Rabbit Anti-Human MDK monoclonal antibody, clone KG107-6

In the brain, specific signalling pathways localized in highly organized regions called niches, allow the persistence of a pool of stem and progenitor cells that generate new neurons and glial cells in adulthood. Much less is known on the spinal cord central canal niche where a sustained adult neurogenesis is not observed. Here we review our current knowledge of this caudal niche in normal and pathological situations. Far from being a simple layer of homogenous cells, this region is composed of several cell types localized at specific locations, expressing characteristic markers and with different morphologies and functions. We further report on a screen of online gene-expression databases to better define this spinal cord niche. Several genes were found to be preferentially expressed within or around the central canal region (Bmp6, CXCR4, Gdf10, Fzd3, Mdk, Nrtn, Rbp1, Shh, Sox4, Wnt7a) some of which by specific cellular subtypes. In depth characterization of the spinal cord niche constitutes a framework to make the most out of this endogenous cell pool in spinal cord disorders.

The elucidation of mechanisms underlying telencephalic neural development has been limited by the lack of knowledge regarding the molecular and cellular aspects of the ganglionic eminence (GE), an embryonic structure that supplies the brain with diverse sets of GABAergic neurons. Here, we report a comprehensive transcriptomic analysis of this structure including its medial (MGE), lateral (LGE) and caudal (CGE) subdivisions and its temporal dynamics in 12.5 to 16 day-old rat embryos. Surprisingly, comparison across subdivisions showed that CGE gene expression was the most unique providing unbiased genetic evidence for its differentiation from MGE and LGE. The molecular signature of the CGE comprised a large set of genes, including Rwdd3, Cyp26b1, Nr2f2, Egr3, Cpta1, Slit3, and Hod, of which several encode cell signaling and migration molecules such as WNT5A, DOCK9, VSNL1 and PRG1. Temporal analysis of the MGE revealed differential expression of unique sets of cell specification and migration genes, with early expression of Hes1, Lhx2, Ctgf and Mdk, and late enrichment of Olfm3, SerpinE2 and Wdr44. These GE profiles reveal new candidate regulators of spatiotemporally governed GABAergic neuronogenesis. (c) 2008 Elsevier Inc. All rights reserved.