An accumulation of tandem DNA repeats on the Y chromosome in Silene latifolia during early stages of sex chromosome evolution.
Sex chromosomes in mammals are about 300 million years old and typically have a highly degenerated Y chromosome. The sex chromosomes in the dioecious plant Silene latifolia in contrast, represent an early stage of evolution in which functional X-Y gene pairs are still frequent. In this study, we characterize a novel tandem repeat called TRAYC, which has accumulated on the Y chromosome in S. latifolia. Its presence demonstrates that processes of satellite accumulation are at work even in this early stage of sex chromosome evolution. The presence of TRAYC in other species of the Elisanthe section suggests that this repeat had spread after the sex chromosomes evolved but before speciation within this section. TRAYC possesses a palindromic character and a strong potential to form secondary structures, which could play a role in satellite evolution. TRAYC accumulation is most prominent near the centromere of the Y chromosome. We propose a role for the centromere as a starting point for the cessation of recombination between the X and Y chromosomes.
Hobza
Roman
R
Laboratory of Plant Developmental Genetics, Institute of Biophysics, Academy of Sciences of Czech Republic, Kralovopolska Street 135, Brno 612 65, Czech Republic.
Lengerova
Martina
M
Svoboda
Julia
J
Kubekova
Hana
H
Kejnovsky
Eduard
E
Vyskot
Boris
B
D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics*; D019143:Evolution, Molecular; D017404:In Situ Hybridization, Fluorescence; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012689:Sequence Homology, Nucleic Acid; D012730:Sex Chromosomes / Q000235:genetics*; D029751:Silene / Q000145:classification / Q000235:genetics*; D013045:Species Specificity; D020080:Tandem Repeat Sequences; D014998:Y Chromosome / Q000235:genetics
D017931:DNA Primers; D018744:DNA, Plant