Brykov V A, Volfson V G, Vorob'ev V I
Chromosoma. 1979 Sep 1;74(1):105-24. doi: 10.1007/BF00344486.
The arrangement of repetitive and single-copy DNA sequences has been studied in DNA of some species of Echinodermata--sea urchin, starfishes and sea-cucumber. Comparison of the reassociation kinetics of short and long DNA fragments indicates that the pattern of DNA sequence organization of all these species is similar to the so-called "Xenopus pattern" characteristic of the genomes of most animals and plants. However, substantional variations have been found in the amount of repetitive nucleotide sequences in DNA of different species and in the length of DNA regions containing adjacent single-copy and repetitive sequences. Measurements of the size of S1-nuclease resistant reassociated repetitive DNA sequences show a variability of ratios between long and short repetitive DNA sequences of different species.--The degree of divergence of short and long repetitive DNA sequences and single-copy DNA was studied by molecular hybridization of the sea urchin Strongylocentrotus intermedius 3H-DNA with the DNA of other species and by determination of the thermostability of the hybridized molecules so obtained. All three fractions of S. intermedius DNA contain sequences homologous to DNA of the other echinoderm species studied. The results obtained suggest that short repetitive DNA sequences are those which have been most highly conserved throughout the evolution of Echinodermata. A new hypothesis is proposed to explain the nature of the evolutionary changes in DNA sequence interspersion patterns.
已对一些棘皮动物（海胆、海星和海参）的DNA中重复和单拷贝DNA序列的排列进行了研究。短DNA片段和长DNA片段重新缔合动力学的比较表明，所有这些物种的DNA序列组织模式类似于大多数动植物基因组所特有的所谓“非洲爪蟾模式”。然而，已发现不同物种DNA中重复核苷酸序列的数量以及包含相邻单拷贝和重复序列的DNA区域的长度存在实质性差异。对S1核酸酶抗性重新缔合的重复DNA序列大小的测量显示，不同物种的长重复DNA序列和短重复DNA序列之间的比例存在变异性。——通过中间球海胆3H-DNA与其他物种的DNA进行分子杂交，并通过测定由此获得的杂交分子的热稳定性，研究了短重复DNA序列、长重复DNA序列和单拷贝DNA的分歧程度。中间球海胆DNA的所有三个部分都含有与所研究的其他棘皮动物物种的DNA同源的序列。所得结果表明，短重复DNA序列是在棘皮动物整个进化过程中最保守的序列。提出了一个新的假说来解释DNA序列散布模式进化变化的本质。
