Which signals pattern dorsal neural tube identities from the roof plate and surface ectoderm?

Which signals pattern dorsal neural tube identities from the roof plate and surface ectoderm?

• A. BMPs (and WNTs)
• B. SHH
• C. FGF8
• D. Retinoic acid

Answer: (A)

Dorsal identities in the neural tube are established by signals that come from the roof plate and the surface ectoderm. These tissues release BMPs and WNTs, which diffuse into the dorsal neural tube to create a dorsalizing gradient. When BMPs bind their receptors and WNTs activate their canonical pathways, they drive the expression of dorsal-specific transcription programs (such as Pax7 and related dorsal genes), guiding the formation of dorsal interneuron populations that process sensory information. This dorsal signal works in opposition to ventral cues from SHH, which come from the notochord and floor plate to specify ventral fates. Retinoic acid and FGF8 influence other axes like anterior-posterior patterning and timing, but they are not the primary dorsal patterning signals from the roof plate and surface ectoderm. Therefore, BMPs and WNTs are the signals responsible for patterning dorsal neural tube identities.

Dorsal identities in the neural tube are established by signals that come from the roof plate and the surface ectoderm. These tissues release BMPs and WNTs, which diffuse into the dorsal neural tube to create a dorsalizing gradient. When BMPs bind their receptors and WNTs activate their canonical pathways, they drive the expression of dorsal-specific transcription programs (such as Pax7 and related dorsal genes), guiding the formation of dorsal interneuron populations that process sensory information. This dorsal signal works in opposition to ventral cues from SHH, which come from the notochord and floor plate to specify ventral fates. Retinoic acid and FGF8 influence other axes like anterior-posterior patterning and timing, but they are not the primary dorsal patterning signals from the roof plate and surface ectoderm. Therefore, BMPs and WNTs are the signals responsible for patterning dorsal neural tube identities.