TY - JOUR
T1 - The chromosomal distributions of Ty1-copia group retrotransposable elements in higher plants and their implications for genome evolution
AU - Heslop-Harrison, J. S.
AU - Brandes, Andrea
AU - Taketa, Shin
AU - Schmidt, Thomas
AU - Vershinin, Alexander V.
AU - Alkhimova, Elena G.
AU - Kamm, Anette
AU - Doudrick, Robert L.
AU - Schwarzacher, Trade
AU - Katsiotis, Andreas
AU - Kubis, Sybille
AU - Kumar, Amar
AU - Pearce, Steven R.
AU - Flavell, Andrew J.
AU - Harrison, Gill E.
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 1997
Y1 - 1997
N2 - Retrotransposons make up a major fraction - sometimes more than 40% - of all plant genomes investigated so far. We have isolated the reverse transcriptase domains of the Ty1-copia group elements from several species, ranging in genome size from some 100 Mbp to 23 000 Mbp, and determined the distribution patterns of these retrotransposons on metaphase chromosomes and within interphase nuclei by DNA:DNA in situ hybridization. With some exceptions, the reverse transcriptase domains were distributed over the length of the chromosomes. Exclusion from rDNA sites and some centromeres (e.g., slash pine, 23 000 Mbp, or barley, 5500 Mbp) is frequent, whereas many species exclude retrotransposons from other sites of heterochromatin (e.g., intercalary and centometric sites in broad bean). In contrast, in the plant Arabidopsis thaliana, widely used for plant molecular genetic studies because of its small genome (c. 100 Mbp), the Ty1-copia group reverse transcriptase gene domains are concentrated in the centromeric regions, collocalizing with the 180 bp satellite sequence pAL1. Unlike the pAL1 sequence, however, the Ty1-copia signal is also detectable as weaker, diffuse hybridization along the lengths of the chromosomes. Possible mechanisms for evolution of the contrasting distributions are discussed. Understanding the physical distribution of retrotransposons and comparisons of the distribution between species is critical to understanding their evolution and the significance for generation of the new patterns of variability and in speciation.
AB - Retrotransposons make up a major fraction - sometimes more than 40% - of all plant genomes investigated so far. We have isolated the reverse transcriptase domains of the Ty1-copia group elements from several species, ranging in genome size from some 100 Mbp to 23 000 Mbp, and determined the distribution patterns of these retrotransposons on metaphase chromosomes and within interphase nuclei by DNA:DNA in situ hybridization. With some exceptions, the reverse transcriptase domains were distributed over the length of the chromosomes. Exclusion from rDNA sites and some centromeres (e.g., slash pine, 23 000 Mbp, or barley, 5500 Mbp) is frequent, whereas many species exclude retrotransposons from other sites of heterochromatin (e.g., intercalary and centometric sites in broad bean). In contrast, in the plant Arabidopsis thaliana, widely used for plant molecular genetic studies because of its small genome (c. 100 Mbp), the Ty1-copia group reverse transcriptase gene domains are concentrated in the centromeric regions, collocalizing with the 180 bp satellite sequence pAL1. Unlike the pAL1 sequence, however, the Ty1-copia signal is also detectable as weaker, diffuse hybridization along the lengths of the chromosomes. Possible mechanisms for evolution of the contrasting distributions are discussed. Understanding the physical distribution of retrotransposons and comparisons of the distribution between species is critical to understanding their evolution and the significance for generation of the new patterns of variability and in speciation.
KW - Arabidopsis
KW - Barley
KW - Centromeres
KW - Evolution
KW - Genome organization
KW - In situ hybridization
KW - Retrotransposons
KW - Sequence evolution
UR - http://www.scopus.com/inward/record.url?scp=6844258847&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=6844258847&partnerID=8YFLogxK
U2 - 10.1023/a:1018337831039
DO - 10.1023/a:1018337831039
M3 - Article
C2 - 9440273
AN - SCOPUS:6844258847
VL - 100
SP - 197
EP - 204
JO - Genetica
JF - Genetica
SN - 0016-6707
IS - 1-3
ER -