Abstract
The patterning of hair and feather follicles requires extensive signalling interactions between the cells of the embryonic skin. Experimental evidence and theory suggest that the spatial arrangement of the follicle pattern relies on a reaction-diffusion mechanism, in which Activatory and Inhibitory pathways interact resulting in spatial heterogeneity across the field. Here we have examined the effects of wave propagation and field properties on the placode patterns of chicken and mouse embryonic skin. In both species a wave initiating follicle formation propagates across the skin. In mouse wave initiation and propagation is an inhibitor-driven mechanism which originates from the mammary placode. This is followed by intercalation of new follicles as the embryo grows. In contrast, wave propagation in chicken skin is a result of a travelling band of developmental competence that limits the skin region undergoing patterning, precluding intercalation of feather follicles behind this wave. We measured placode pattern fidelity and found that avian skin displays higher fidelity than mammalian skin. These morphometric studies identified systematic deviations from a perfectly hexagonal pattern in both species indicating the effects of wave propagation and embryo growth in determining the follicle pattern. Our mathematical modelling confirms that the distinct pattern fidelities observed can be explained simply by overall wave and field properties, without altering specific components describing core cell signalling interactions in the model.
Original language | Undefined/Unknown |
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Pages (from-to) | S68, abstract 03-P004 |
Journal | Mechanisms of Development |
Volume | 126 |
Issue number | Supplement 1 |
DOIs | |
Publication status | Published - 2009 |
Event | 16th International Society of Developmental Biologists Congress 2009 - Edinburgh, United Kingdom Duration: 6 Sept 2009 → 10 Sept 2009 |