Aneuploidies and micronuclei in the germ cells of male mice of advanced age

摘要: Abstract The objective of this research was to determine whether the frequencies chromosomally defective germ cells increased with age in male laboratory mice. Two types chromosomal abnormalities were characterized: (1) testicular spermatid aneuploidy (TSA) as measured by a new method multi-color fluorescence situ hybridization (FISH) DNA probes specific for mouse chromosomes X, Y and 8, (2) micronucleus (SMN) analyses using anti-kinetochore antibodies. B6C3F1 mice (aged 22.5 30.5 months, heavier than controls but otherwise good health) showed significant ~ 2.0 fold increases phenotypes X-X-8, Y-Y-8, 8-8-X 8-8-Y greatest effects appearing animals aged greater 28 months. No effect observed, however, X-Y-8 hyperhaploidy. Major age-related seen Y-Y-8 X-X-8 hyperhaploidies suggesting that advanced paternal is associated primarily meiosis II rather I disjunction errors. A 5 increase also found frequency micronucleated spermatids when compared young controls. All micronuclei detected lacked kinetochore labeling, they either did not contain intact or detectable kinetochores. findings TSA SMN assays are consistent meiotic premeiotic on cell chromosomes, there differences dependencies micronuclei. In summary, may be risk factor (both structural abnormalities) cells.