Barr bodies: Difference between revisions
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A barr body<ref>''Barr body'' http://en.wikipedia.org/wiki/Barr_body September 3, 2014.</ref> is an inactive [[X chromosome|X chromosome]] in female cells or the inactive Z in a male. [[Lyonization|Lyonization]] is the process where the chromosome is inactivated in species. In addition to this, it is thought to be down to complete chance as to which X chromosome is inactivated and it is still unknown to this day as to how the cell decide which X chromosome is to be made into a Barr body. | A barr body<ref>''Barr body'' http://en.wikipedia.org/wiki/Barr_body September 3, 2014.</ref> is an inactive [[X chromosome|X chromosome]] in female cells or the inactive Z in a male. [[Lyonization|Lyonization]] is the process where the chromosome is inactivated in species. In addition to this, it is thought to be down to complete chance as to which X chromosome is inactivated and it is still unknown to this day as to how the cell decide which X chromosome is to be made into a Barr body. | ||
In men and women with more than one X chromosome, the number of Barr bodies visible at interphase is always one less than the total number of X chromosomes. | In men and women with more than one X chromosome, the number of Barr bodies visible at interphase is always one less than the total number of X chromosomes. | ||
For example, a man with [[ | For example, a man with [[Klinefelter syndrome|Klinefelters syndrome]], with 47 chromosomes, XXY [[Karyotype|karyotype]] have two Barr bodies, whereas an female with [[Turner syndrome|Turners syndrome]], with 45 chromosomes, XO karyotype does not have any Barr bodies<ref>Sloane.E, The Biology of Women, 4th Edition, Cengage Learning, 2002, pages 133</ref>.<br> | ||
=== References | === References<br> === | ||
<references /> | |||
Revision as of 08:41, 28 October 2015
A barr body[1] is an inactive X chromosome in female cells or the inactive Z in a male. Lyonization is the process where the chromosome is inactivated in species. In addition to this, it is thought to be down to complete chance as to which X chromosome is inactivated and it is still unknown to this day as to how the cell decide which X chromosome is to be made into a Barr body.
In men and women with more than one X chromosome, the number of Barr bodies visible at interphase is always one less than the total number of X chromosomes.
For example, a man with Klinefelters syndrome, with 47 chromosomes, XXY karyotype have two Barr bodies, whereas an female with Turners syndrome, with 45 chromosomes, XO karyotype does not have any Barr bodies[2].
References
- ↑ Barr body http://en.wikipedia.org/wiki/Barr_body September 3, 2014.
- ↑ Sloane.E, The Biology of Women, 4th Edition, Cengage Learning, 2002, pages 133