COMPARATIVE GENOME ANALYSIS IN CRUCIFEROUS PLANTS

¹ Max-Delbrueck-Laboratory in the MPG, Carl-von-Linne-Weg 10, 50829 Cologne, Germany

² present address: Max-Planck-Institute for chemical ecology, Tatzendpromenade 1a, 07745 Jena, Germany

We are aiming to elucidate the degree of microsynteny in three related cruciferous plant species, Arabidopsis thaliana, Capsella rubella and Brassica oleracea. To demonstrate conservation of gene repertoire, gene order and structure of intergenic regions in these species we have chosen a 200 kbp long region of Arabidopsis thaliana which is located on the long arm of chromosome 4. The region contains at least 17 different genes most of which are single copy genes in Arabidopsis thaliana. cDNAs corresponding to these genes were used as probes to screen a cosmid library generated from DNA of the diploid Capsella rubella and cosmid clones carrying the corresponding Capsella rubella genes have been identified. The analysis of these clones indicates that most of the closely linked genes in Arabidopsis thaliana are also closely linked in Capsella rubella. So far two DNA contigs could be assembled for Capsella rubella which encompass genomic regions of similar size when compared to Arabidopsis thaliana. Where studied gene order is identical in Arabidopsis thaliana and Capsella rubella. These data indicate a high degree of microsynteny for these two species. Further characterization of the cosmid clones spanning the area will reveal to which extent gene orientation and spacing are conserved. The same approach is used to analyze the homoeologous regions in the palaeopolyploid Brassica oleracea.