High intrachromosomal similarity of retrotransposon long terminal repeats: evidence for homogenization by gene conversion on plant sex chromosomes?
Retrotransposons are ubiquitous in the plant genomes and are responsible for their plasticity. Recently, we described a novel family of gypsy-like retrotransposons, named Retand, in the dioecious plant Silene latifolia possessing evolutionary young sex chromosomes of the mammalian type (XY). Here we have analyzed long terminal repeats (LTRs) of Retand that were amplified from laser microdissected X and Y sex chromosomes and autosomes of S. latifolia. A majority of X and Y-derived LTRs formed a few separate clades in phylogenetic analysis reflecting their high intrachromosomal similarity. Moreover, the LTRs localized on the Y chromosome were less divergent than the X chromosome-derived or autosomal LTRs. These data can be explained by a homogenization process, such as gene conversion, working more intensively on the Y chromosome.
Kejnovsky
Eduard
E
Laboratory of Plant Developmental Genetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, Kralovopolska 135, CZ-612 65 Brno, Czech Republic. kejnovsk@ibp.cz
Hobza
Roman
R
Kubat
Zdenek
Z
Widmer
Alex
A
Marais
Gabriel A B
GA
Vyskot
Boris
B
D001483:Base Sequence; D032461:Chromosomes, Plant / Q000235:genetics*; D017931:DNA Primers / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D019143:Evolution, Molecular; D005785:Gene Conversion; D017404:In Situ Hybridization, Fluorescence; D008957:Models, Genetic; D010802:Phylogeny; D018626:Retroelements; D029751:Silene / Q000235:genetics; D020079:Terminal Repeat Sequences
D017931:DNA Primers; D018744:DNA, Plant; D018626:Retroelements