Analysis of 5S rDNA organization and variation in polyploid hybrids from crosses of different fish subfamilies.
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.
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.
Qinbo
Q
Qin
Weiguo
W
He
Shaojun
S
Liu
Jing
J
Wang
Jun
J
Xiao
Yun
Y
Liu
D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D003433:Crosses, Genetic; D017931:DNA Primers; D004275:DNA, Ribosomal / Q000235:genetics*; D005399:Fishes / Q000235:genetics*; D014644:Genetic Variation; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011123:Polyploidy; D012341:RNA, Ribosomal, 5S / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
D017931:DNA Primers; D004275:DNA, Ribosomal; D012341:RNA, Ribosomal, 5S