Haploidisation is the process of halving the chromosomal content of a cell, producing a
haploid cell. Within the normal reproductive cycle, haploidisation is one of the major functional consequences of
meiosis
Meiosis (; , since it is a reductional division) is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately r ...
, the other being a process of
chromosomal crossover that mingles the genetic content of the parental chromosomes. Usually, haploidisation creates a monoploid cell from a diploid progenitor, or it can involve halving of a polyploid cell, for example to make a diploid potato plant from a tetraploid lineage of potato plants.
If haploidisation is not followed by
fertilisation, the result is a haploid lineage of cells. For example, experimental haploidisation may be used to recover a strain of haploid ''
Dictyostelium
''Dictyostelium'' is a genus of single- and multi-celled eukaryotic, phagotrophic bacterivores. Though they are Protista and in no way fungal, they traditionally are known as "slime molds". They are present in most terrestrial ecosystems ...
'' from a diploid strain. It sometimes occurs naturally in plants when meiotically reduced cells (usually egg cells) develop by
parthenogenesis
Parthenogenesis (; from the Greek grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and developmen ...
.
Haploidisation was one of the procedures used by
Japanese researchers to produce
Kaguya, a
mouse which had
same-sex parents; two haploids were then combined to make the diploid mouse.
Haploidisation commitment is a checkpoint in meiosis which follows the successful completion of premeiotic DNA replication and recombination commitment.
[{{cite journal , pmc = 218468 , pmid=762020 , volume=137 , title=Uncontrolled septation in a cell division cycle mutant of the fission yeast Schizosaccharomyces pombe , journal=J Bacteriol , pages=440–6 , last1 = Minet , first1 = M , last2 = Nurse , first2 = P , last3 = Thuriaux , first3 = P , last4 = Mitchison , first4 = JM]
See also
*
Polyploidy
Polyploidy is a condition in which the biological cell, cells of an organism have more than one pair of (Homologous chromosome, homologous) chromosomes. Most species whose cells have Cell nucleus, nuclei (eukaryotes) are diploid, meaning they ha ...
*
Ploidy
References
Genetics