Interspecific micronuclear transplantation in Paramecium: nucleogenesis and stomatogenesis in asexual and sexual reproduction

Development ◽  
1988 ◽  
Vol 103 (1) ◽  
pp. 179-191
Author(s):  
M.F. Chau ◽  
S.F. Ng
Keyword(s):  
Cell Division ◽  
Sexual Reproduction ◽  
Cell Lines ◽  
Essential Role ◽  
The Other ◽  
Sexual Cycle ◽  
Interspecific Incompatibility ◽  
Multicellular Development ◽  
Oral Development ◽  
Species Specific

The micronucleus of Paramecium plays an essential role in the development of the oral apparatus in both asexual and sexual cycles. The present study analyses this somatic function of the micronucleus by interspecific transplantation of the micronucleus between two species, P. jenningsi and P. tetraurelia. The two species are similar in nucleogenesis in the sexual cycle, in the dependence of stomatogenesis on the micronucleus and in the pattern of the oral ciliature. P. jenningsi, however, has a longer oral apparatus. Renucleated cell lines were derived from heterospecific transplantation (P. jenningsi amicronucleates implanted with micronuclei of P. tetraurelia), and also from homospecific transplantation (P. jenningsi). Both homo- and heterospecific transplants exhibited abnormal micronuclear propagation during cell division. In the sexual cycle, the heterospecific transplants exhibited more severe micronuclear anomalies, suggesting interspecific incompatibility. On the other hand, the stomatogenic consequences of the two types of transplants in the asexual and sexual cycles were similar. It is concluded that micronuclear functions, in the assembly and normal patterning of the oral ciliature in the sexual cycle, are not species-specific. However, the oral apparatuses developed by the homo- and heterospecific transplants were similar in length, and approaching that of normal P. jenningsi. Hence, even though the micronucleus is necessary for developing normal oral length, the oral length characteristic of a species is determined by species-specific nonmicronuclear factors. The present findings resemble heterospecific dermal-epidermal inductive interactions in multicellular development, with the micronucleus exerting a nonspecies-specific ‘intracellular inductive stimulus’ on the oral anarchic field to promote oral development.

The rescue of oral development of defective-micronucleate conjugants of Paramecium tetraurelia by normal gametic nuclei

1988 ◽  
Vol 90 (2) ◽  
pp. 287-293
Author(s):  
M. F. CHAU ◽  
STEPHEN F. NG
Keyword(s):  
Sexual Reproduction ◽  
Cell Lines ◽  
Early Stage ◽  
Sexual Cycle ◽  
Paramecium Tetraurelia ◽  
Laser Microbeam ◽  
Nuclear Reorganization ◽  
Oral Development ◽  
Derivatives Of

The present study further analyses the importance of postmeiotic divisional derivatives of the micronucleus in the development of the oral apparatus of Paramecium during sexual reproduction. Cell lines possessing defective micronuclei generated by laser microbeam irradiation of the micronucleus were employed. They exhibited anomalies in nuclear reorganization and stomatogenesis in the sexual cycle. During autogamy, in some cells the micronuclear cycle terminated shortly after meiosis, resulting in the loss of all postmeiotic micronuclear derivatives. Stomatogenesis became arrested at an early stage of assembly of the oral membranelles, but the old oral apparatus was resorbed as usual, leading to the production of astomatous cells at the end of the sexual cycle. Conjugation of these cell lines with normal micronucleates rescued both nucleogenesis and stomatogenesis in the defective micronucleate conjugant, primarily as a result of transfer of the male gametic nucleus from the normal conjugant to the defective-micronucleate mate. These observations demonstrate the stomatogenic significance, in particular in the initiation of oral membranelle assembly, of the gametic nuclei during sexual reproduction. The present study also suggests the possibility of micronuclear activities in the early part of the sexual cycle affecting postzygotic nucleogenesis.

