Meiocyte
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A meiocyte is a type of cell that differentiates into a gamete through the process of meiosis. Through meiosis, the diploid meiocyte divides into four genetically different haploid gametes.[1][2] The control of the meiocyte through the meiotic cell cycle varies between different groups of organisms.
The process of meiosis has been extensively studied in model organisms, such as yeast.[1][3] Because of this, the way in which the meiocyte is controlled through the meiotic cell cycle is best understood in this group of organisms.[3] A yeast meiocyte that is undergoing meiosis must pass through a number of checkpoints in order to complete the cell cycle.[3] If a meiocyte divides and this division results in a mutant cell, the mutant cell will undergo apoptosis and, therefore, will not complete the cycle.[3]
In natural populations of the yeast Saccharomyces cerevisiae, diploid meiocytes produce haploid cells that then mainly undergo either clonal reproduction, or selfing (intratetrad mating) to form progeny diploid meiocytes.[4] When the ancestry of natural S. cerevisiae strains was analyzed, it was determined that formation of diploid meiocytes by outcrossing (as opposed to inbreeding or selfing) occurs only about once every 50,000 cell divisions.[5] These findings suggest that the principal adaptive function of meiocytes may not be related to the production of genetic diversity that occurs infrequently by outcrossing, but rather may be mainly related to recombinational repair of DNA damage (that can occur in meiocytes at each mating cycle).[6]
Animal
The animal meiotic cell cycle is very much like that of yeast. Checkpoints within the animal meiotic cell cycle serve to stop mutant meiocytes from progressing further within the cycle.[3] Like yeast meiocytes, if an animal meiocyte differentiates into a mutant cell, the cell will undergo apoptosis.[3]