The gene distribution in the genomes of pea, tomato and date palm

The vast majority of genes of maize, rice, barley and wheat are contained i n long gene-rich regions (collectively called the 'gene space') separated b y long gene-empty regions. The gene space covers a narrow, 0.8-1.6%, GC ran ge, possibly because of the presence of abundant transposons, Here we repor t that the gene space is not an exclusive property of Gramineae, because it also exists in the large genome of pea (5000 Mb), Moreover, the gene space is not just dependent upon genome size, since a gene space is found in ric e (415 Mb), but not in Arabidopsis (120 Mb), nor in two other plants invest igated in the present work, date palm (250 Mb) and tomato (1000 Mb). (C) 19 99 Federation of European Biochemical Societies.