Comparative analysis of genic structure in plants

The availability of fully sequenced genomes and comprehensive expression studies offer new opportunities for studying the relationships between structures and functions of genes. These topics are relevant for the fields of plant biotechnology since the debate on transgenic plants has raised concerns about the impact of heterologous gene expression and structure on host genome integrity.In this thesis we adopted comparative approaches to study the degree of variation of genic structures among plant species.Inchapter 1we revised the relationship between average expression level of a gene and its architecture in 8 plant species. The results indicate that gene expression is non monotonically related to gene size.Inchapter 2we present the results of a thorough characterization of intron size inA. thalianaandV. vinifera. Our data suggest thatVitis viniferahas on average longer introns thanA. thaliana. Data indicate that Vitis intron tend to become longer due to the insertion of repetitive element but not for an increased rate of small insertion over deletions.Chapter 3reports on the evolution of intron-exon organization in eleven species spanning an evolutionary range from green algae to extant dicots. The picture confirmed the tenet that intron losses outnumbered the gains. However we identified several examples suggesting that the general view may be punctated by relevant exceptions.