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Published January 20, 1986 | public
Journal Article

Characterization of the genome of Arabidopsis thaliana

Abstract

The small crucifer Arabidopsis thaliana has many useful features as an experimental organism for the study of plant molecular biology. It has a four-week life-cycle, only five chromosomes and a genome size less than half that of Drosophila. To characterize the DNA sequence organization of this plant, we have randomly selected 50 recombinant lambda clones containing inserts with an average length of 12,800 base-pairs and analyzed their content of repetitive and unique DNA by various genome blot, restriction digestion and RNA blot procedures. The following conclusions can be drawn. (1) The DNA represented in this random sample is composed predominantly of single-copy sequences. This presumably reflects the organization of the Arabidopsis genome as a whole and supports prior conclusions reached on the basis of kinetics of DNA reassociation. (2) The DNA that encodes the ribosomal RNAs constitutes the only major class of cloned nuclear repetitive DNA. It consists of approximately 570 tandem copies of a heterogeneous 9900-base-pair repeat unit. (3) There is an average of approximately 660 copies of the chloroplast genome per cell. Therefore, the chloroplast genome constitutes the major component of the repetitive sequences found in A. thaliana DNA made from whole plants. (4) The inner cytosine residue in the sequence C-C-G-G is methylated more often than the outer in the tandem ribosomal DNA units, whereas very few differences in the methylation state of these two cytosine residues are detected in unique sequences.

Additional Information

© 1986 Elsevier Ltd. Received 25 March 1985, Revised 1 September 1985. We thank Robin K. Wilson for technical assistance and members of the Meyerowitz laboratory for reading and commenting on the manuscript. This work was supported by grant number 82-CRCR-1-1063 from the Science and Education Administration of the U.S. Department of Agriculture and by grant number PCM-8408504 from the National Science Foundation to E.M.M. R.E.P. was supported by a National Science Foundation pre-doctoral fellowship and by National Research Service Award number 5T32GM07616 from the National Institutes of Health. This work was supported by grant number 82-CRCR-1-1063 from the Science and Education Administration of the U.S. Department of Agriculture and by grant number PCM-8408504 from the National Science Foundation to E.M.M.

Additional details

Created:
August 19, 2023
Modified:
October 23, 2023