title: Instability of a (CGG)98 repeat in the Fmr1 promoter.
abstract: Fragile X syndrome is one of 14 trinucleotide repeat diseases. It arises due to expansion of a CGG repeat which is present in the 5'-untranslated region of the FMR1 gene, disruption of which leads to mental retardation. The mechanisms involved in trinucleotide repeat expansion are poorly understood and to date, transgenic mouse models containing transgenic expanded CGG repeats have failed to reproduce the instability seen in humans. As both cis-acting factors and the genomic context of the CGG repeat are thought to play a role in expansion, we have now generated a knock-in mouse Fmr1 gene in which the murine (CGG)8 repeat has been exchanged with a human (CGG)98 repeat. Unlike other CGG transgenic models, this model shows moderate CGG repeat instability upon both in maternal and paternal transmission. This model will now enable us to study the timing and the mechanism of repeat expansion in mice.
authors.affiliation: CBG Department of Clinical Genetics, Erasmus University Rotterdam, PO Box 1738, 3000DR Rotterdam, The Netherlands.
authors.forename: C J
authors.initials: CJ
authors.lastname: Bontekoe
authors.forename: C E
authors.initials: CE
authors.lastname: Bakker
authors.forename: I M
authors.initials: IM
authors.lastname: Nieuwenhuizen
authors.forename: H
authors.initials: H
authors.lastname: van der Linde
authors.forename: H
authors.initials: H
authors.lastname: Lans
authors.forename: D
authors.initials: D
authors.lastname: de Lange
authors.forename: M C
authors.initials: MC
authors.lastname: Hirst
authors.forename: B A
authors.initials: BA
authors.lastname: Oostra
mesh_terms: D000483:Alleles; D000818:Animals; D004195:Disease Models, Animal; D018274:Electroporation; D005260:Female; D051860:Fragile X Messenger Ribonucleoprotein 1; D005600:Fragile X Syndrome / Q000235:genetics*; D005784:Gene Amplification; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009419:Nerve Tissue Proteins / Q000235:genetics*; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D016601:RNA-Binding Proteins; D013234:Stem Cells; D018911:Trinucleotide Repeats
chemical_list: D051860:Fragile X Messenger Ribonucleoprotein 1; D009419:Nerve Tissue Proteins; D016601:RNA-Binding Proteins; C497683:FMR1 protein, human; C497684:Fmr1 protein, mouse