Verma R S, Babu A, Chemitiganti S, Dosik H
Mol Gen Genet. 1986 Mar;202(3):339-41. doi: 10.1007/BF00333259.
A possible cause of non-disjunction of chromosome 21 in Down Syndromes has been cytogenetically evaluated by examining the parents by Ag-staining technique. In all the cases studied so far, the contributing parents have active ribosomal cistrons on both chromosomes 21 i.e. both chromosomes are stained positively by silver staining. These results show that the active NORs might play an essential role in meiotic non-disjunction. Furthermore, the preliminary results demonstrate that the acrocentric associations of homologous and non-homologous nature involving chromosome 21 are the most frequent in the contributing parent which may further indicate the role of multiple cellular factors affecting the associations in promoting the nondisjunction in addition to active NORs. The possible mechanisms regarding the non-disjunction of chromosome 21 have been described.
通过银染技术检查父母，对唐氏综合征中21号染色体不分离的一个可能原因进行了细胞遗传学评估。在迄今为止研究的所有病例中，相关父母的两条21号染色体上都有活跃的核糖体顺反子，即两条染色体经银染均呈阳性。这些结果表明，活跃的核仁组织区可能在减数分裂不分离中起重要作用。此外，初步结果表明，在相关父母中，涉及21号染色体的同源和非同源性质的近端着丝粒联合最为常见，这可能进一步表明，除了活跃的核仁组织区外，多种影响联合的细胞因子在促进不分离方面也发挥了作用。已经描述了关于21号染色体不分离的可能机制。
