Embryonic cortical neural stem cells migrate ventrally and persist as postnatal striatal stem cells

Embryonic cortical neural stem cells apparently have a transient existence, as they do not persist in the adult cortex. We sought to determine the fate of embryonic cortical stem cells by following Emx1(IREScre); LacZ/EGFP double-transgenic murine cells from midgestation into adulthood. Lineage tracing in combination with direct cell labeling and time-lapse video microscopy demonstrated that Emx1-lineage embryonic cortical stem cells migrate ventrally into the striatal germinal zone (GZ) perinatally and intermingle with striatal stem cells. Upon integration into the striatal GZ, cortical stem cells down-regulate Emx1 and up-regulate Dlx2, which is a homeobox gene characteristic of the developing striatum and striatal neural stem cells. This demonstrates the existence of a novel dorsal-to-ventral migration of neural stem cells in the perinatal forebrain.     

PREPL: a putative novel oligopeptidase propelled into the limelight

The prolyl endopeptidase-like protein PREPL has recently attracted attention because its gene is located within two contiguous gene-deletion syndromes, the 2p21 deletion syndrome and the hypotonia-cystinuria syndrome. Deletion of the gene results in hypotonia at birth, failure to thrive and growth hormone deficiency. PREPL is highly reactive against an activity-based probe, which indicates the presence of an intact catalytic machinery. However, no substrate has been found yet. The unique carboxy-terminus of the catalytic domain might contain the key to the as yet elusive specificity.