Insights into the Structural and Functional Evolution of Plant Genomes Afforded by the Nucleotide Sequences of Chromosomes 2 and 4 ofArabidopsis thaliana

Abstract

The rapidly accumulating genome sequence data from the plantArabidopsis thalianaallows more detailed analysis of genome content and organisation than ever bafore possible in plants. The genome shows a surprisingly high level of genetic redundancy, with as many as 75% of gene products showing signficant homology to another protien ofA. thaliana.Many duplicated genes occur in arrays of conserved order and indicate thatA. thalianais likely to have had a tetraploid ancestor. Analysis of the divergence of duplicated genome segments leads to the prediction of two major modes of plant genome evolution: macro-scale duplication and rearrangement of chromosomes and micro-scale translocation, duplication and loss of individual genes or small groups of genes.