A large portion of plant and particularly cereal genomes consist of repetitive DNA families, many of which are likely to be or to have evolved from retroelements. Molecular evidence suggests that repeated DNA sequences, although perhaps originating as innocuous or 'selfish' elements, can have dramatic effects on genome organization and function. Knowledge of chromosomal distribution of retroelements is important for understanding plant chromosome structure/functional organization, and could shed light on the dynamics of retroelements and their role in the evolutionary process. In the present study we aim to find a possible correlation between physical location of the regions with species-specific sequences and the distribution of conserved RT domains of the Ty1-copia, Ty3-gypsy and LINE groups of retroelements on the chromosomes of two diploid species that belong to the different branches of the tribe Triticeae, namely Aegilops speltoides Tausch (2n=2x=14) and Hordeum spontaneum L (2n=2x=14). All three groups of retroelements were found in large quantities in the genomes of the tested species. They are cluster-distributed, and the important role of these elements in the formation of terminal heterochromatin is shown. We found that there was a predominance of Ty1-copia and LINE elements in the chromosome regions with preferential content of species-specific sequences.
|Number of pages||8|
|State||Published - 2001|
Bibliographical noteFunding Information:
The authors are grateful to Benjamin Podbilewich, Department of Biology, Israel Institute of Technology, for the opportunity to use the confocal microscope. We thank Irina Kolotueva for her excellent confocal microscope technical assistance. This work was supported by grants from the Ministry of Absorbtion awarded to A.B. and O.R., the Discont Bank Chair of Evolutionary Biology and the Ancell-Teicher Research Foundation for Genetics and Molecular Evolution to E.N.
- In situ hybridization
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