Balancing the Dose in the Mouse
Organisms that use a chromosomal basis of sex determination have a problem of gene inequality. In the mouse, this dimorphism is evident by the presence of two X-chromosomes in females, while males have a single X- and a single Y-chromosome. To balance this disparity, one of the two female X-chromosomes is transcriptionally silenced to neutralize the gene dose with the XY male. Dosage compensation in mammals is known as X-chromosome inactivation (XCI) and is a crucial early developmental process. XCI is an example of epigenetics: a phenotype resulting in changes on a chromosome without a change in nucleic acid sequence. Studies in mouse embryology and genetics have answered many questions about the process of balancing the dose. In this chapter, I highlight how the mouse dosage compensates the gene disparity between XX females and XY males in a crucial epigenetic process called X-chromosome inactivation (XCI).
KeywordsNoncoding RNAs Extraembryonic Tissue Trophoblast Stem Barr Body Xist Expression
I am grateful to the members of my lab for their valuable input on this chapter.
- Zheng W, Liu K (2012) Maternal control of mouse preimplantation development. In: Kubiak JZ (ed) Results and problems in cell differentiation. Springer-Verlag, HeidelbergGoogle Scholar