Developmental study of fragile X syndrome using human embryonic stem cells derived from preimplantation genetically diagnosed embryos.
We report on the establishment of a human embryonic stem cell (HESC) line from a preimplantation fragile X-affected embryo and demonstrate its value as an appropriate model to study developmentally regulated events that are involved in the pathogenesis of this disorder. Fragile X syndrome results from FMR1 gene inactivation due to a CGG expansion at the 5'UTR region of the gene. Early events in FMR1 silencing have not been fully characterized due to the lack of appropriate animal or cellular models. Here we show that, despite the presence of a full mutation, affected undifferentiated HESCs express FMR1 and are DNA unmethylated. However, epigenetic silencing by DNA methylation and histone modification occurs upon differentiation. Our unique cell system allows the dissection of the sequence by which these epigenetic changes are acquired and illustrates the importance of HESCs in unraveling developmentally regulated mechanisms associated with human genetic disorders.
Eiges
Rachel
R
Department of Genetics, Silberman Institute of Life Science, The Hebrew University, Jerusalem 91904, Israel.
Urbach
Achia
A
Malcov
Mira
M
Frumkin
Tsvia
T
Schwartz
Tamar
T
Amit
Ami
A
Yaron
Yuval
Y
Eden
Amir
A
Yanuka
Ofra
O
Benvenisty
Nissim
N
Ben-Yosef
Dalit
D
D000818:Animals; D001755:Blastocyst / Q000378:metabolism / Q000473:pathology*; D002454:Cell Differentiation / Q000235:genetics*; D002460:Cell Line; D019175:DNA Methylation; D053595:Embryonic Stem Cells / Q000378:metabolism / Q000473:pathology*; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics* / Q000378:metabolism; D005600:Fragile X Syndrome / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D020868:Gene Silencing; D006657:Histones / Q000378:metabolism; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D009154:Mutation; D019836:Preimplantation Diagnosis; D013724:Teratoma / Q000235:genetics / Q000473:pathology; D014407:Tumor Cells, Cultured
D051860:Fragile X Messenger Ribonucleoprotein 1; D006657:Histones; C497683:FMR1 protein, human