High impact information on T(X;16)16H

• Using this allelic variation, we assessed expression of the two Zfx genes in females carrying the T(X;16)16H translocation (from laboratory strain of mouse [corrected]) and an intact X chromosome (from M. spretus) [1].
• We took advantage of both the preferential inactivation of the normal X chromosome in females carrying the T(X;16)16H translocation and the high degree of nucleotide sequence variation between the laboratory strain of mouse [corrected] and Mus spretus genomes [1].
• Similarly, it is now clear that the T(X;16)16H X-autosome translocation breakpoint lies distal to the DXPas8 (St14-1) locus, narrowing the X-chromosome breakpoint down to a region flanked proximally by this marker and representing, as expected from previous data, the distal quarter of the Hprt-Ta subchromosomal span [2].
• In contrast to the human DXS423E gene, the mouse Sb1.8 gene is subject to X inactivation, as shown by restriction enzyme and sequence analysis of mRNA from mice with Searle's translocation (T(X;16)16H) [3].
• Matings between female mice carrying Searle's translocation, T(X;16)16H, and normal males give rise to chromosomally unbalanced zygotes with two complete sets of autosomes, one normal X chromosome and one X16 translocation chromosome (XnX16 embryos) [4].

Biological context of T(X;16)16H

• Analysis of F1 heterozygous female mice from T(X;16)16H x MSM crosses and two cell clones derived from inter-subspecific F1 female mice demonstrated that the packaging level of the transcribed Xist region on inactive X Chr was as tight as that of the repressed Pgk-1 allele on the same chromosome [5].
• Sex ratio and testis size in mice carrying Sxr and T(X;16)16H [6].
• Nonrandom X chromosome inactivation in mouse embryos carrying Searle's T(X;16)16H translocation visualized using X-linked LACZ and GFP transgenes [7].

Anatomical context of T(X;16)16H

• X chromosome activity in female germ cells of mice heterozygous for Searle's translocation T(X;16)16H [8].
• We have mapped the genes for murine immunoglobulin lambda light chains to the region of chromosome 16 proximal to band B5 by hybridizing a cDNA probe for gamma light chains to the DNA of a series of hybrid clones made between mouse fibroblasts carrying Searle's translocation, T(X;16)16H, and Chinese hamster cells [9].

Other interactions of T(X;16)16H

• To help resolve this issue, we analysed XCI in embryos which carry the T(X;16)16H (Searle's) translocation and are heterozygous at the X-linked Hprt and Pgk-1 genes [10].
• In mice with the reciprocal T(X;16)16H translocation, XMR was also associated with the heterochromatic translocation product that emerges from the XY body [11].

References