Today's Science has a special section covering breakthroughs of 2007. The two biggest breakthroughs were genetic variation and personal genomics, with reprogramming cells among the runners-up. Global warming got a special breakthrough mention, as 2007, the magazine writes, was the year when the debate about its reality ended. In 2008, Science editors will be watching miRNAs, human-made microbes, paleogenomics, and the human microbiome, among others.
Finally published this month, a paper from University of Wisconsin-Madison researchers proves that by introducing four genes into human fibroblasts, these skin cells can be transformed into human embryonic stem cells. Another paper out of Rudolf Jaenisch's lab shows that by using a humanized sickle cell anemia mouse model, mice can be cured after being transplanted with induced pluripotent stem (iPS) cells. In light of these breakthroughs, Jose Cibelli examines whether somatic cell nuclear transfer, otherwise known as human therapeutic cloning, will ever happen.
HHMI researcher Joan Steitz proves that miRNAs don't always down-regulate translation, and what they do depends on the stage of the cell cycle. Her work shows that human miR369-3 binds the TNFalpha ARE, directs association of proteins AGO1 and FXR1, and activates translation in non-proliferating cells. However, miR369-3 represses translation of the same mRNA in proliferating cells. A perspective takes a closer look at the two faces of miRNA.