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The mating of yeast, also known as yeast sexual reproduction, is a biological process that promotes genetic diversity and adaptation in yeast species. Yeast species, such as Saccharomyces cerevisiae (baker's yeast), are single-celled eukaryotes that can exist as either haploid cells, which contain a single set of chromosomes , or diploid cells ...
The most common mode of vegetative growth in yeast is asexual reproduction by budding, [47] where a small bud (also known as a bleb or daughter cell) is formed on the parent cell. The nucleus of the parent cell splits into a daughter nucleus and migrates into the daughter cell.
Budding yeast form a bud from the mother cell. This bud grows during the cell cycle and detaches; fission yeast divide by forming a cell wall [30] Cytokinesis begins at G1 for budding yeast, while cytokinesis begins at G2 for fission yeast. Fission yeast "select" the midpoint, whereas budding yeast "select" a bud site [38]
Saccharomyces cerevisiae, brewer's and baker's yeast, is in the phylum Ascomycota. During vegetative growth that ordinarily occurs when nutrients are abundant, S. cerevisiae reproduces by mitosis as either haploid or diploid cells. However, when starved, diploid cells undergo meiosis to form haploid spores. [13]
For example, the small bulb-like projection coming out from the yeast cell is known as a bud. Since the reproduction is asexual, the newly created organism is a clone and, excepting mutations, is genetically identical to the parent organism. Organisms such as hydra use regenerative cells for reproduction in the process of budding.
Some cells divide by budding (for example baker's yeast), resulting in a "mother" and a "daughter" cell that is initially smaller than the parent. Budding is also known on a multicellular level; an animal example is the hydra , [ 10 ] which reproduces by budding.
The fission yeast Schizosaccharomyces pombe, treated with H 2 O 2 to cause oxidative stress, substantially increases the proportion of cells which undergo meiosis. [12] The simple multicellular eukaryote Volvox carteri undergoes sex in response to oxidative stress [ 13 ] or stress from heat shock. [ 14 ]
Fission yeast switches mating type by a replication-coupled recombination event, which takes place during S phase of the cell cycle. Fission yeast uses intrinsic asymmetry of the DNA replication process to switch the mating type; it was the first system where the direction of replication was shown to be required for the change of the cell type.