Pde6brd1, the recessive retinal degeneration 1 mutation, is segregating in this colony. Animals that are homozygous for rd1 will be blind. Stock No. 005252 is an alternative strain, with a virtually identical genetic background except that it is wild-type for Pde6brd1.
Segmentally trisomic Ts(1716)65Dn mice provide a postnatal model for Down syndrome. Ts65Dn mice have three copies of most of the genes on mouse Chr 16 that are homologues of human Chr 21 genes. These extra genes, along with the centromere and about 5% of proximal Chr 17 are contained in a small extra chromosome derived from a reciprocal translocation.
Neural cognitive deficits and behavioral abnormalities have been noted in Ts65Dn mice. They have spatial learning and memory defects as assessed in the Morris water maze and the radial arm maze, show developmental delay in sensorimotor milestones, and exhibit locomotor hyperactivity, lack of behavioral inhibition, and stereotypic behavior. They perform similar to controls in visual placing, balance, prehensile reflex and traction on a horizontal bar, motor coordination, swimming ability and olfaction orienting. They also show altered noradrenergic transmission in the hippocampus and cerebral cortex and degeneration of basal forebrain cholinergic neurons by 6 months of age. Trisomic females are smaller and produce fewer, smaller litters than euploid females while trisomic males are effectively sterile with hypospermia.
The precise locations of the Chr 16 and Chr 17 breakpoints are 84,351,351 bp and 9,426,822 bp, respectively. The Chr 16 segment contains about two thirds of the human Chr 21 homologues in the mouse, from mitochondrial ribosomal protein L39 (Mrpl39) gene to the distal telomere. These data were used to generate a PCR genotyping assay for Ts65Dn (Reinholdt et al., 2011), replacing the previous methods of chromosome analysis or qPCR. For comparison of segments conserved in human Chr 21 with mouse Chrs 16, 17, 10 and genetic definition of Ts65Dn, see the Human - Mouse Orthology Map. Northern and Western blotting, enzyme activity assays and reverse phase protein arrays (RPPA) demonstrate that some but not all genes in the translocation product are expressed at elevated levels in segmentally trisomic animals. RPPA shows a loss of correlation among some brain proteins (Ahmed et al., 2012). The Clcc1m1J spontaneous mutation, which causes increased sensitivity to endoplasmic reticulum stress in the cerebellum, is a homozygous strain characteristic of C3H/HeSnJ (Jia et al., 2015) so is segregating in this strain.
Please see the Down Syndrome and Cytogenetics Models Resource for more information.
Cesium irradiation was used to produce a reciprocal translocation, T (16;17) 65Dn. One of the translocation chromosomes is a small marker chromosome, comprised of the centromere and proximal end of Chr 17 (~9.5Mb) and the distal end of mouse Chr 16 (~34Mb). Translocation heterozygous females produced progeny trisomic for this small translocation product and a stock was established in which Ts65Dn mice are trisomic for the genes carried in the small translocation chromosome, symbolized Ts(1716)65Dn.
|Allele Name||trisomy, Chr 16 translocation to Chr 17, Davisson 65|
|Allele Type||Radiation induced|
|Allele Synonym(s)||T(16C3-4;17A2)65Dn; Ts16; Ts65Dn|
|Gene Symbol and Name||Ts(1716)65Dn, trisomy, Chr 16 translocation to Chr 17, Davisson 65|
|Strain of Origin||DBA/2J|
|Molecular Note||About 15% of the distal end of chromosome 16 is fused to less than 10% of the centromeric end of chromosome 17 to form a small translocation chromosome. The translocation breaks mouse Chr 16 just proximal to the amyloid precursor protein ( App ) gene and contains the HSA21-homologous genes from App to the telomere. The translocation chromosome also contains the centromere and a small portion (~5%) of Chr 17. Northern and Western blotting and enzyme activity assays demonstrate that genes on the translocation product are expressed at elevated levels in segmentally trisomic animals.|
Male carriers are sterile.
When using the Ts65Dn mouse strain in a publication, please cite the originating article(s) and include JAX stock #001924 in your Materials and Methods section.