Quantitation of Human Ribosomal DNA: Hybridization of Human DNA with Ribosomal RNA for Quantitation and Fractionation
Quantitation of Human Ribosomal DNA: Hybridization of Human DNA with Ribosomal RNA for Quantitation and Fractionation
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DOI：
10.1203/00006450-197301000-00002
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发表时间：
1973
影响因子：
3.6
通讯作者：
R. Schmickel
中科院分区：
文献类型：
--
作者：
R. Schmickel
提取物：通过硝酸纤维素圆盘上的分子DNA/RNA杂交，可以对核糖体RNA（rRNA）的人类基因进行定量。标记的核糖体RNA与平均14 × 10-5的总人类DNA杂交。如果我们假设二倍体细胞含有5.5 × 1012道尔顿的DNA，那么核糖体RNA与7.7 × 108道尔顿的核糖体DNA（rDNA）杂交，这相当于大约320个基因。rRNA与三种不同二倍体来源的DNA杂交显示rRNA/DNA比值在12-15.4 × 10 ~（-5）之间。来源于21三体细胞的DNA的rRNA/DNA比率与正常细胞没有显著差异。发现rRNA基因在高于Tm 10°或以上的温度下抵抗融化。推测：核糖体RNA基因可能存在于几条人类染色体上。相对于整个人类DNA富集这些基因的能力表明它们是成簇的。
Extract: Quantitation of human genes for ribosomal RNA (rRNA) was possible by molecular DNA/RNA hybridization on nitrocellulose discs. Labeled ribosomal RNA hybridizes with an average of 14 × 10-5 of the total human DNA. If we assume that the diploid cell contains 5.5 × 1012 daltons of DNA, the ribosomal RNA hybridizes with 7.7 × 108 daltons of ribosomal DNA (rDNA), which is equal to about 320 genes. Hybridization of rRNA with DNA of three different diploid sources shows a rRNA/DNA ratio which varies from 12–15.4 × 10-5. The rRNA/DNA ratio of DNA derived from trisomy 21 cells is not significantly different from the normal cells. The genes for rRNA were found to resist melting at temperatures 10° or more above the Tm. This property permits enrichment of these genes by thermal fractionation.Speculation: Ribosomal RNA genes are probably present on several human chromosomes. The ability to enrich these genes in relation to the whole human DNA indicates that they are clustered.