Jotterand-Bellomo M, van Melle G
Hum Genet. 1981;59(2):141-7. doi: 10.1007/BF00293064.
Chromosomes with Ag staining that varies from one metaphase to the other can be distinguished from those with an Ag-staining that is the same in all metaphases. The intercellular variation of an Ag-NOR can be attributed to many different factors. Whatever the importance of technical factors, they do not seem to account for the large variations in Ag-staining which were observed for each ac. This suggests the existence of a natural intercellular variability of the NOR's activity. The variation of the Ag-stainability of a given NOR, the diversity of Ag-stainings observed on the ten ac of one individual and the differences that exist between individuals raise the question of the existence of a compensation of activity between nucleolar organizers. The study, for each individual, of the mean sum of staining per metaphase reveals that this value is not absolutely constant from one individual to another; in the carriers of Robertsonian fusions it is smaller than in chromosomally normal individuals. The analysis of the transmission shows that inactive NORs remain inactive and that active NORs present a variation in the activity from one generation to the next.
在不同中期银染情况不同的染色体，可与在所有中期银染情况相同的染色体区分开来。银染核仁组织区（Ag-NOR）的细胞间变异可归因于许多不同因素。无论技术因素有多重要，它们似乎都无法解释在每个常染色体（ac）上观察到的银染的巨大差异。这表明核仁组织区（NOR）的活性存在自然的细胞间变异性。给定NOR的银染性变化、在一个个体的十条常染色体上观察到的银染多样性以及个体之间存在的差异，引发了核仁组织者之间活性补偿是否存在的问题。对每个个体每个中期染色平均总和的研究表明，该值在个体之间并非绝对恒定；在罗伯逊融合携带者中，该值比染色体正常个体中的小。传递分析表明，无活性的NOR保持无活性，而有活性的NOR在一代到下一代之间活性存在变化。
