Neural crest (NC) cells are a
multipotent, highly migratory cell population that generates most of the components of the
peripheral nervous system (PNS), including the
glial Schwann cells (SC) and boundary cap (BC) cells. These latter cells are located at the interface between the
central nervous system and PNS, at the exit/entry points of
ventral motor/
dorsal sensory
axons and give rise to all SC in the
nerve roots and to a subset of
nociceptive neurons and
satellite cells in the
dorsal root ganglia. In the present study we have compared BC cells with two closely related cell types, NC and
Schwann cell precursors (SCpr), by
RNA profiling. This
led to the definition of a set of 10 genes that show specific expression in BC cells and/or in their derivatives along the
nerve roots. Analysis of the expression of these genes during
mouse development revealed novel features, of those most important are: (i)
dorsal and
ventral nerve root BC cell derivatives express different sets of genes, suggesting that they have distinct properties; (ii) these cells undergo major modifications in their
gene expression pattern between
embryonic days 14.5 and 17.5, possibly linked to the SCpr-immature
Schwann cell transition; (iii)
nerve roots SC differ from more
distal SC not only in their origins and locations, but also in their
gene expression patterns. In conclusion, the identification of these novel makers opens the way for a detailed characterization of BC cells in both
mouse and man.
