title: Nondisjunction and transmission ratio distortion ofChromosome 2 in a (2.8) Robertsonian translocation mouse strain.
abstract: Aneuploidy results from nondisjunction of chromosomes in meiosis and is the leading cause of developmental disabilities and mental retardation in humans. Therefore, understanding aspects of chromosome segregation in a genetic model is of value. Mice heterozygous for a (2.8) Robertsonian translocation were intercrossed with chromosomally normal mice and Chromosome 2 was genotyped for number and parental origin in 836 individuals at 8.5 dpc. The frequency of nondisjunction of this Robertsonian chromosome is 1.58%. Trisomy of Chromosome 2 with two maternally derived chromosomes is the most developmentally successful aneuploid karyotype at 8.5 dpc. Trisomy of Chromosome 2 with two paternally derived chromosomes is developmentally delayed and less frequent than the converse. Individuals with maternal or paternal uniparental disomy of Chromosome 2 were not detected at 8.5 dpc. Nondisjunction events were distributed randomly across litters, i.e., no evidence for clustering was found. Transmission ratio distortion is frequently observed in Robertsonian chromosomes and a bias against the transmission of the (2.8) Chromosome was detected. Interestingly, this was observed for female and male transmitting parents.
authors.affiliation: Department of Medical and Molecular Genetics, King's College London, UK.
authors.forename: Reiner
authors.initials: R
authors.lastname: Schulz
authors.forename: Lara A
authors.initials: LA
authors.lastname: Underkoffler
authors.forename: Joelle N
authors.initials: JN
authors.lastname: Collins
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Oakey
mesh_terms: D000782:Aneuploidy; D000818:Animals; D002874:Chromosome Mapping; D020090:Chromosome Segregation; D002875:Chromosomes / Q000235:genetics*; D003433:Crosses, Genetic; D005260:Female; D006579:Heterozygote; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL / Q000196:embryology / Q000235:genetics*; D009630:Nondisjunction, Genetic; D014178:Translocation, Genetic; D014314:Trisomy