into a nucleus visualized with pulse-chase autoradiography of semithin sections. The immunogold technique with the use of the antibodies to protamine-type proteins isolated from Chara tomentosa show that both ER cisternae and vesicles are labeled with gold grains, which are absent from the spermatids not treated with the antibodies; thus, the ER is probably the site of the protamine-type protein synthesis. These proteins then are translocated to a nucleus through ER channels connected with the nuclear envelop...
-
phosphorylation of h2ax histone as indirect evidence for double stranded dna breaks related to the exchange of nuclear proteins and chromatin remodeling in Chara vulgaris spermiogenesis
Protoplasma, 2008Co-Authors: Agnieszka Wojtczak, Katarzyna Poplonska, Maria KwiatkowskaAbstract:Phosphorylation of H2AX histone results not only from DNA damage (caused by ionizing radiation, UV or chemical substances, e.g. hydroxyurea), but also regularly takes place during spermiogenesis, enabling correct chromatin remodeling. Immunocytochemical analysis using antibodies against H2AX histone phosphorylated at serine 139 indirectly revealed endogenous double-stranded DNA breaks in Chara vulgaris spermatids in mid-spermiogenesis (stages V, VI and VII), when protamine-type proteins appear in the nucleus. Fluorescent foci were not observed in early (stages I-IV) and late (VIII-X) spermiogenesis, after replacement of histones by protamine-type proteins was finished. A similar phenomenon exists in animals. Determination of the localization of fluorescent foci and the ultrastructure of nuclei led to the hypothesis that DNA breaks at stage V, when condensed chromatin adheres to the nuclear envelope. This is transformed into a net-like structure during stage VI, probably allowing chromosome repositioning to specific regions in the mature spermatozoid. However, at stages VI and VII, DNA breaks are necessary for transformation of the nucleosomal structure into a fibrillar and finally the extremely condensed status of sleeping genes at stage X.
Katarzyna Poplonska - One of the best experts on this subject based on the ideXlab platform.
-
occurrence of calreticulin during the exchange of nucleohistones into protamine type proteins in Chara vulgaris spermiogenesis
Protoplasma, 2013Co-Authors: Katarzyna PoplonskaAbstract:During spermiogenesis of an alga Chara vulgaris, which resembles that of animals, nucleohistones are replaced by protamine-type proteins. This exchange takes place in a spermatid nucleus during the key V spermiogenesis stage, in which rough endoplasmic reticulum is the site of protamine-type protein synthesis and is also the pathway guiding the proteins to their destination, nucleus. In the present work, it was shown that a chaperon protein, calreticulin (CRT), abundantly present at this significant V stage of spermiogenesis in a few cellular compartments, i.e., a nucleus, lumen of cisternae, and vesicles of significantly swollen ER as well as outside these structures, e.g., in Golgi apparatus, could have taken part in the process of exchange of nuclear proteins. Colocalization of two proteins, protamine-type proteins, crucial for reproduction, and CRT, was especially visible in a nucleus, mainly on its peripheries where condensed chromatin was present. Localization of protamine-type proteins and CRT in nucleus is in agreement with our previous results showing that protamine-type proteins were twofold more labelled in the peripheral area in comparison to the nucleus center occupied by noncondensed chromatin. The role of CRT in the reproduction of both plants and animals is also discussed.
-
immunogold evidence suggests that endoplasmic reticulum is the site of protamine type protein synthesis and participates in translocation of these proteins into the nucleus during Chara vulgaris spermiogenesis
Biology of Reproduction, 2009Co-Authors: Katarzyna Poplonska, Maria Kwiatkowska, Agnieszka Wojtczak, Justyna Teresa PolitAbstract:Abstract During spermiogenesis of an alga Chara vulgaris, which in many aspects resembles that of animals, histones are replaced by protamine-type proteins. Our earlier immunocytochemical studies showed that this replacement started during the short stage V of spermiogenesis, when electronograms revealed an extensive system of cisternae and vesicles of endoplasmic reticulum (ER). The present studies revealed at stage V intensive incorporation of labeled 3H-arginine and 3H-lysine quickly translocating into a nucleus visualized with pulse-chase autoradiography of semithin sections. The immunogold technique with the use of the antibodies to protamine-type proteins isolated from Chara tomentosa show that both ER cisternae and vesicles are labeled with gold grains, which are absent from the spermatids not treated with the antibodies; thus, the ER is probably the site of the protamine-type protein synthesis. These proteins then are translocated to a nucleus through ER channels connected with the nuclear envelop...
