Neuromesodermal Progenitors: A Basis for Robust Axial Patterning in Development and Evolution

Area of Science:

• Developmental Biology
• Evolutionary Biology
• Genetics

Background:

• Vertebrate embryonic elongation requires coordinated morphogenesis, growth, and progenitor cell expansion.
• The interplay between these processes across the body axis is crucial for generating proportional body plans and understanding evolutionary diversification.
• Neuromesodermal progenitors (NMps) in the posterior embryo generate spinal cord and paraxial mesoderm, key components of the elongating body axis.

Purpose of the Study:

• To investigate the coordination of tissue shape change, growth, and progenitor cell expansion during vertebrate embryonic elongation.
• To understand the role of neuromesodermal progenitors and their gene regulatory networks in shaping the vertebrate body axis.
• To explore how variations in progenitor contribution and growth rates may have influenced embryonic development and evolution.

Main Methods:

• Comparative analysis of neuromesodermal progenitor lineages across species.
• Examination of gene-regulatory networks, including Wnt/FGF and Sox2/T/Tbx6 pathways.
• Investigating the relationship between progenitor pool dynamics and regional growth rates in the embryo.

Main Results:

• A conserved characteristic of posterior NMps is their bipotency to generate neural and mesodermal cells.
• A conserved gene regulatory network (Wnt/FGF and Sox2/T/Tbx6) underlies NMp function across species and development.
• The contribution of NMps to the elongating body axis varies based on relative anterior and posterior growth rates.

Conclusions:

• A flexible pool of multi-germ layer competent progenitors at the posterior allows adaptation of body axis elongation.
• Variations in NM specification timing and proportions may have been critical for evolutionary changes in embryonic growth rates.
• Understanding these mechanisms provides insight into the robust evolution of diverse vertebrate body plans.