title: Topological determination of early morphogenesis in Metazoa.
abstract: This paper presents a topological interpretation of some developmental events through the use of well-known concepts and theorems of combinatorial geometry. The organization of early embryo using a simulation of cleavage considering only blastomere contacts is examined. Each blastomere is modeled as a topological cell and whole embryo--as cell packing. The egg cleavage results in a pattern of cellular contacts on the surface of each blastomere and whole embryo, a discrete morphogenetic field. We find topological distinctions between different types of early egg cleavage and suggest a topological classification of cleavage. Blastulation and gastrulation may be related to an inevitable emergence of discrete curvature that directs development in three-dimensional space. The relationship between local and global orders in metazoan development, i.e., between local morphogenetic processes and integral developmental patterns, is established. Thus, this methodology reveals a topological imperative: a certain set of topological rules that constrains and directs biological morphogenesis.
authors.affiliation: The Volcani Center, 85280 Gilat, Israel. epresnov@agri.gov.il
authors.forename: Eugene
authors.initials: E
authors.lastname: Presnov
authors.forename: Valeria
authors.initials: V
authors.lastname: Isaeva
authors.forename: Nikolay
authors.initials: N
authors.lastname: Kasyanov
mesh_terms: D000465:Algorithms; D000818:Animals; D001757:Blastomeres / Q000502:physiology; D002970:Cleavage Stage, Ovum; D015509:Developmental Biology; D005775:Gastrula / Q000502:physiology; D008954:Models, Biological; D015233:Models, Statistical; D008962:Models, Theoretical; D009024:Morphogenesis; D016011:Normal Distribution; D049490:Systems Biology