What is a role of the morphogens gradients in development?
The core idea of the gradient theory, a paradigm for developmental biology, is that biological morphogensis is based on a gradient-like distribution of a certain substance and its subsequent interpretation. This is an attempt at systematic criticism of this theory: I will argue that the experimental results do not support its core idea. Crucial in this context are the global reactions of an embryonic tissue upon chemical, genetic and mechanical manipulation and the possibility of regulation of the global and local events including redistribution of morphogens and de novo formation of the gene expression pattern. In addition to this, the possibility of other mechanisms should be explored.
Tsikolia
Nikoloz
N
Institute for Formal Ontology and Medical Information Science (IFOMIS), Faculty of Medicine University of Leipzig, Härtelstrasse 16-18, 04107 Leipzig, Germany. nikoloztsikolia@hotmail.com
D000818:Animals; D001685:Biological Factors / Q000502:physiology*; D009024:Morphogenesis / Q000502:physiology*
D001685:Biological Factors