-
phosphorylation of h2ax histone as indirect evidence for double stranded dna breaks related to the exchange of nuclear proteins and chromatin remodeling in Chara vulgaris spermiogenesis
Protoplasma, 2008Co-Authors: Agnieszka Wojtczak, Katarzyna Poplonska, Maria KwiatkowskaAbstract:Phosphorylation of H2AX histone results not only from DNA damage (caused by ionizing radiation, UV or chemical substances, e.g. hydroxyurea), but also regularly takes place during spermiogenesis, enabling correct chromatin remodeling. Immunocytochemical analysis using antibodies against H2AX histone phosphorylated at serine 139 indirectly revealed endogenous double-stranded DNA breaks in Chara vulgaris spermatids in mid-spermiogenesis (stages V, VI and VII), when protamine-type proteins appear in the nucleus. Fluorescent foci were not observed in early (stages I-IV) and late (VIII-X) spermiogenesis, after replacement of histones by protamine-type proteins was finished. A similar phenomenon exists in animals. Determination of the localization of fluorescent foci and the ultrastructure of nuclei led to the hypothesis that DNA breaks at stage V, when condensed chromatin adheres to the nuclear envelope. This is transformed into a net-like structure during stage VI, probably allowing chromosome repositioning to specific regions in the mature spermatozoid. However, at stages VI and VII, DNA breaks are necessary for transformation of the nucleosomal structure into a fibrillar and finally the extremely condensed status of sleeping genes at stage X.
-
immunocytochemical localization of ubiquitin and proteasomes in spermatids during spermiogenesis of Chara vulgaris charophyceae
European Journal of Phycology, 2004Co-Authors: Katarzyna Poplonska, Maria Kwiatkowska, A Gosek, Dariusz Stepinski, Agnieszka WojtczakAbstract:Immunocytochemistry with anti-ubiquitin and anti-proteasome antibodies revealed antigenic signals in spermatids of Chara vulgaris in all ten spermiogenesis phases defined on the basis of morphological features. The strongest antigenic signals, indicating the presence of both ubiquitin and proteasome, were observed mainly in the cytoplasm in early and mid-spermiogenesis (phases II – V). During the transition of histone into protamine-type proteins, stronger anti-ubiquitin and anti-proteasome antigenic signals were present in the nucleus than in the cytoplasm (phases VII – VIII). In late spermiogenesis both types of signals were very scarce. We hypothesiZe that the roles of the proteasome/ubiquitin system may be: (1) participation in the degradation of short-lived proteins that appear temporarily after gene expression is triggered and initiates the programme of major ultrastructural changes in spermatids in early spermiogenesis; and (2) participation in the transition of histones into protamine-type protein...
-
the influence of epoxomicin inhibitor of proteasomal proteolytic activity on spermiogenesis in Chara vulgaris
Folia Histochemica Et Cytobiologica, 2003Co-Authors: Maria Kwiatkowska, Katarzyna Poplonska, Agnieszka Wojtczak, Marta TeodorczykAbstract:The influence of 48-h treatment with epoxomicin, an inhibitor of proteolytic activity of proteasomes, at the concentration 10 microM, on spermiogenesis in algae Chara vulgaris was examined. In the presence of the inhibitor, the frequency of early spermiogenesis phases significantly increased, the number of spermatids in mid-phases decreased and disappearance of late phases was observed. A hypothesis has been put forward that epoxomicin stops spermiogenesis during the period of preparation to further deep reorganisation of spermatids by blocking proteolysis of short-lived regulatory proteins which are responsible among others for triggering the exchange of nucleohistones into nucleoprotamines.
Claude Lemieux - One of the best experts on this subject based on the ideXlab platform.
-
1
2014Co-Authors: Chara Vulgaris, Monique Turmel, Christian Otis, Of Green Algae, Claude LemieuxAbstract:Mitochondrial DNA (mtDNA) has undergone radical changes during the evolution of green plants, yet little is known about the dynamics of mtDNA evolution in this phylum. Land plant mtDNAs differ from the few green algal mtDNAs that have been analyzed to date by their expanded size, long spacers, and diversity of introns. We have determined the mtDNA sequence of Chara vulgaris (Charophyceae), a green alga belonging to the charophycean order (Charales) that is thought to be the most closely related alga to land plants. This 67,737-bp mtDNA sequence, displaying 68 conserved genes and 27 introns, was compared with those of three angiosperms, the bryophyt
-
Intron insertion sites in the mitochondrial rnl genes of selected green algae.
