Fig. 8. Function of spg/pou2 during MHB establishment. Model showing spg/pou2 activity positioned within the cascade of known MHB patterning genes in zebrafish. Three parallel pathways are involved in the activation of wnt1, pax2.1 and fgf8 in the mid-/hindbrain (Lun and Brand, 1998) during MHB establishment. Our data suggests that spg/pou2 functions upstream of both pax2.1 and wnt1. fgf8 is initiated normally in the anterior hindbrain during late gastrulation, but requires pou2 for its continued expression during MHB establishment. Arrows do not necessarily indicate direct interactions.
