Notchless is required for axial skeleton formation in mice

Area of Science:

• Developmental Biology
• Genetics
• Cell Biology

Background:

• Cell survival is vital for embryonic development.
• Notchless homolog 1 (Drosophila) (Nle1) is important for inner cell mass survival post-implantation in mice.

Purpose of the Study:

• To investigate the function of Nle1 in mouse epiblast cells after implantation.
• To analyze the effects of mosaic Nle1 deletion during organogenesis using a Cre-lox system.

Main Methods:

• Utilized the Meox2(tm1(cre)Sor) mouse model for epiblast-specific Cre recombinase expression.
• Induced mosaic deletion of Nle1 in developing embryos.
• Examined developmental anomalies and cell death in mutant embryos.

Main Results:

• Nle1-deficient epiblast cells were rapidly eliminated, confirming Nle1's requirement for cell survival.
• Mosaic Nle1 deletion led to severe developmental abnormalities and lethality at birth.
• Mutant embryos exhibited defects in axial skeletal formation, linked to increased apoptotic cell death in somites.

Conclusions:

• Nle1 plays an essential role in post-implantation epiblast cell survival.
• Nle1 is critical for proper organogenesis, particularly axial skeletal development.
• Loss of Nle1 function results in increased apoptosis during embryonic development.