We have examined the structure and chromatin organization of telomeres in Nicotiana tabacum. In tobacco the blocks of simple telomeric repeats (TT-TAGGG)n are many times larger than in other plants, e.g., Arabidopsis thaliana or tomato. They are resolved as multiple fragments 60-160 kb in size (in most cases 90-130 kb) on pulsed-field gel electrophoresis (PFGE) of restriction endonuclease-digested DNA. The major subtelomeric repeat of the HRS60 family forms large homogeneous blocks of a basic 180 bp motif having comparable lengths. Micrococcal nuclease (MNase) cleaves tobacco telomeric chromatin into subunits with a short repeat length of 157 +/- 5 bp; the subtelomeric heterochromatin characterized by tandemly repeated sequences of the HRS60 family is cut by MNase with a 180 bp periodicity. The monomeric and dimeric particles of telomeric and subtelomeric chromatin differ in sensitivity to MNase treatment: the telomeric particles are readily digested, producing ladders with a periodicity of 7 bp, while the subtelomeric particles appear to be rather resistant to intranucleosomal cleavage. The results presented show apparent similarities in the organization of telomeric chromatin in higher plants and mammals.

Institute of Biophysics Academy of Sciences of the Czech Republic Brno

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J Mol Biol. 1984 Jul 15;176(4):535-57 PubMed

Mol Gen Genet. 1993 Aug;240(2):159-69 PubMed

Mol Cell Biol. 1994 Sep;14(9):5777-85 PubMed

Cell. 1989 Dec 1;59(5):871-80 PubMed

Plant Mol Biol. 1993 Mar;21(5):847-57 PubMed

Cell. 1993 May 21;73(4):775-87 PubMed

J Biol Chem. 1986 Jan 5;261(1):363-9 PubMed

Nucleic Acids Res. 1980 Sep 11;8(17):4041-53 PubMed

FEBS Lett. 1992 Dec 7;314(1):13-6 PubMed

Cell. 1988 Apr 8;53(1):127-36 PubMed

Annu Rev Genet. 1989;23:579-604 PubMed

Comput Appl Biosci. 1993 Aug;9(4):435-40 PubMed

Plant Cell. 1991 Jan;3(1):87-94 PubMed

Planta. 1991 Jul;184(4):487-90 PubMed

Genes Dev. 1992 Feb;6(2):197-210 PubMed

Proc Natl Acad Sci U S A. 1992 Feb 15;89(4):1354-7 PubMed

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