Uncovering a weed's true worth
EU and US researchers have achieved a scientific first: the complete DNA sequence of a plant chromosome. In an international effort to analyse all the genetic material - the entire genome - of a plant, the full sequences of two chromosomes from the small weed, Arabidopsis thaliana, have been determined. Background Many genes in plants are similar, so studying the genes of one plant can help understand how they function in others. Knowing how genes operate in plants can also provide knowledge about how human genes work. However, one difficulty with this is that plant genomes are normally very large. Arabidopsis thaliana, a small flowering plant of the cabbage or Brassica family is one exception. This common garden weed has a small and compact genome with the DNA organised into only five chromosomes. EU networks of European laboratories are helping in an international effort to determine the first complete sequencing of a plant genome using Arabidopsis. The work is part of the European Commission's Biotech programme, and the ultimate goal is to link the genetic information obtained to other European research activities on crop plants and gene function. Description, impact and results The chemical compounds that form the links between two DNA strands are called base pairs. Sequencing concerns the identification of the thousands of such base pairs that form the DNA in a living organism. In collaboration with a US consortium, a European team has sequenced more than 37 million base pairs from chromosomes II and IV of Arabidopsis thaliana. These chromosomes contain 7 781 genes representing around a third of the estimated 26 000 genes in this particular plant. The resulting information on specific genes and their function is being transferred to a wide range of crop species such as wheat and rice. New and fundamental knowledge is being obtained on important biological processes and the means to develop new crop plants. Researchers have managed to deduce the functions of well over half the genes found in the two chromosomes by comparing them with genes of known function from other plants and animals. However, many genes are totally new to science and their function is yet unknown. These new plant genes will be a rich resource in supporting research by plant scientists and stimulating developments within Europe's agricultural and food industries. Working partnerships The international network comprises the EU, The National Science Foundation (NSF) in the United States, and the Kazusa Institute in Japan. In Europe, there are two laboratory networks: the first, which concentrates on chromosomes IV and V, is led by Mike Bevan at the John Innes Centre in Norwich (United Kingdom). The second, led by Francis Quetier at the Genoscope in Evry (France), is focusing on chromosome III. These two networks currently involve up to 40 partner laboratories from ten European countries.