AUTHOR=Qin QinBo , Liu QiWen , Wang ChongQing , Cao Liu , Zhou YuWei , Qin Huan , Zhao Chun , Liu ShaoJun 

TITLE=Molecular Organization and Chromosomal Localization Analysis of 5S rDNA Clusters in Autotetraploids Derived From Carassius auratus Red Var. (♀) × Megalobrama amblycephala (♂)

JOURNAL=Frontiers in Genetics

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2019.00437

DOI=10.3389/fgene.2019.00437

ISSN=1664-8021

ABSTRACT=<p>The autotetraploid fish (4<italic>n</italic> = 200, RRRR) (abbreviated as 4<italic>n</italic>RR) resulted from the whole genome duplication of red crucian carp (<italic>Carassius auratus</italic> red var., 2<italic>n</italic> = 100, RR) (abbreviated as RCC). During investigation of the influence of polyploidization on organization and evolution of the multigene family of <italic>5S</italic> rDNA, molecular organization and chromosomal localization of the <italic>5S</italic> rDNA were characterized in autotetraploid fish. By sequence analysis of the coding region (<italic>5S</italic>) and adjacent non-transcribed spacer (NTS), three distinct <italic>5S</italic> rDNA units (type I: 203 bp; type II: 340 bp; and type III: 477bp) were identified and characterized in 4<italic>n</italic>RR. These <italic>5S</italic> rDNA units were inherited from their female parent (RCC), in which obvious base variations in NTS and array recombination of repeat units were found. Using fluorescence <italic>in situ</italic> hybridization employing different <italic>5S</italic> rDNA units as probes, these <italic>5S</italic> rDNA clusters were localized in chromosomes of 4<italic>n</italic>RR, respectively, and showed obvious loss of chromosomal loci (type I and type II). Our data revealed genetic variation of the <italic>5S</italic> rDNA multigene family in the genome of autopolyploid fish. Furthermore, results provided new insights into the evolutionary patterns of this vertebrate multigene family.</p>