title: CAG repeat lengths in X- and Y-bearing sperm indicate that gender bias during transmission of Huntington's disease gene is determined in the embryo.
abstract: The size of the CAG tract at the Huntington's disease (HD) locus upon transmission depends on the gender of the parent. However, the basis for the parent-of-origin effect is unknown. To test whether expansion and contraction in HD are "imprinted" in the germ cells, we isolated the X- and Y-bearing sperm of HD transgenic mice. Here we show that CAG repeat distributions in the X- and Y-bearing spermatozoa of founding fathers do not differ. These data show that gender-dependent changes in CAG repeat length arise in the embryo.
authors.affiliation: Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
authors.forename: Irina V
authors.initials: IV
authors.lastname: Kovtun
authors.forename: Glenn
authors.initials: G
authors.lastname: Welch
authors.forename: H David
authors.initials: HD
authors.lastname: Guthrie
authors.forename: Kari L
authors.initials: KL
authors.lastname: Hafner
authors.forename: Cynthia T
authors.initials: CT
authors.lastname: McMurray
mesh_terms: D000818:Animals; D004622:Embryo, Mammalian / Q000502:physiology; D006801:Humans; D006816:Huntington Disease / Q000196:embryology / Q000209:etiology / Q000235:genetics*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D012091:Repetitive Sequences, Nucleic Acid; D012737:Sex Factors; D013094:Spermatozoa / Q000502:physiology; D018911:Trinucleotide Repeats; D014960:X Chromosome; D014998:Y Chromosome