Dictionary > Amitosis

Amitosis

Definition
noun, plural: amitoses
A direct type of cell division wherein the nucleus and the cytoplasm go through a simple mass division into two parts
Supplement
Cell division is the process in which a parent cell divides, giving rise to two or more daughter cells. It is an essential biological process in many organisms. It is the means used by multicellular organisms in order to grow, replenish (repair), and reproduce. In unicellular organisms, a cell division is equivalent to reproduction. There are two forms of cell division: (1) direct cell division and (2) indirect cell division.
The direct cell division is one in which the cell directly divides and does not undergo complicated changes before it divides, just as in indirect cell division (such as mitosis). The nucleus and the cytoplasm of the cell divide by constriction without the prior formation of chromosomes. This type of direct cell division is also called amitosis.
Few studies on amitosis in mammalian cells were reported. It was observed in cells grown from placental tissue in rats1, and in the cultured trophoblasts of mouse2, and in human3.
Word origin: a– (not, without, lack of) + mitosis
Also called:

  • direct cell division

Compare:

  • mitosis
  • See also:

    Reference(s):

    1 Ferguson FG, Palm J. 1976. Histologic characteristics of cells cultured from rat placental tissue. Am J Obstet Gynecol.124(4):415-20.

    2 Kuhn EM, Therman E, Susman B. 1991. Amitosis and endocycles in early cultured mouse trophoblast. Placenta. 12(3):251-61.

    3 Cotte C, Easty GC, Neville AM, Monaghan P. 1980. Preparation of highly purified cytotrophoblast from human placenta with subsequent modulation to form syncytiotrophoblast in monolayer cultures. In Vitro. 16(8):639-46.


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