Figure 2

Differential expression of mRNAs coding for pan-neuronal and synaptic proteins in anlagen of adrenal gland and sympathetic ganglia at E12.5. (A) In consecutive sections from E12.5 mouse embryos, the position of the adrenal anlagen is marked by ISH for Nr5a1, also known as steroidogenic factor (SF1), expressed in cells destined to form prospective adrenal cortex (white arrowhead). Ganglion primordia (black arrowheads) show strong signals for (B) NF-M and (C) NF-L, which are also observed, albeit often at lower levels in adrenal anlagen. (D) SCG10 signals are barely detected in adrenal anlagen but are strong in ganglion primordia. (E) Catecholaminergic cells of the sympathoadrenal lineage are shown by expression of DBH in the adrenal anlage adjacent to Nr5a1-positive cells and in primordia of sympathetic ganglia. While (F) Snap25 is expressed in ganglion and adrenal anlagen, (G) Rab3a and (H) Syt1 signals are not above background. As all labeled cell populations may still be migratory active, those contributing to adrenal medulla and the different sympathetic ganglia, including the paraaortic, suprarenal and celiac-superior mesenteric ganglion complex, cannot safely be attributed at this stage. The distribution of the Nr5a1-positive cells roughly marks the adrenal anlage. Scale bar: 100 μm.