A paper to be published online in the February 2007 issue of Nature Methods introduces a tool to rapidly delete regions of chromosome in mammalian cells including embryonic stem cells. This new technique makes it possible to screen many different genomic regions and identify those essential for specific functions in adult and embryonic stem cells.
Guy Sauvageau and colleagues used the enzyme Cre -- which joins two stretches of DNA (loxP sites) -- thereby cutting out all DNA in between. By putting the loxP sites in separate retroviral vectors -- viruses that have been stripped of most of their genetic material and can now be safely used to deliver DNA into cells -- and sequentially infecting stem cells, the authors ensured a random distribution of loxP sites in the genome. Addition of the enzyme Cre led to deletion of chromosomal regions, ranging in size from 6kb, likely to include only one gene, to 23Mb, including many genes and their regulatory regions.
Guy Sauvageau (University of Montreal, QC, Canada)
Abstract available online.
(C) Nature Methods press release.
Message posted by: Trevor M. D'Souza