The genome: an isochore ensemble and its evolution
Article first published online: 6 SEP 2012
© 2012 New York Academy of Sciences.
Annals of the New York Academy of Sciences
Volume 1267, Effects of Genome Structure and Sequence on Variation and Evolution pages 31–34, September 2012
How to Cite
Bernardi, G. (2012), The genome: an isochore ensemble and its evolution. Annals of the New York Academy of Sciences, 1267: 31–34. doi: 10.1111/j.1749-6632.2012.06591.x
- Issue published online: 6 SEP 2012
- Article first published online: 6 SEP 2012
- genome organization;
- genome evolution;
The genomes of eukaryotes are mosaics of isochores. These are long DNA stretches that are fairly homogeneous in base composition and that belong to a small number of families characterized by different ratios of GC to AT and different short-sequence patterns (i.e., different DNA structures that interact with different proteins). This genome organization led to two discoveries: (1) the genomic code, which refers to two correlations, that of the composition of coding and contiguous noncoding sequences, and that of coding sequences and the structural properties of the encoded proteins; and (2) the genome phenotypes, which correspond to the patterns of isochore families in the genomes. These patterns indicate that genome evolution may proceed either according to a conservative mode or to a transitional (isochore shifting) mode, apparently depending upon whether the environment is constant or shifting. According to the neoselectionist theory, natural selection is responsible for both modes.