Mukherjee A B, Wallace K C
Department of Biological Sciences, Fordham University, Bronx, N.Y. 10458.
Mech Ageing Dev. 1990 Mar 31;53(1):61-71. doi: 10.1016/0047-6374(90)90034-d.
We have investigated the degree of hypodiploidy of human X (inactive) and Y chromosomes and their relative localization in the interphase nuclei during in vitro aging of diploid fibroblasts. It is found that significant proportions of both female and male cells lose the inactive X and Y chromosome, respectively during cellular aging. Our results from fibroblasts are consistent with comparable findings of other investigators utilizing lymphocytes and bone marrow cells. However, we have observed a relatively higher proportion of X and Y chromosomal hypodiploidy in older fibroblasts than the frequencies reported for lymphocytes or bone marrow cells from aged people. Significant changes in the relative localization pattern of the inactive X and Y chromosomes in the nuclei are also noted during in vitro aging of female and male cells, respectively, and these changes in localization pattern are not identical in both sexes. We believe that, during cellular aging, the analysis of sex chromosomal aneuploidy at interphase is highly likely to provide more accurate results as opposed to the analysis of metaphase chromosomes since the latter is dependent upon the divisional capacity of cells which declines with age. Analysis of interphase cells also avoids the artifacts that accompany metaphase chromosome preparations.
我们研究了人类X（失活）和Y染色体的亚二倍体程度及其在二倍体成纤维细胞体外老化过程中在间期核内的相对定位。结果发现，在细胞老化过程中，分别有相当比例的雌性和雄性细胞丢失了失活的X和Y染色体。我们对成纤维细胞的研究结果与其他研究人员利用淋巴细胞和骨髓细胞得出的类似发现一致。然而，我们观察到，与老年人淋巴细胞或骨髓细胞报告的频率相比，老年成纤维细胞中X和Y染色体亚二倍体的比例相对较高。在雌性和雄性细胞的体外老化过程中，还分别注意到核内失活的X和Y染色体相对定位模式的显著变化，而且两性的定位模式变化并不相同。我们认为，在细胞老化过程中，与中期染色体分析相比，间期性染色体非整倍体分析极有可能提供更准确的结果，因为后者依赖于随年龄下降的细胞分裂能力。间期细胞分析还避免了中期染色体制备过程中出现的假象。
