Identified UGA, normally a ‘STOP’ codon, as encoding the 21st amino acid selenocysteine.
Co-discoverer of Nanog, a homeodomain protein with a key role in conferring and maintaining pluripotency. In recognition of this, the protein was named after the Celtic Land-of-the-Ever-Young, Tir nan Og. The significance of this work was cited in the Report & Recommendations of the UK Stem Cell Initiative chaired by Sir John Pattison; “The UK has a strong history of discovery in stem cell research, indicative of a robust base of world-class academic researchers in developmental and reproductive biology. Amongst many landmark achievements in UK stem cell research were the first isolation of mammalian embryonic stem cells at Cambridge in 1981, the first cloning of a mammal at the Roslin Institute in 1997 and the first identification of the stem cell ‘immortality’ gene, Nanog, at the Institute for Stem Cell Research in Edinburgh in 2003.”
First to demonstrate heterogeneous transcription factor expression within the pluripotent cell compartment. Cells with lowered Nanog expression are primed for, but uncommitted to differentiation and can fluctuate back to a high Nanog expressing, differentiation-resistant state.