Cover photograph (Copyright © 2006, American Society for Microbiology. All Rights Reserved.): ZPR1 is essential for nuclear accumulation of Survival Motor Neurons (SMN) protein. Wild-type Zpr^+/+ blastocysts (embryonic day 3.5) cultured in vitro for 96 h were stained with antibodies to SMN (red) and ZPR1 (green). Colocalization of SMN and ZPR1 in the cytoplasm and in the nuclear bodies is represented by yellow. Nuclei were stained with DAPI (4′,6′-diamidino-2-phenylindole; blue). ZPR1 deficiency caused mislocalization of SMN protein and loss of nuclear gems and Cajal bodies. (See related article in April 2005, vol. 25: issue 7, p. 2744.)