Meneveri R, Agresti A, Ginelli E
Biochem Biophys Res Commun. 1984 Oct 30;124(2):400-6. doi: 10.1016/0006-291x(84)91567-5.
By means of restriction enzymes analysis and molecular hybridization, the distribution of repeated DNA families has been studied in the different DNA components into which the human genome can be fractionated by density gradient techniques. Three classes of DNA molecules have been analyzed: i) an homogeneous DNA component (satellite-like sequences; Q = 1.696 g/cm3, 3% of total DNA, AT repeated), ii) AT rich (Q = 1.698 g/cm3, 30% of total DNA, AT main-band) and GC rich (Q = 1.708 g/cm3, 6% of total DNA, GC main-band) DNA components. By this approach we have observed that Sau3A digestion of GC main-band gives rise to two bands of 75bp and 150bp, absent or under-represented in both AT rich DNA components. A preliminary characterization of these DNA fragments suggests that they contain one or more families of repeated sequences which fail to hybridize to EcoRI, HindIII and AluI families of repeats. In addition, we have observed that EcoRI sequences (alpha-RI DNA) are under-represented in GC main-band and show the same clustered organization in both AT rich DNA components.
通过限制性内切酶分析和分子杂交技术，研究了重复DNA家族在人类基因组经密度梯度技术分离得到的不同DNA组分中的分布情况。分析了三类DNA分子：i）一种均匀的DNA组分（类卫星序列；Q = 1.696 g/cm³，占总DNA的3%，富含AT且重复），ii）富含AT的组分（Q = 1.698 g/cm³，占总DNA的30%，AT主带）和富含GC的组分（Q = 1.708 g/cm³，占总DNA的6%，GC主带）。通过这种方法，我们观察到GC主带经Sau3A酶切产生两条75bp和150bp的条带，在富含AT的两种DNA组分中不存在或含量不足。对这些DNA片段的初步表征表明，它们包含一个或多个重复序列家族，这些家族不能与EcoRI、HindIII和AluI重复序列家族杂交。此外，我们还观察到EcoRI序列（α-RI DNA）在GC主带中含量不足，并且在富含AT的两种DNA组分中显示出相同的聚集组织。
