title: Monoallelic gene targeting in hypoblast stem cells reveals X chromosome inactivation.
abstract: We recently isolated hypoblast stem cells (HypoSC), which are related to embryonic stem (ES) cells. ES cells efficiently perform homologous recombination (HR) and lack X chromosome inactivation (Xi), but it is unknown whether the same applies to HypoSC. Using the X-linked hypoxanthine phosphoribosyl transferase (HPRT) gene, we find that HypoSC perform HR with similar frequency as ES cells. Monoallelic targeting in female HypoSC eliminated HPRT gene expression, implying epigenetic inactivation of the other allele. Although density-induced differentiation complicated selection, the targeted clones maintained their original properties. These results will facilitate targeted genetic manipulation of HypoSC and the study of Xi.
authors.affiliation: Division of Molecular & Life Science, College of Science & Technology, Hanyang University, Ansan 426-791, South Korea.
authors.forename: Dongjun
authors.initials: D
authors.lastname: Han
authors.forename: Bert
authors.initials: B
authors.lastname: Binas
mesh_terms: D000483:Alleles; D000818:Animals; D002460:Cell Line; D002999:Clone Cells; D053595:Embryonic Stem Cells; D005260:Female; D018390:Gene Targeting / Q000379:methods*; D005855:Germ Layers; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D051379:Mice; D051381:Rats; D011995:Recombination, Genetic; D049951:X Chromosome Inactivation / Q000235:genetics*
chemical_list: D007041:Hypoxanthine Phosphoribosyltransferase