QUANTITATIVE VARIATIONS IN NUCLEAR DNA AND PHYLOGENESIS OF AMPHIBIA
QUANTITATIVE VARIATIONS IN NUCLEAR DNA AND PHYLOGENESIS OF AMPHIBIA
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DOI：
10.1080/00087114.1973.10796525
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发表时间：
1973-01-01
期刊：
影响因子：
2.1
通讯作者：
OLMO, E
中科院分区：
文献类型：
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作者：
OLMO, E
利用血液涂片，用Feulgen‘s反应染色，研究了无尾两栖动物Apode、13种Urodela和23种的核DNA含量，由于这些两栖动物复杂的系统发育，其中某些种属于古老而重要的科。这项研究的结果强调了两栖动物在DNA含量上存在广泛的种间差异，以及某些可能具有系统意义的事实：Urodela的核DNA含量比大多数足目和无尾两栖动物都多；然而，今天存在的一些更原始的物种(小虾属)的DNA含量在顺序上相对较低；在两栖动物中，DNA数量的变化似乎与系统发育的行为无关，而似乎反映了冗余现象。到目前为止，关于两栖动物DNA数量变化的重要性的理论似乎至少部分相互矛盾：事实上，某些作者认为类似的变化代表了脊椎动物进化的重要机制，而另一些作者认为它们更应该与适应现象有关。本文讨论了这些变化的意义的问题，考虑到关于真核生物中DNA重复部分的存在和特征的最新发现，特别是在两栖动物中，以及这些研究为研究这一问题提供的可能前景。
Using blood smears, stained with Feulgen's reaction, a study has been made of the nuclear DNA content of an Apode, thirteen species of Urodela and twenty-three species of Anura, certain of which belong to old and important families on account of the complex phylogeny of these Amphibia.The results of this study emphasize the existence of extensive interspecific variations in the amounts of DNA in the Amphibia, as well as certain facts of possible systematic interest: the Urodela possess greater amounts of nuclear DNA than most of the Apoda and the Anura; however, some of the more primitive species existing today (genusHynobius) have DNA amounts that are relatively low in the order; in the Amphibia, the variations in the DNA amounts do not seem to be correlated with the behaviour of the phylogeny but seem rather to reflect phenomena of redundancy.The theories that have been put forward so far on the significance of the quantitative variations in the DNA of the Amphibia seem to be at least partly conflicting: in fact, certain authors maintain that similar variations represent an important mechanism in the evolution of the Vertebrates, whereas others consider that they should rather be related to adaptive phenomena.The problem of the significance of these variations is discussed, account being taken of the latest discoveries on the presence and characteristics of the repetitive DNA fractions in the eukaryotes in general, and in the Amphibia in particular, as well as of the possible prospects offered by these researches for a study of this problem.