Molecular characterization of the translocation breakpoints in the Down syndrome mouse model Ts65Dn
Ts65Dn is a mouse model of Down syndrome: a syndrome that results from chromosome (Chr) 21 trisomy and is associated with congenital defects, cognitive impairment, and ultimately Alzheimer’s disease. Ts65Dn mice have segmental trisomy for distal mouse Chr 16, a region sharing conserved synteny with human Chr 21. As a result, this strain harbors three copies of over half of the human Chr 21 orthologs. The trisomic segment of Chr 16 is present as a translocation chromosome (Mmu1716), with breakpoints that have not been defined previously. To molecularly characterize the Chrs 16 and 17 breakpoints on the translocation chromosome in Ts65Dn mice, we used a selective enrichment and high-throughput paired-end sequencing approach. Analysis of paired-end reads flanking the Chr 16, Chr 17 junction on Mmu1716 and de novo assembly of the reads directly spanning the junction provided the precise locations of the Chrs 16 and 17 breakpoints at 84,351,351 and 9,426,822 bp, respectively. These data provide the basis for low-cost, highly efficient genotyping of Ts65Dn mice. More importantly, these data provide, for the first time, complete characterization of gene dosage in Ts65Dn mice.
KeywordsBacterial Artificial Chromosome Down Syndrome Translocation Chromosome Copy Number Gain Breakpoint Region
We are grateful to the High Throughput Sequencing and Genome Sciences cores at The Jackson Laboratory for their excellent services and advice. The Transgenic Genotyping core at The Jackson Laboratory provided DNA samples and genotyping data that were critical for validation. This work was supported by funding from NICHD CYTO-01, a Cancer Center Core Grant at The Jackson Laboratory (CA34196), and NIH DE021034 (RJR).
- Akeson EC, Davisson MT (2001) Mitotic chromosome preparations from mouse cells for karyotyping. Curr Protoc Hum Genet Chapter 4: Unit 4.10Google Scholar
- D’Ascenzo M, Meacham C, Kitzman J, Middle C, Knight J, Winer R, Kukricar M, Richmond T, Albert TJ, Czechanski A, Donahue LR, Affourtit J, Jeddeloh JA, Reinholdt L (2009) Mutation discovery in the mouse using genetically guided array capture and resequencing. Mamm Genome 20:424–436PubMedCrossRefGoogle Scholar
- Kahlem P, Sultan M, Herwig R, Steinfath M, Balzereit D, Eppens B, Saran NG, Pletcher MT, South ST, Stetten G, Lehrach H, Reeves RH, Yaspo ML (2004) Transcript level alterations reflect gene dosage effects across multiple tissues in a mouse model of Down syndrome. Genome Res 14:1258–1267PubMedCrossRefGoogle Scholar
- Li Z, Yu T, Morishima M, Pao A, LaDuca J, Conroy J, Nowak N, Matsui S, Shiraishi I, Yu YE (2007) Duplication of the entire 22.9 Mb human chromosome 21 syntenic region on mouse chromosome 16 causes cardiovascular and gastrointestinal abnormalities. Hum Mol Genet 16:1359–1366PubMedCrossRefGoogle Scholar
- Talkowski ME, Ernst C, Heilbut A, Chiang C, Hanscom C, Lindgren A, Kirby A, Liu S, Muddukrishna B, Ohsumi TK, Shen Y, Borowsky M, Daly MJ, Morton CC, Gusella JF (2011) Next-generation sequencing strategies enable routine detection of balanced chromosome rearrangements for clinical diagnostics and genetic research. Am J Hum Genet 88:469–481PubMedCrossRefGoogle Scholar