Production of species-specific monoclonal antibodies that react with surface components on zoospores and cysts of Phytophthora nicotianae

1998 ◽  
Vol 44 (12) ◽  
pp. 1161-1170 ◽  
Author(s):  
A V Robold ◽  
A R Hardham
Keyword(s):  
Monoclonal Antibodies ◽  
Cell Lines ◽  
Phytophthora Cinnamomi ◽  
Phytophthora Nicotianae ◽  
The Other ◽  
Hybridoma Cells ◽  
Enzyme Linked Immunosorbent Assay ◽  
Specific Antibodies ◽  
Hybridoma Cell Lines ◽  
Species Specific

Monoclonal antibodies were generated against components on the surface of zoospores and cysts of the Oomycete, Phytophthora nicotianae, with the aim of obtaining antibodies diagnostic for this species of plant pathogen. A dipstick version of an enzyme-linked immunosorbent assay was used to screen hybridoma cell lines produced by following a coimmunization protocol in which a mouse was immunized with Phytophthora nicotianae cysts mixed with murine antisera raised against cysts of Phytophthora cinnamomi and Phytophthora cryptogea. Of the nine hybridoma cells lines which remained positive, five produced antibodies that reacted with species-specific epitopes on the surface of the spores. Immunofluorescence, immunogold, and immunoblot labelling showed that three of the five species-specific antibodies reacted with a polypeptide of relative molecular mass greater than 205 kDa which was distributed over the entire zoospore surface, including that of the two flagella. These antibodies also labelled the surface of cysts to varying degrees. The other two species-specific antibodies bound to the shaft of tubular mastigonemes that form two rows on the anterior flagellum. In immunoblots, one of these antibodies recognised a 40-kDa glycoprotein. Antibodies produced by the other four hybridoma cell lines reacted with all Phytophthora and Pythium species tested. The results (i) showed that the coimmunization technique effectively produced antibodies directed towards components specific for Phytophthora nicotianae in the presence of antigens common to many Phytophthora species, and (ii) revealed for the first time the biochemical nature of molecular constituents of flagellar mastigonemes in the Oomycetes.Key words: cell surface, flagella, immunodiagnostics, mastigonemes, monoclonal antibodies.

5-Azacytidine affects the programming of expression of the somatic nucleus of Paramecium

Development ◽  
1989 ◽  
Vol 105 (3) ◽  
pp. 559-568 ◽  
Author(s):  
F.W. Kwok ◽  
S.F. Ng
Keyword(s):  
Sexual Reproduction ◽  
Cell Lines ◽  
Compensatory Mechanism ◽  
Paramecium Tetraurelia ◽  
Growth Depression ◽  
Somatic Nucleus ◽  
Asexual Propagation ◽  
Oral Development ◽  
Asexual Cycle

This report introduces a new system in the study of programming of genomic function during development of the somatic nucleus of Paramecium tetraurelia. Previous works have established a definite, but replaceable, role of the germ nuclei (micronuclei) in oral development in the asexual cycle; their removal from the cell generates viable amicronucleate cell lines, which characteristically suffer a transient period of growth depression marked by abnormal oral development. Such cell lines gradually recover, showing that a compensatory mechanism is activated in the absence of the germ nuclei to bring the cell back to near-normal. To test the notion that the somatic nucleus (macronucleus) is involved in this compensation, cells possessing micronuclei were treated with 5-azacytidine during sexual reproduction when new somatic nuclei develop. These cells were then propagated asexually for a number of fissions in the absence of the drug, and thereafter micronuclei were removed from them. The amicronucleate cell lines generated in this manner clearly did not suffer a depression as severe as the untreated controls did in terms of growth rate and oral development, and they recovered much sooner. This supports the notion that the somatic nucleus is the physical basis of the compensatory mechanism. This study suggests that the stomatogenic sequences in question normally become repressed in the somatic nucleus developing in sexual reproduction, and that 5-azacytidine administered to the cells at this time could alter this programme which then persists during subsequent asexual propagation. The possibility that the somatic nucleus is programmed by methylation of cytosine at the 5′ position is discussed.

scholarly journals Differential Requirements for the CENP-O Complex Reveal Parallel PLK1 Kinetochore Recruitment Pathways

