[
Nat Methods,
2011]
Engineering precise genetic changes in a genome is powerful way to study gene function, and several recent papers describe new applications of gene-editing tools. Working with researchers at Sangamo BioSciences, Howard Hughes Medical Institute investigator Barbara Meyer and her colleagues at the University of California, Berkeley, described the first systems for making targeted genomic modifications in the roundworm Caenorhabditis elegans, a valuable model organism (Wood et al., 2011).
[
Nature,
1996]
Classical results in experimental embryology established long ago that cells of the developing animal have a regional identity. They can be characterized not only as 'skin', 'nerve' and 'bone', but also as 'arm' and 'leg'. But how cells know what body region they belong to, and what to do there, is not known. Results reported in this issue and in Development describe unexpected properties of a key player, one of the Hox genes-the dynamic, lineage-based regulation of a Hox gene in the nematode Caenorhabditis elegans is at odds with a traditional view of Hox genes as relatively fixed markers of regional identity.