Topic
Gametangium
About: Gametangium is a research topic. Over the lifetime, 141 publications have been published within this topic receiving 2670 citations. The topic is also known as: gametangia.
Papers published on a yearly basis
Papers
TL;DR: The gametophyte phase of early land plants can now be considered within an ecological and evolutionary framework that can be used to develop hypotheses about some aspects of the population dynamics and growth of these earlyLand plants.
Abstract: The ca. 400-million-year-old Rhynie chert biota represents a benchmark for studies of early terrestrial ecosystems. The exquisite preservation of the organisms documents an ancient biodiversity that also includes various levels of biological interaction. Absent from the picture until recently has been detailed information about the development of the gametophyte phase and the alternation of generations of the macroplants in this ecosystem. Here, we trace the development of the gametophyte phase of Aglaophyton, an early land plant with an unusual complement of structural and morphological characters. Mature gametophytes consist of a fleshy protocorm attached to the substrate by basal rhizoids; arising from the upper surface are one to several upright gametangiophores bearing multiple gametangia. Stomata are present on the upper surface of the protocorm and gametangiophore, and endomycorrhizal fungi extend throughout the gametophyte. Gametophytes are unisexual, producing either antheridiophores or archegoniophores. There is no evidence that gametophytes later become hermaphroditic. The sexual dimorphism of the Rhynie chert gametophytes is inconsistent with theoretical ideas about the haploid phase of early land plants. The gametophyte phase of early land plants can now be considered within an ecological and evolutionary framework that, in turn, can be used to develop hypotheses about some aspects of the population dynamics and growth of these early land plants.
135 citations
TL;DR: Sexual reproduction takes many forms within the diatoms, but the distinctions between their main categories have depended on the number of gametes produced per gametangium, and on how many zygotes per pair of copulating cells, and upon whether fusion is oogamous, anisogamous or isogamous.
Abstract: Sexual reproduction takes many forms within the diatoms. The variation has been classified by several authors, but in most cases the distinctions between their main categories have depended on the number of gametes produced per gametangium (and thus on how many zygotes per pair of copulating cells), and upon whether fusion is oogamous, anisogamous or isogamous. These classifications are not themselves an adequate basis for taxonomic comparison, which should be based on individual characteristics of the sexual process. Diatoms seem to be primitively oogamous. In araphid pennate diatoms and some raphid diatoms the gametes and gametangia are morphologically alike but physiologically distinct; one gametangium produces active gametes and the other passive ones. This may be the primitive condition in pennate diatoms, providing a link to the oogamy of centrics via the morphological anisogamy of Rhabdonema Kutz.
122 citations
1 Feb 1990
TL;DR: Partheno-sporophytes developing from such gametes carry the viral particles expressed in deformed unilocular and plurilocular sporangia, suggesting that the particles are viruses.
Abstract: Laboratory cultures of Ectocarpus siliculosus originating from New Zealand showed a defect in gametangium formation. Nuclear divisions in gametangium initials are not followed by cell wall formation. In the resulting multinucleate cells nuclear DNA increases dramatically, and nuclear membranes disintegrate. Eventually, the entire structure is filled with hexagonal particles of approximately 130 nm diameter. These were isolated and shown by EM to consist of a dense core surrounded by a 3-layered shell. They are released into the culture medium when the host cells burst. Ectocarpus gametes from healthy cultures could be infected by these particles. The resulting partheno-sporophytes developed pathological symptoms, suggesting that the particles are viruses.
The expression of the defect is temperature dependent. At 10°C all gametangia are abnormal, while between 15 and 20 °C defective and normal gametangia and gametes are formed on the same plant. Partheno-sporophytes developing from such gametes carry the viral particles expressed in deformed unilocular and plurilocular sporangia.
70 citations
TL;DR: The data suggest that the virus genome passes through the host's meiosis like an extra chromosome, or as a provirus linked to one of the host’s autosomes, or in most progeny families the virus symptoms segregated with either the male or female sex.
68 citations
TL;DR: The evolutionary history of male gametogenesis in streptophytes (green plants) and the underlying developmental biology is discussed, including recent advances in bryophyte and angiosperm models and a perspective on research trends that promise to deliver a deeper understanding of the evolutionary and developmental mechanisms.
Abstract: The reproductive adaptations of land plants have played a key role in their terrestrial colonization and radiation. This encompasses mechanisms used for the production, dispersal and union of gametes to support sexual reproduction. The production of small motile male gametes and larger immotile female gametes (oogamy) in specialized multicellular gametangia evolved in the charophyte algae, the closest extant relatives of land plants. Reliance on water and motile male gametes for sexual reproduction was retained by bryophytes and basal vascular plants, but was overcome in seed plants by the dispersal of pollen and the guided delivery of non-motile sperm to the female gametes. Here we discuss the evolutionary history of male gametogenesis in streptophytes (green plants) and the underlying developmental biology, including recent advances in bryophyte and angiosperm models. We conclude with a perspective on research trends that promise to deliver a deeper understanding of the evolutionary and developmental mechanisms of male gametogenesis in plants.
67 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
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| 2021 | 2 |
| 2019 | 3 |
| 2018 | 1 |
| 2017 | 1 |
| 2016 | 1 |
| 2015 | 1 |