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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 ...
Zygospores are formed in certain fungi (zygomycota, for example Rhizopus) and some algae (for example Chlamydomonas). The zygospore forms through the isogamic fusion of two cells (motile single cells in Chlamydomonas) or sexual conjugation between two hyphae (in zygomycota). Plasmogamy is followed by karyogamy, therefore zygospores are diploid ...
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.
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.
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 ]
[12] [13] [14] In the extremely halotolerant black yeast Hortaea werneckii it was discovered that while the species is clonal, both haploid and diploid strains can be found in nature and the diploid strains are highly heterozygous hybrids, which appear to be stable over large time scales and geographical distances. [15]
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 diploid nuclei of blastospores can undergo meiosis, including recombination, to form haploid basidiospores that can be dispersed. [234] This process is referred to as monokaryotic fruiting. This process requires a gene called DMC1 , which is a conserved homologue of genes recA in bacteria and RAD51 in eukaryotes, that mediates homologous ...