Antibodies to liver cell adhesion molecule perturb inductive interactions and alter feather pattern and structure

Area of Science:

• Developmental Biology
• Cell Biology
• Biophysics

Background:

• Cell adhesion molecules (CAMs) are crucial for morphogenesis, regulating cell motion, tissue boundaries, and intercellular communication during embryonic development.
• Feather germ formation in chicken skin involves interactions between epidermal and dermal cell layers, with distinct CAMs (L-CAM and N-CAM) mediating cell-cell adhesion within each layer.

Purpose of the Study:

• To investigate the causal role of CAMs in embryonic induction using an in vitro feather induction system.
• To determine how perturbing CAM linkage in one tissue affects the development and patterning of an adjacent, differently linked tissue.

Main Methods:

• An in vitro system using developing chicken skin explants was employed.
• Epidermal L-CAM linkage was perturbed using antibodies to L-CAM.
• Pattern formation, cell density, and morphology of dermal condensations were analyzed histologically and morphologically.
• A computer model simulating cell-signal interactions was developed.

Main Results:

• Perturbation of L-CAM in the epidermis resulted in non-hexagonal, striped patterns of dermal condensations, deviating from the normal hexagonal feather germ arrangement.
• Histological analysis revealed altered dermal cell density distributions and a shift in morphology from feather-like filaments to scale-like plaques after L-CAM perturbation.
• The computer model successfully replicated hexagonal patterns in unperturbed conditions and striped patterns upon simulated L-CAM bond perturbation.

Conclusions:

• CAMs play a critical role in regulating embryonic induction and pattern formation, as demonstrated by the disruption of feather development upon L-CAM perturbation.
• Altering CAM-mediated adhesion in one cell population can influence the inductive signaling and developmental outcomes of a neighboring cell population.
• The findings highlight the cooperative dependence of cell responses on CAM linkage and intercellular signaling in establishing complex biological patterns.