Schematic karyogram of a human. Each row is vertically aligned at centromere level. The top of chromosomes 13, 14, 15, 21, & 22 are satellites, with a secondary constriction between the satellite and the centromere.
Further information: Karyotype
Satellite chromosomes or SAT-chromosomes are chromosomes that contain secondary constructs that serve as identification. They are observed in acrocentric chromosomes. In addition to the centromere, one or more secondary constrictions can be observed in some chromosomes at metaphase. In humans they are usually associated with the short arm of an acrocentric chromosome,[1] such as in the chromosomes 13, 14, 15, 21, & 22.[2][3] The Y chromosome can also contain satellites, although these are thought to be translocations from autosomes.[4] The secondary constriction always keeps its position, so it can be used as markers to identify specific chromosomes.
The name derives from the small chromosomal segment behind the secondary constriction, called a satellite, named by Sergei Navashin, in 1912.[5] Later, Heitz (1931) qualified the secondary constriction as the SAT state (Sine Acido Thymonucleinico, which means "without thymonucleic acid"), because it didn't stain with the Feulgen reaction. With time, the term "SAT-chromosome" became an abbreviation for satellite chromosome.[6][7][8]
The satellite at metaphase appears to be attached to the chromosomes by a thread of chromatin.
SAT-chromosomes whose secondary constriction is associated with the formation of the nucleolus are referred to as nucleolar SAT-chromosomes. There are at least 4 SAT-chromosomes in each diploid nucleus, and the constriction corresponds to a nucleolar organizer (NOR), a region containing multiple copies of the 18S and 28S ribosomal genes that synthesize ribosomal RNA required by ribosomes. The appearance of secondary constrictions at NORs is thought to be due to rRNA transcription and/or structural features of the nucleolus impeding chromosome condensation.[9]
^"chromosome satellite. (n.d.)". The Free Dictionary. Medical Dictionary for the Health Professions and Nursing. 2012. Retrieved 26 September 2020.
^Sullivan, G.J.; Bridger, J.M.; Cuthbert, A.P.; Newbold, R.F.; Bickmore, W.A.; McStay, B. (2001), "Human acrocentric chromosomes with transcriptionally silent nucleolar organizer regions associate with nucleoli", The EMBO Journal, 20 (11): 2867–2877, doi:10.1093/emboj/20.11.2867, PMC 125486, PMID 11387219
^Nussbaum, Robert L.; McInnes, Roderick R.; Willard, Huntington F.; Hamosh, Ada (21 May 2015). Thompson & Thompson genetics in medicine (8th ed.). Philadelphia, PA. ISBN 9781437706963. OCLC 908336124.{{cite book}}: CS1 maint: location missing publisher (link)
^Schmid, M.; Haaf, T.; Solleder, E.; Schempp, W.; Leipoldt, M.; Heilbronner, H. (1984). "Satellited Y chromosomes: structure, origin, and clinical significance". Human Genetics. 67 (1): 72–85. doi:10.1007/bf00270562. ISSN 0340-6717. PMID 6745929. S2CID 25550661.
^Rieger, R.; Michaelis, A.; Green, M.M. (1968). A glossary of genetics and cytogenetics: Classical and molecular. New York: Springer-Verlag. ISBN 9780387076683.
^Jeon, Kwang W. (2004). International review of cytology : a survey of cell biology. Academic Press. ISBN 0-12-364639-1. OCLC 648269868.
^Battaglia, E.. (1999). The chromosome satellite (Navashin's "sputnik" or satelles): A terminological comment. Acta biologica Cracoviensia. Series botanica. 41. 15-18.
^Berger, C. A. (1940-10-25). "SAT-Chromosomes". Science. 92 (2391): 380–381. doi:10.1126/science.92.2391.380.b. ISSN 0036-8075. PMID 17734582. S2CID 239873007.
^Pikaard, C.S. (2000), "The epigenetics of nucleolar dominance", Trends in Genetics, 16 (11): 495–500, doi:10.1016/S0168-9525(00)02113-2, PMID 11074291
and 24 Related for: Satellite chromosome information
Satellitechromosomes or SAT-chromosomes are chromosomes that contain secondary constructs that serve as identification. They are observed in acrocentric...
chromatids together during cell division. This constricted region of chromosome connects the sister chromatids, creating a short arm (p) and a long arm...
Telomere Sub telomere satellitechromosome or trabant. NOR region During cell division, the molecules that compose chromosomes (DNA and proteins) undergo...
present on chromosome 1. Due to secondary constriction, a knob-like structure is formed at the end called a satellitechromosome (SAT chromosome). DNA in...
A chromosome is a package of DNA with part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated...
those two original chromosomes have been translocated to other chromosomes. Differences in number and position of satellites. Satellites are small bodies...
repeat units were clustered. Most satellite DNA is localized to the telomeric or the centromeric region of the chromosome. The nucleotide sequence of the...
part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukaryotes, there are two distinct types of cell...
artificial chromosome (HAC) is a microchromosome that can act as a new chromosome in a population of human cells. That is, instead of 46 chromosomes, the cell...
chromosomes (also known as supernumerary, accessory, (conditionally-)dispensable, or lineage-specific chromosomes). By definition, these chromosomes are...
Chromosomal crossover, or crossing over, is the exchange of genetic material during sexual reproduction between two homologous chromosomes' non-sister...
syndrome, is an aneuploid genetic condition in which a male has an extra Y chromosome. There are usually few symptoms. These may include being taller than average...
Holocentric chromosomes are chromosomes that possess multiple kinetochores along their length rather than the single centromere typical of other chromosomes. They...
Eukaryotic chromosome fine structure refers to the structure of sequences for eukaryotic chromosomes. Some fine sequences are included in more than one...
X-chromatin is an inactive X chromosome. In species with XY sex-determination (including humans), females typically have two X chromosomes, and one is rendered...
DNA sequences on chromosomes. Fluorescence microscopy can be used to find out where the fluorescent probe is bound to the chromosomes. FISH is often used...
micronucleus is a small nucleus that forms whenever a chromosome or a fragment of a chromosome is not incorporated into one of the daughter nuclei during...
the chromosome. C-banding stains the constitutive heterochromatin, which usually lies near the centromere, and NOR staining highlights the satellites and...
also called marker chromosome 15 syndrome, idic(15), partial tetrasomy 15q, or inverted duplication 15 (inv dup 15), is a chromosome abnormality in which...
points in the chromosome, so replication forks meet and terminate at many points in the chromosome. Because eukaryotes have linear chromosomes, DNA replication...
extrachromosomal DNA molecule within a cell that is physically separated from chromosomal DNA and can replicate independently. They are most commonly found as...
Global Information