Key Laboratory of Protein Chemistry and Fish Developmental Biology of Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha, People's Republic of China.
J Exp Zool B Mol Dev Evol. 2010 Jul 15;314(5):403-11. doi: 10.1002/jez.b.21346.
In this article, sequence analysis of the coding region (5S) and adjacent nontranscribed spacer (NTS) were conducted in red crucian carp (RCC), blunt snout bream (BSB), and their polyploid offspring. Three monomeric 5S rDNA classes (designated class I: 203 bp; class II: 340 bp; and class III: 477 bp) of RCC were characterized by distinct NTS types (designated NTS-I, II, and III for the 83, 220, and 357 bp monomers, respectively). In BSB, only one monomeric 5S rDNA was observed (designated class IV: 188 bp), which was characterized by one NTS type (designated NTS-IV: 68 bp). In the polyploid offspring, the tetraploid (4nRB) hybrids partially inherited 5S rDNA classes from their female parent (RCC); however, they also possessed a unique 5S rDNA sequence (designated class I-L: 203 bp) with a novel NTS sequence (designated NTS-I-L: 83 bp). The characteristic paternal 5S rDNA sequences (class IV) were not observed. The 5S rDNA of triploid (3nRB) hybrids was completely inherited from the parental species, and generally preserved the parental 5S rDNA structural organization. These results first revealed the influence of polyploidy on the organization and evolution of the multigene family of 5S rDNA of fish, and are also useful in clarifying aspects of vertebrate genome evolution.
本文对红鲫、团头鲂及其同源多倍体的编码区（5S）及其相邻非转录间隔区（NTS）进行了序列分析。红鲫的 3 种单体 5S rDNA（分别命名为 I 类：203 bp；II 类：340 bp；III 类：477 bp）具有不同的 NTS 类型（分别命名为 I、II 和 III 型，对应的 NTS 长度为 83、220 和 357 bp）。团头鲂仅存在 1 种单体 5S rDNA（命名为 IV 类：188 bp），其 NTS 类型也只有 1 种（命名为 IV 型：68 bp）。在多倍体后代中，四倍体（4nRB）杂种部分继承了其母本（红鲫）的 5S rDNA 类群；然而，它们也拥有独特的 5S rDNA 序列（命名为 I-L 类：203 bp）和新型 NTS 序列（命名为 I-L 型：83 bp）。特征性的父本 5S rDNA 序列（IV 类）并未观察到。三倍体（3nRB）杂种的 5S rDNA 完全来自亲本物种，通常保留了亲本的 5S rDNA 结构组织。这些结果首次揭示了多倍化对鱼类 5S rDNA 多基因家族的组织和进化的影响，也有助于阐明脊椎动物基因组进化的某些方面。
