Generating Diverse Spinal Motor Neuron Subtypes from Human Pluripotent Stem Cells

Figure 2

A schematic depicting expression patterns of chromosomally linked Hox genes along the rostrocaudal axis. Hox genes at one end of the cluster are expressed more rostrally, while those at the opposite end are expressed caudally. As indicated, RA is responsible for rostral spinal cord patterning (i.e., the cervical spinal cord). Caudal spinal areas are patterned by FGFs and GDFs. The precise nature of how these caudalizing factors conspire with one another has yet to be resolved. RA: retinoic acid; FGF: fibroblast growth factor; GDF: growth/differentiation factor.