Preparations of high-molecular nuclear DNA were obtained from embroys of the sea urchin Strongylocentrotus droebachiensis at the stages of early and late blastula, gastrula, and pluteus. In an equilibrium cesium chloride density gradient, these preparations exhibit a single narrow symmetrical band at 1.695-1.703 g/cm3 with a maximum at l.699 plus or minus 0.001 g/cm3 and do not contain satellite components. Nuclear DNA of embroys at the stage of 128 blastomeres (morula), which has a molecular weight of 10-6, exhibits a single broad symmetrical band at 1.690-1.710 g/cm3 with a maximum at 1.699 g/cm3 in a density gradient. Fragments of blastula and pluteus DNA obtained as a result of treatment with ultrasound give an analogous distribution. Preparations of total DNA of unfertilized ovicells, total DNA of spermatozoids, and cytoplasmic DNA of the morula contain satellite components with buoyant densities of 1.717-1.725 g/cm3 side by side with the main band.

中文翻译：

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海胆胚胎在不同发育阶段的DNA的Bouyant密度。

从海胆Strongylocentrotus droebachiensis的胚芽，在早期和晚期囊胚，腹足和臀肌的阶段获得了高分子核DNA的制备物。在平衡的氯化铯密度梯度中，这些制剂在1.695-1.703 g / cm3处显示出一条狭窄的对称带，最大值为1.699（正负0.001 g / cm3），并且不包含卫星成分。分子量为10-6的128个卵裂球（桑ula属）阶段的胚芽核DNA在密度梯度中在1.690-1.710 g / cm3处显示单个宽对称带，最大在1.699 g / cm3处。超声处理后获得的囊胚和臀大肌DNA片段具有相似的分布。未受精卵子总DNA，精子总DNA，