A mathematical model based on spider embryo for testing evolutionary pathways for arthropod body plans

Abstract

Shaping body axes is a critical developmental process in embryos of multicellular animals. During this process, cellcell interactions and cell rearrangements occur in a coordinated manner, which results in global remodeling of the multicellular architecture. In arthropod embryos, the early developmental process leading to body axis segmentation varies at the cellular and molecular level depending on the species. Developmental studies in insect and spider model species have provided specific examples of diverse mechanisms that regulate axis formation and segmentation in arthropod embryos. However, it is difficult to address the problem of how such developmental variations arose during the course of arthropod evolution, because of technical limitations in testing evolutionary processes. In this study, we attempted to construct a mathematical model with which evolution of developmental processes realizing major features of arthropod body plans could be tested in silico. This multicellular mathematical model was constructed with some mechanical forces of cells derived from the cytoskeleton and cell contraction in addition to the forces derived from intercellular adhesion, which changes in conjunction with each cell in the direction of planar cell polarity. This study is a theoretical research based on spider embryo model to understand the evolution of developmental processes for arthropod body plans.