Korean J Parasitol.  2003 Dec;41(4):209-219. 10.3347/kjp.2003.41.4.209.

Evolutionary course of CsRn1 long-terminal-repeat retrotransposon and its heterogeneous integrations into the genome of the liver fluke, Clonorchis sinensis

• Bae YA
• Kong Y

• KMID: 662761
• DOI: http://doi.org/10.3347/kjp.2003.41.4.209

Abstract

The evolutionary course of the CsRn1 long-terminal-repeat (LTR) retrotransposon was predicted by conducting a phylogenetic analysis with its paralog LTR sequences. Based on the clustering patterns in the phylogenetic tree, multiple CsRn1 copies could be grouped into four subsets, which were shown to have different integration times. Their differential sequence divergences and heterogeneous integration patterns strongly suggested that these subsets appeared sequentially in the genome of C. sinensis. Members of recently expanding subset showed the lowest level of divergence in their LTR and reverse transcriptase gene sequences. They were also shown to be highly polymorphic among individual genomes of the trematode. The CsRn1 element exhibited a preference for repetitive, agenic chromosomal regions in terms of selecting integration targets. Our results suggested that CsRn1 might induce a considerable degree of intergenomic variation and, thereby, have influenced the evolution of the C. sinensis genome.

Keyword

Clonorchis sinensis; CsRn1 LTR retrotransposon; IRAP; locus-specific typing; intergenomic polymorphism; evolutionary course of retrotransposon

MeSH Terms

Animals
Clonorchis sinensis/*genetics
DNA, Helminth/analysis/genetics
*Evolution, Molecular
Gene Dosage
*Genome
Phylogeny
Polymorphism, Genetic
RNA-Directed DNA Polymerase
Retroelements/*genetics
Sequence Analysis, DNA
Terminal Repeat Sequences/*genetics