2013Co-Authors: Jean-françois Pombert, Monique Turmel, Christian Otis, Claude LemieuxAbstract:Cis- and trans-spliced introns are shown by triangles and broken triangles, respectively. When present, intronic ORFs are shown by filled triangles. Intron insertion sites are given relative to the E. coli 23S rRNA; for each site, the position corresponding to the nucleotide immediately preceding the intron is reported. Accession numbers for the rnl sequences represented are as follows: Prasinoderma coloniale, KF387569; Monomastix sp, KF060939; Nephroselmis olivacea, NC_008239; Oltmannsiellopsis viridis, NC_008256; Pseudendoclonium akinetum, NC_005926; Chlamydomonas eugametos, NC_001872; Dunaliella salina, NC_012930; Mesostigma viride, NC_008240; and Chara vulgaris, NC_005255.
-
The Chloroplast Genome Sequence of Chara vulgaris Sheds New Light into the Closest Green Algal Relatives of Land Plants
Molecular Biology and Evolution, 2006Co-Authors: Monique Turmel, Christian Otis, Claude LemieuxAbstract:: The phylum Streptophyta comprises all land plants and six monophyletic groups of charophycean green algae (Mesostigmatales, Chlorokybales, Klebsormidiales, Zygnematales, Coleochaetales, and Charales). Phylogenetic analyses of four genes encoded in three cellular compartments suggest that the Charales are sister to land plants and that charophycean green algae evolved progressively toward an increasing cellular complexity. To validate this phylogenetic hypothesis and to understand how and when the highly conservative pattern displayed by land plant chloroplast DNAs (cpDNAs) originated in the Streptophyta, we have determined the complete chloroplast genome sequence (184,933 bp) of a representative of the Charales, Chara vulgaris, and compared this genome to those of Mesostigma (Mesostigmatales), Chlorokybus (Chlorokybales), Staurastrum and Zygnema (Zygnematales), Chaetosphaeridium (Coleochaetales), and selected land plants. The phylogenies we inferred from 76 cpDNA-encoded proteins and genes using various methods favor the hypothesis that the Charales diverged before the Coleochaetales and Zygnematales. The Zygnematales were identified as sister to land plants in the best tree topology (T1), whereas Chaetosphaeridium (T2) or a clade uniting the Zygnematales and Chaetosphaeridium (T3) occupied this position in alternative topologies. Chara remained at the same basal position in trees including more land plant taxa and inferred from 56 proteins/genes. Phylogenetic inference from gene order data yielded two most parsimonious trees displaying the T1 and T3 topologies. Analyses of additional structural cpDNA features (gene order, gene content, intron content, and indels in coding regions) provided better support for T1 than for the topology of the above-mentioned four-gene tree. Our structural analyses also revealed that many of the features conserved in land plant cpDNAs were inherited from their green algal ancestors. The intron content data predicted that at least 15 of the 21 land plant group II introns were gained early during the evolution of streptophytes and that a single intron was acquired during the transition from charophycean green algae to land plants. Analyses of genome rearrangements based on inversions predicted no alteration in gene order during the transition from charophycean green algae to land plants.
-
The Mitochondrial Genome of Chara vulgaris: Insights into the Mitochondrial DNA Architecture of the Last Common Ancestor of Green Algae and Land Plants
The Plant Cell, 2003Co-Authors: Monique Turmel, Christian Otis, Claude LemieuxAbstract:Mitochondrial DNA (mtDNA) has undergone radical changes during the evolution of green plants, yet little is known about the dynamics of mtDNA evolution in this phylum. Land plant mtDNAs differ from the few green algal mtDNAs that have been analyzed to date by their expanded size, long spacers, and diversity of introns. We have determined the mtDNA sequence of Chara vulgaris (Charophyceae), a green alga belonging to the charophycean order (Charales) that is thought to be the most closely related alga to land plants. This 67,737-bp mtDNA sequence, displaying 68 conserved genes and 27 introns, was compared with those of three angiosperms, the bryophyte Marchantia polymorpha, the charophycean alga Chaetosphaeridium globosum (Coleochaetales), and the green alga Mesostigma viride. Despite important differences in size and intron composition, Chara mtDNA strikingly resembles Marchantia mtDNA; for instance, all except 9 of 68 conserved genes lie within blocks of colinear sequences. Overall, our genome comparisons and phylogenetic analyses provide unequivocal support for a sister-group relationship between the Charales and the land plants. Only four introns in land plant mtDNAs appear to have been inherited vertically from a Charalean algar ancestor. We infer that the common ancestor of green algae and land plants harbored a tightly packed, gene-rich, and relatively intron-poor mitochondrial genome. The group II introns in this ancestral genome appear to have spread to new mtDNA sites during the evolution of bryophytes and Charalean green algae, accounting for part of the intron diversity found in Chara and land plant mitochondria.
A Gosek - One of the best experts on this subject based on the ideXlab platform.
