A DNA insulator prevents repression of a targeted X-linked transgene but not its random or imprinted X inactivation.

ABSTRACT: Some genes on the inactive X chromosome escape silencing. One possible escape mechanism is that heterochromatization during X inactivation can be blocked by boundary elements. DNA insulators are candidates for blocking because they shield genes from influences of their chromosomal environment. To test whether DNA insulators can act as boundaries on the X chromosome, we inserted into the mouse X-linked Hprt locus a GFP transgene flanked with zero, one, or two copies of a prototypic vertebrate insulator from the chicken beta-globin locus, chicken hypersensitive site 4, which contains CCCTC binding factor binding sites. On the active X chromosome the insulators blocked repression of the transgene, which commences during early development and persists in adults, in a copy number-dependent mann

SUBMITTER: Ciavatta D 

PROVIDER: S-EPMC1479543 | biostudies-literature | 2006 Jun

REPOSITORIES: biostudies-literature