Meis2 is essential for cranial and cardiac neural crest development

Area of Science:

• Developmental Biology
• Genetics
• Molecular Biology

Background:

• TALE-class homeodomain transcription factors Meis and Pbx are crucial for embryonic development.
• While Pbx and Meis1 functions are known, Meis2's role in mouse embryogenesis remained uncharacterized.
• Systemic Meis2 gene inactivation in mice leads to embryonic lethality by day 14, accompanied by hemorrhaging.

Purpose of the Study:

• To investigate the functional role of Meis2 during mouse embryogenesis.
• To determine the specific developmental processes regulated by Meis2, particularly in neural crest cells.

Main Methods:

• Generation of a conditional Meis2 allele in mice.
• Systemic inactivation of the Meis2 gene.
• Conditional inactivation of Meis2 in neural crest cells using an AP2α-IRES-Cre driver line.

Main Results:

• Meis2 is expressed in neural crest cells.
• Meis2-deficient embryos exhibit defects in neural crest-derived tissues, including abnormal heart outflow tracts (persistent truncus arteriosus) and cranial nerves.
• Conditional inactivation in neural crest cells results in craniofacial skeleton anomalies, heart defects, and cranial nerve abnormalities.

Conclusions:

• Meis2 is essential for mouse embryonic development, with null mutants being embryonic lethal.
• Meis2 plays a critical role in the development of cranial and cardiac neural crest cells in mice.