Cholesterol-rich membrane microdomains modulate Wnt/β-catenin morphogen gradient during Xenopus development

Area of Science:

• Developmental Biology
• Cell Signaling
• Molecular Biology

Background:

• Wnt/β-catenin signaling is vital for embryonic patterning.
• Cholesterol-rich membrane microdomains (CRMMs) act as signaling platforms.
• The role of CRMMs in prechordal plate formation and axis patterning is unknown.

Purpose of the Study:

• To investigate the role of CRMMs in Wnt/β-catenin signaling during embryonic development.
• To determine how CRMMs affect prechordal plate formation and embryo axis patterning.
• To explore the interaction between CRMMs and Wnt antagonists like dkk1.

Main Methods:

• Disruption of CRMMs using methyl-beta-cyclodextrin (MβCD) in vitro and in vivo.
• Analysis of Wnt/β-catenin signaling pathway activation.
• Assessment of embryonic head development and axis patterning.
• Investigation of interactions with dkk1 overexpression.

Main Results:

• CRMMs disruption potentiates Wnt/β-catenin signaling in vitro and in vivo.
• CRMMs disruption causes head defects by expanding the Wnt expression domain.
• CRMMs function is context-dependent, interacting with dkk1 during overexpression.

Conclusions:

• CRMMs play a protective role in prechordal plate development by regulating Wnt signaling.
• CRMMs act as a mechanism to shield the prechordal plate from excessive Wnt signals.
• CRMMs complement secreted antagonists in maintaining embryonic axis integrity.