2021 ◽  
pp. mbc.E20-11-0751
Author(s):  
Alexandra L. Nguyen ◽  
Marie Diane Fadel ◽  
Iain M. Cheeseman
Keyword(s):  
Cell Division ◽  
Cell Lines ◽  
Chromosome Segregation ◽  
Human Cell ◽  
Threshold Level ◽  
The Other ◽  
Biological Processes ◽  
Human Cell Lines ◽  
State Dependent ◽  
Genome Wide

Similar to other core biological processes, the vast majority of cell division components are essential for viability across human cell lines. However, recent genome‐wide screens have identified a number of proteins that exhibit cell line‐specific essentiality. Defining the behaviors of these proteins is critical to our understanding of complex biological processes. Here, we harness differential essentiality to reveal the contributions of the 4‐subunit centromere‐localized CENP‐O complex, whose precise function has been difficult to define. Our results support a model in which the CENP‐O complex and BUB1 act in parallel pathways to recruit a threshold level of PLK1 to mitotic kinetochores, ensuring accurate chromosome segregation. We demonstrate that targeted changes to either pathway sensitizes cells to the loss of the other component, resulting in cell‐state dependent requirements. This approach also highlights the advantage of comparing phenotypes across diverse cell lines to define critical functional contributions and behaviors that could be exploited for the targeted treatment of disease.

scholarly journals First Report of Sexual Reproduction by the Soybean Sudden Death Syndrome Pathogen Fusarium tucumaniae in Nature

Plant Disease ◽  
2010 ◽  
Vol 94 (12) ◽  
pp. 1411-1416 ◽  
Author(s):  
M. M. Scandiani ◽  
T. Aoki ◽  
A. G. Luque ◽  
M. A. Carmona ◽  
K. O'Donnell
Keyword(s):  
Sudden Death ◽  
Sexual Reproduction ◽  
Basal Cell ◽  
Apical Cell ◽  
Sudden Death Syndrome ◽  
The Other ◽  
Sexual Cycle ◽  
Morphological Identification ◽  
Species Determination ◽  
Field Surveys

Of the four fusaria that have been shown to cause soybean sudden death syndrome (SDS), field surveys indicate that Fusarium tucumaniae is the most important and genetically diverse SDS pathogen in Argentina. Although none of the SDS fusaria have been shown to produce perithecia in nature, a heterothallic sexual cycle has been demonstrated for F. tucumaniae via laboratory crosses. Herein we report on the discovery of perithecia of F. tucumaniae on soybean in Argentina. Ascospores derived from these perithecia gave rise to colonies that produced sporodochial conidia diagnostic of F. tucumaniae. Sporodochial conidia were longer and narrower than those produced by the other SDS fusaria; these conidia also possessed a diagnostic acuate apical cell and a distinctly foot-shaped basal cell. Sixteen strains derived from single ascospores subjected to a validated multilocus genotyping assay (MLGT) for SDS species determination, together with 16 conidial isolates from two sites where teleomorphs were collected, independently confirmed the morphological identification as F. tucumaniae. This study represents the first authentic report of sexual reproduction by a soybean SDS pathogen in nature.

scholarly journals Differential Requirements for the CENP-O Complex Reveal Parallel PLK1 Kinetochore Recruitment Pathways

2020 ◽  
Author(s):  
Alexandra L. Nguyen ◽  
Marie Diane Fadel ◽  
Iain M. Cheeseman
Keyword(s):  
Cell Division ◽  
Cell Lines ◽  
Chromosome Segregation ◽  
Human Cell ◽  
Threshold Level ◽  
The Other ◽  
Biological Processes ◽  
Human Cell Lines ◽  
State Dependent ◽  
Genome Wide

