In spinal cord development, which signaling pathways govern dorsal-ventral patterning?

In spinal cord development, which signaling pathways govern dorsal-ventral patterning?

• A. BMPs ventralize; SHH dorsalize; WNTs ventralize
• B. SHH ventralizes; BMPs dorsalize; WNTs contribute to dorsal patterning
• C. WNTs ventralize; SHH ventralize; BMPs dorsalize
• D. SHH dorsalizes; BMPs ventralize; WNTs ventralize

Answer: (B)

Dorsal-ventral patterning in the spinal cord is shaped by opposing signaling gradients. Sonic hedgehog (SHH) from the notochord and floor plate spreads ventrally to drive ventral neural progenitor identities. Bone morphogenetic proteins (BMPs) released from the roof plate promote dorsal identities, establishing the dorsal pattern. WNT signaling originates from the dorsal side and helps refine and reinforce dorsal patterning, contributing to the dorsal fate alongside BMP signals. Together, these cues set up distinct progenitor domains along the dorsal-ventral axis. So the correct view is that SHH ventralizes, BMPs dorsalize, and WNTs contribute to dorsal patterning. The alternatives misstate these roles—for example, BMPs ventralizing, SHH dorsalizing, or WNTs ventralizing—and do not align with how these pathways regulate spinal cord development.

Dorsal-ventral patterning in the spinal cord is shaped by opposing signaling gradients. Sonic hedgehog (SHH) from the notochord and floor plate spreads ventrally to drive ventral neural progenitor identities. Bone morphogenetic proteins (BMPs) released from the roof plate promote dorsal identities, establishing the dorsal pattern. WNT signaling originates from the dorsal side and helps refine and reinforce dorsal patterning, contributing to the dorsal fate alongside BMP signals. Together, these cues set up distinct progenitor domains along the dorsal-ventral axis.

So the correct view is that SHH ventralizes, BMPs dorsalize, and WNTs contribute to dorsal patterning. The alternatives misstate these roles—for example, BMPs ventralizing, SHH dorsalizing, or WNTs ventralizing—and do not align with how these pathways regulate spinal cord development.