Meiotic Drive

from Wikipedia, the free encyclopedia

Meiotic drive or segregation distortion , rarely also meiotic drive , denotes a deviation from the second Mendelian rule of inheritance , the rule of splitting or segregation, and sometimes also from the usual course of meiosis . While homologous genes ( alleles ) or homologous chromosomes usually get into the sex cells ( gametes ) with the same frequency , genes or chromosomes (sections) that show a drive are overrepresented in the functioning gametes, which often also means that these chromosomes or alleles are disproportionately passed on to the offspring. Well-studied examples are the SD system ( segregation distorter ) in the fruit fly Drosophila melanogaster , the t- haplotypes ( transmission ratio distortion ) in the house mouse and the spore killer system (Sk) in molds of the genus Neurospora . Larry Sandler and Edward Novitski proposed the term meiotic drive in 1957.

The drive can start on whole chromosomes or on individual genes and is accordingly referred to as chromosomal or genetic drive. The chromosomal drive usually occurs in the female sex, where generally only one of the four products of division of meiosis, usually referred to as the egg cell , survives. Here, the drive is based on the fact that a certain chromosome, due to its size or some other structural property, prefers to get into the egg cell (see Non-random segregation of chromosomes ). The genetic drive, on the other hand, occurs in males, where all four products of division usually develop into functional gametes. It is based on a developmental disorder (dysfunction) of those gametes that do not have the gene in question. The molecular basis of the genetic drive is mostly an interaction between a drive or distorter gene in the beneficiary gametes and a target or responder gene in the disadvantaged. In addition to the distorter gene itself, other genes on the same chromosome are also subject to the drive, provided they are not separated from the former by crossing-over .

While the chromosomal drive basically results in a preferred transmission of the chromosome in question to the offspring, the genetic drive is associated with a reduction in the number of functional gametes and the absolute number of functional gametes that carry the distorter gene and with Containing genes linked to this remains unchanged. The genetic drive therefore only leads to increased transmission if the reduction in fertility due to the reduced number of functional gametes has less of an impact than the increased relative presence of the alleles in question. This is particularly the case with organisms with more monogamous mating behavior.

Chromosomes or chromosome segments that are transmitted preferentially over their homologues in the case of heterozygosity, i.e. that have a drive, have been known since 1928 and are widespread among eukaryotes . The numerous well-known examples range from flowering plants to mushrooms and insects to humans. How common the phenomenon is, however, remains unclear, since the proof is quite time-consuming and particularly moderate manifestations are hardly noticeable.



  1. Terrence W. Lyttle: Segregation distorters , Annual Review of Genetics 25 : 511-557 (1991); ders .: Cheaters sometimes prosper: distortion of mendelian segregation by meiotic drive , Trends in Genetics 9 : 205-210 (1993) doi : 10.1016 / 0168-9525 (93) 90120-7
  2. Lyttle 1991, pp. 522-545
  3. L. Sandler, E. Novitski: Meiotic drive as an evolutionary force , American Naturalist 91 : 105-110 (1957)
  4. Lyttle 1991, p. 512f
  5. Lyttle 1991, p. 513
  6. JF Crow: Genes that do not obey Mendel's laws. In: Spektrum der Wissenschaft 4/1979, pp. 28-38.
  7. ^ S. Zimmering, L. Sandler, B. Nicoletti: Mechanisms of meiotic drive. In: Annual Review of Genetics 4 , pp. 409-436 (1970)
  8. Emily A. Gileva: Meiotic drive in the sex chromosome system of the varying lemming, Dicrostonyx torquatus Pall. (Rodentia, Microtinae). In: Heredity 59 , pp. 383-389 (1987).
  9. Fernando Pardo-Manuel de Villena and Carmen Sapienza: Nonrandom segregation during meiosis: the unfairness of females. In: Mammalian Genome 12 , pp. 331-339 (2001).