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The name Zygomycota refers to the zygosporangia characteristically formed by the members of this clade, in which resistant spherical spores are formed during sexual reproduction. Zygos is Greek for "joining" or "a yoke ", referring to the fusion of two hyphal strands which produces these spores, and -mycota is a suffix referring to a division ...
Phycomyces have two mating types that are indistinguishable morphologically. The sexual cycle is thought to occur by the following steps. Two hyphae of different mating type encounter each other, and their tips undergo a septation event to produce gametangia. Gametangia are haploid multinuclear cells equivalent to gametes.
The diploid zygote becomes a multinucleated plasmodium through multiple nuclear divisions without further cell division. If the resulting cells were peritrichous, they change their shape before the fusion from the peritrichous form to the myxamoeba. The production of a zygote requires two cells of different mating types (heterothallic). [11] [19]
However, when starved, diploid cells undergo meiosis to form haploid spores. [13] Mating occurs when haploid cells of opposite mating type, MATa and MATα, come into contact. Ruderfer et al. [14] pointed out that such contacts are frequent between closely related yeast cells for two reasons. The first is that cells of opposite mating type are ...
The gametangia grow toward each other, then fuse, forming a diploid zygote at the point of fusion. The zygote develops a resistant cell wall, forming a single-celled zygospore, the characteristic that gives its name to this group of fungi. Meiosis occurs within the zygospore (see article Phycomyces). Upon germination, a new haploid mycelium or ...
For Zygomycota, sexual reproduction occurs when the haploid hyphae from two individuals join to form a zygosporangium in response to unfavorable conditions. The haploid nuclei within the zygosporangium then fuse into diploid nuclei. [ 5 ]
These gametes are produced by meiosis, which halves the number of chromosomes in the diploid germ cells. 6) The short-lived diploid state of haploid organisms, a zygote generated by the union of two haploid gametes during sex. 7) The diploid zygote which has just been fertilized by the union of haploid egg and sperm during sex.
The Zoopagomycotina are a subdivision (incertae sedis) of the fungal division Zygomycota sensu lato. [1] It contains 5 families and 20 genera. [2] Relationships among and within subphyla of Zygomycota are poorly understood, and their monophyly remains in question, so they are sometimes referred to by the informal name zygomycetes.