Dabeva M D, Dudov K P, Hadjiolov A A, Stoykova A S
Biochem J. 1978 May 1;171(2):367-74. doi: 10.1042/bj1710367.
rRNA from detergent-purified nuclei was fractionated quantitatively, by two independent methods, into nucleolar and nucleoplasmic RNA fractions. The two RNA fractions were analysed by urea/agar-gel electrophoresis and the amount of pre-rRNA (precursor of rRNA) and rRNA components was determined. The rRNA constitutes 35% of total nuclear RNA, of which two-thirds are in nucleolar RNA and one-third in nucleoplasmic RNA. The identified pre-rRNA components (45 S, 41 S, 39 S, 36 S, 32 S and 21 S) are confined to the nucleolus and constitute about 70% of its rRNA. The remaining 30% are represented by 28 S and 18 S rRNA, in a molar ratio of 1.4. The bulk of rRNA in nucleoplasmic RNA is represented by 28 S and 18 S rRNA in a molar ratio close to 1.0. Part of the mature rRNA species in nucleoplasmic RNA originate from ribosomes attached to the outer nuclear membrane, which resist detergent treatment. The absolute amount of nuclear pre-rRNA and rRNA components was evaluated. The amount of 32 S and 21 S pre-rRNA (2.9 x 10(4) and 2.5 x 10(4) molecules per nucleus respectively) is 2-3-fold higher than that of 45 S, 41 S and 36 S pre-rRNA.
通过两种独立方法对经去污剂纯化的细胞核中的核糖体RNA（rRNA）进行定量分级分离，得到核仁RNA和核质RNA级分。对这两个RNA级分进行尿素/琼脂糖凝胶电泳分析，并测定前体rRNA（rRNA的前体）和rRNA组分的量。rRNA占细胞核RNA总量的35%，其中三分之二存在于核仁RNA中，三分之一存在于核质RNA中。已鉴定的前体rRNA组分（45S、41S、39S、36S、32S和21S）局限于核仁，约占其rRNA的70%。其余30%由28S和18S rRNA代表，摩尔比为1.4。核质RNA中的大部分rRNA由摩尔比接近1.0的28S和18S rRNA代表。核质RNA中部分成熟rRNA物种来源于附着在外核膜上的核糖体，这些核糖体能够抵抗去污剂处理。评估了细胞核前体rRNA和rRNA组分的绝对量。32S和21S前体rRNA的量（分别为每个细胞核2.9×10⁴和2.5×10⁴个分子）比45S、41S和36S前体rRNA的量高2至3倍。
