Ayres K N
J Cell Physiol. 1978 Jul;96(1):105-14. doi: 10.1002/jcp.1040960113.
Embryonic chick DNA from different tissues was examined for differences which might indicate specific DNA amplification in somatic cells. The problem was approached by determining the DNA compositional heterogeneity and searching for possible variation in different tissues of the 12-day chick. Neural retina, muscle, and whole decapitated (general) chick DNA were analyzed in CsCl and Cs2SO4 density gradients. While overloaded CsCl gradients showed a main band (rho = 1.701 g/cm3) and a heavy shoulder (rho = 1.716 g/cm3), overloaded Cs2SO4 gradients displayed a main band (rho = 1.426 g/cm3) and a discrete heavy satellite (rho = 1.447 g/cm3). This satellite, comprising approximately 1% of the whole cell DNA, appeared to be of nuclear origin and not related to mitochondrial DNA, which was found to have a density of 1.426 g/cm3 in Cs2SO4. No differences were found in the densities of the main band or the satellite DNA in the DNA samples isolated from the different tissues. However, the method of DNA isolation was found to be of crucial importance when comparing satellite DNA's among different tissues.
对来自不同组织的鸡胚DNA进行了检测，以寻找可能表明体细胞中存在特定DNA扩增的差异。通过测定DNA组成的异质性并在12日龄鸡的不同组织中寻找可能的变异来解决这个问题。在CsCl和Cs2SO4密度梯度中分析了神经视网膜、肌肉和全头摘除（整体）鸡的DNA。虽然过载的CsCl梯度显示出一条主带（ρ = 1.701 g/cm3）和一个重肩峰（ρ = 1.716 g/cm3），但过载的Cs2SO4梯度显示出一条主带（ρ = 1.426 g/cm3）和一个离散的重卫星带（ρ = 1.447 g/cm3）。这条卫星带约占全细胞DNA的1%，似乎起源于细胞核，与线粒体DNA无关，线粒体DNA在Cs2SO4中的密度为1.426 g/cm3。从不同组织分离的DNA样本中，主带或卫星DNA的密度没有差异。然而，在比较不同组织之间的卫星DNA时，发现DNA分离方法至关重要。
