cell biology Cell biology (also cellular biology or cytology) is a branch of biology that studies the structure, function, and behavior of cells. All living organisms are made of cells. A cell is the basic unit of life that is responsible for the living and ...

, chromosome territories are regions of the

nucleus Nucleus ( : nuclei) is a Latin word for the seed inside a fruit. It most often refers to: *Atomic nucleus, the very dense central region of an atom *Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA Nucle ...

preferentially occupied by particular

chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...

Interphase Interphase is the portion of the cell cycle that is not accompanied by visible changes under the microscope, and includes the G1, S and G2 phases. During interphase, the cell grows (G1), replicates its DNA (S) and prepares for mitosis (G2). A c ...

chromosomes are long DNA strands that are extensively folded, and are often described as appearing like a bowl of

spaghetti Spaghetti () is a long, thin, solid, cylindrical pasta.spaghetti
Dictionary.com. Dictionary.com Unabridg ...

. The chromosome territory concept holds that despite this apparent disorder, chromosomes largely occupy defined regions of the nucleus. Most

eukaryote Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacte ...

s are thought to have chromosome territories, although the budding

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constitut ...

S. cerevisiae ''Saccharomyces cerevisiae'' () (brewer's yeast or baker's yeast) is a species of yeast (single-celled fungus microorganisms). The species has been instrumental in winemaking, baking, and brewing since ancient times. It is believed to have bee ...

'' is an exception to this.

Characteristics

Chromosome territories are spheroid with diameters on the order of one to few micrometers. Nuclear compartments devoid of DNA called interchromatin compartments have been reported to tunnel into chromosome territories to facilitate molecular diffusion into the otherwise tightly packed chromosome-occupied regions.

History and experimental support

The concept of chromosome territories was proposed by

Carl Rabl Carl Rabl (2 May 1853 in Wels, Austria – 24 December 1917 in Leipzig, Germany Carl Rabl
at

fluorescence in situ hybridization Fluorescence ''in situ'' hybridization (FISH) is a molecular cytogenetic technique that uses fluorescent probes that bind to only particular parts of a nucleic acid sequence with a high degree of sequence complementarity. It was developed b ...

). Studies of genomic proximity using techniques like

chromosome conformation capture Chromosome conformation capture techniques (often abbreviated to 3C technologies or 3C-based methods) are a set of molecular biology methods used to analyze the spatial organization of chromatin in a cell. These methods quantify the number of int ...

have supported the chromosome territory concept by showing that DNA-DNA contacts predominantly happen within particular chromosomes.

References

{{reflist Molecular biology Nuclear organization

Characteristics

History and experimental support

See also

References