Biomaterial Database

DNA replication and sister chromatid exchange in 9qh+. 1983

P E Crossen

The frequency of sister chromatid exchanges (SCE's) in the euchromatin and heterochromatin of a human 9qh + chromosome was determined using the BrdU-Giemsa technique. The 9qh + region contained fewer exchanges than the euchromatin, and there was an excess number of exchanges at the junction of the euchromatin and heterochromatin of the long arm. BrdU incorporation and differential staining of sister chromatids showed that the heterochromatic region of the 9 was always the last region to replicate and was among the last areas of the whole human chromosome complement to complete replication.

UI	MeSH Term	Description	Entries
D001973	Bromodeoxyuridine	A nucleoside that substitutes for thymidine in DNA and thus acts as an antimetabolite. It causes breaks in chromosomes and has been proposed as an antiviral and antineoplastic agent. It has been given orphan drug status for use in the treatment of primary brain tumors.	BUdR,BrdU,Bromouracil Deoxyriboside,Broxuridine,5-Bromo-2'-deoxyuridine,5-Bromodeoxyuridine,NSC-38297,5 Bromo 2' deoxyuridine,5 Bromodeoxyuridine,Deoxyriboside, Bromouracil
D002906	Chromosomes, Human, 6-12 and X	The medium-sized, submetacentric human chromosomes, called group C in the human chromosome classification. This group consists of chromosome pairs 6, 7, 8, 9, 10, 11, and 12 and the X chromosome.	Chromosomes C,Group C Chromosomes,Chromosomes, Human, 6-12,Chromosome, Group C,Chromosomes, Group C,Group C Chromosome
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
D004261	DNA Replication	The process by which a DNA molecule is duplicated.	Autonomous Replication,Replication, Autonomous,Autonomous Replications,DNA Replications,Replication, DNA,Replications, Autonomous,Replications, DNA
D006570	Heterochromatin	The portion of chromosome material that remains condensed and is transcriptionally inactive during INTERPHASE.	Heterochromatins
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012854	Sister Chromatid Exchange	An exchange of segments between the sister chromatids of a chromosome, either between the sister chromatids of a meiotic tetrad or between the sister chromatids of a duplicated somatic chromosome. Its frequency is increased by ultraviolet and ionizing radiation and other mutagenic agents and is particularly high in BLOOM SYNDROME.	Chromatid Exchange, Sister,Chromatid Exchanges, Sister,Exchange, Sister Chromatid,Exchanges, Sister Chromatid,Sister Chromatid Exchanges