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Molecular diversification of tandemly organized DNA sequences and heterochromatic chromosome regions in some Triticeae species.
Chromosome Res. 1996 Nov; 4(7):517-25.CR

Abstract

The subtelomeric heterochromatin of rye (Secale cereale) chromosomes makes up 12-18% of the genome and consists largely of a small number of tandemly organized DNA sequence families. The genomic organization, chromosomal locations and the structural organization of monomer units of the major DNA sequences from these regions were investigated and compared in other Triticeae species from the genera Secale, Agropyron, Dasypyrum, Triticum and Hordeum. Southern hybridization and polymerase chain reaction analysis established that all studied species preserve the tandem type of sequence organization but the copy number is altered drastically between species. In the pSc200 family, a fraction of the tandem arrays is present with a head-to-head orientation of dimers in S. cereale and S. montanum. Members of the same family are more heterogeneous and present as head-to-head monomers in the Dasypyrum species and A. cristatum. In situ hybridization demonstrates different organization of the sequence families in the various species: pSc200 and pSc250 are concentrated in major blocks at the ends of most rye chromosome arms, whereas they are more dispersed and in smaller blocks in Dasypyrum and Agropyron, indicating that accumulation is not simply due to the sequence itself. In contrast to rye, D. villisum has large blocks of only pSc200 whereas D. breviaristatum shows greater amplification of pSc250. These data indicate that each repetitive family is an independent unit of evolution, and suggest that the two Dasypyrum species are not closely related. The data are discussed in terms of existing evolutionary models for repetitive DNA sequences. The contribution of random events, through molecular drive and selection, to the evolution of heterochromatic regions is considered.

Authors+Show Affiliations

Department of Cell Biology, John Innes Centre, Norwich, UK. Alexander.Vershinin@bbsrc.ac.ukNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

8939363

Citation

Vershinin, A V., et al. "Molecular Diversification of Tandemly Organized DNA Sequences and Heterochromatic Chromosome Regions in some Triticeae Species." Chromosome Research : an International Journal On the Molecular, Supramolecular and Evolutionary Aspects of Chromosome Biology, vol. 4, no. 7, 1996, pp. 517-25.
Vershinin AV, Alkhimova EG, Heslop-Harrison JS. Molecular diversification of tandemly organized DNA sequences and heterochromatic chromosome regions in some Triticeae species. Chromosome Res. 1996;4(7):517-25.
Vershinin, A. V., Alkhimova, E. G., & Heslop-Harrison, J. S. (1996). Molecular diversification of tandemly organized DNA sequences and heterochromatic chromosome regions in some Triticeae species. Chromosome Research : an International Journal On the Molecular, Supramolecular and Evolutionary Aspects of Chromosome Biology, 4(7), 517-25.
Vershinin AV, Alkhimova EG, Heslop-Harrison JS. Molecular Diversification of Tandemly Organized DNA Sequences and Heterochromatic Chromosome Regions in some Triticeae Species. Chromosome Res. 1996;4(7):517-25. PubMed PMID: 8939363.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Molecular diversification of tandemly organized DNA sequences and heterochromatic chromosome regions in some Triticeae species. AU - Vershinin,A V, AU - Alkhimova,E G, AU - Heslop-Harrison,J S, PY - 1996/11/1/pubmed PY - 1996/11/1/medline PY - 1996/11/1/entrez SP - 517 EP - 25 JF - Chromosome research : an international journal on the molecular, supramolecular and evolutionary aspects of chromosome biology JO - Chromosome Res VL - 4 IS - 7 N2 - The subtelomeric heterochromatin of rye (Secale cereale) chromosomes makes up 12-18% of the genome and consists largely of a small number of tandemly organized DNA sequence families. The genomic organization, chromosomal locations and the structural organization of monomer units of the major DNA sequences from these regions were investigated and compared in other Triticeae species from the genera Secale, Agropyron, Dasypyrum, Triticum and Hordeum. Southern hybridization and polymerase chain reaction analysis established that all studied species preserve the tandem type of sequence organization but the copy number is altered drastically between species. In the pSc200 family, a fraction of the tandem arrays is present with a head-to-head orientation of dimers in S. cereale and S. montanum. Members of the same family are more heterogeneous and present as head-to-head monomers in the Dasypyrum species and A. cristatum. In situ hybridization demonstrates different organization of the sequence families in the various species: pSc200 and pSc250 are concentrated in major blocks at the ends of most rye chromosome arms, whereas they are more dispersed and in smaller blocks in Dasypyrum and Agropyron, indicating that accumulation is not simply due to the sequence itself. In contrast to rye, D. villisum has large blocks of only pSc200 whereas D. breviaristatum shows greater amplification of pSc250. These data indicate that each repetitive family is an independent unit of evolution, and suggest that the two Dasypyrum species are not closely related. The data are discussed in terms of existing evolutionary models for repetitive DNA sequences. The contribution of random events, through molecular drive and selection, to the evolution of heterochromatic regions is considered. SN - 0967-3849 UR - https://www.unboundmedicine.com/medline/citation/8939363/Molecular_diversification_of_tandemly_organized_DNA_sequences_and_heterochromatic_chromosome_regions_in_some_Triticeae_species_ DB - PRIME DP - Unbound Medicine ER -