Spatial anisotropies and temporal fluctuations in extracellular matrix network texture during early embryogenesis

Area of Science:

• Developmental Biology
• Biophysics
• Biomaterials Science

Background:

• Embryonic development involves complex shape changes driven by molecular, cellular, and tissue-level biophysical processes.
• Extracellular matrix (ECM) networks are crucial for cell motility and providing material properties for embryonic deformations.
• Little is known about the micrometer-scale surface properties of primordial ECM networks during early embryogenesis.

Purpose of the Study:

• To quantitatively analyze the micrometer-scale surface textural properties of extracellular matrix (ECM) networks in avian embryos.
• To investigate differences in ECM texture between fibronectin and fibrillin-2 networks.
• To characterize stage-specific and regional variations in ECM texture during early amniote morphogenesis.

Main Methods:

• Computed five textural properties (inertia, correlation, uniformity, homogeneity, entropy) of fluorescently tagged ECM networks in avian embryos.
• Analyzed fibronectin and fibrillin-2 as representative fibrous ECM constituents.
• Examined ECM texture at different embryonic stages (Day 1 gastrulation, Stage 5, Stage 6) and in distinct regions (primitive streak, lateral plate mesoderm).

Main Results:

• Significant differences in surface texture were observed between fibronectin and fibrillin-2 networks in early gastrulating embryos.
• Fibronectin networks were coarser than fibrillin-2 networks.
• Stage-specific regional anisotropy in fibronectin texture was identified, with texture differences between medial and lateral regions changing from Stage 5 to Stage 6.

Conclusions:

• The study identifies and characterizes stage-specific regional anisotropy of fibronectin texture in warm-blooded embryos.
• Changes in ECM textural properties suggest time-dependent rearrangements of the embryonic biomaterial.
• The ECM microenvironment exhibits significant spatial and temporal changes during critical periods of amniote morphogenesis.