AbstractSimilar to other core biological processes, the vast majority of cell division components are essential for viability across human cell lines. However, genome-wide screens have identified a number of proteins that exhibit cell line-specific essentiality. Defining the behaviors of these proteins is critical to our understanding of complex biological processes. Here, we harness differential essentiality to reveal the contributions of the 4-subunit centromere-localized CENP-O complex, whose precise function has been difficult to define. Our results support a model in which the CENP-O complex and BUB1 act in parallel pathways to recruit a threshold level of PLK1 to mitotic kinetochores, ensuring accurate chromosome segregation. We demonstrate that targeted changes to either pathway sensitizes cells to the loss of the other component, resulting in cell-state dependent requirements. This approach also highlights the advantage of comparing phenotypes across diverse cell lines to define critical functional contributions and behaviors that could be exploited for the targeted treatment of disease.

scholarly journals Prebiotic Combinations Effects on the Colonization of Staphylococcal Skin Strains

2020 ◽  
Vol 9 (1) ◽  
pp. 37
Author(s):  
Silvia Di Lodovico ◽  
Franco Gasparri ◽  
Emanuela Di Campli ◽  
Paola Di Fermo ◽  
Simonetta D’Ercole ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Commensal Bacteria ◽  
The Other ◽  
Bacteriostatic Effect ◽  
Skin Microbiota ◽  
Relevant Effect ◽  
Planktonic Phase ◽  
Species Specific ◽  
Biomass Quantification ◽  
General Reduction

Background: An unbalanced skin microbiota due to an increase in pathogenic vs. commensal bacteria can be efficiently tackled by using prebiotics. The aim of this work was to identify novel prebiotic combinations by exerting species-specific action between S. aureus and S. epidermidis strains. Methods: First, the antimicrobial/antibiofilm effect of Xylitol-XYL and Galacto-OligoSaccharides–GOS combined with each other at different concentrations (1, 2.5, 5%) against S. aureus and S. epidermidis clinical strains was evaluated in time. Second, the most species-specific concentration was used to combine XYL with Fructo-OligoSaccharides–FOS, IsoMalto-Oligosaccharides–IMO, ArabinoGaLactan–LAG, inulin, dextran. Experiments were performed by OD600 detection, biomass quantification and LIVE/DEAD staining. Results: 1% XYL + 1% GOS showed the best species-specific action with an immediate antibacterial/antibiofilm action against S. aureus strains (up to 34.54% ± 5.35/64.68% ± 4.77) without a relevant effect on S. epidermidis. Among the other prebiotic formulations, 1% XYL plus 1% FOS (up to 49.17% ± 21.46/37.59% ± 6.34) or 1% IMO (up to 41.28% ± 4.88/36.70% ± 10.03) or 1% LAG (up to 38.21% ± 5.31/83.06% ± 5.11) showed antimicrobial/antibiofilm effects similar to 1% XYL+1% GOS. For all tested formulations, a prevalent bacteriostatic effect in the planktonic phase and a general reduction of S. aureus biofilm formation without loss of viability were recorded. Conclusion: The combinations of 1% XYL with 1% GOS or 1% FOS or 1% IMO or 1% LAG may help to control the balance of skin microbiota, representing good candidates for topic formulations.

scholarly journals Species-Specific Segregation of Gender-Associated Mitochondrial DNA Types in an Area Where Two Mussel Species (Mytilus edulis and M. trossulus) Hybridize

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1359-1367 ◽  
Author(s):  
Carlos Saavedra ◽  
Donald T Stewart ◽  
Rebecca R Stanwood ◽  
Eleftherios Zouros
Keyword(s):  
Mytilus Edulis ◽  
The Other ◽  
Allozyme Analysis ◽  
Mussel Species ◽  
Species Origin ◽  
Species Pairs ◽  
Nuclear Background ◽  
Species Specific ◽  
Dna Types ◽  
Fertile Hybrids

