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Plasmogamy: Definition, Alternatives Karyogamy & Meiosis

Fungi undertake Plasmogamy, in which the protoplasm of two-parent cells (typically from the mycelia) fuse without merging the nuclei, essentially combining two haploid nuclei in one cell as part of sexual reproduction. The two nuclei then join and proceed through meiosis to form spores, which is called Karyogamy.

After Plasmogamy, fungi frequently stay in dikaryotic states for several generations before undergoing Karyogamy. In lower fungi, it is commonly followed by Karyogamy. Comparative genomics revealed that Plasmogamy, Karyogamy, and meiosis machinery are all present in Amoebozoa.

If you want to know about Plasmogamy, you’ve come to the right place. Read on as we shed ample light on our topic.

Definition

In fungus, this chnage occurs when the cytoplasms of haploid gametes fuse together during syngamy. Following the merger of the two nuclei, cell fusion occurs. Nonetheless, it brings two haploid nuclei closer together within a cell for them to combine. After Plasmogamy, there is a dikaryotic stage that can last several generations before Karyogamy takes over.

Two different types of thalli fuse to form a heterothallic creature. Heterothallism is present in Basidiomycota. Within the mycelia of Basidiomycota, there is a haploid parent cell and two hyphal protoplasts. A single cell consists of 2 haploid nuclei over numerous generations (dikaryon). During the dikaryon process, these cells divide and expand.

Planogametic copulation and gametangial contact are the two basic types of Plasmogamy in lower fungi. Chytridiomycetes and Plasmodiophoromycetes copulate with mobile gametes.

During gametangial contact, oomycetes, like fungi, produce non-motile gametes termed aplanogametes. By using gametangial copulation, a lesser fungus-like Mucorales can fuse gametangia. Homothallism is a fungus-specific form of sexual reproduction in which one thallus unites with another of the same species.

Plasmogamy Alternatives: Karyogamy

The nuclei of dikaryotic cells fuse together during fungal syngamy. Karyogamy is the term for this process. The ultimate step in the syngamy process is this. Thus nuclear envelope of a haploid nucleus unite three times. The outer membranes of the two nuclei fuse in the first step.

The dikaryotic cell becomes diploid after undergoing Karyogamy. Zygotes or zygospores are the diploid cells that arise. In the fungal life cycle, the zygote is the only diploid phase. In diploid cells, Karyogamy is follows meiosis. By replicating chromosomes and recombining genetic information, a cell divides into four daughter cells, each haploid.

As a result, Karyogamy contributes to the genetic diversity of the fungal population. Daughter cells undergo mitosis to increase their number of cells. Spores are what they’re known as . Fungi produce haploid spores as a result of sexual reproduction.

Karyogamy is delayed in Ascomycetes and Basidiomycetes, and the dikaryotic cells survive for numerous generations. Mitotic division and conventional cytokinesis are both possible in dikaryotic. The growth phase of a fungus is  dikaryotic phase. The two dikaryotic nuclei spread into two daughter cells. Simultaneously as the mycelium expands, it resulting in the development of the mycelium and dikaryotic.

Plasmogamy in Comparison with Karyogamy

Fungi engage in Plasmogamy and Karyogamy at the same time. Syngamy is a mechanism of recombination that relates to the sexual reproduction of the fungus. Plasmogamy, Karyogamy, and mitotic division are all performed on the developing diploid nucleus. When the cytoplasms of lower fungi merge, this is Plasmogamy. It is also conceivable for the two opposing forms of fungal thalli to fuse, resulting in eukaryotic cell stages.

Lower-level fungi use Plasmogamy or Karyogamy to reproduce. Higher fungi keep cells at the dikaryotic stage for numerous generations by delaying Karyogamy. In fungi, Karyogamy is the joining of two haploid nuclei, whereas it joins two hyphal protoplasts.

Main Differences Between Plasmogamy and Karyogamy

Syngamy is the merging of two gametes during sexual reproduction. Plasmogamy and Karyogamy are the two stages of syngamy. The initial step of syngamy is Plasmogamy. It fuses the cytoplasm of two gametes or mating cells without the nuclei or mating cells combining. Plasmogamy is the union of the male and female nuclei. When Plasmogamy develops, a cell with two nuclei inherits from each parent. It is a dikaryotic cell. Following cytoplasm fusion, two nuclei move closer to each other and unite. Karyogamy is the name for this stage. The distinction between Plasmogamy and Karyogamy is this.

When Karyogamy occurs, a diploid cell, (a zygote) is produced. The zygote can either divide by meiosis to produce spores or by mitosis to create a new person. Karyogamy occurs soon after Plasmogamy in some organisms, such as lower fungi. The dikaryon phase can last multiple generations in some animals.

Commonly Searched Terms on Plasmogamy

Is it a fusion?

In fungi, Plasmogamy occurs when the cytoplasms of haploid gametes fuse during syngamy. Following the merger of the two nuclei, cell fusion occurs. Nonetheless, this stage brings two haploid nuclei closer together within a cell for them to combine.

Plasmogamy in Fungi

Fungi undertake Plasmogamy, in which the protoplasm of two-parent cells (typically from the mycelia) fuse without merging the nuclei, essentially combining two haploid nuclei in one cell as part of sexual reproduction. The two nuclei then join and proceed through meiosis to form spores, which is Karyogamy.

Plasmogamy Karyogamy and Meiosis

Plasmogamy, Karyogamy and Meiosis are significant to each other. After Plasmogamy, two fungi nuclei then merge and proceed through meiosis to form spores. This process is Karyogamy.

Plasmogamy

Conclusion

Both of them occur in fungi during syngamy. Syngamy is a sort of recombination that occurs when fungi reproduce sexually. Karyogamy follows Plasmogamy. This is the stage where fusing of two protoplasts occur from either gamete of two different types of thalli. Since this stage produces haploid cells with two haploid nuclei, they are dikaryon. Higher fungi, such as Basidiomycota sustain these dikaryotic phases for several generations.

In lower fungi, however, Plasmogamy follows Karyogamy almost immediately. In a dikaryotic cell, Karyogamy occurs when two haploid nuclei fuse. Plasmogamy happens when two mating types of thalli create a pair in Basidiomycetes. The basidiocarp, which has a big fruiting body, is developing into a dikaryotic thallus. In lesser fungi like Oomycota, two gametes fuse during the syngamy process.

During meiosis, Karyogamy between the two haploid nuclei might result in the formation of a diploid nucleus. Haploid pores create mycelium, which germinates. The significant distinction between Plasmogamy and Karyogamy is their easily fusabe structures.