1. For somatic cells
X Chrosome Inactivation: solve the imblance of X-chromosome in somatic cells between female and male
For mammalian, there are two x chromosomes in female while only one in male. To solve this X chromsome imblance in somatic cells between female and male, one X chrosome will randomly silence in female by forming the Barr-body.
https://www.nature.com/scitable/topicpage/x-chromosome-x-inactivation-323/
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https://www.sciencedirect.com/science/article/pii/S0960982205002897
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2. For germline cells
Meiotic Sex Chromesome Inactivation: solve the imblance of X-chromosome in postmeiotic male germ cells
In mammalian male postmeiotic germline cells, the sex chrosomes (both X and Y) will be silenced by forming the XY-body.
https://journals.biologists.com/dev/article/134/10/1823/52756/Meiotic-sex-chromosome-inactivation
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https://www.cell.com/current-biology/fulltext/S0960-9822(10)01159-0
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https://www.sciencedirect.com/science/article/pii/S0960982205002897
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