Mesoderm patterning by a dynamic gradient of retinoic acid signalling

Area of Science:

• Developmental Biology
• Molecular Biology
• Teratology

Background:

• Retinoic acid (RA), derived from vitamin A, is a known teratogen.
• RA is naturally present in the embryo and its molecular mechanisms are understood through animal models.
• RA is a critical morphogen that tightly regulates organ formation during embryonic development.

Purpose of the Study:

• To review advances in understanding how endogenously produced RA provides positional information to cells.
• To compare RA signaling in three distinct mesodermal tissues: limb, somites, and heart.
• To discuss RA's role in regulating antero-posterior and left-right patterning.

Main Methods:

• Review of scientific literature on retinoic acid signaling in embryonic development.
• Comparative analysis of RA's role in limb, somite, and heart development.
• Discussion of molecular mechanisms including feedback loops and FGF signaling.

Main Results:

• Endogenous RA provides crucial positional information for cell differentiation and organogenesis.
• RA signaling regulates antero-posterior and left-right patterning in mesodermal tissues.
• Spatio-temporal dynamics of RA are controlled by feedback and FGF signaling, but cell-specific responses indicate unknown cofactors.

Conclusions:

• RA's precise spatio-temporal control is essential for normal embryonic development.
• While common principles govern RA signaling, cell-specific responses highlight the need for further research into cofactors and effectors.