-
immunocytochemical localization of ubiquitin and proteasomes in spermatids during spermiogenesis of Chara vulgaris charophyceae
European Journal of Phycology, 2004Co-Authors: Katarzyna Poplonska, Maria Kwiatkowska, A Gosek, Dariusz Stepinski, Agnieszka WojtczakAbstract:Immunocytochemistry with anti-ubiquitin and anti-proteasome antibodies revealed antigenic signals in spermatids of Chara vulgaris in all ten spermiogenesis phases defined on the basis of morphological features. The strongest antigenic signals, indicating the presence of both ubiquitin and proteasome, were observed mainly in the cytoplasm in early and mid-spermiogenesis (phases II – V). During the transition of histone into protamine-type proteins, stronger anti-ubiquitin and anti-proteasome antigenic signals were present in the nucleus than in the cytoplasm (phases VII – VIII). In late spermiogenesis both types of signals were very scarce. We hypothesiZe that the roles of the proteasome/ubiquitin system may be: (1) participation in the degradation of short-lived proteins that appear temporarily after gene expression is triggered and initiates the programme of major ultrastructural changes in spermatids in early spermiogenesis; and (2) participation in the transition of histones into protamine-type protein...
-
occurrence of ubiquitin during spermiogenesis in Chara vulgaris
Folia Histochemica Et Cytobiologica, 2001Co-Authors: Maria Kwiatkowska, Katarzyna Poplonska, Agnieszka Wojtczak, A GosekAbstract:Experiments with an anti-ubiquitin antibody proved the presence of ubiquitin in spermatids at all spermiogenesis stages in Charta vulgaris. Its level increased before marked ultrastructural changes of spermatids correlated with disappearance of somatic proteins (histones) and appearance of protamine-type generative proteins. The obtained results seem to confirm our earlier hypotheses concerning a significant role of ubiquitin-proteasome system in Chara spermatozoid differentiation.
-
disappearance of 3h leucine incorporation circadian rhythm induced by symplasmic isolation of Chara vulgaris antheridium from thallus
Folia Histochemica Et Cytobiologica, 1999Co-Authors: Maria Kwiatkowska, Katarzyna Poplonska, A GosekAbstract:Autoradiographic research with the use of 3H-leucine demonstrates that circadian rhythm of protein synthesis Characteristic of manubria at the proliferative phase of spermatogenesis in Chara vulgaris disappears after symplasmic isolation of antheridium from thallus during the time preceding block of DNA endoreplication in manubria following initiation of spermiogenesis insensitive to light.
-
autoradiographic studies on mucilage synthesis in Chara vulgaris antheridium with the use of 3h fucose in total darkness and light
Folia Histochemica Et Cytobiologica, 1996Co-Authors: A GosekAbstract:Autoradiographic studies with 3H-fucose have shown that this precursor of polysaccharide compounds is incorporated into manubria and antheridial mucilage of Chara vulgaris both in the light and in the darkness. The dynamics of this process is lower in total darkness. The decrease in overall labelling of antheridium (manubria and mucilage) reflects secondary metabolic changes both in proliferative phase and in spermiogenesis. The pulse (2 and 5 min) incubations with the isotope confirm the intensive mucilage translocation which at later developmental stages is more dynamic than at earlier ones. It can explain previously observed decrease in manubria radioactivity at later stages after long (40 min) incubation, because PAS-positive polysaccharide synthesis is simultaneous with their fast translocation to the antheridial space. The present and previous autoradiographic and cytophotometric data taken altogether confirm the assumption about a nutritive role of mucilage filling Chara antheridium during the process of spermatogenesis.
-
circadian rhythm of protein synthesis in generative and non generative antheridial cells of Chara vulgaris l
Biological Rhythm Research, 1995Co-Authors: Maria Kwiatkowska, A Gosek, K Poptonska, S MalinowskiAbstract:Abstract Autoradiographic studies have shown that in a natural light/dark alternation there is a clear circadian rhytm of translational activity in manubria, capitular cells and antheridial filament cells of Chara vulgaris. The manubria, which are the secretory cells, exhibited rapid decreases and increases of translational activity. The reaction of capitular and antheridial filament cells to day/night changes is delayed in comparison with the reaction of manubria. It seems that the manubria play the role of oscillators (starter cells) inducing the wave of changes of activity in other cells functionally connected with them. The manubria and, maybe, the capitular cells and antheridial filament cells as well, have a circadian rhythm entrained to 24 hours by natural day/night alternation and, because ofthat, the translational rhythm can be observed under constant illumination, although the rhythm tends to decrease in amplitude after 5–6 days. No circadian rhythm of translational activity was observed in anth...