Lowe X, Collins B, Allen J, Titenko-Holland N, Breneman J, van Beek M, Bishop J, Wyrobek A J
Biology and Biotechnology Research Program, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
Mutat Res. 1995 Oct;338(1-6):59-76. doi: 10.1016/0921-8734(95)00012-u.
The objective of this research was to determine whether the frequencies of chromosomally defective germ cells increased with age in male laboratory mice. Two types of chromosomal abnormalities were characterized: (1) testicular spermatid aneuploidy (TSA) as measured by a new method of multi-color fluorescence in situ hybridization (FISH) with DNA probes specific for mouse chromosomes X, Y and 8, and (2) spermatid micronucleus (SMN) analyses using anti-kinetochore antibodies. B6C3F1 mice (aged 22.5 to 30.5 months, heavier than controls but otherwise in good health) showed significant approximately 2.0 fold increases in the aneuploidy phenotypes X-X-8, Y-Y-8, 8-8-X and 8-8-Y with the greatest effects appearing in animals aged greater than 28 months. No age effect was observed, however, in X-Y-8 hyperhaploidy. Major age-related increases were seen in Y-Y-8 and X-X-8 hyperhaploidies suggesting that advanced paternal age is associated primarily with meiosis II rather than meiosis I disjunction errors. A approximately 5 fold increase was also found in the frequency of micronucleated spermatids in aged mice when compared with young controls. All micronuclei detected in the aged animals lacked kinetochore labeling, suggesting that they either did not contain intact chromosomes or the chromosomes lacked detectable kinetochores. The findings of the TSA and SMN assays are consistent with meiotic or premeiotic effects of advanced age on germ cell chromosomes, but there were differences in the age dependencies of aneuploidy and micronuclei. In summary, advanced paternal age may be a risk factor for chromosomal abnormalities (both aneuploidy and structural abnormalities) in male germ cells.
本研究的目的是确定雄性实验小鼠中染色体缺陷生殖细胞的频率是否随年龄增加。研究表征了两种类型的染色体异常：（1）通过一种新的多色荧光原位杂交（FISH）方法，使用针对小鼠X、Y和8号染色体的DNA探针测量睾丸精子细胞非整倍体（TSA）；（2）使用抗动粒抗体进行精子细胞微核（SMN）分析。B6C3F1小鼠（年龄在22.5至30.5个月之间，比对照组重但健康状况良好）显示非整倍体表型X-X-8、Y-Y-8、8-8-X和8-8-Y显著增加约2.0倍，最大影响出现在年龄大于28个月的动物中。然而，在X-Y-8超单倍体中未观察到年龄效应。在Y-Y-8和X-X-8超单倍体中观察到与年龄相关的主要增加，表明父亲年龄较大主要与减数分裂II而非减数分裂I的分离错误有关。与年轻对照组相比，老年小鼠中微核化精子细胞的频率也增加了约5倍。在老年动物中检测到的所有微核均缺乏动粒标记，表明它们要么不包含完整的染色体，要么染色体缺乏可检测的动粒。TSA和SMN分析的结果与年龄增长对生殖细胞染色体的减数分裂或减数分裂前效应一致，但非整倍体和微核的年龄依赖性存在差异。总之，父亲年龄较大可能是雄性生殖细胞中染色体异常（非整倍体和结构异常）的一个风险因素。
