An inactivated X chromosome that appears as a small, black dot in the cells of genetic females, distinguishing them from male cells.
A highly condensed mass of chromatin found in the cell nuclei of normal female somatic cells, but not in the cell nuclei of normal male somatic cells. The body represents a condensed X chromosome.
A single condensed X chromosome. The Barr body is found in the nuclei of female somatic cells.
a condensed, deactivated X chromosome found in some cells of mammals.
In mammals, an inactivated X chromosome.
The name given to the inactive X chromosome present in all non-dividing body cells of female mammals. The Barr body has a distinctive appearance under the microscope.
The condensation of the inactive X chromosome seen in the nucleus of certain types of cells from females. See Sex chromatin.
BAR BOD-ee The dark-staining body in the nucleus of a female mammal's cell, corresponding to the inactivated X chromosome. 294
A condensed, inactive X chromosome found in some cells in females.
The highly condensed chromatin formed by an inactivated X chromosome.
Inactivated X-chromosome in mammalian females. Although inactivated, the Barr body is replicated prior to cell division and thus is passed on to all descendant cells of the embryonic cell that had one of its X-chromosomes inactivated. PICTURE 1 PICTURE 2
Inactive, repressed X chromosome seen in the female
A condensed mass of chromatin found in the nuclei of female mammals. It is a late-replicating, inactive X-chromosome. Named after its discoverer, Murray Barr (1908-).
the condensed single X chromosome seen in the nuclei of somatic cells of female mammals
A densely staining mass that represents an inactivated X chromosome.
Randomly condensed one of two X chromosomes in cells of female mammals.
a cytogenetic structure associated with the second X-chromosome in female mammals, and absent in males
In those species in which sex is determined by the presence of the Y or W chromosome rather than the diploidy of the X or Z, a Barr body is the inactive X chromosome in a female cell, or the inactive Z in a male (Lyon, 2003), rendered inactive in a process called Lyonization. The Lyon hypothesis states that in cells with multiple X chromosomes, all but one is inactivated during mammalian embryogenesis. This happens early in embryonic development at random in mammals, (Brown, 1997) except in marsupials and in some extra-embryonic tissues of some placental mammals, in which the father's X chromosome is always deactivated (Lee, 2003).
