Nature Methods doi:10.1038/nmeth.1226; (2008) and Nature Methods doi:10.1038/nmeth.1223 (2008)

High-throughput sequencing techniques have been harnessed to catalogue the messenger RNA (mRNA) molecules produced by many types of mouse cell.

The catalogue is known as the transcriptome. Barbara Wold and her colleagues at the California Institute of Technology in Pasadena sequenced mRNA from mouse brain, liver and skeletal muscle. They found that about 3,500 mouse genes are alternatively spliced — that is, the initial mRNA sequence can be chopped up and put back together in various ways to form different mRNA sequences.

Meanwhile, Sean Grimmond at the University of Queensland in St Lucia, Australia, and his collaborators sequenced mRNA from mouse embryonic stem cells. The results should help elucidate pathways controlling embryonic stem cells' ability to develop into any cell type.