Noun
Barr body (plural Barr bodies)
(biology) A sex chromosome inactivated by packing in heterochromatin.
Men with Klinefelter syndrome (47,XXY karyotype) have a single Barr body, whereas women with a 47,XXX karyotype have two Barr bodies.
A Barr body (named after discoverer Murray Barr ) Barr, M. L., Bertram, E. G., (1949), A Morphological Distinction between Neurones of the Male and Female, and the Behaviour of the Nucleolar Satellite during Accelerated Nucleoprotein Synthesis. Source: Internet
Left: DAPI stained female human fibroblast with Barr body (arrow). Source: Internet
It is thought that this constitutes the mechanism of choice, and allows downstream processes to establish the compact state of the Barr body. Source: Internet
The Barr body is indicated by the arrow, it identifies the inactive X (Xi). Source: Internet