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Chromosome 21

About: Chromosome 21 is a research topic. Over the lifetime, 4736 publications have been published within this topic receiving 206655 citations. The topic is also known as: chr21 & Homo sapiens chromosome 21.


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Journal ArticleDOI
11 Mar 1976-Nature
TL;DR: The experiments indicate that chromosome 21 codes for a cell-surface component required as a specific receptor for human interferon, and these inhibit the response of live human cells to interferons.
Abstract: ANTICELLULAR sera able to block specific cell responses are important in the study of surface receptors. Particularly useful are antibodies against the human cellular antigens coded for by a specific chromosome, which can be prepared by immunising mice with mouse–human somatic cell hybrids containing defined human chromosomes1. We have applied this method to the study of the mechanism by which the presence of human chromosome 21 renders such hybrids sensitive to human interferon2. Interaction of an interferon with sensitive cells induces intracellular biochemical changes, including the formation of an inhibitor of protein synthesis, making the cell unable to support virus replication3,4. We have obtained antibodies to hybrid cells containing human chromosome 21, and these inhibit the response of live human cells to interferon. Our experiments indicate that chromosome 21 codes for a cell-surface component required as a specific receptor for human interferon.

122 citations

Journal ArticleDOI
TL;DR: The entire DNA sequence for human chromosome 21 is now complete, and it is predicted to contain only about 225 genes, which is approximately three-fold fewer than the number initially predicted just 10 years ago.
Abstract: The entire DNA sequence for human chromosome 21 is now complete, and it is predicted to contain only about 225 genes, which is approximately three-fold fewer than the number initially predicted just 10 years ago. Despite this remarkable achievement, very little is known about the mechanism(s) whereby increased gene copy number (gene dosage) results in the characteristic phenotype of Down syndrome. Although many of the phenotypic traits show large individual variation, neuromotor dysfunction and cognitive and language impairment are observed in virtually all individuals. Currently, there are no efficacious biomedical treatments for these central nervous system-associated impairments. To develop novel therapeutic strategies, the effects of gene dosage imbalance need to be understood within the framework of those critical biological events that regulate brain organization and function.

122 citations

Journal ArticleDOI
TL;DR: The double FISH technique showed that the B chromosome (B2 type) is mainly composed of a 180 bp tandem repeat and ribosomal DNA, the minute short arm being the only region that does not hybridize with them.
Abstract: Double fluorescentin situ hybridization (FISH) with two DNA probes (a 180 bp tandemly repeated DNA and ribosomal DNA) was performed in embryo cells of the grasshopperEyprepocnemis plorans. Repetitive DNA was present in most standard chromosomes (excepting 7, 8 and 10) and in the proximal two-thirds of the B chromosome, which was its major location in the complement. Ribosomal DNA was present distally on the B, and in the active nucleolar organizer regions (NORs) of the X, 9, 10 and 11 chromosomes. A small number of rRNA gene clusters was also observed in the pericentromeric regions of chromosomes 1–8. The double FISH technique showed that the B chromosome (B2 type) is mainly composed of a 180 bp tandem repeat and ribosomal DNA, the minute short arm being the only region that does not hybridize with them. The location and order of the centromere and both the DNA sequences on the B chromosome coincide only with those in the X chromosome, indicating that the B most probably derives from the X.

122 citations

Journal ArticleDOI
TL;DR: It is reported for the first time that compared to diploid controls, the hippocampus from the Ts1Cje mouse had a smaller LTP and an increased LTD and these findings suggest that genes from Ts 1Cje chromosome, including GIRK2 potassium channel, contribute to abnormal short- and long-term plasticity.

122 citations

Journal ArticleDOI
TL;DR: It is confirmed that an error in maternal meiosis II (MII) is the most frequent cause of non-disjunction for chromosome 18, and chiasma distributions from normal chromosome 18 meioses provide no evidence for normal disjunction from nullichiasmate tetrads generally.
Abstract: A sample of 100 trisomy 18 conceptuses analysed separately and together with a published sample of 61 conceptuses confirms that an error in maternal meiosis II (MII) is the most frequent cause of non-disjunction for chromosome 18. This is unlike all other human trisomies that have been studied, which show a higher frequency in maternal meiosis I (MI). Maternal MI trisomy 18 shows a low frequency of recombination in proximal p and medial q, but not the reduction in proximal q observed in chromosome 21 MI non-disjunction. Maternal MII non-disjunction does not fit the entanglement model that predicts increased recombination, especially near the centromere. Whereas recent data on MII trisomy 21 show the predicted increase in recombination proximally, maternal MII trisomy 18 has non-significantly reduced recombination. Therefore, chromosome-specific factors must complicate the simple model of susceptible chiasma distributions interacting with age-dependent deterioration of the meiotic mechanism. For chromosome 18, 30% of tetrads are nullichiasmate in maternal MI non-disjunction, but nullichiasmates are not observed in maternal MII non-disjunction. Chiasma distributions from normal chromosome 18 meioses provide no evidence for normal disjunction from nullichiasmate tetrads. We extend this study to examine the remaining autosomes and find no evidence for normal disjunction from nullichiasmate tetrads generally.

122 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202320
202259
202147
202061
201943
201858