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The genome project has resulted in an avalanche of data, as well as an avalanche of philosophical revisionism to justify the lack of a hypothesis behind most genomics research. While sometimes heralded as a new age in biological reasoning, little has changed in the way conclusions are reached. What has changed is the richness of the information space within which experiments can be designed. Plants were the first organisms subjected to genetic analysis, and some of the first for which genetic maps assigned functions to chromosomal regions known as genes. The resolution provided by the genome project catapults genetic analysis into the computer age. As in Physics, it is only when significant algorithmic power is brought to bear that Popper's revolution can occur. As at the dawn of genetics, plants have properties particularly favorable to the study of higher eukaryotic genomes. Perhaps the real Green Revolution is only just beginning.Lin Kaul Rounsley Shea Benito Town Fujii Mason Bowman Barnstead 1999xLin, X., Kaul, S., Rounsley, S., Shea, T.P., Benito, M.I., Town, C.D., Fujii, C.Y., Mason, T., Bowman, C.L., Barnstead, M. et al. Nature. 1999; 402: 761–768Crossref | PubMed | Scopus (490)See all References, Wang Stec Hey Lukens Doebley 1999xWang, R.L., Stec, A., Hey, J., Lukens, L., and Doebley, J. Nature. 1999; 18: 236–239See all References

Heterochromatin, constitutively condensed chromosomal material, is widespread among eukaryotes but incompletely characterized at the nucleotide level. We have sequenced and analyzed 2.1 megabases (Mb) of Arabidopsis thaliana chromosome 4 that includes 0.5–0.7 Mb of isolated heterochromatin that resembles the chromosomal knobs described by Barbara McClintock in maize. This isolated region has a low density of expressed genes, low levels of recombination and a low incidence of genetrap insertion. Satellite repeats were absent, but tandem arrays of long repeats and many transposons were found. Methylation of these sequences was dependent on chromatin remodeling. Clustered repeats were associated with condensed chromosomal domains elsewhere. The complete sequence of a heterochromatic island provides an opportunity to study sequence determinants of chromosome condensation.