Biomaterial Database

Exchange within heterozygous inversions in Drosophila melanogaster. 1974

L G Robbins

The exchange behavior of non-attached, whole arm, X chromosome inversions was reexamined using nondisjunction in XXY females as an indirect measure of the frequency of nonexchange tetrads. Crossing over is quite normal in these inversion heterozygotes and is independent of the arrangement of the basal heterochromatin.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008540	Meiosis	A type of CELL NUCLEUS division, occurring during maturation of the GERM CELLS. Two successive cell nucleus divisions following a single chromosome duplication (S PHASE) result in daughter cells with half the number of CHROMOSOMES as the parent cells.	M Phase, Meiotic,Meiotic M Phase,M Phases, Meiotic,Meioses,Meiotic M Phases,Phase, Meiotic M,Phases, Meiotic M
D002869	Chromosome Aberrations	Abnormal number or structure of chromosomes. Chromosome aberrations may result in CHROMOSOME DISORDERS.	Autosome Abnormalities,Cytogenetic Aberrations,Abnormalities, Autosome,Abnormalities, Chromosomal,Abnormalities, Chromosome,Chromosomal Aberrations,Chromosome Abnormalities,Cytogenetic Abnormalities,Aberration, Chromosomal,Aberration, Chromosome,Aberration, Cytogenetic,Aberrations, Chromosomal,Aberrations, Chromosome,Aberrations, Cytogenetic,Abnormalities, Cytogenetic,Abnormality, Autosome,Abnormality, Chromosomal,Abnormality, Chromosome,Abnormality, Cytogenetic,Autosome Abnormality,Chromosomal Aberration,Chromosomal Abnormalities,Chromosomal Abnormality,Chromosome Aberration,Chromosome Abnormality,Cytogenetic Aberration,Cytogenetic Abnormality
D003433	Crosses, Genetic	Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.	Cross, Genetic,Genetic Cross,Genetic Crosses
D003434	Crossing Over, Genetic	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.	Crossing Over,Crossing-Over, Genetic,Crossing Overs,Genetic Crossing Over,Genetic Crossing-Over
D004331	Drosophila melanogaster	A species of fruit fly frequently used in genetics because of the large size of its chromosomes.	D. melanogaster,Drosophila melanogasters,melanogaster, Drosophila
D005260	Female		Females
D006570	Heterochromatin	The portion of chromosome material that remains condensed and is transcriptionally inactive during INTERPHASE.	Heterochromatins
D006579	Heterozygote	An individual having different alleles at one or more loci regarding a specific character.	Carriers, Genetic,Genetic Carriers,Carrier, Genetic,Genetic Carrier,Heterozygotes
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia