Gpr177/mouse Wntless is essential for Wnt-mediated craniofacial and brain development

Area of Science:

• Developmental Biology
• Genetics
• Molecular Biology

Background:

• Gpr177, the mouse orthologue of Drosophila Wls/Evi/Srt, is essential for establishing the anterior-posterior axis in mice.
• The Gpr177 null phenotype closely resembles Wnt3 loss, indicating a significant role in early embryonic development.

Purpose of the Study:

• To investigate the reciprocal regulation between Wnt and Gpr177 in developmental and pathogenic processes.
• To elucidate the specific role of Gpr177 in Wnt1-mediated embryonic development using a conditional knockout mouse model.

Main Methods:

• Creation of a novel mouse strain for conditional inactivation of Gpr177.
• Analysis of mid/hindbrain and craniofacial defects in Gpr177 conditional knockout mice.
• Comparison of phenotypes with Wnt1 knockout, Wnt1/Wnt3a double knockout, and β-catenin deletion models.

Main Results:

• Conditional loss of Gpr177 in Wnt1-expressing cells resulted in severe mid/hindbrain and craniofacial defects.
• The observed defects were more severe than those in Wnt1 knockout mice.
• Phenotypes mimicked those of Wnt1/Wnt3a double knockouts and β-catenin deletion in Wnt1-expressing cells.

Conclusions:

• Gpr177 plays a critical role in Wnt1-mediated development of the mouse embryo.
• Findings suggest overlapping functions among Wnt family members within Wnt1-expressing cells.
• Highlights the importance of Gpr177 in regulating Wnt signaling during embryogenesis.