Functional analysis of a first hindlimb positioning enhancer via Gdf11 expression

Area of Science:

• Developmental Biology
• Genetics
• Molecular Biology

Background:

• Embryonic development involves body elongation and vertebral morphogenesis, crucial for limb positioning.
• Gdf11 is known to regulate hindlimb and sacral vertebrae positioning.
• The precise molecular mechanisms controlling Gdf11 expression remain largely unknown.

Purpose of the Study:

• To investigate the regulatory mechanisms controlling Gdf11 gene expression.
• To identify non-coding regulatory elements associated with the Gdf11 locus.
• To understand the upstream factors influencing Gdf11 expression during embryonic development.

Main Methods:

• Bioinformatic analysis to identify conserved non-coding regions near the Gdf11 gene.
• Generation and analysis of HCR knockout mice to assess Gdf11 expression and anatomical development.
• Experimental manipulation of FGF signaling pathways to determine their effect on Gdf11 expression.

Main Results:

• Identification of a novel enhancer, the highly conserved region (HCR), in intron 1 of the Gdf11 gene.
• HCR knockout mice exhibited reduced Gdf11 expression and posterior shift of the sacral-hindlimb unit.
• FGF signaling was found to negatively regulate Gdf11 expression independently of HCR activity.

Conclusions:

• The HCR plays a significant role in regulating endogenous Gdf11 expression and embryonic hindlimb positioning.
• FGF signaling acts as a negative regulator of Gdf11 expression through a mechanism distinct from HCR.
• The findings suggest the existence of additional, species-specific Gdf11 enhancers beyond HCR.