Heterokaryon
Encyclopedia
A heterokaryon is a cell
that contains multiple, genetically different nuclei
. This can occur naturally, such as in the mycelium
of fungi
during sexual reproduction, or artificially as formed by the experimental fusion of two genetically different cells. A medical example is a heterokaryon composed of nuclei from Hurler syndrome
and Hunter syndrome
. Both of these diseases result in problems in mucopolysaccharide metabolism. However, a heterokaryon of nuclei from both of these diseases exhibits normal mucopolysaccharide metabolism, proving that the two syndromes affect different proteins and so can correct each other in the heterokaryon. In an experimental setting, polyethylene glycol
may be applied to a culture of cells to induce the individual cells to fuse together, forming a heterokaryon.
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
that contains multiple, genetically different nuclei
Cell nucleus
In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...
. This can occur naturally, such as in the mycelium
Mycelium
thumb|right|Fungal myceliaMycelium is the vegetative part of a fungus, consisting of a mass of branching, thread-like hyphae. The mass of hyphae is sometimes called shiro, especially within the fairy ring fungi. Fungal colonies composed of mycelia are found in soil and on or within many other...
of fungi
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
during sexual reproduction, or artificially as formed by the experimental fusion of two genetically different cells. A medical example is a heterokaryon composed of nuclei from Hurler syndrome
Hurler syndrome
Hurler syndrome, also known as mucopolysaccharidosis type I , Hurler's disease, also gargoylism, is a genetic disorder that results in the buildup of glycosaminoglycans due to a deficiency of alpha-L iduronidase, an enzyme responsible for the degradation of mucopolysaccharides in lysosomes...
and Hunter syndrome
Hunter syndrome
Hunter syndrome, or mucopolysaccharidosis Type II, is a lysosomal storage disease caused by a deficient enzyme, iduronate-2-sulfatase . The syndrome is named after physician Charles A. Hunter , who first described it in 1917...
. Both of these diseases result in problems in mucopolysaccharide metabolism. However, a heterokaryon of nuclei from both of these diseases exhibits normal mucopolysaccharide metabolism, proving that the two syndromes affect different proteins and so can correct each other in the heterokaryon. In an experimental setting, polyethylene glycol
Polyethylene glycol
Polyethylene glycol is a polyether compound with many applications from industrial manufacturing to medicine. It has also been known as polyethylene oxide or polyoxyethylene , depending on its molecular weight, and under the tradename Carbowax.-Available forms:PEG, PEO, or POE refers to an...
may be applied to a culture of cells to induce the individual cells to fuse together, forming a heterokaryon.
- See heterokaryosisHeterokaryosisHeterokaryosis is a term used in biology meaning to have two or more genetically different nuclei within the same mycelium of a fungus or other life form. This is a special type of syncytium.A heterokaryon is a cell with more than one nucleus of differing genetic origin...
for a more general account of this phenomenon.