A centromeric tandem repeat family originating from a part of Ty3/gypsy-retroelement in wheat and its relatives.
From a wild diploid species that is a relative of wheat, Aegilops speltoides, a 301-bp repeat containing 16 copies of a CAA microsatellite was isolated. Southern blot and fluorescence in situ hybridization revealed that approximately 250 bp of the sequence is tandemly arrayed at the centromere regions of A- and B-genome chromosomes of common wheat and rye chromosomes. Although the DNA sequence of this 250-bp repeat showed no notable homology in the databases, the flanking or intervening sequences between the repeats showed high homologies (>82%) to two separate sequences of the gag gene and its upstream region in cereba, a Ty3/gypsy-like retroelement of Hordeum vulgare. Since the amino acid sequence deduced from the 250 bp with seven CAAs showed some similarity ( approximately 53%) to that of the gag gene, we concluded that the 250-bp repeats had also originated from the cereba-like retroelements in diploid wheat such as Ae. speltoides and had formed tandem arrays, whereas the 300-bp repeats were dispersed as a part of cereba-like retroelements. This suggests that some tandem repeats localized at the centromeric regions of cereals and other plant species originated from parts of retrotransposons.
Cheng
Zhi-Jun
ZJ
Core Research for Evolutionary Science and Technology Program, Japan Science Technology Corporation, Tokyo 103-0027, Japan.
Murata
Minoru
M
D001483:Base Sequence; D015139:Blotting, Southern; D002503:Centromere / Q000648:ultrastructure; D032461:Chromosomes, Plant; D003001:Cloning, Molecular; D018744:DNA, Plant; D019143:Evolution, Molecular; D017343:Genes, Plant; D001467:Hordeum / Q000235:genetics; D017404:In Situ Hybridization, Fluorescence; D018895:Microsatellite Repeats; D008957:Models, Genetic; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D018626:Retroelements; D012434:Secale / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D020080:Tandem Repeat Sequences; D014908:Triticum / Q000235:genetics*
D018744:DNA, Plant; D018626:Retroelements