MeSH Browser

MeSH Heading: Crossing Over, Genetic
Tree Number(s): G05.728.615.200
Unique ID: D003434
RDF Unique Identifier: http://id.nlm.nih.gov/mesh/D003434
Annotation: do not confuse with CROSSES, GENETIC, the result of breeding 2 varieties of the same species
Scope Note: The reciprocal exchange of segments at corresponding positions along pairs of homologous CHROMOSOMES by symmetrical breakage and crosswise rejoining forming cross-over sites (HOLLIDAY JUNCTIONS) that are resolved during CHROMOSOME SEGREGATION. Crossing-over typically occurs during MEIOSIS but it may also occur in the absence of meiosis, for example, with bacterial chromosomes, organelle chromosomes, or somatic cell nuclear chromosomes.
Entry Version: CROSSING OVER GENET
Entry Term(s): Crossing Over; Crossing-Over, Genetic
Previous Indexing: Cytogenetics (1967); Genetics (1966-1967)
See Also: Chromosome Pairing; Pachytene Stage; Sister Chromatid Exchange
Public MeSH Note: 2005; see CROSSING OVER (GENETICS) 1968-2004
History Note: 2005(1968)
Date Established: 1968/01/01
Date of Entry: 1999/01/01
Revision Date: 2016/06/17

Allowable Qualifiers: drug effects (DE)

ethics (ES)

genetics (GE)

immunology (IM)

physiology (PH)

radiation effects (RE)

Concept UI: M0005351
Scope Note: The reciprocal exchange of segments at corresponding positions along pairs of homologous CHROMOSOMES by symmetrical breakage and crosswise rejoining forming cross-over sites (HOLLIDAY JUNCTIONS) that are resolved during CHROMOSOME SEGREGATION. Crossing-over typically occurs during MEIOSIS but it may also occur in the absence of meiosis, for example, with bacterial chromosomes, organelle chromosomes, or somatic cell nuclear chromosomes.
Terms: Crossing Over, Genetic Preferred Term
Term UI T583983
Date04/19/2004
LexicalTag NON
ThesaurusID NLM (2005); Crossing Over
Term UI T009998
Date03/23/1979
LexicalTag NON
ThesaurusID UNK (19XX); Crossing-Over, Genetic
Term UI T583984
Date04/19/2004
LexicalTag NON
ThesaurusID NLM (2005)

Crossing Over, Genetic MeSH Descriptor Data 2025