Abstract In each of the mussel species Mytilus edulis and M. trossulus there exist two types of mtDNA, the F type transmitted through females and the M type transmitted through males. Because the two species produce fertile hybrids in nature, F and M types of one may introgress into the other. We present the results from a survey of a population in which extensive hybridization occurs between these two species. Among specimens classified as “pure” M. edulis or “pure” M. trossulus on the basis of allozyme analysis, we observed no animal that carried the F or the M mitotype of the other species. In most animals of mixed nuclear background, an individual's mtDNA came from the species that contributed the majority of the individual's nuclear genes. Most importantly, the two mtDNA types in post-F1 male hybrids were of the same species origin. We interpret this to mean that there are intrinsic barriers to the exchange of mtDNA between these two species. Because such barriers were not noted in other hybridizing species pairs (many being even less interfertile than M. edulis and M. trossulus), their presence in Mytilus could be another feature of the unusual mtDNA system in this genus.

scholarly journals Parasexuality and Ploidy Change in Candida tropicalis

2013 ◽  
Vol 12 (12) ◽  
pp. 1629-1640 ◽  
Author(s):  
Riyad N. H. Seervai ◽  
Stephen K. Jones ◽  
Matthew P. Hirakawa ◽  
Allison M. Porman ◽  
Richard J. Bennett
Keyword(s):  
Sexual Reproduction ◽  
Candida Tropicalis ◽  
Culture Conditions ◽  
Sexual Cycle ◽  
Chromosome Loss ◽  
Parasexual Cycle ◽  
Content Type ◽  
Ploidy Changes ◽  
Diploid Cells

ABSTRACTCandidaspecies exhibit a variety of ploidy states and modes of sexual reproduction. Most species possess the requisite genes for sexual reproduction, recombination, and meiosis, yet only a few have been reported to undergo a complete sexual cycle including mating and sporulation.Candida albicans, the most studiedCandidaspecies and a prevalent human fungal pathogen, completes its sexual cycle via a parasexual process of concerted chromosome loss rather than a conventional meiosis. In this study, we examine ploidy changes inCandida tropicalis, a closely related species toC. albicansthat was recently revealed to undergo sexual mating.C. tropicalisdiploid cells mate to form tetraploid cells, and we show that these can be induced to undergo chromosome loss to regenerate diploid forms by growth on sorbose medium. The diploid products are themselves mating competent, thereby establishing a parasexual cycle in this species for the first time. Extended incubation (>120 generations) ofC. tropicalistetraploid cells under rich culture conditions also resulted in instability of the tetraploid form and a gradual reduction in ploidy back to the diploid state. The fitness levels ofC. tropicalisdiploid and tetraploid cells were compared, and diploid cells exhibited increased fitness relative to tetraploid cellsin vitro, despite diploid and tetraploid cells having similar doubling times. Collectively, these experiments demonstrate distinct pathways by which a parasexual cycle can occur inC. tropicalisand indicate that nonmeiotic mechanisms drive ploidy changes in this prevalent human pathogen.

Vocal Learning of Japanese and Rhesus Monkeys

Behaviour ◽  
1989 ◽  
Vol 109 (3-4) ◽  
pp. 191-199 ◽  
Author(s):  
Nobuo Masataka ◽  
Kazuo Fujita
Keyword(s):  
Rhesus Monkeys ◽  
Japanese Monkey ◽  
Species Difference ◽  
Vocal Learning ◽  
The Other ◽  
Playback Experiments ◽  
Biological Mothers ◽  
Japanese Monkeys ◽  
The Cross ◽  
Species Specific

AbstractForaging vocalizations given by Japanese and rhesus momkeys reared by their biological mothers differed from each other in a single parameter. Calls made by a Japanese monkey fostered by a rhesus female were dissimilar to those of conspecifics reared by their biological mothers, but similar to those of rhesus monkeys reared by their biological mothers, and the vocalizations given by rhesus monkeys fostered by Japanese monkey mothers were dissimilar to those of conspecifics reared by their biological mothers, but similar to those of Japanese monkeys reared by their biological mothers. Playback experiments revealed that both Japanese and rhesus monkeys distinguished between the calls of Japanese monkeys reared by their biological mothers and of the cross-fostered rhesus monkeys on one hand, and the vocalizations of rhesus monkeys reared by their biological mothers and of the cross-fostered Japanese monkey on the other hand. Thus, production of species-specific vocalizations was learned by each species, and it was the learned species-difference which the monkeys themselves discriminated.

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