Mating type

Source: Wikipedia, the free encyclopedia.

Mating types are the microorganism equivalent to sexes in multicellular lifeforms and are thought to be the ancestor to distinct sexes. They also occur in macro-organisms such as fungi.

Definition

Mating types are the

Syngamy can only take place between gametes carrying different mating types.[citation needed
]

Occurrence

Reproduction by mating types is especially prevalent in

ascomycetes usually have two mating types referred to as "MAT1-1" and "MAT1-2", following the yeast mating-type locus (MAT).[3] Under standard nomenclature, MAT1-1 (which may informally be called MAT1) encodes for a regulatory protein with an alpha box motif, while MAT1-2 (informally called MAT2) encodes for a protein with a high motility-group (HMG) DNA-binding motif, as in the yeast mating type MATα1.[4] The corresponding mating types in yeast, a non-filamentous ascomycete, are referred to as MATa and MATα.[5]

Mating type genes in ascomycetes are called idiomorphs rather than

homothallic ascomycetes produce gametes that can fuse with every other gamete in the population (including its own mitotic descendants) most often because each haploid contains the two alternate forms of the Mat locus in its genome.[6]

Basidiomycetes can have thousands of different mating types.[7]

In the ascomycete Neurospora crassa matings are restricted to interaction of strains of opposite mating type. This promotes some degree of outcrossing. Outcrossing, through complementation, could provide the benefit of masking recessive deleterious mutations in genes which function in the dikaryon and/or diploid stage of the life cycle.[8]

Evolution

Mating types likely predate anisogamy,[9] and sexes evolved directly from mating types or independently in some lineages.[10]

In 2006 Japanese researchers found a gene in males of the alga Pleodorina starrii that’s an orthologue to a gene for a mating type in the alga Chlamydomonas reinhardtii, providing evidence for an evolutionary link between sexes and mating types.[11]

Secondary mating types evolved alongside simultaneous hermaphrodites in several lineages.[12]: 71 [clarification needed]

In

genomic conflict has been considered the leading explanation for the evolution of two mating types.[14]

See also

References

  1. ^ a b "mating type". Oxford Reference. Retrieved 2021-08-26.
  2. ^ From Mating Types to Sexes. Bachtrog D, Mank JE, Peichel CL, Kirkpatrick M, Otto SP, et al. (2014) Sex Determination: Why So Many Ways of Doing It? PLoS Biol 12(7): e1001899. doi:10.1371/journal.pbio.1001899
  3. . Retrieved 11 November 2015.
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  8. ^ Bernstein H, Byerly HC, Hopf FA, Michod RE. Genetic damage, mutation, and the evolution of sex. Science. 1985 Sep 20;229(4719):1277-81. doi: 10.1126/science.3898363. PMID 3898363
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