Topic
Plasmogamy
About: Plasmogamy is a research topic. Over the lifetime, 98 publications have been published within this topic receiving 2836 citations.
Papers published on a yearly basis
Papers
TL;DR: Coprinus cinereus has two main types of mycelia, the asexual monokaryon and the sexual dikaryon, formed by fusion of compatible monokARYons, and several genes involved in these processes have been identified.
Abstract: Coprinus cinereus has two main types of mycelia, the asexual monokaryon and the sexual dikaryon, formed by fusion of compatible monokaryons. Syngamy (plasmogamy) and karyogamy are spatially and temporally separated, which is typical for basidiomycetous fungi. This property of the dikaryon enables an easy exchange of nuclear partners in further dikaryotic-monokaryotic and dikaryotic-dikaryotic mycelial fusions. Fruiting bodies normally develop on the dikaryon, and the cytological process of fruiting-body development has been described in its principles. Within the specialized basidia, present within the gills of the fruiting bodies, karyogamy occurs in a synchronized manner. It is directly followed by meiosis and by the production of the meiotic basidiospores. The synchrony of karyogamy and meiosis has made the fungus a classical object to study meiotic cytology and recombination. Several genes involved in these processes have been identified. Both monokaryons and dikaryons can form multicellular resting bodies (sclerotia) and different types of mitotic spores, the small uninucleate aerial oidia, and, within submerged mycelium, the large thick-walled chlamydospores. The decision about whether a structure will be formed is made on the basis of environmental signals (light, temperature, humidity, and nutrients). Of the intrinsic factors that control development, the products of the two mating type loci are most important. Mutant complementation and PCR approaches identified further genes which possibly link the two mating-type pathways with each other and with nutritional regulation, for example with the cAMP signaling pathway. Among genes specifically expressed within the fruiting body are those for two galectins, β-galactoside binding lectins that probably act in hyphal aggregation. These genes serve as molecular markers to study development in wild-type and mutant strains. The isolation of genes for potential non-DNA methyltransferases, needed for tissue formation within the fruiting body, promises the discovery of new signaling pathways, possibly involving secondary fungal metabolites.
483 citations
TL;DR: Ca2+ waves and oscillation are key signalling elements during the fertilization process of animals, and are involved, for example, in egg activation, and here they seem to represent highly specific signatures that coordinate successful double fertilization in the flowering plants.
Abstract: Ca(2+) waves and oscillation are key signalling elements during the fertilization process of animals, and are involved, for example, in egg activation. In the unique double fertilization process in flowering plants, both the egg cell and the neighbouring central cell fuse with a sperm cell each. Here we succeeded in imaging cytosolic Ca(2+) in these two cells, and in the two synergid cells that accompany the gametes during semi-in vivo double fertilization. Following pollen tube discharge and plasmogamy, the egg and central cells displayed transient Ca(2+) spikes, but not oscillations. Only the events in the egg cell correlated with the plasmogamy. In contrast, the synergid cells displayed Ca(2+) oscillations on pollen tube arrival. The two synergid cells showed distinct Ca(2+) dynamics depending on their respective roles in tube reception. These Ca(2+) dynamics in the female gametophyte seem to represent highly specific signatures that coordinate successful double fertilization in the flowering plants.
134 citations
TL;DR: Sexual reproduction is induced in the dinoflagelate Peridinium cinctum f.
Abstract: SUMMARY
Sexual reproduction is induced in the dinoflagelate Peridinium cinctum f. ovoplanum Lindemann when exponentially growing cells are inoculated into nitrogen deficient medium. Small, naked vegetative cells, produced by division of the thecate cells, then act as gametes. The zygote remains motile for 12–13 days during which time it enlarges and the theca which it forms becomes warty. Thirteen to 14 day s following plasmogamy the zygote is nonmotile, the protoplast contracts, a large red oil droplet appears, the wall thickens and becomes chitinized. This hypnozygote germinates within 7–8 weeks at 20 c producing 1 post-zygotic cell retaining the large red oil droplet. The presence of 4 nuclei in these post-zygotic cells may be demonstrated by staining them with acetocarmine. Two of these nuclei are smaller than the other two and probably abort. One may infer that meiosis occurs immediately prior to or at the germinartion of the hypnozygote. This post-zygotic cell divides within 24 h into 2 daughter cells each with a promment red oil droplet. These daughter cells divide after 2–3 days into ordinary vegetative cells.
Attempts to induce sexual reproduction by changes in temperature or light and by inoculation of cells into media deficient in a number of basic elements were unsuccessful.
129 citations
TL;DR: Sexual reproduction was induced in the dinoflagellate Peridinium gatunense Nygaard when exponentially growing cells were inoculated into nitrogen deficient medium when small thecate cells produced by division of vegetative cells then acted as gametes.
Abstract: Sexual reproduction was induced in the dinoflagellate Peridinium gatunense Nygaard when exponentially growing cells were inoculated into nitrogen deficient medium. Small thecate cells produced by division of vegetative cells then acted as gametes. Thecae of fusing gametes broke in the girdle region and were lost. Zygotes thus formed remained motile 3–5 days during which time they enlarged slightly with the newly formed theca becoming warty. Three to 5 days following plasmogamy the zygote became nonmotile, the protoplast contracted, and the cell wall thickened. Hypnozygotes with 4 nuclei were observed ca. 10–12 h following formation. Meiosis was inferred. Hypnozygotes germinated within 12 h of formation producing 2 vegetative cells which divided within a 24 h period. Attempts to induce sexual reproduction by inoculation of cells into media deficient in a number of basic elements other than N were unsuccessful.
101 citations
TL;DR: A new species of Microspora, Amblyospora dyxenoides, is described, which has three sporulation sequences: two in Culex annulirostris, the mosquito host, and one in Mesocyclops albicans, the intermediate copepod host.
65 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 2 |
| 2020 | 1 |
| 2019 | 2 |
| 2018 | 2 |
| 2017 | 1 |
| 2016 | 2 |