Telomere shortening in mouse strains with constitutional chromosomal aberrations.

Purpose : To compare telomere length in mouse strains with constitutional chromosomal aberrations generated either by exposure of parents to ionizing radiation, a chemical mutagen or arising spontaneously with that of the karyotypically normal mouse from the same genetic background. Materials and methods : Telomere length was assessed in five independently derived strains of mouse with constitutional chromosomal aberrations and in the karyotypically normal control mouse using quantitative fluorescence in situ hybridization (Q-FISH). Bone marrow cells obtained directly from the animals were used for the analysis. Results : Chromosomal aberrations, one in each mouse strain, included three reciprocal translocations induced by ionizing radiation, one insertion induced by a chemical mutagen and one spontaneous Robertsonian translocation. There was no cytogenetically detectable loss of material in any of the strains and most mice were phenotypically normal. Telomeres were significantly shorter in all mouse stra...